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1. Preamble

Copyright 2014-2023 The Khronos Group Inc.

This Specification is protected by copyright laws and contains material proprietary to Khronos. Except as described by these terms, it or any components may not be reproduced, republished, distributed, transmitted, displayed, broadcast or otherwise exploited in any manner without the express prior written permission of Khronos.

Khronos grants a conditional copyright license to use and reproduce the unmodified Specification for any purpose, without fee or royalty, EXCEPT no licenses to any patent, trademark or other intellectual property rights are granted under these terms.

Khronos makes no, and expressly disclaims any, representations or warranties, express or implied, regarding this Specification, including, without limitation: merchantability, fitness for a particular purpose, non-infringement of any intellectual property, correctness, accuracy, completeness, timeliness, and reliability. Under no circumstances will Khronos, or any of its Promoters, Contributors or Members, or their respective partners, officers, directors, employees, agents or representatives be liable for any damages, whether direct, indirect, special or consequential damages for lost revenues, lost profits, or otherwise, arising from or in connection with these materials.

This Specification has been created under the Khronos Intellectual Property Rights Policy, which is Attachment A of the Khronos Group Membership Agreement available at https://www.khronos.org/files/member_agreement.pdf. Parties desiring to implement the Specification and make use of Khronos trademarks in relation to that implementation, and receive reciprocal patent license protection under the Khronos Intellectual Property Rights Policy must become Adopters and confirm the implementation as conformant under the process defined by Khronos for this Specification; see https://www.khronos.org/adopters.

This Specification contains substantially unmodified functionality from, and is a successor to, Khronos specifications including OpenGL, OpenGL ES and OpenCL.

The Khronos Intellectual Property Rights Policy defines the terms 'Scope', 'Compliant Portion', and 'Necessary Patent Claims'.

Some parts of this Specification are purely informative and so are EXCLUDED the Scope of this Specification. The Document Conventions section of the Introduction defines how these parts of the Specification are identified.

Where this Specification uses technical terminology, defined in the Glossary or otherwise, that refer to enabling technologies that are not expressly set forth in this Specification, those enabling technologies are EXCLUDED from the Scope of this Specification. For clarity, enabling technologies not disclosed with particularity in this Specification (e.g. semiconductor manufacturing technology, hardware architecture, processor architecture or microarchitecture, memory architecture, compiler technology, object oriented technology, basic operating system technology, compression technology, algorithms, and so on) are NOT to be considered expressly set forth; only those application program interfaces and data structures disclosed with particularity are included in the Scope of this Specification.

For purposes of the Khronos Intellectual Property Rights Policy as it relates to the definition of Necessary Patent Claims, all recommended or optional features, behaviors and functionality set forth in this Specification, if implemented, are considered to be included as Compliant Portions.

Where this Specification identifies specific sections of external references, only those specifically identified sections define normative functionality. The Khronos Intellectual Property Rights Policy excludes external references to materials and associated enabling technology not created by Khronos from the Scope of this Specification, and any licenses that may be required to implement such referenced materials and associated technologies must be obtained separately and may involve royalty payments.

Khronos and Vulkan are registered trademarks, and SPIR-V is a trademark of The Khronos Group Inc. OpenCL is a trademark of Apple Inc., used under license by Khronos. OpenGL is a registered trademark and the OpenGL ES logo is a trademark of Hewlett Packard Enterprise, used under license by Khronos. ASTC is a trademark of ARM Holdings PLC. All other product names, trademarks, and/or company names are used solely for identification and belong to their respective owners.

2. Introduction

This document, referred to as the “Vulkan Specification” or just the “Specification” hereafter, describes the Vulkan Application Programming Interface (API). Vulkan is a C99 API designed for explicit control of low-level graphics and compute functionality.

The canonical version of the Specification is available in the official Vulkan Registry (https://registry.khronos.org/vulkan/). The source files used to generate the Vulkan specification are stored in the Vulkan Documentation Repository (https://github.com/KhronosGroup/Vulkan-Docs). The source repository additionally has a public issue tracker and allows the submission of pull requests that improve the specification.

2.1. Document Conventions

The Vulkan specification is intended for use by both implementors of the API and application developers seeking to make use of the API, forming a contract between these parties. Specification text may address either party; typically the intended audience can be inferred from context, though some sections are defined to address only one of these parties. (For example, Valid Usage sections only address application developers). Any requirements, prohibitions, recommendations or options defined by normative terminology are imposed only on the audience of that text.

Note

Structure and enumerated types defined in extensions that were promoted to core in a later version of Vulkan are now defined in terms of the equivalent Vulkan core interfaces. This affects the Vulkan Specification, the Vulkan header files, and the corresponding XML Registry.

2.1.1. Informative Language

Some language in the specification is purely informative, intended to give background or suggestions to implementors or developers.

If an entire chapter or section contains only informative language, its title will be suffixed with “(Informative)”.

All NOTEs are implicitly informative.

2.1.2. Normative Terminology

Within this specification, the key words must, required, should, recommended, may, and optional are to be interpreted as described in RFC 2119 - Key words for use in RFCs to Indicate Requirement Levels (https://www.ietf.org/rfc/rfc2119.txt). The additional key word optionally is an alternate form of optional, for use where grammatically appropriate.

These key words are highlighted in the specification for clarity. In text addressing application developers, their use expresses requirements that apply to application behavior. In text addressing implementors, their use expresses requirements that apply to implementations.

In text addressing application developers, the additional key words can and cannot are to be interpreted as describing the capabilities of an application, as follows:

can

This word means that the application is able to perform the action described.

cannot

This word means that the API and/or the execution environment provide no mechanism through which the application can express or accomplish the action described.

These key words are never used in text addressing implementors.

Note

There is an important distinction between cannot and must not, as used in this Specification. Cannot means something the application literally is unable to express or accomplish through the API, while must not means something that the application is capable of expressing through the API, but that the consequences of doing so are undefined and potentially unrecoverable for the implementation (see Valid Usage).

Unless otherwise noted in the section heading, all sections and appendices in this document are normative.

2.1.3. Technical Terminology

The Vulkan Specification makes use of common engineering and graphics terms such as Pipeline, Shader, and Host to identify and describe Vulkan API constructs and their attributes, states, and behaviors. The Glossary defines the basic meanings of these terms in the context of the Specification. The Specification text provides fuller definitions of the terms and may elaborate, extend, or clarify the Glossary definitions. When a term defined in the Glossary is used in normative language within the Specification, the definitions within the Specification govern and supersede any meanings the terms may have in other technical contexts (i.e. outside the Specification).

2.1.4. Normative References

References to external documents are considered normative references if the Specification uses any of the normative terms defined in Normative Terminology to refer to them or their requirements, either as a whole or in part.

The following documents are referenced by normative sections of the specification:

IEEE. August, 2008. IEEE Standard for Floating-Point Arithmetic. IEEE Std 754-2008. https://dx.doi.org/10.1109/IEEESTD.2008.4610935 .

Andrew Garrard. Khronos Data Format Specification, version 1.3. https://registry.khronos.org/DataFormat/specs/1.3/dataformat.1.3.html .

John Kessenich. SPIR-V Extended Instructions for GLSL, Version 1.00 (February 10, 2016). https://registry.khronos.org/spir-v/ .

John Kessenich, Boaz Ouriel, and Raun Krisch. SPIR-V Specification, Version 1.5, Revision 3, Unified (April 24, 2020). https://registry.khronos.org/spir-v/ .

ITU-T. H.264 Advanced Video Coding for Generic Audiovisual Services (August, 2021). https://www.itu.int/rec/T-REC-H.264-202108-I/ .

ITU-T. H.265 High Efficiency Video Coding (August, 2021). https://www.itu.int/rec/T-REC-H.265-202108-I/ .

Jon Leech. The Khronos Vulkan API Registry (February 26, 2023). https://registry.khronos.org/vulkan/specs/1.3/registry.html .

Jon Leech and Tobias Hector. Vulkan Documentation and Extensions: Procedures and Conventions (February 26, 2023). https://registry.khronos.org/vulkan/specs/1.3/styleguide.html .

Architecture of the Vulkan Loader Interfaces (October, 2021). https://github.com/KhronosGroup/Vulkan-Loader/blob/master/docs/LoaderInterfaceArchitecture.md .

3. Fundamentals

This chapter introduces fundamental concepts including the Vulkan architecture and execution model, API syntax, queues, pipeline configurations, numeric representation, state and state queries, and the different types of objects and shaders. It provides a framework for interpreting more specific descriptions of commands and behavior in the remainder of the Specification.

3.1. Host and Device Environment

The Vulkan Specification assumes and requires: the following properties of the host environment with respect to Vulkan implementations:

  • The host must have runtime support for 8, 16, 32 and 64-bit signed and unsigned twos-complement integers, all addressable at the granularity of their size in bytes.

  • The host must have runtime support for 32- and 64-bit floating-point types satisfying the range and precision constraints in the Floating Point Computation section.

  • The representation and endianness of these types on the host must match the representation and endianness of the same types on every physical device supported.

Note

Since a variety of data types and structures in Vulkan may be accessible by both host and physical device operations, the implementation should be able to access such data efficiently in both paths in order to facilitate writing portable and performant applications.

3.2. Execution Model

This section outlines the execution model of a Vulkan system.

Vulkan exposes one or more devices, each of which exposes one or more queues which may process work asynchronously to one another. The set of queues supported by a device is partitioned into families. Each family supports one or more types of functionality and may contain multiple queues with similar characteristics. Queues within a single family are considered compatible with one another, and work produced for a family of queues can be executed on any queue within that family. This specification defines the following types of functionality that queues may support: graphics, compute, transfer, and sparse memory management.

Note

A single device may report multiple similar queue families rather than, or as well as, reporting multiple members of one or more of those families. This indicates that while members of those families have similar capabilities, they are not directly compatible with one another.

Device memory is explicitly managed by the application. Each device may advertise one or more heaps, representing different areas of memory. Memory heaps are either device-local or host-local, but are always visible to the device. Further detail about memory heaps is exposed via memory types available on that heap. Examples of memory areas that may be available on an implementation include:

  • device-local is memory that is physically connected to the device.

  • device-local, host visible is device-local memory that is visible to the host.

  • host-local, host visible is memory that is local to the host and visible to the device and host.

On other architectures, there may only be a single heap that can be used for any purpose.

3.2.1. Queue Operation

Vulkan queues provide an interface to the execution engines of a device. Commands for these execution engines are recorded into command buffers ahead of execution time, and then submitted to a queue for execution. Once submitted to a queue, command buffers will begin and complete execution without further application intervention, though the order of this execution is dependent on a number of implicit and explicit ordering constraints.

Work is submitted to queues using queue submission commands that typically take the form vkQueue* (e.g. vkQueueSubmit, vkQueueBindSparse), and can take a list of semaphores upon which to wait before work begins and a list of semaphores to signal once work has completed. The work itself, as well as signaling and waiting on the semaphores are all queue operations. Queue submission commands return control to the application once queue operations have been submitted - they do not wait for completion.

There are no implicit ordering constraints between queue operations on different queues, or between queues and the host, so these may operate in any order with respect to each other. Explicit ordering constraints between different queues or with the host can be expressed with semaphores and fences.

Command buffer submissions to a single queue respect submission order and other implicit ordering guarantees, but otherwise may overlap or execute out of order. Other types of batches and queue submissions against a single queue (e.g. sparse memory binding) have no implicit ordering constraints with any other queue submission or batch. Additional explicit ordering constraints between queue submissions and individual batches can be expressed with semaphores and fences.

Before a fence or semaphore is signaled, it is guaranteed that any previously submitted queue operations have completed execution, and that memory writes from those queue operations are available to future queue operations. Waiting on a signaled semaphore or fence guarantees that previous writes that are available are also visible to subsequent commands.

Command buffer boundaries, both between primary command buffers of the same or different batches or submissions as well as between primary and secondary command buffers, do not introduce any additional ordering constraints. In other words, submitting the set of command buffers (which can include executing secondary command buffers) between any semaphore or fence operations execute the recorded commands as if they had all been recorded into a single primary command buffer, except that the current state is reset on each boundary. Explicit ordering constraints can be expressed with explicit synchronization primitives.

There are a few implicit ordering guarantees between commands within a command buffer, but only covering a subset of execution. Additional explicit ordering constraints can be expressed with the various explicit synchronization primitives.

Note

Implementations have significant freedom to overlap execution of work submitted to a queue, and this is common due to deep pipelining and parallelism in Vulkan devices.

Commands recorded in command buffers can perform actions, set state that persists across commands, synchronize other commands, or indirectly launch other commands, with some commands fulfilling several of these roles. The “Command Properties” section for each such command lists which of these roles the command takes. State setting commands update the current state of the command buffer. Some commands that perform actions (e.g. draw/dispatch) do so based on the current state set cumulatively since the start of the command buffer. The work involved in performing action commands is often allowed to overlap or to be reordered, but doing so must not alter the state to be used by each action command. In general, action commands are those commands that alter framebuffer attachments, read/write buffer or image memory, or write to query pools.

Synchronization commands introduce explicit execution and memory dependencies between two sets of action commands, where the second set of commands depends on the first set of commands. These dependencies enforce both that the execution of certain pipeline stages in the later set occurs after the execution of certain stages in the source set, and that the effects of memory accesses performed by certain pipeline stages occur in order and are visible to each other. When not enforced by an explicit dependency or implicit ordering guarantees, action commands may overlap execution or execute out of order, and may not see the side effects of each other’s memory accesses.

3.3. Object Model

The devices, queues, and other entities in Vulkan are represented by Vulkan objects. At the API level, all objects are referred to by handles. There are two classes of handles, dispatchable and non-dispatchable. Dispatchable handle types are a pointer to an opaque type. This pointer may be used by layers as part of intercepting API commands, and thus each API command takes a dispatchable type as its first parameter. Each object of a dispatchable type must have a unique handle value during its lifetime.

Non-dispatchable handle types are a 64-bit integer type whose meaning is implementation-dependent. If the privateData feature is enabled for a VkDevice, each object of a non-dispatchable type created on that device must have a handle value that is unique among objects created on that device, for the duration of the object’s lifetime. Otherwise, non-dispatchable handles may encode object information directly in the handle rather than acting as a reference to an underlying object, and thus may not have unique handle values. If handle values are not unique, then destroying one such handle must not cause identical handles of other types to become invalid, and must not cause identical handles of the same type to become invalid if that handle value has been created more times than it has been destroyed.

All objects created or allocated from a VkDevice (i.e. with a VkDevice as the first parameter) are private to that device, and must not be used on other devices.

3.3.1. Object Lifetime

Objects are created or allocated by vkCreate* and vkAllocate* commands, respectively. Once an object is created or allocated, its “structure” is considered to be immutable, though the contents of certain object types is still free to change. Objects are destroyed or freed by vkDestroy* and vkFree* commands, respectively.

Objects that are allocated (rather than created) take resources from an existing pool object or memory heap, and when freed return resources to that pool or heap. While object creation and destruction are generally expected to be low-frequency occurrences during runtime, allocating and freeing objects can occur at high frequency. Pool objects help accommodate improved performance of the allocations and frees.

It is an application’s responsibility to track the lifetime of Vulkan objects, and not to destroy them while they are still in use.

The ownership of application-owned memory is immediately acquired by any Vulkan command it is passed into. Ownership of such memory must be released back to the application at the end of the duration of the command, so that the application can alter or free this memory as soon as all the commands that acquired it have returned.

The following object types are consumed when they are passed into a Vulkan command and not further accessed by the objects they are used to create. They must not be destroyed in the duration of any API command they are passed into:

  • VkShaderModule

  • VkPipelineCache

A VkRenderPass or VkPipelineLayout object passed as a parameter to create another object is not further accessed by that object after the duration of the command it is passed into. A VkRenderPass used in a command buffer follows the rules described below.

VkDescriptorSetLayout objects may be accessed by commands that operate on descriptor sets allocated using that layout, and those descriptor sets must not be updated with vkUpdateDescriptorSets after the descriptor set layout has been destroyed. Otherwise, a VkDescriptorSetLayout object passed as a parameter to create another object is not further accessed by that object after the duration of the command it is passed into.

The application must not destroy any other type of Vulkan object until all uses of that object by the device (such as via command buffer execution) have completed.

The following Vulkan objects must not be destroyed while any command buffers using the object are in the pending state:

  • VkEvent

  • VkQueryPool

  • VkBuffer

  • VkBufferView

  • VkImage

  • VkImageView

  • VkPipeline

  • VkSampler

  • VkSamplerYcbcrConversion

  • VkDescriptorPool

  • VkFramebuffer

  • VkRenderPass

  • VkCommandBuffer

  • VkCommandPool

  • VkDeviceMemory

  • VkDescriptorSet

Destroying these objects will move any command buffers that are in the recording or executable state, and are using those objects, to the invalid state.

The following Vulkan objects must not be destroyed while any queue is executing commands that use the object:

  • VkFence

  • VkSemaphore

  • VkCommandBuffer

  • VkCommandPool

In general, objects can be destroyed or freed in any order, even if the object being freed is involved in the use of another object (e.g. use of a resource in a view, use of a view in a descriptor set, use of an object in a command buffer, binding of a memory allocation to a resource), as long as any object that uses the freed object is not further used in any way except to be destroyed or to be reset in such a way that it no longer uses the other object (such as resetting a command buffer). If the object has been reset, then it can be used as if it never used the freed object. An exception to this is when there is a parent/child relationship between objects. In this case, the application must not destroy a parent object before its children, except when the parent is explicitly defined to free its children when it is destroyed (e.g. for pool objects, as defined below).

VkCommandPool objects are parents of VkCommandBuffer objects. VkDescriptorPool objects are parents of VkDescriptorSet objects. VkDevice objects are parents of many object types (all that take a VkDevice as a parameter to their creation).

The following Vulkan objects have specific restrictions for when they can be destroyed:

  • VkQueue objects cannot be explicitly destroyed. Instead, they are implicitly destroyed when the VkDevice object they are retrieved from is destroyed.

  • Destroying a pool object implicitly frees all objects allocated from that pool. Specifically, destroying VkCommandPool frees all VkCommandBuffer objects that were allocated from it, and destroying VkDescriptorPool frees all VkDescriptorSet objects that were allocated from it.

  • VkDevice objects can be destroyed when all VkQueue objects retrieved from them are idle, and all objects created from them have been destroyed. This includes the following objects:

    • VkFence

    • VkSemaphore

    • VkEvent

    • VkQueryPool

    • VkBuffer

    • VkBufferView

    • VkImage

    • VkImageView

    • VkShaderModule

    • VkPipelineCache

    • VkPipeline

    • VkPipelineLayout

    • VkSampler

    • VkSamplerYcbcrConversion

    • VkDescriptorSetLayout

    • VkDescriptorPool

    • VkFramebuffer

    • VkRenderPass

    • VkCommandPool

    • VkCommandBuffer

    • VkDeviceMemory

  • VkPhysicalDevice objects cannot be explicitly destroyed. Instead, they are implicitly destroyed when the VkInstance object they are retrieved from is destroyed.

  • VkInstance objects can be destroyed once all VkDevice objects created from any of its VkPhysicalDevice objects have been destroyed.

3.3.2. External Object Handles

As defined above, the scope of object handles created or allocated from a VkDevice is limited to that logical device. Objects which are not in scope are said to be external. To bring an external object into scope, an external handle must be exported from the object in the source scope and imported into the destination scope.

Note

The scope of external handles and their associated resources may vary according to their type, but they can generally be shared across process and API boundaries.

3.4. Application Binary Interface

The mechanism by which Vulkan is made available to applications is platform- or implementation- defined. On many platforms the C interface described in this Specification is provided by a shared library. Since shared libraries can be changed independently of the applications that use them, they present particular compatibility challenges, and this Specification places some requirements on them.

Shared library implementations must use the default Application Binary Interface (ABI) of the standard C compiler for the platform, or provide customized API headers that cause application code to use the implementation’s non-default ABI. An ABI in this context means the size, alignment, and layout of C data types; the procedure calling convention; and the naming convention for shared library symbols corresponding to C functions. Customizing the calling convention for a platform is usually accomplished by defining calling convention macros appropriately in vk_platform.h.

On platforms where Vulkan is provided as a shared library, library symbols beginning with “vk” and followed by a digit or uppercase letter are reserved for use by the implementation. Applications which use Vulkan must not provide definitions of these symbols. This allows the Vulkan shared library to be updated with additional symbols for new API versions or extensions without causing symbol conflicts with existing applications.

Shared library implementations should provide library symbols for commands in the highest version of this Specification they support, and for Window System Integration extensions relevant to the platform. They may also provide library symbols for commands defined by additional extensions.

Note

These requirements and recommendations are intended to allow implementors to take advantage of platform-specific conventions for SDKs, ABIs, library versioning mechanisms, etc. while still minimizing the code changes necessary to port applications or libraries between platforms. Platform vendors, or providers of the de facto standard Vulkan shared library for a platform, are encouraged to document what symbols the shared library provides and how it will be versioned when new symbols are added.

Applications should only rely on shared library symbols for commands in the minimum core version required by the application. vkGetInstanceProcAddr and vkGetDeviceProcAddr should be used to obtain function pointers for commands in core versions beyond the application’s minimum required version.

3.5. Command Syntax and Duration

The Specification describes Vulkan commands as functions or procedures using C99 syntax. Language bindings for other languages such as C++ and JavaScript may allow for stricter parameter passing, or object-oriented interfaces.

Vulkan uses the standard C types for the base type of scalar parameters (e.g. types from <stdint.h>), with exceptions described below, or elsewhere in the text when appropriate:

VkBool32 represents boolean True and False values, since C does not have a sufficiently portable built-in boolean type:

// Provided by VK_VERSION_1_0
typedef uint32_t VkBool32;

VK_TRUE represents a boolean True (unsigned integer 1) value, and VK_FALSE a boolean False (unsigned integer 0) value.

All values returned from a Vulkan implementation in a VkBool32 will be either VK_TRUE or VK_FALSE.

Applications must not pass any other values than VK_TRUE or VK_FALSE into a Vulkan implementation where a VkBool32 is expected.

VK_TRUE is a constant representing a VkBool32 True value.

#define VK_TRUE                           1U

VK_FALSE is a constant representing a VkBool32 False value.

#define VK_FALSE                          0U

VkDeviceSize represents device memory size and offset values:

// Provided by VK_VERSION_1_0
typedef uint64_t VkDeviceSize;

VkDeviceAddress represents device buffer address values:

// Provided by VK_VERSION_1_0
typedef uint64_t VkDeviceAddress;

Commands that create Vulkan objects are of the form vkCreate* and take Vk*CreateInfo structures with the parameters needed to create the object. These Vulkan objects are destroyed with commands of the form vkDestroy*.

The last in-parameter to each command that creates or destroys a Vulkan object is pAllocator. The pAllocator parameter can be set to a non-NULL value such that allocations for the given object are delegated to an application provided callback; refer to the Memory Allocation chapter for further details.

Commands that allocate Vulkan objects owned by pool objects are of the form vkAllocate*, and take Vk*AllocateInfo structures. These Vulkan objects are freed with commands of the form vkFree*. These objects do not take allocators; if host memory is needed, they will use the allocator that was specified when their parent pool was created.

Commands are recorded into a command buffer by calling API commands of the form vkCmd*. Each such command may have different restrictions on where it can be used: in a primary and/or secondary command buffer, inside and/or outside a render pass, and in one or more of the supported queue types. These restrictions are documented together with the definition of each such command.

The duration of a Vulkan command refers to the interval between calling the command and its return to the caller.

3.5.1. Lifetime of Retrieved Results

Information is retrieved from the implementation with commands of the form vkGet* and vkEnumerate*.

Unless otherwise specified for an individual command, the results are invariant; that is, they will remain unchanged when retrieved again by calling the same command with the same parameters, so long as those parameters themselves all remain valid.

3.6. Threading Behavior

Vulkan is intended to provide scalable performance when used on multiple host threads. All commands support being called concurrently from multiple threads, but certain parameters, or components of parameters are defined to be externally synchronized. This means that the caller must guarantee that no more than one thread is using such a parameter at a given time.

More precisely, Vulkan commands use simple stores to update the state of Vulkan objects. A parameter declared as externally synchronized may have its contents updated at any time during the host execution of the command. If two commands operate on the same object and at least one of the commands declares the object to be externally synchronized, then the caller must guarantee not only that the commands do not execute simultaneously, but also that the two commands are separated by an appropriate memory barrier (if needed).

Note

Memory barriers are particularly relevant for hosts based on the ARM CPU architecture, which is more weakly ordered than many developers are accustomed to from x86/x64 programming. Fortunately, most higher-level synchronization primitives (like the pthread library) perform memory barriers as a part of mutual exclusion, so mutexing Vulkan objects via these primitives will have the desired effect.

Similarly the application must avoid any potential data hazard of application-owned memory that has its ownership temporarily acquired by a Vulkan command. While the ownership of application-owned memory remains acquired by a command the implementation may read the memory at any point, and it may write non-const qualified memory at any point. Parameters referring to non-const qualified application-owned memory are not marked explicitly as externally synchronized in the Specification.

Many object types are immutable, meaning the objects cannot change once they have been created. These types of objects never need external synchronization, except that they must not be destroyed while they are in use on another thread. In certain special cases mutable object parameters are internally synchronized, making external synchronization unnecessary. Any command parameters that are not labeled as externally synchronized are either not mutated by the command or are internally synchronized. Additionally, certain objects related to a command’s parameters (e.g. command pools and descriptor pools) may be affected by a command, and must also be externally synchronized. These implicit parameters are documented as described below.

Parameters of commands that are externally synchronized are listed below.

Externally Synchronized Parameters

For VkPipelineCache objects created with flags containing VK_PIPELINE_CACHE_CREATE_EXTERNALLY_SYNCHRONIZED_BIT, the above table is extended with the pipelineCache parameter to vkCreate*Pipelines being externally synchronized.

There are also a few instances where a command can take in a user allocated list whose contents are externally synchronized parameters. In these cases, the caller must guarantee that at most one thread is using a given element within the list at a given time. These parameters are listed below.

Externally Synchronized Parameter Lists

In addition, there are some implicit parameters that need to be externally synchronized. For example, when a commandBuffer parameter needs to be externally synchronized, it implies that the commandPool from which that command buffer was allocated also needs to be externally synchronized. The implicit parameters and their associated object are listed below.

Implicit Externally Synchronized Parameters

3.7. Valid Usage

Valid usage defines a set of conditions which must be met in order to achieve well-defined runtime behavior in an application. These conditions depend only on Vulkan state, and the parameters or objects whose usage is constrained by the condition.

The core layer assumes applications are using the API correctly. Except as documented elsewhere in the Specification, the behavior of the core layer to an application using the API incorrectly is undefined, and may include program termination. However, implementations must ensure that incorrect usage by an application does not affect the integrity of the operating system, the Vulkan implementation, or other Vulkan client applications in the system. In particular, any guarantees made by an operating system about whether memory from one process can be visible to another process or not must not be violated by a Vulkan implementation for any memory allocation. Vulkan implementations are not required to make additional security or integrity guarantees beyond those provided by the OS unless explicitly directed by the application’s use of a particular feature or extension.

Note

For instance, if an operating system guarantees that data in all its memory allocations are set to zero when newly allocated, the Vulkan implementation must make the same guarantees for any allocations it controls (e.g. VkDeviceMemory).

Similarly, if an operating system guarantees that use-after-free of host allocations will not result in values written by another process becoming visible, the same guarantees must be made by the Vulkan implementation for device memory.

If the protectedMemory feature is supported, the implementation provides additional guarantees when invalid usage occurs to prevent values in protected memory from being accessed or inferred outside of protected operations, as described in Protected Memory Access Rules.

Some valid usage conditions have dependencies on runtime limits or feature availability. It is possible to validate these conditions against Vulkan’s minimum supported values for these limits and features, or some subset of other known values.

Valid usage conditions do not cover conditions where well-defined behavior (including returning an error code) exists.

Valid usage conditions should apply to the command or structure where complete information about the condition would be known during execution of an application. This is such that a validation layer or linter can be written directly against these statements at the point they are specified.

Note

This does lead to some non-obvious places for valid usage statements. For instance, the valid values for a structure might depend on a separate value in the calling command. In this case, the structure itself will not reference this valid usage as it is impossible to determine validity from the structure that it is invalid - instead this valid usage would be attached to the calling command.

Another example is draw state - the state setters are independent, and can cause a legitimately invalid state configuration between draw calls; so the valid usage statements are attached to the place where all state needs to be valid - at the drawing command.

Valid usage conditions are described in a block labelled “Valid Usage” following each command or structure they apply to.

3.7.1. Usage Validation

Vulkan is a layered API. The lowest layer is the core Vulkan layer, as defined by this Specification. The application can use additional layers above the core for debugging, validation, and other purposes.

One of the core principles of Vulkan is that building and submitting command buffers should be highly efficient. Thus error checking and validation of state in the core layer is minimal, although more rigorous validation can be enabled through the use of layers.

Validation of correct API usage is left to validation layers. Applications should be developed with validation layers enabled, to help catch and eliminate errors. Once validated, released applications should not enable validation layers by default.

3.7.2. Implicit Valid Usage

Some valid usage conditions apply to all commands and structures in the API, unless explicitly denoted otherwise for a specific command or structure. These conditions are considered implicit, and are described in a block labelled “Valid Usage (Implicit)” following each command or structure they apply to. Implicit valid usage conditions are described in detail below.

Valid Usage for Object Handles

Any input parameter to a command that is an object handle must be a valid object handle, unless otherwise specified. An object handle is valid if:

  • It has been created or allocated by a previous, successful call to the API. Such calls are noted in the Specification.

  • It has not been deleted or freed by a previous call to the API. Such calls are noted in the Specification.

  • Any objects used by that object, either as part of creation or execution, must also be valid.

The reserved values VK_NULL_HANDLE and NULL can be used in place of valid non-dispatchable handles and dispatchable handles, respectively, when explicitly called out in the Specification. Any command that creates an object successfully must not return these values. It is valid to pass these values to vkDestroy* or vkFree* commands, which will silently ignore these values.

Valid Usage for Pointers

Any parameter that is a pointer must be a valid pointer only if it is explicitly called out by a Valid Usage statement.

A pointer is “valid” if it points at memory containing values of the number and type(s) expected by the command, and all fundamental types accessed through the pointer (e.g. as elements of an array or as members of a structure) satisfy the alignment requirements of the host processor.

Valid Usage for Strings

Any parameter that is a pointer to char must be a finite sequence of values terminated by a null character, or if explicitly called out in the Specification, can be NULL.

Valid Usage for Enumerated Types

Any parameter of an enumerated type must be a valid enumerant for that type. Use of an enumerant is valid if the following conditions are true:

  • The enumerant is defined as part of the enumerated type.

  • The enumerant is not a value suffixed with _MAX_ENUM1.

    • This value exists only to ensure that C enum types are 32 bits in size and must not be used by applications.

  • If the enumerant is used in a function that has a VkInstance as its first parameter and either:

  • If the enumerant is used in a function that has a VkPhysicalDevice object as its first parameter and either:

  • If the enumerant is used in a function that has any other dispatchable object as its first parameter and either:

Any enumerated type returned from a query command or otherwise output from Vulkan to the application must not have a reserved value. Reserved values are values not defined by any extension for that enumerated type.

Note

In some special cases, an enumerant is only meaningful if a feature defined by an extension is also enabled, as well as the extension itself. The global “valid enumerant” rule described here does not address such cases.
Note

This language is intended to accommodate cases such as “hidden” extensions known only to driver internals, or layers enabling extensions without knowledge of the application, without allowing return of values not defined by any extension.
Note

Application developers are encouraged to be careful when using switch statements with Vulkan API enums. This is because new extensions can add new values to existing enums. Using a default: statement within a switch may avoid future compilation issues.

This is particularly true for enums such as VkDriverId, which may have values added that do not belong to a corresponding new extension.
Valid Usage for Flags

A collection of flags is represented by a bitmask using the type VkFlags:

// Provided by VK_VERSION_1_0
typedef uint32_t VkFlags;

Bitmasks are passed to many commands and structures to compactly represent options, but VkFlags is not used directly in the API. Instead, a Vk*Flags type which is an alias of VkFlags, and whose name matches the corresponding Vk*FlagBits that are valid for that type, is used.

Any Vk*Flags member or parameter used in the API as an input must be a valid combination of bit flags. A valid combination is either zero or the bitwise OR of valid bit flags.

An individual bit flag is valid for a Vk*Flags type if it would be a valid enumerant when used with the equivalent Vk*FlagBits type, where the bits type is obtained by taking the flag type and replacing the trailing Flags with FlagBits. For example, a flag value of type VkColorComponentFlags must contain only bit flags defined by VkColorComponentFlagBits.

Any Vk*Flags member or parameter returned from a query command or otherwise output from Vulkan to the application may contain bit flags undefined in its corresponding Vk*FlagBits type. An application cannot rely on the state of these unspecified bits.

Only the low-order 31 bits (bit positions zero through 30) are available for use as flag bits.

Note

This restriction is due to poorly defined behavior by C compilers given a C enumerant value of 0x80000000. In some cases adding this enumerant value may increase the size of the underlying Vk*FlagBits type, breaking the ABI.

A collection of 64-bit flags is represented by a bitmask using the type VkFlags64:

// Provided by VK_VERSION_1_3
typedef uint64_t VkFlags64;

When the 31 bits available in VkFlags are insufficient, the VkFlags64 type can be passed to commands and structures to represent up to 64 options. VkFlags64 is not used directly in the API. Instead, a Vk*Flags2 type which is an alias of VkFlags64, and whose name matches the corresponding Vk*FlagBits2 that are valid for that type, is used.

Any Vk*Flags2 member or parameter used in the API as an input must be a valid combination of bit flags. A valid combination is either zero or the bitwise OR of valid bit flags.

An individual bit flag is valid for a Vk*Flags2 type if it would be a valid enumerant when used with the equivalent Vk*FlagBits2 type, where the bits type is obtained by taking the flag type and replacing the trailing Flags2 with FlagBits2. For example, a flag value of type VkAccessFlags2KHR must contain only bit flags defined by VkAccessFlagBits2KHR.

Any Vk*Flags2 member or parameter returned from a query command or otherwise output from Vulkan to the application may contain bit flags undefined in its corresponding Vk*FlagBits2 type. An application cannot rely on the state of these unspecified bits.

Note

Both the Vk*FlagBits2 type, and the individual bits defined for that type, are defined as uint64_t integers in the C API. This is in contrast to the 32-bit types, where the Vk*FlagBits type is defined as a C enum and the individual bits as enumerants belonging to that enum. As a result, there is less compile-time type checking possible for the 64-bit types. This is unavoidable since there is no sufficiently portable way to define a 64-bit enum type in C99.
Valid Usage for Structure Types

Any parameter that is a structure containing a sType member must have a value of sType which is a valid VkStructureType value matching the type of the structure.

Valid Usage for Structure Pointer Chains

Any parameter that is a structure containing a void* pNext member must have a value of pNext that is either NULL, or is a pointer to a valid extending structure, containing sType and pNext members as described in the Vulkan Documentation and Extensions document in the section “Extending Structures”. The set of structures connected by pNext pointers is referred to as a pNext chain.

Each structure included in the pNext chain must be defined at runtime by either:

  • a core version which is supported

  • an extension which is enabled

  • a supported device extension in the case of physical-device-level functionality added by the device extension

Each type of extending structure must not appear more than once in a pNext chain, including any aliases. This general rule may be explicitly overridden for specific structures.

Any component of the implementation (the loader, any enabled layers, and drivers) must skip over, without processing (other than reading the sType and pNext members) any extending structures in the chain not defined by core versions or extensions supported by that component.

As a convenience to implementations and layers needing to iterate through a structure pointer chain, the Vulkan API provides two base structures. These structures allow for some type safety, and can be used by Vulkan API functions that operate on generic inputs and outputs.

The VkBaseInStructure structure is defined as:

// Provided by VK_VERSION_1_0
typedef struct VkBaseInStructure {
    VkStructureType                    sType;
    const struct VkBaseInStructure*    pNext;
} VkBaseInStructure;

  • sType is the structure type of the structure being iterated through.

  • pNext is NULL or a pointer to the next structure in a structure chain.

VkBaseInStructure can be used to facilitate iterating through a read-only structure pointer chain.

The VkBaseOutStructure structure is defined as:

// Provided by VK_VERSION_1_0
typedef struct VkBaseOutStructure {
    VkStructureType               sType;
    struct VkBaseOutStructure*    pNext;
} VkBaseOutStructure;

  • sType is the structure type of the structure being iterated through.

  • pNext is NULL or a pointer to the next structure in a structure chain.

VkBaseOutStructure can be used to facilitate iterating through a structure pointer chain that returns data back to the application.

Valid Usage for Nested Structures

The above conditions also apply recursively to members of structures provided as input to a command, either as a direct argument to the command, or themselves a member of another structure.

Specifics on valid usage of each command are covered in their individual sections.

Valid Usage for Extensions

Instance-level functionality or behavior added by an instance extension to the API must not be used unless that extension is supported by the instance as determined by vkEnumerateInstanceExtensionProperties, and that extension is enabled in VkInstanceCreateInfo.

Physical-device-level functionality or behavior added by an instance extension to the API must not be used unless that extension is supported by the instance as determined by vkEnumerateInstanceExtensionProperties, and that extension is enabled in VkInstanceCreateInfo.

Physical-device-level functionality or behavior added by a device extension to the API must not be used unless the conditions described in Extending Physical Device Core Functionality are met.

Device-level functionality added by a device extension that is dispatched from a VkDevice, or from a child object of a VkDevice must not be used unless that extension is supported by the device as determined by vkEnumerateDeviceExtensionProperties, and that extension is enabled in VkDeviceCreateInfo.

Valid Usage for Newer Core Versions

Instance-level functionality or behavior added by a new core version of the API must not be used unless it is supported by the instance as determined by vkEnumerateInstanceVersion and the specified version of VkApplicationInfo::apiVersion.

Physical-device-level functionality or behavior added by a new core version of the API must not be used unless it is supported by the physical device as determined by VkPhysicalDeviceProperties::apiVersion and the specified version of VkApplicationInfo::apiVersion.

Device-level functionality or behavior added by a new core version of the API must not be used unless it is supported by the device as determined by VkPhysicalDeviceProperties::apiVersion and the specified version of VkApplicationInfo::apiVersion.

3.8. VkResult Return Codes

While the core Vulkan API is not designed to capture incorrect usage, some circumstances still require return codes. Commands in Vulkan return their status via return codes that are in one of two categories:

  • Successful completion codes are returned when a command needs to communicate success or status information. All successful completion codes are non-negative values.

  • Run time error codes are returned when a command needs to communicate a failure that could only be detected at runtime. All runtime error codes are negative values.

All return codes in Vulkan are reported via VkResult return values. The possible codes are:

// Provided by VK_VERSION_1_0
typedef enum VkResult {
    VK_SUCCESS = 0,
    VK_NOT_READY = 1,
    VK_TIMEOUT = 2,
    VK_EVENT_SET = 3,
    VK_EVENT_RESET = 4,
    VK_INCOMPLETE = 5,
    VK_ERROR_OUT_OF_HOST_MEMORY = -1,
    VK_ERROR_OUT_OF_DEVICE_MEMORY = -2,
    VK_ERROR_INITIALIZATION_FAILED = -3,
    VK_ERROR_DEVICE_LOST = -4,
    VK_ERROR_MEMORY_MAP_FAILED = -5,
    VK_ERROR_LAYER_NOT_PRESENT = -6,
    VK_ERROR_EXTENSION_NOT_PRESENT = -7,
    VK_ERROR_FEATURE_NOT_PRESENT = -8,
    VK_ERROR_INCOMPATIBLE_DRIVER = -9,
    VK_ERROR_TOO_MANY_OBJECTS = -10,
    VK_ERROR_FORMAT_NOT_SUPPORTED = -11,
    VK_ERROR_FRAGMENTED_POOL = -12,
    VK_ERROR_UNKNOWN = -13,
  // Provided by VK_VERSION_1_1
    VK_ERROR_OUT_OF_POOL_MEMORY = -1000069000,
  // Provided by VK_VERSION_1_1
    VK_ERROR_INVALID_EXTERNAL_HANDLE = -1000072003,
  // Provided by VK_VERSION_1_2
    VK_ERROR_FRAGMENTATION = -1000161000,
  // Provided by VK_VERSION_1_2
    VK_ERROR_INVALID_OPAQUE_CAPTURE_ADDRESS = -1000257000,
  // Provided by VK_VERSION_1_3
    VK_PIPELINE_COMPILE_REQUIRED = 1000297000,
} VkResult;
Success Codes

  • VK_SUCCESS Command successfully completed

  • VK_NOT_READY A fence or query has not yet completed

  • VK_TIMEOUT A wait operation has not completed in the specified time

  • VK_EVENT_SET An event is signaled

  • VK_EVENT_RESET An event is unsignaled

  • VK_INCOMPLETE A return array was too small for the result

  • VK_PIPELINE_COMPILE_REQUIRED A requested pipeline creation would have required compilation, but the application requested compilation to not be performed.

Error codes

  • VK_ERROR_OUT_OF_HOST_MEMORY A host memory allocation has failed.

  • VK_ERROR_OUT_OF_DEVICE_MEMORY A device memory allocation has failed.

  • VK_ERROR_INITIALIZATION_FAILED Initialization of an object could not be completed for implementation-specific reasons.

  • VK_ERROR_DEVICE_LOST The logical or physical device has been lost. See Lost Device

  • VK_ERROR_MEMORY_MAP_FAILED Mapping of a memory object has failed.

  • VK_ERROR_LAYER_NOT_PRESENT A requested layer is not present or could not be loaded.

  • VK_ERROR_EXTENSION_NOT_PRESENT A requested extension is not supported.

  • VK_ERROR_FEATURE_NOT_PRESENT A requested feature is not supported.

  • VK_ERROR_INCOMPATIBLE_DRIVER The requested version of Vulkan is not supported by the driver or is otherwise incompatible for implementation-specific reasons.

  • VK_ERROR_TOO_MANY_OBJECTS Too many objects of the type have already been created.

  • VK_ERROR_FORMAT_NOT_SUPPORTED A requested format is not supported on this device.

  • VK_ERROR_FRAGMENTED_POOL A pool allocation has failed due to fragmentation of the pool’s memory. This must only be returned if no attempt to allocate host or device memory was made to accommodate the new allocation. This should be returned in preference to VK_ERROR_OUT_OF_POOL_MEMORY, but only if the implementation is certain that the pool allocation failure was due to fragmentation.

  • VK_ERROR_OUT_OF_POOL_MEMORY A pool memory allocation has failed. This must only be returned if no attempt to allocate host or device memory was made to accommodate the new allocation. If the failure was definitely due to fragmentation of the pool, VK_ERROR_FRAGMENTED_POOL should be returned instead.

  • VK_ERROR_INVALID_EXTERNAL_HANDLE An external handle is not a valid handle of the specified type.

  • VK_ERROR_FRAGMENTATION A descriptor pool creation has failed due to fragmentation.

  • VK_ERROR_INVALID_OPAQUE_CAPTURE_ADDRESS A buffer creation or memory allocation failed because the requested address is not available.

  • VK_ERROR_UNKNOWN An unknown error has occurred; either the application has provided invalid input, or an implementation failure has occurred.

If a command returns a runtime error, unless otherwise specified any output parameters will have undefined contents, except that if the output parameter is a structure with sType and pNext fields, those fields will be unmodified. Any structures chained from pNext will also have undefined contents, except that sType and pNext will be unmodified.

VK_ERROR_OUT_OF_*_MEMORY errors do not modify any currently existing Vulkan objects. Objects that have already been successfully created can still be used by the application.

Note

As a general rule, Free, Release, and Reset commands do not return VK_ERROR_OUT_OF_HOST_MEMORY, while any other command with a return code may return it. Any exceptions from this rule are described for those commands.

VK_ERROR_UNKNOWN will be returned by an implementation when an unexpected error occurs that cannot be attributed to valid behavior of the application and implementation. Under these conditions, it may be returned from any command returning a VkResult.

Note

VK_ERROR_UNKNOWN is not expected to ever be returned if the application behavior is valid, and if the implementation is bug-free. If VK_ERROR_UNKNOWN is received, the application should be checked against the latest validation layers to verify correct behavior as much as possible. If no issues are identified it could be an implementation issue, and the implementor should be contacted for support.

Performance-critical commands generally do not have return codes. If a runtime error occurs in such commands, the implementation will defer reporting the error until a specified point. For commands that record into command buffers (vkCmd*) runtime errors are reported by vkEndCommandBuffer.

3.9. Numeric Representation and Computation

Implementations normally perform computations in floating-point, and must meet the range and precision requirements defined under “Floating-Point Computation” below.

These requirements only apply to computations performed in Vulkan operations outside of shader execution, such as texture image specification and sampling, and per-fragment operations. Range and precision requirements during shader execution differ and are specified by the Precision and Operation of SPIR-V Instructions section.

In some cases, the representation and/or precision of operations is implicitly limited by the specified format of vertex or texel data consumed by Vulkan. Specific floating-point formats are described later in this section.

3.9.1. Floating-Point Computation

Most floating-point computation is performed in SPIR-V shader modules. The properties of computation within shaders are constrained as defined by the Precision and Operation of SPIR-V Instructions section.

Some floating-point computation is performed outside of shaders, such as viewport and depth range calculations. For these computations, we do not specify how floating-point numbers are to be represented, or the details of how operations on them are performed, but only place minimal requirements on representation and precision as described in the remainder of this section.

We require simply that numbers’ floating-point parts contain enough bits and that their exponent fields are large enough so that individual results of floating-point operations are accurate to about 1 part in 105. The maximum representable magnitude for all floating-point values must be at least 232.

x × 0 = 0 × x = 0 for any non-infinite and non-NaN x.

1 × x = x × 1 = x.

x + 0 = 0 + x = x.

00 = 1.

Occasionally, further requirements will be specified. Most single-precision floating-point formats meet these requirements.

The special values Inf and -Inf encode values with magnitudes too large to be represented; the special value NaN encodes “Not A Number” values resulting from undefined arithmetic operations such as 0 / 0. Implementations may support Inf and NaN in their floating-point computations. Any computation which does not support either Inf or NaN, for which that value is an input or output will yield an undefined value.

3.9.2. Floating-Point Format Conversions

When a value is converted to a defined floating-point representation, finite values falling between two representable finite values are rounded to one or the other. The rounding mode is not defined. Finite values whose magnitude is larger than that of any representable finite value may be rounded either to the closest representable finite value or to the appropriately signed infinity. For unsigned destination formats any negative values are converted to zero. Positive infinity is converted to positive infinity; negative infinity is converted to negative infinity in signed formats and to zero in unsigned formats; and any NaN is converted to a NaN.

3.9.3. 16-Bit Floating-Point Numbers

16-bit floating point numbers are defined in the “16-bit floating point numbers” section of the Khronos Data Format Specification.

3.9.4. Unsigned 11-Bit Floating-Point Numbers

Unsigned 11-bit floating point numbers are defined in the “Unsigned 11-bit floating point numbers” section of the Khronos Data Format Specification.

3.9.5. Unsigned 10-Bit Floating-Point Numbers

Unsigned 10-bit floating point numbers are defined in the “Unsigned 10-bit floating point numbers” section of the Khronos Data Format Specification.

3.9.6. General Requirements

Any representable floating-point value in the appropriate format is legal as input to a Vulkan command that requires floating-point data. The result of providing a value that is not a floating-point number to such a command is unspecified, but must not lead to Vulkan interruption or termination. For example, providing a negative zero (where applicable) or a denormalized number to a Vulkan command must yield deterministic results, while providing a NaN or Inf yields unspecified results.

Some calculations require division. In such cases (including implied divisions performed by vector normalization), division by zero produces an unspecified result but must not lead to Vulkan interruption or termination.

3.10. Fixed-Point Data Conversions

When generic vertex attributes and pixel color or depth components are represented as integers, they are often (but not always) considered to be normalized. Normalized integer values are treated specially when being converted to and from floating-point values, and are usually referred to as normalized fixed-point.

In the remainder of this section, b denotes the bit width of the fixed-point integer representation. When the integer is one of the types defined by the API, b is the bit width of that type. When the integer comes from an image containing color or depth component texels, b is the number of bits allocated to that component in its specified image format.

The signed and unsigned fixed-point representations are assumed to be b-bit binary two’s-complement integers and binary unsigned integers, respectively.

3.10.1. Conversion from Normalized Fixed-Point to Floating-Point

Unsigned normalized fixed-point integers represent numbers in the range [0,1]. The conversion from an unsigned normalized fixed-point value c to the corresponding floating-point value f is defined as

Signed normalized fixed-point integers represent numbers in the range [-1,1]. The conversion from a signed normalized fixed-point value c to the corresponding floating-point value f is performed using

Only the range [-2b-1 + 1, 2b-1 - 1] is used to represent signed fixed-point values in the range [-1,1]. For example, if b = 8, then the integer value -127 corresponds to -1.0 and the value 127 corresponds to 1.0. This equation is used everywhere that signed normalized fixed-point values are converted to floating-point.

Note that while zero is exactly expressible in this representation, one value (-128 in the example) is outside the representable range, and implementations must clamp it to -1.0. Where the value is subject to further processing by the implementation, e.g. during texture filtering, values less than -1.0 may be used but the result must be clamped before the value is returned to shaders.

3.10.2. Conversion from Floating-Point to Normalized Fixed-Point

The conversion from a floating-point value f to the corresponding unsigned normalized fixed-point value c is defined by first clamping f to the range [0,1], then computing

c = convertFloatToUint(f × (2b - 1), b)

where convertFloatToUint(r,b) returns one of the two unsigned binary integer values with exactly b bits which are closest to the floating-point value r. Implementations should round to nearest. If r is equal to an integer, then that integer value must be returned. In particular, if f is equal to 0.0 or 1.0, then c must be assigned 0 or 2b - 1, respectively.

The conversion from a floating-point value f to the corresponding signed normalized fixed-point value c is performed by clamping f to the range [-1,1], then computing

c = convertFloatToInt(f × (2b-1 - 1), b)

where convertFloatToInt(r,b) returns one of the two signed two’s-complement binary integer values with exactly b bits which are closest to the floating-point value r. Implementations should round to nearest. If r is equal to an integer, then that integer value must be returned. In particular, if f is equal to -1.0, 0.0, or 1.0, then c must be assigned -(2b-1 - 1), 0, or 2b-1 - 1, respectively.

This equation is used everywhere that floating-point values are converted to signed normalized fixed-point.

3.11. Common Object Types

Some types of Vulkan objects are used in many different structures and command parameters, and are described here. These types include offsets, extents, and rectangles.

3.11.1. Offsets

Offsets are used to describe a pixel location within an image or framebuffer, as an (x,y) location for two-dimensional images, or an (x,y,z) location for three-dimensional images.

A two-dimensional offset is defined by the structure:

// Provided by VK_VERSION_1_0
typedef struct VkOffset2D {
    int32_t    x;
    int32_t    y;
} VkOffset2D;

  • x is the x offset.

  • y is the y offset.

A three-dimensional offset is defined by the structure:

// Provided by VK_VERSION_1_0
typedef struct VkOffset3D {
    int32_t    x;
    int32_t    y;
    int32_t    z;
} VkOffset3D;

  • x is the x offset.

  • y is the y offset.

  • z is the z offset.

3.11.2. Extents

Extents are used to describe the size of a rectangular region of pixels within an image or framebuffer, as (width,height) for two-dimensional images, or as (width,height,depth) for three-dimensional images.

A two-dimensional extent is defined by the structure:

// Provided by VK_VERSION_1_0
typedef struct VkExtent2D {
    uint32_t    width;
    uint32_t    height;
} VkExtent2D;

  • width is the width of the extent.

  • height is the height of the extent.

A three-dimensional extent is defined by the structure:

// Provided by VK_VERSION_1_0
typedef struct VkExtent3D {
    uint32_t    width;
    uint32_t    height;
    uint32_t    depth;
} VkExtent3D;

  • width is the width of the extent.

  • height is the height of the extent.

  • depth is the depth of the extent.

3.11.3. Rectangles

Rectangles are used to describe a specified rectangular region of pixels within an image or framebuffer. Rectangles include both an offset and an extent of the same dimensionality, as described above. Two-dimensional rectangles are defined by the structure

// Provided by VK_VERSION_1_0
typedef struct VkRect2D {
    VkOffset2D    offset;
    VkExtent2D    extent;
} VkRect2D;

  • offset is a VkOffset2D specifying the rectangle offset.

  • extent is a VkExtent2D specifying the rectangle extent.

3.11.4. Structure Types

Each value corresponds to a particular structure with a sType member with a matching name. As a general rule, the name of each VkStructureType value is obtained by taking the name of the structure, stripping the leading Vk, prefixing each capital letter with _, converting the entire resulting string to upper case, and prefixing it with VK_STRUCTURE_TYPE_. For example, structures of type VkImageCreateInfo correspond to a VkStructureType value of VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO, and thus a structure of this type must have its sType member set to this value before it is passed to the API.

The values VK_STRUCTURE_TYPE_LOADER_INSTANCE_CREATE_INFO and VK_STRUCTURE_TYPE_LOADER_DEVICE_CREATE_INFO are reserved for internal use by the loader, and do not have corresponding Vulkan structures in this Specification.

Structure types supported by the Vulkan API include:

// Provided by VK_VERSION_1_0
typedef enum VkStructureType {
    VK_STRUCTURE_TYPE_APPLICATION_INFO = 0,
    VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO = 1,
    VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO = 2,
    VK_STRUCTURE_TYPE_DEVICE_CREATE_INFO = 3,
    VK_STRUCTURE_TYPE_SUBMIT_INFO = 4,
    VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_INFO = 5,
    VK_STRUCTURE_TYPE_MAPPED_MEMORY_RANGE = 6,
    VK_STRUCTURE_TYPE_BIND_SPARSE_INFO = 7,
    VK_STRUCTURE_TYPE_FENCE_CREATE_INFO = 8,
    VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO = 9,
    VK_STRUCTURE_TYPE_EVENT_CREATE_INFO = 10,
    VK_STRUCTURE_TYPE_QUERY_POOL_CREATE_INFO = 11,
    VK_STRUCTURE_TYPE_BUFFER_CREATE_INFO = 12,
    VK_STRUCTURE_TYPE_BUFFER_VIEW_CREATE_INFO = 13,
    VK_STRUCTURE_TYPE_IMAGE_CREATE_INFO = 14,
    VK_STRUCTURE_TYPE_IMAGE_VIEW_CREATE_INFO = 15,
    VK_STRUCTURE_TYPE_SHADER_MODULE_CREATE_INFO = 16,
    VK_STRUCTURE_TYPE_PIPELINE_CACHE_CREATE_INFO = 17,
    VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_CREATE_INFO = 18,
    VK_STRUCTURE_TYPE_PIPELINE_VERTEX_INPUT_STATE_CREATE_INFO = 19,
    VK_STRUCTURE_TYPE_PIPELINE_INPUT_ASSEMBLY_STATE_CREATE_INFO = 20,
    VK_STRUCTURE_TYPE_PIPELINE_TESSELLATION_STATE_CREATE_INFO = 21,
    VK_STRUCTURE_TYPE_PIPELINE_VIEWPORT_STATE_CREATE_INFO = 22,
    VK_STRUCTURE_TYPE_PIPELINE_RASTERIZATION_STATE_CREATE_INFO = 23,
    VK_STRUCTURE_TYPE_PIPELINE_MULTISAMPLE_STATE_CREATE_INFO = 24,
    VK_STRUCTURE_TYPE_PIPELINE_DEPTH_STENCIL_STATE_CREATE_INFO = 25,
    VK_STRUCTURE_TYPE_PIPELINE_COLOR_BLEND_STATE_CREATE_INFO = 26,
    VK_STRUCTURE_TYPE_PIPELINE_DYNAMIC_STATE_CREATE_INFO = 27,
    VK_STRUCTURE_TYPE_GRAPHICS_PIPELINE_CREATE_INFO = 28,
    VK_STRUCTURE_TYPE_COMPUTE_PIPELINE_CREATE_INFO = 29,
    VK_STRUCTURE_TYPE_PIPELINE_LAYOUT_CREATE_INFO = 30,
    VK_STRUCTURE_TYPE_SAMPLER_CREATE_INFO = 31,
    VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_CREATE_INFO = 32,
    VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_CREATE_INFO = 33,
    VK_STRUCTURE_TYPE_DESCRIPTOR_SET_ALLOCATE_INFO = 34,
    VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET = 35,
    VK_STRUCTURE_TYPE_COPY_DESCRIPTOR_SET = 36,
    VK_STRUCTURE_TYPE_FRAMEBUFFER_CREATE_INFO = 37,
    VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO = 38,
    VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO = 39,
    VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO = 40,
    VK_STRUCTURE_TYPE_COMMAND_BUFFER_INHERITANCE_INFO = 41,
    VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO = 42,
    VK_STRUCTURE_TYPE_RENDER_PASS_BEGIN_INFO = 43,
    VK_STRUCTURE_TYPE_BUFFER_MEMORY_BARRIER = 44,
    VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER = 45,
    VK_STRUCTURE_TYPE_MEMORY_BARRIER = 46,
    VK_STRUCTURE_TYPE_LOADER_INSTANCE_CREATE_INFO = 47,
    VK_STRUCTURE_TYPE_LOADER_DEVICE_CREATE_INFO = 48,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SUBGROUP_PROPERTIES = 1000094000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_BIND_BUFFER_MEMORY_INFO = 1000157000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_BIND_IMAGE_MEMORY_INFO = 1000157001,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_16BIT_STORAGE_FEATURES = 1000083000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_MEMORY_DEDICATED_REQUIREMENTS = 1000127000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_MEMORY_DEDICATED_ALLOCATE_INFO = 1000127001,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_MEMORY_ALLOCATE_FLAGS_INFO = 1000060000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_DEVICE_GROUP_RENDER_PASS_BEGIN_INFO = 1000060003,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_DEVICE_GROUP_COMMAND_BUFFER_BEGIN_INFO = 1000060004,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_DEVICE_GROUP_SUBMIT_INFO = 1000060005,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_DEVICE_GROUP_BIND_SPARSE_INFO = 1000060006,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_BIND_BUFFER_MEMORY_DEVICE_GROUP_INFO = 1000060013,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_BIND_IMAGE_MEMORY_DEVICE_GROUP_INFO = 1000060014,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_GROUP_PROPERTIES = 1000070000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_DEVICE_GROUP_DEVICE_CREATE_INFO = 1000070001,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_BUFFER_MEMORY_REQUIREMENTS_INFO_2 = 1000146000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_IMAGE_MEMORY_REQUIREMENTS_INFO_2 = 1000146001,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_IMAGE_SPARSE_MEMORY_REQUIREMENTS_INFO_2 = 1000146002,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_MEMORY_REQUIREMENTS_2 = 1000146003,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_SPARSE_IMAGE_MEMORY_REQUIREMENTS_2 = 1000146004,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FEATURES_2 = 1000059000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROPERTIES_2 = 1000059001,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_FORMAT_PROPERTIES_2 = 1000059002,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_IMAGE_FORMAT_PROPERTIES_2 = 1000059003,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_IMAGE_FORMAT_INFO_2 = 1000059004,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_QUEUE_FAMILY_PROPERTIES_2 = 1000059005,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MEMORY_PROPERTIES_2 = 1000059006,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_SPARSE_IMAGE_FORMAT_PROPERTIES_2 = 1000059007,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SPARSE_IMAGE_FORMAT_INFO_2 = 1000059008,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_POINT_CLIPPING_PROPERTIES = 1000117000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_RENDER_PASS_INPUT_ATTACHMENT_ASPECT_CREATE_INFO = 1000117001,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_IMAGE_VIEW_USAGE_CREATE_INFO = 1000117002,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PIPELINE_TESSELLATION_DOMAIN_ORIGIN_STATE_CREATE_INFO = 1000117003,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_RENDER_PASS_MULTIVIEW_CREATE_INFO = 1000053000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MULTIVIEW_FEATURES = 1000053001,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MULTIVIEW_PROPERTIES = 1000053002,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VARIABLE_POINTERS_FEATURES = 1000120000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PROTECTED_SUBMIT_INFO = 1000145000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROTECTED_MEMORY_FEATURES = 1000145001,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PROTECTED_MEMORY_PROPERTIES = 1000145002,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_DEVICE_QUEUE_INFO_2 = 1000145003,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_SAMPLER_YCBCR_CONVERSION_CREATE_INFO = 1000156000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_SAMPLER_YCBCR_CONVERSION_INFO = 1000156001,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_BIND_IMAGE_PLANE_MEMORY_INFO = 1000156002,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_IMAGE_PLANE_MEMORY_REQUIREMENTS_INFO = 1000156003,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SAMPLER_YCBCR_CONVERSION_FEATURES = 1000156004,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_SAMPLER_YCBCR_CONVERSION_IMAGE_FORMAT_PROPERTIES = 1000156005,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_DESCRIPTOR_UPDATE_TEMPLATE_CREATE_INFO = 1000085000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_EXTERNAL_IMAGE_FORMAT_INFO = 1000071000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_EXTERNAL_IMAGE_FORMAT_PROPERTIES = 1000071001,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_EXTERNAL_BUFFER_INFO = 1000071002,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_EXTERNAL_BUFFER_PROPERTIES = 1000071003,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_ID_PROPERTIES = 1000071004,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_EXTERNAL_MEMORY_BUFFER_CREATE_INFO = 1000072000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_EXTERNAL_MEMORY_IMAGE_CREATE_INFO = 1000072001,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_EXPORT_MEMORY_ALLOCATE_INFO = 1000072002,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_EXTERNAL_FENCE_INFO = 1000112000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_EXTERNAL_FENCE_PROPERTIES = 1000112001,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_EXPORT_FENCE_CREATE_INFO = 1000113000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_EXPORT_SEMAPHORE_CREATE_INFO = 1000077000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_EXTERNAL_SEMAPHORE_INFO = 1000076000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_EXTERNAL_SEMAPHORE_PROPERTIES = 1000076001,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MAINTENANCE_3_PROPERTIES = 1000168000,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_SUPPORT = 1000168001,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_DRAW_PARAMETERS_FEATURES = 1000063000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_1_FEATURES = 49,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_1_PROPERTIES = 50,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_2_FEATURES = 51,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_2_PROPERTIES = 52,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_IMAGE_FORMAT_LIST_CREATE_INFO = 1000147000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_ATTACHMENT_DESCRIPTION_2 = 1000109000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_ATTACHMENT_REFERENCE_2 = 1000109001,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_SUBPASS_DESCRIPTION_2 = 1000109002,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_SUBPASS_DEPENDENCY_2 = 1000109003,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_RENDER_PASS_CREATE_INFO_2 = 1000109004,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_SUBPASS_BEGIN_INFO = 1000109005,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_SUBPASS_END_INFO = 1000109006,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_8BIT_STORAGE_FEATURES = 1000177000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DRIVER_PROPERTIES = 1000196000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_ATOMIC_INT64_FEATURES = 1000180000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_FLOAT16_INT8_FEATURES = 1000082000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_FLOAT_CONTROLS_PROPERTIES = 1000197000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_DESCRIPTOR_SET_LAYOUT_BINDING_FLAGS_CREATE_INFO = 1000161000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DESCRIPTOR_INDEXING_FEATURES = 1000161001,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DESCRIPTOR_INDEXING_PROPERTIES = 1000161002,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_DESCRIPTOR_SET_VARIABLE_DESCRIPTOR_COUNT_ALLOCATE_INFO = 1000161003,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_DESCRIPTOR_SET_VARIABLE_DESCRIPTOR_COUNT_LAYOUT_SUPPORT = 1000161004,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DEPTH_STENCIL_RESOLVE_PROPERTIES = 1000199000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_SUBPASS_DESCRIPTION_DEPTH_STENCIL_RESOLVE = 1000199001,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SCALAR_BLOCK_LAYOUT_FEATURES = 1000221000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_IMAGE_STENCIL_USAGE_CREATE_INFO = 1000246000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SAMPLER_FILTER_MINMAX_PROPERTIES = 1000130000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_SAMPLER_REDUCTION_MODE_CREATE_INFO = 1000130001,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_MEMORY_MODEL_FEATURES = 1000211000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_IMAGELESS_FRAMEBUFFER_FEATURES = 1000108000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_FRAMEBUFFER_ATTACHMENTS_CREATE_INFO = 1000108001,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_FRAMEBUFFER_ATTACHMENT_IMAGE_INFO = 1000108002,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_RENDER_PASS_ATTACHMENT_BEGIN_INFO = 1000108003,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_UNIFORM_BUFFER_STANDARD_LAYOUT_FEATURES = 1000253000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_SUBGROUP_EXTENDED_TYPES_FEATURES = 1000175000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SEPARATE_DEPTH_STENCIL_LAYOUTS_FEATURES = 1000241000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_ATTACHMENT_REFERENCE_STENCIL_LAYOUT = 1000241001,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_ATTACHMENT_DESCRIPTION_STENCIL_LAYOUT = 1000241002,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_HOST_QUERY_RESET_FEATURES = 1000261000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_TIMELINE_SEMAPHORE_FEATURES = 1000207000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_TIMELINE_SEMAPHORE_PROPERTIES = 1000207001,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_SEMAPHORE_TYPE_CREATE_INFO = 1000207002,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_TIMELINE_SEMAPHORE_SUBMIT_INFO = 1000207003,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_SEMAPHORE_WAIT_INFO = 1000207004,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_SEMAPHORE_SIGNAL_INFO = 1000207005,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_BUFFER_DEVICE_ADDRESS_FEATURES = 1000257000,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_BUFFER_DEVICE_ADDRESS_INFO = 1000244001,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_BUFFER_OPAQUE_CAPTURE_ADDRESS_CREATE_INFO = 1000257002,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_MEMORY_OPAQUE_CAPTURE_ADDRESS_ALLOCATE_INFO = 1000257003,
  // Provided by VK_VERSION_1_2
    VK_STRUCTURE_TYPE_DEVICE_MEMORY_OPAQUE_CAPTURE_ADDRESS_INFO = 1000257004,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_3_FEATURES = 53,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_3_PROPERTIES = 54,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PIPELINE_CREATION_FEEDBACK_CREATE_INFO = 1000192000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_TERMINATE_INVOCATION_FEATURES = 1000215000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_TOOL_PROPERTIES = 1000245000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_DEMOTE_TO_HELPER_INVOCATION_FEATURES = 1000276000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PRIVATE_DATA_FEATURES = 1000295000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_DEVICE_PRIVATE_DATA_CREATE_INFO = 1000295001,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PRIVATE_DATA_SLOT_CREATE_INFO = 1000295002,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PIPELINE_CREATION_CACHE_CONTROL_FEATURES = 1000297000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_MEMORY_BARRIER_2 = 1000314000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_BUFFER_MEMORY_BARRIER_2 = 1000314001,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_IMAGE_MEMORY_BARRIER_2 = 1000314002,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_DEPENDENCY_INFO = 1000314003,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_SUBMIT_INFO_2 = 1000314004,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_SEMAPHORE_SUBMIT_INFO = 1000314005,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_COMMAND_BUFFER_SUBMIT_INFO = 1000314006,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SYNCHRONIZATION_2_FEATURES = 1000314007,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_ZERO_INITIALIZE_WORKGROUP_MEMORY_FEATURES = 1000325000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_IMAGE_ROBUSTNESS_FEATURES = 1000335000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_COPY_BUFFER_INFO_2 = 1000337000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_COPY_IMAGE_INFO_2 = 1000337001,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_COPY_BUFFER_TO_IMAGE_INFO_2 = 1000337002,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_COPY_IMAGE_TO_BUFFER_INFO_2 = 1000337003,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_BLIT_IMAGE_INFO_2 = 1000337004,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_RESOLVE_IMAGE_INFO_2 = 1000337005,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_BUFFER_COPY_2 = 1000337006,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_IMAGE_COPY_2 = 1000337007,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_IMAGE_BLIT_2 = 1000337008,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_BUFFER_IMAGE_COPY_2 = 1000337009,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_IMAGE_RESOLVE_2 = 1000337010,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SUBGROUP_SIZE_CONTROL_PROPERTIES = 1000225000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PIPELINE_SHADER_STAGE_REQUIRED_SUBGROUP_SIZE_CREATE_INFO = 1000225001,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SUBGROUP_SIZE_CONTROL_FEATURES = 1000225002,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_INLINE_UNIFORM_BLOCK_FEATURES = 1000138000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_INLINE_UNIFORM_BLOCK_PROPERTIES = 1000138001,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET_INLINE_UNIFORM_BLOCK = 1000138002,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_DESCRIPTOR_POOL_INLINE_UNIFORM_BLOCK_CREATE_INFO = 1000138003,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_TEXTURE_COMPRESSION_ASTC_HDR_FEATURES = 1000066000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_RENDERING_INFO = 1000044000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_RENDERING_ATTACHMENT_INFO = 1000044001,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PIPELINE_RENDERING_CREATE_INFO = 1000044002,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DYNAMIC_RENDERING_FEATURES = 1000044003,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_COMMAND_BUFFER_INHERITANCE_RENDERING_INFO = 1000044004,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_INTEGER_DOT_PRODUCT_FEATURES = 1000280000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_INTEGER_DOT_PRODUCT_PROPERTIES = 1000280001,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_TEXEL_BUFFER_ALIGNMENT_PROPERTIES = 1000281001,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_FORMAT_PROPERTIES_3 = 1000360000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MAINTENANCE_4_FEATURES = 1000413000,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_MAINTENANCE_4_PROPERTIES = 1000413001,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_DEVICE_BUFFER_MEMORY_REQUIREMENTS = 1000413002,
  // Provided by VK_VERSION_1_3
    VK_STRUCTURE_TYPE_DEVICE_IMAGE_MEMORY_REQUIREMENTS = 1000413003,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VARIABLE_POINTER_FEATURES = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VARIABLE_POINTERS_FEATURES,
  // Provided by VK_VERSION_1_1
    VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_DRAW_PARAMETER_FEATURES = VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_DRAW_PARAMETERS_FEATURES,
} VkStructureType;

3.12. API Name Aliases

A small number of APIs did not follow the naming conventions when initially defined. For consistency, when we discover an API name that violates the naming conventions, we rename it in the Specification, XML, and header files. For backwards compatibility, the original (incorrect) name is retained as a “typo alias”. The alias is deprecated and should not be used, but will be retained indefinitely.

Note

VK_STENCIL_FRONT_AND_BACK is an example of a typo alias. It was initially defined as part of VkStencilFaceFlagBits. Once the naming inconsistency was noticed, it was renamed to VK_STENCIL_FACE_FRONT_AND_BACK, and the old name was aliased to the correct name.

4. Initialization

Before using Vulkan, an application must initialize it by loading the Vulkan commands, and creating a VkInstance object.

4.1. Command Function Pointers

Vulkan commands are not necessarily exposed by static linking on a platform. Commands to query function pointers for Vulkan commands are described below.

Note

When extensions are promoted or otherwise incorporated into another extension or Vulkan core version, command aliases may be included. Whilst the behavior of each command alias is identical, the behavior of retrieving each alias’s function pointer is not. A function pointer for a given alias can only be retrieved if the extension or version that introduced that alias is supported and enabled, irrespective of whether any other alias is available.

Function pointers for all Vulkan commands can be obtained with the command:

// Provided by VK_VERSION_1_0
PFN_vkVoidFunction vkGetInstanceProcAddr(
    VkInstance                                  instance,
    const char*                                 pName);

  • instance is the instance that the function pointer will be compatible with, or NULL for commands not dependent on any instance.

  • pName is the name of the command to obtain.

vkGetInstanceProcAddr itself is obtained in a platform- and loader- specific manner. Typically, the loader library will export this command as a function symbol, so applications can link against the loader library, or load it dynamically and look up the symbol using platform-specific APIs.

The table below defines the various use cases for vkGetInstanceProcAddr and expected return value (“fp” is “function pointer”) for each case. A valid returned function pointer (“fp”) must not be NULL.

The returned function pointer is of type PFN_vkVoidFunction, and must be cast to the type of the command being queried before use.

Table 1. vkGetInstanceProcAddr behavior
instance pName return value

*1

NULL

undefined

invalid non-NULL instance

*1

undefined

NULL

global command2

fp

NULL

vkGetInstanceProcAddr

fp5

instance

vkGetInstanceProcAddr

fp

instance

core dispatchable command

fp3

instance

enabled instance extension dispatchable command for instance

fp3

instance

available device extension4 dispatchable command for instance

fp3

any other case, not covered above

NULL
1

"*" means any representable value for the parameter (including valid values, invalid values, and NULL).

2

The global commands are: vkEnumerateInstanceVersion, vkEnumerateInstanceExtensionProperties, vkEnumerateInstanceLayerProperties, and vkCreateInstance. Dispatchable commands are all other commands which are not global.

3

The returned function pointer must only be called with a dispatchable object (the first parameter) that is instance or a child of instance, e.g. VkInstance, VkPhysicalDevice, VkDevice, VkQueue, or VkCommandBuffer.

4

An “available device extension” is a device extension supported by any physical device enumerated by instance.

5

Starting with Vulkan 1.2, vkGetInstanceProcAddr can resolve itself with a NULL instance pointer.

Valid Usage (Implicit)

  • VUID-vkGetInstanceProcAddr-instance-parameter
    If instance is not NULL, instance must be a valid VkInstance handle

  • VUID-vkGetInstanceProcAddr-pName-parameter
    pName must be a null-terminated UTF-8 string

In order to support systems with multiple Vulkan implementations, the function pointers returned by vkGetInstanceProcAddr may point to dispatch code that calls a different real implementation for different VkDevice objects or their child objects. The overhead of the internal dispatch for VkDevice objects can be avoided by obtaining device-specific function pointers for any commands that use a device or device-child object as their dispatchable object. Such function pointers can be obtained with the command:

// Provided by VK_VERSION_1_0
PFN_vkVoidFunction vkGetDeviceProcAddr(
    VkDevice                                    device,
    const char*                                 pName);

The table below defines the various use cases for vkGetDeviceProcAddr and expected return value (“fp” is “function pointer”) for each case. A valid returned function pointer (“fp”) must not be NULL.

The returned function pointer is of type PFN_vkVoidFunction, and must be cast to the type of the command being queried before use. The function pointer must only be called with a dispatchable object (the first parameter) that is device or a child of device.

Table 2. vkGetDeviceProcAddr behavior
device pName return value

NULL

*1

undefined

invalid device

*1

undefined

device

NULL

undefined

device

requested core version2 device-level dispatchable command3

fp4

device

enabled extension device-level dispatchable command3

fp4

any other case, not covered above

NULL
1

"*" means any representable value for the parameter (including valid values, invalid values, and NULL).

2

Device-level commands which are part of the core version specified by VkApplicationInfo::apiVersion when creating the instance will always return a valid function pointer. Core commands beyond that version which are supported by the implementation may either return NULL or a function pointer, though the function pointer must not be called.

3

In this function, device-level excludes all physical-device-level commands.

4

The returned function pointer must only be called with a dispatchable object (the first parameter) that is device or a child of device e.g. VkDevice, VkQueue, or VkCommandBuffer.

Valid Usage (Implicit)

  • VUID-vkGetDeviceProcAddr-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkGetDeviceProcAddr-pName-parameter
    pName must be a null-terminated UTF-8 string

The definition of PFN_vkVoidFunction is:

// Provided by VK_VERSION_1_0
typedef void (VKAPI_PTR *PFN_vkVoidFunction)(void);

This type is returned from command function pointer queries, and must be cast to an actual command function pointer before use.

4.1.1. Extending Physical Device Core Functionality

New core physical-device-level functionality can be used when the physical-device version is greater than or equal to the version of Vulkan that added the new functionality. The Vulkan version supported by a physical device can be obtained by calling vkGetPhysicalDeviceProperties.

4.1.2. Extending Physical Device From Device Extensions

When the VK_KHR_get_physical_device_properties2 extension is enabled, or when both the instance and the physical-device versions are at least 1.1, physical-device-level functionality of a device extension can be used with a physical device if the corresponding extension is enumerated by vkEnumerateDeviceExtensionProperties for that physical device, even before a logical device has been created.

To obtain a function pointer for a physical-device-level command from a device extension, an application can use vkGetInstanceProcAddr. This function pointer may point to dispatch code, which calls a different real implementation for different VkPhysicalDevice objects. Applications must not use a VkPhysicalDevice in any command added by an extension or core version that is not supported by that physical device.

Device extensions may define structures that can be added to the pNext chain of physical-device-level commands.

4.2. Instances

There is no global state in Vulkan and all per-application state is stored in a VkInstance object. Creating a VkInstance object initializes the Vulkan library and allows the application to pass information about itself to the implementation.

Instances are represented by VkInstance handles:

// Provided by VK_VERSION_1_0
VK_DEFINE_HANDLE(VkInstance)

To query the version of instance-level functionality supported by the implementation, call:

// Provided by VK_VERSION_1_1
VkResult vkEnumerateInstanceVersion(
    uint32_t*                                   pApiVersion);

  • pApiVersion is a pointer to a uint32_t, which is the version of Vulkan supported by instance-level functionality, encoded as described in Version Numbers.

Note

The intended behaviour of vkEnumerateInstanceVersion is that an implementation should not need to perform memory allocations and should unconditionally return VK_SUCCESS. The loader, and any enabled layers, may return VK_ERROR_OUT_OF_HOST_MEMORY in the case of a failed memory allocation.
Valid Usage (Implicit)

  • VUID-vkEnumerateInstanceVersion-pApiVersion-parameter
    pApiVersion must be a valid pointer to a uint32_t value

Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

To create an instance object, call:

// Provided by VK_VERSION_1_0
VkResult vkCreateInstance(
    const VkInstanceCreateInfo*                 pCreateInfo,
    const VkAllocationCallbacks*                pAllocator,
    VkInstance*                                 pInstance);

  • pCreateInfo is a pointer to a VkInstanceCreateInfo structure controlling creation of the instance.

  • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

  • pInstance points a VkInstance handle in which the resulting instance is returned.

vkCreateInstance verifies that the requested layers exist. If not, vkCreateInstance will return VK_ERROR_LAYER_NOT_PRESENT. Next vkCreateInstance verifies that the requested extensions are supported (e.g. in the implementation or in any enabled instance layer) and if any requested extension is not supported, vkCreateInstance must return VK_ERROR_EXTENSION_NOT_PRESENT. After verifying and enabling the instance layers and extensions the VkInstance object is created and returned to the application. If a requested extension is only supported by a layer, both the layer and the extension need to be specified at vkCreateInstance time for the creation to succeed.

Valid Usage
Valid Usage (Implicit)

  • VUID-vkCreateInstance-pCreateInfo-parameter
    pCreateInfo must be a valid pointer to a valid VkInstanceCreateInfo structure

  • VUID-vkCreateInstance-pAllocator-parameter
    If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

  • VUID-vkCreateInstance-pInstance-parameter
    pInstance must be a valid pointer to a VkInstance handle

Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

  • VK_ERROR_INITIALIZATION_FAILED

  • VK_ERROR_LAYER_NOT_PRESENT

  • VK_ERROR_EXTENSION_NOT_PRESENT

  • VK_ERROR_INCOMPATIBLE_DRIVER

The VkInstanceCreateInfo structure is defined as:

// Provided by VK_VERSION_1_0
typedef struct VkInstanceCreateInfo {
    VkStructureType             sType;
    const void*                 pNext;
    VkInstanceCreateFlags       flags;
    const VkApplicationInfo*    pApplicationInfo;
    uint32_t                    enabledLayerCount;
    const char* const*          ppEnabledLayerNames;
    uint32_t                    enabledExtensionCount;
    const char* const*          ppEnabledExtensionNames;
} VkInstanceCreateInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • flags is a bitmask of VkInstanceCreateFlagBits indicating the behavior of the instance.

  • pApplicationInfo is NULL or a pointer to a VkApplicationInfo structure. If not NULL, this information helps implementations recognize behavior inherent to classes of applications. VkApplicationInfo is defined in detail below.

  • enabledLayerCount is the number of global layers to enable.

  • ppEnabledLayerNames is a pointer to an array of enabledLayerCount null-terminated UTF-8 strings containing the names of layers to enable for the created instance. The layers are loaded in the order they are listed in this array, with the first array element being the closest to the application, and the last array element being the closest to the driver. See the Layers section for further details.

  • enabledExtensionCount is the number of global extensions to enable.

  • ppEnabledExtensionNames is a pointer to an array of enabledExtensionCount null-terminated UTF-8 strings containing the names of extensions to enable.

Valid Usage (Implicit)

  • VUID-VkInstanceCreateInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_INSTANCE_CREATE_INFO

  • VUID-VkInstanceCreateInfo-pNext-pNext
    pNext must be NULL

  • VUID-VkInstanceCreateInfo-flags-zerobitmask
    flags must be 0

  • VUID-VkInstanceCreateInfo-pApplicationInfo-parameter
    If pApplicationInfo is not NULL, pApplicationInfo must be a valid pointer to a valid VkApplicationInfo structure

  • VUID-VkInstanceCreateInfo-ppEnabledLayerNames-parameter
    If enabledLayerCount is not 0, ppEnabledLayerNames must be a valid pointer to an array of enabledLayerCount null-terminated UTF-8 strings

  • VUID-VkInstanceCreateInfo-ppEnabledExtensionNames-parameter
    If enabledExtensionCount is not 0, ppEnabledExtensionNames must be a valid pointer to an array of enabledExtensionCount null-terminated UTF-8 strings

// Provided by VK_VERSION_1_0
typedef enum VkInstanceCreateFlagBits {
} VkInstanceCreateFlagBits;
Note

All bits for this type are defined by extensions, and none of those extensions are enabled in this build of the specification.

 
// Provided by VK_VERSION_1_0
typedef VkFlags VkInstanceCreateFlags;

VkInstanceCreateFlags is a bitmask type for setting a mask, but is currently reserved for future use.

The VkApplicationInfo structure is defined as:

// Provided by VK_VERSION_1_0
typedef struct VkApplicationInfo {
    VkStructureType    sType;
    const void*        pNext;
    const char*        pApplicationName;
    uint32_t           applicationVersion;
    const char*        pEngineName;
    uint32_t           engineVersion;
    uint32_t           apiVersion;
} VkApplicationInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • pApplicationName is NULL or is a pointer to a null-terminated UTF-8 string containing the name of the application.

  • applicationVersion is an unsigned integer variable containing the developer-supplied version number of the application.

  • pEngineName is NULL or is a pointer to a null-terminated UTF-8 string containing the name of the engine (if any) used to create the application.

  • engineVersion is an unsigned integer variable containing the developer-supplied version number of the engine used to create the application.

  • apiVersion must be the highest version of Vulkan that the application is designed to use, encoded as described in Version Numbers. The patch version number specified in apiVersion is ignored when creating an instance object. Only the major and minor versions of the instance must match those requested in apiVersion.

Vulkan 1.0 implementations were required to return VK_ERROR_INCOMPATIBLE_DRIVER if apiVersion was larger than 1.0. Implementations that support Vulkan 1.1 or later must not return VK_ERROR_INCOMPATIBLE_DRIVER for any value of apiVersion.

Note

Because Vulkan 1.0 implementations may fail with VK_ERROR_INCOMPATIBLE_DRIVER, applications should determine the version of Vulkan available before calling vkCreateInstance. If the vkGetInstanceProcAddr returns NULL for vkEnumerateInstanceVersion, it is a Vulkan 1.0 implementation. Otherwise, the application can call vkEnumerateInstanceVersion to determine the version of Vulkan.

As long as the instance supports at least Vulkan 1.1, an application can use different versions of Vulkan with an instance than it does with a device or physical device.

Note

The Khronos validation layers will treat apiVersion as the highest API version the application targets, and will validate API usage against the minimum of that version and the implementation version (instance or device, depending on context). If an application tries to use functionality from a greater version than this, a validation error will be triggered.

For example, if the instance supports Vulkan 1.1 and three physical devices support Vulkan 1.0, Vulkan 1.1, and Vulkan 1.2, respectively, and if the application sets apiVersion to 1.2, the application can use the following versions of Vulkan:

  • Vulkan 1.0 can be used with the instance and with all physical devices.

  • Vulkan 1.1 can be used with the instance and with the physical devices that support Vulkan 1.1 and Vulkan 1.2.

  • Vulkan 1.2 can be used with the physical device that supports Vulkan 1.2.

If we modify the above example so that the application sets apiVersion to 1.1, then the application must not use Vulkan 1.2 functionality on the physical device that supports Vulkan 1.2.
Note

Providing a NULL VkInstanceCreateInfo::pApplicationInfo or providing an apiVersion of 0 is equivalent to providing an apiVersion of VK_MAKE_API_VERSION(0,1,0,0).
Valid Usage

  • VUID-VkApplicationInfo-apiVersion-04010
    If apiVersion is not 0, then it must be greater than or equal to VK_API_VERSION_1_0

Valid Usage (Implicit)

  • VUID-VkApplicationInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_APPLICATION_INFO

  • VUID-VkApplicationInfo-pNext-pNext
    pNext must be NULL

  • VUID-VkApplicationInfo-pApplicationName-parameter
    If pApplicationName is not NULL, pApplicationName must be a null-terminated UTF-8 string

  • VUID-VkApplicationInfo-pEngineName-parameter
    If pEngineName is not NULL, pEngineName must be a null-terminated UTF-8 string

To destroy an instance, call:

// Provided by VK_VERSION_1_0
void vkDestroyInstance(
    VkInstance                                  instance,
    const VkAllocationCallbacks*                pAllocator);

  • instance is the handle of the instance to destroy.

  • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

Valid Usage

  • VUID-vkDestroyInstance-instance-00629
    All child objects created using instance must have been destroyed prior to destroying instance

  • VUID-vkDestroyInstance-instance-00630
    If VkAllocationCallbacks were provided when instance was created, a compatible set of callbacks must be provided here

  • VUID-vkDestroyInstance-instance-00631
    If no VkAllocationCallbacks were provided when instance was created, pAllocator must be NULL

Valid Usage (Implicit)

  • VUID-vkDestroyInstance-instance-parameter
    If instance is not NULL, instance must be a valid VkInstance handle

  • VUID-vkDestroyInstance-pAllocator-parameter
    If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

Host Synchronization

  • Host access to instance must be externally synchronized

  • Host access to all VkPhysicalDevice objects enumerated from instance must be externally synchronized

5. Devices and Queues

Once Vulkan is initialized, devices and queues are the primary objects used to interact with a Vulkan implementation.

Vulkan separates the concept of physical and logical devices. A physical device usually represents a single complete implementation of Vulkan (excluding instance-level functionality) available to the host, of which there are a finite number. A logical device represents an instance of that implementation with its own state and resources independent of other logical devices.

Physical devices are represented by VkPhysicalDevice handles:

// Provided by VK_VERSION_1_0
VK_DEFINE_HANDLE(VkPhysicalDevice)

5.1. Physical Devices

To retrieve a list of physical device objects representing the physical devices installed in the system, call:

// Provided by VK_VERSION_1_0
VkResult vkEnumeratePhysicalDevices(
    VkInstance                                  instance,
    uint32_t*                                   pPhysicalDeviceCount,
    VkPhysicalDevice*                           pPhysicalDevices);

  • instance is a handle to a Vulkan instance previously created with vkCreateInstance.

  • pPhysicalDeviceCount is a pointer to an integer related to the number of physical devices available or queried, as described below.

  • pPhysicalDevices is either NULL or a pointer to an array of VkPhysicalDevice handles.

If pPhysicalDevices is NULL, then the number of physical devices available is returned in pPhysicalDeviceCount. Otherwise, pPhysicalDeviceCount must point to a variable set by the user to the number of elements in the pPhysicalDevices array, and on return the variable is overwritten with the number of handles actually written to pPhysicalDevices. If pPhysicalDeviceCount is less than the number of physical devices available, at most pPhysicalDeviceCount structures will be written, and VK_INCOMPLETE will be returned instead of VK_SUCCESS, to indicate that not all the available physical devices were returned.

Valid Usage (Implicit)

  • VUID-vkEnumeratePhysicalDevices-instance-parameter
    instance must be a valid VkInstance handle

  • VUID-vkEnumeratePhysicalDevices-pPhysicalDeviceCount-parameter
    pPhysicalDeviceCount must be a valid pointer to a uint32_t value

  • VUID-vkEnumeratePhysicalDevices-pPhysicalDevices-parameter
    If the value referenced by pPhysicalDeviceCount is not 0, and pPhysicalDevices is not NULL, pPhysicalDevices must be a valid pointer to an array of pPhysicalDeviceCount VkPhysicalDevice handles

Return Codes
Success

  • VK_SUCCESS

  • VK_INCOMPLETE

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

  • VK_ERROR_INITIALIZATION_FAILED

To query general properties of physical devices once enumerated, call:

// Provided by VK_VERSION_1_0
void vkGetPhysicalDeviceProperties(
    VkPhysicalDevice                            physicalDevice,
    VkPhysicalDeviceProperties*                 pProperties);

  • physicalDevice is the handle to the physical device whose properties will be queried.

  • pProperties is a pointer to a VkPhysicalDeviceProperties structure in which properties are returned.

Valid Usage (Implicit)

  • VUID-vkGetPhysicalDeviceProperties-physicalDevice-parameter
    physicalDevice must be a valid VkPhysicalDevice handle

  • VUID-vkGetPhysicalDeviceProperties-pProperties-parameter
    pProperties must be a valid pointer to a VkPhysicalDeviceProperties structure

The VkPhysicalDeviceProperties structure is defined as:

// Provided by VK_VERSION_1_0
typedef struct VkPhysicalDeviceProperties {
    uint32_t                            apiVersion;
    uint32_t                            driverVersion;
    uint32_t                            vendorID;
    uint32_t                            deviceID;
    VkPhysicalDeviceType                deviceType;
    char                                deviceName[VK_MAX_PHYSICAL_DEVICE_NAME_SIZE];
    uint8_t                             pipelineCacheUUID[VK_UUID_SIZE];
    VkPhysicalDeviceLimits              limits;
    VkPhysicalDeviceSparseProperties    sparseProperties;
} VkPhysicalDeviceProperties;

  • apiVersion is the version of Vulkan supported by the device, encoded as described in Version Numbers.

  • driverVersion is the vendor-specified version of the driver.

  • vendorID is a unique identifier for the vendor (see below) of the physical device.

  • deviceID is a unique identifier for the physical device among devices available from the vendor.

  • deviceType is a VkPhysicalDeviceType specifying the type of device.

  • deviceName is an array of VK_MAX_PHYSICAL_DEVICE_NAME_SIZE char containing a null-terminated UTF-8 string which is the name of the device.

  • pipelineCacheUUID is an array of VK_UUID_SIZE uint8_t values representing a universally unique identifier for the device.

  • limits is the VkPhysicalDeviceLimits structure specifying device-specific limits of the physical device. See Limits for details.

  • sparseProperties is the VkPhysicalDeviceSparseProperties structure specifying various sparse related properties of the physical device. See Sparse Properties for details.

Note

The value of apiVersion may be different than the version returned by vkEnumerateInstanceVersion; either higher or lower. In such cases, the application must not use functionality that exceeds the version of Vulkan associated with a given object. The pApiVersion parameter returned by vkEnumerateInstanceVersion is the version associated with a VkInstance and its children, except for a VkPhysicalDevice and its children. VkPhysicalDeviceProperties::apiVersion is the version associated with a VkPhysicalDevice and its children.
Note

The encoding of driverVersion is implementation-defined. It may not use the same encoding as apiVersion. Applications should follow information from the vendor on how to extract the version information from driverVersion.

On implementations that claim support for the Roadmap 2022 profile, the major and minor version expressed by apiVersion must be at least Vulkan 1.3.

The vendorID and deviceID fields are provided to allow applications to adapt to device characteristics that are not adequately exposed by other Vulkan queries.

Note

These may include performance profiles, hardware errata, or other characteristics.

The vendor identified by vendorID is the entity responsible for the most salient characteristics of the underlying implementation of the VkPhysicalDevice being queried.

Note

For example, in the case of a discrete GPU implementation, this should be the GPU chipset vendor. In the case of a hardware accelerator integrated into a system-on-chip (SoC), this should be the supplier of the silicon IP used to create the accelerator.

If the vendor has a PCI vendor ID, the low 16 bits of vendorID must contain that PCI vendor ID, and the remaining bits must be set to zero. Otherwise, the value returned must be a valid Khronos vendor ID, obtained as described in the Vulkan Documentation and Extensions: Procedures and Conventions document in the section “Registering a Vendor ID with Khronos”. Khronos vendor IDs are allocated starting at 0x10000, to distinguish them from the PCI vendor ID namespace. Khronos vendor IDs are symbolically defined in the VkVendorId type.

The vendor is also responsible for the value returned in deviceID. If the implementation is driven primarily by a PCI device with a PCI device ID, the low 16 bits of deviceID must contain that PCI device ID, and the remaining bits must be set to zero. Otherwise, the choice of what values to return may be dictated by operating system or platform policies - but should uniquely identify both the device version and any major configuration options (for example, core count in the case of multicore devices).

Note

The same device ID should be used for all physical implementations of that device version and configuration. For example, all uses of a specific silicon IP GPU version and configuration should use the same device ID, even if those uses occur in different SoCs.

Khronos vendor IDs which may be returned in VkPhysicalDeviceProperties::vendorID are:

// Provided by VK_VERSION_1_0
typedef enum VkVendorId {
    VK_VENDOR_ID_VIV = 0x10001,
    VK_VENDOR_ID_VSI = 0x10002,
    VK_VENDOR_ID_KAZAN = 0x10003,
    VK_VENDOR_ID_CODEPLAY = 0x10004,
    VK_VENDOR_ID_MESA = 0x10005,
    VK_VENDOR_ID_POCL = 0x10006,
    VK_VENDOR_ID_MOBILEYE = 0x10007,
} VkVendorId;
Note

Khronos vendor IDs may be allocated by vendors at any time. Only the latest canonical versions of this Specification, of the corresponding vk.xml API Registry, and of the corresponding vulkan_core.h header file must contain all reserved Khronos vendor IDs.

Only Khronos vendor IDs are given symbolic names at present. PCI vendor IDs returned by the implementation can be looked up in the PCI-SIG database.

VK_MAX_PHYSICAL_DEVICE_NAME_SIZE is the length in char values of an array containing a physical device name string, as returned in VkPhysicalDeviceProperties::deviceName.

#define VK_MAX_PHYSICAL_DEVICE_NAME_SIZE  256U

The physical device types which may be returned in VkPhysicalDeviceProperties::deviceType are:

// Provided by VK_VERSION_1_0
typedef enum VkPhysicalDeviceType {
    VK_PHYSICAL_DEVICE_TYPE_OTHER = 0,
    VK_PHYSICAL_DEVICE_TYPE_INTEGRATED_GPU = 1,
    VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU = 2,
    VK_PHYSICAL_DEVICE_TYPE_VIRTUAL_GPU = 3,
    VK_PHYSICAL_DEVICE_TYPE_CPU = 4,
} VkPhysicalDeviceType;

  • VK_PHYSICAL_DEVICE_TYPE_OTHER - the device does not match any other available types.

  • VK_PHYSICAL_DEVICE_TYPE_INTEGRATED_GPU - the device is typically one embedded in or tightly coupled with the host.

  • VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU - the device is typically a separate processor connected to the host via an interlink.

  • VK_PHYSICAL_DEVICE_TYPE_VIRTUAL_GPU - the device is typically a virtual node in a virtualization environment.

  • VK_PHYSICAL_DEVICE_TYPE_CPU - the device is typically running on the same processors as the host.

The physical device type is advertised for informational purposes only, and does not directly affect the operation of the system. However, the device type may correlate with other advertised properties or capabilities of the system, such as how many memory heaps there are.

To query general properties of physical devices once enumerated, call:

// Provided by VK_VERSION_1_1
void vkGetPhysicalDeviceProperties2(
    VkPhysicalDevice                            physicalDevice,
    VkPhysicalDeviceProperties2*                pProperties);

  • physicalDevice is the handle to the physical device whose properties will be queried.

  • pProperties is a pointer to a VkPhysicalDeviceProperties2 structure in which properties are returned.

Each structure in pProperties and its pNext chain contains members corresponding to implementation-dependent properties, behaviors, or limits. vkGetPhysicalDeviceProperties2 fills in each member to specify the corresponding value for the implementation.

Valid Usage (Implicit)

  • VUID-vkGetPhysicalDeviceProperties2-physicalDevice-parameter
    physicalDevice must be a valid VkPhysicalDevice handle

  • VUID-vkGetPhysicalDeviceProperties2-pProperties-parameter
    pProperties must be a valid pointer to a VkPhysicalDeviceProperties2 structure

The VkPhysicalDeviceProperties2 structure is defined as:

// Provided by VK_VERSION_1_1
typedef struct VkPhysicalDeviceProperties2 {
    VkStructureType               sType;
    void*                         pNext;
    VkPhysicalDeviceProperties    properties;
} VkPhysicalDeviceProperties2;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • properties is a VkPhysicalDeviceProperties structure describing properties of the physical device. This structure is written with the same values as if it were written by vkGetPhysicalDeviceProperties.

The pNext chain of this structure is used to extend the structure with properties defined by extensions.

Valid Usage (Implicit)

The VkPhysicalDeviceVulkan11Properties structure is defined as:

// Provided by VK_VERSION_1_2
typedef struct VkPhysicalDeviceVulkan11Properties {
    VkStructureType            sType;
    void*                      pNext;
    uint8_t                    deviceUUID[VK_UUID_SIZE];
    uint8_t                    driverUUID[VK_UUID_SIZE];
    uint8_t                    deviceLUID[VK_LUID_SIZE];
    uint32_t                   deviceNodeMask;
    VkBool32                   deviceLUIDValid;
    uint32_t                   subgroupSize;
    VkShaderStageFlags         subgroupSupportedStages;
    VkSubgroupFeatureFlags     subgroupSupportedOperations;
    VkBool32                   subgroupQuadOperationsInAllStages;
    VkPointClippingBehavior    pointClippingBehavior;
    uint32_t                   maxMultiviewViewCount;
    uint32_t                   maxMultiviewInstanceIndex;
    VkBool32                   protectedNoFault;
    uint32_t                   maxPerSetDescriptors;
    VkDeviceSize               maxMemoryAllocationSize;
} VkPhysicalDeviceVulkan11Properties;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • deviceUUID is an array of VK_UUID_SIZE uint8_t values representing a universally unique identifier for the device.

  • driverUUID is an array of VK_UUID_SIZE uint8_t values representing a universally unique identifier for the driver build in use by the device.

  • deviceLUID is an array of VK_LUID_SIZE uint8_t values representing a locally unique identifier for the device.

  • deviceNodeMask is a uint32_t bitfield identifying the node within a linked device adapter corresponding to the device.

  • deviceLUIDValid is a boolean value that will be VK_TRUE if deviceLUID contains a valid LUID and deviceNodeMask contains a valid node mask, and VK_FALSE if they do not.

  • subgroupSize is the default number of invocations in each subgroup. subgroupSize is at least 1 if any of the physical device’s queues support VK_QUEUE_GRAPHICS_BIT or VK_QUEUE_COMPUTE_BIT. subgroupSize is a power-of-two.

  • subgroupSupportedStages is a bitfield of VkShaderStageFlagBits describing the shader stages that group operations with subgroup scope are supported in. subgroupSupportedStages will have the VK_SHADER_STAGE_COMPUTE_BIT bit set if any of the physical device’s queues support VK_QUEUE_COMPUTE_BIT.

  • subgroupSupportedOperations is a bitmask of VkSubgroupFeatureFlagBits specifying the sets of group operations with subgroup scope supported on this device. subgroupSupportedOperations will have the VK_SUBGROUP_FEATURE_BASIC_BIT bit set if any of the physical device’s queues support VK_QUEUE_GRAPHICS_BIT or VK_QUEUE_COMPUTE_BIT.

  • subgroupQuadOperationsInAllStages is a boolean specifying whether quad group operations are available in all stages, or are restricted to fragment and compute stages.

  • pointClippingBehavior is a VkPointClippingBehavior value specifying the point clipping behavior supported by the implementation.

  • maxMultiviewViewCount is one greater than the maximum view index that can be used in a subpass.

  • maxMultiviewInstanceIndex is the maximum valid value of instance index allowed to be generated by a drawing command recorded within a subpass of a multiview render pass instance.

  • protectedNoFault specifies how an implementation behaves when an application attempts to write to unprotected memory in a protected queue operation, read from protected memory in an unprotected queue operation, or perform a query in a protected queue operation. If this limit is VK_TRUE, such writes will be discarded or have undefined values written, reads and queries will return undefined values. If this limit is VK_FALSE, applications must not perform these operations. See Protected Memory Access Rules for more information.

  • maxPerSetDescriptors is a maximum number of descriptors (summed over all descriptor types) in a single descriptor set that is guaranteed to satisfy any implementation-dependent constraints on the size of a descriptor set itself. Applications can query whether a descriptor set that goes beyond this limit is supported using vkGetDescriptorSetLayoutSupport.

  • maxMemoryAllocationSize is the maximum size of a memory allocation that can be created, even if there is more space available in the heap.

If the VkPhysicalDeviceVulkan11Properties structure is included in the pNext chain of the VkPhysicalDeviceProperties2 structure passed to vkGetPhysicalDeviceProperties2, it is filled in with each corresponding implementation-dependent property.

These properties correspond to Vulkan 1.1 functionality.

The members of VkPhysicalDeviceVulkan11Properties have the same values as the corresponding members of VkPhysicalDeviceIDProperties, VkPhysicalDeviceSubgroupProperties, VkPhysicalDevicePointClippingProperties, VkPhysicalDeviceMultiviewProperties, VkPhysicalDeviceProtectedMemoryProperties, and VkPhysicalDeviceMaintenance3Properties.

Valid Usage (Implicit)

  • VUID-VkPhysicalDeviceVulkan11Properties-sType-sType
    sType must be VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_1_PROPERTIES

The VkPhysicalDeviceVulkan12Properties structure is defined as:

// Provided by VK_VERSION_1_2
typedef struct VkPhysicalDeviceVulkan12Properties {
    VkStructureType                      sType;
    void*                                pNext;
    VkDriverId                           driverID;
    char                                 driverName[VK_MAX_DRIVER_NAME_SIZE];
    char                                 driverInfo[VK_MAX_DRIVER_INFO_SIZE];
    VkConformanceVersion                 conformanceVersion;
    VkShaderFloatControlsIndependence    denormBehaviorIndependence;
    VkShaderFloatControlsIndependence    roundingModeIndependence;
    VkBool32                             shaderSignedZeroInfNanPreserveFloat16;
    VkBool32                             shaderSignedZeroInfNanPreserveFloat32;
    VkBool32                             shaderSignedZeroInfNanPreserveFloat64;
    VkBool32                             shaderDenormPreserveFloat16;
    VkBool32                             shaderDenormPreserveFloat32;
    VkBool32                             shaderDenormPreserveFloat64;
    VkBool32                             shaderDenormFlushToZeroFloat16;
    VkBool32                             shaderDenormFlushToZeroFloat32;
    VkBool32                             shaderDenormFlushToZeroFloat64;
    VkBool32                             shaderRoundingModeRTEFloat16;
    VkBool32                             shaderRoundingModeRTEFloat32;
    VkBool32                             shaderRoundingModeRTEFloat64;
    VkBool32                             shaderRoundingModeRTZFloat16;
    VkBool32                             shaderRoundingModeRTZFloat32;
    VkBool32                             shaderRoundingModeRTZFloat64;
    uint32_t                             maxUpdateAfterBindDescriptorsInAllPools;
    VkBool32                             shaderUniformBufferArrayNonUniformIndexingNative;
    VkBool32                             shaderSampledImageArrayNonUniformIndexingNative;
    VkBool32                             shaderStorageBufferArrayNonUniformIndexingNative;
    VkBool32                             shaderStorageImageArrayNonUniformIndexingNative;
    VkBool32                             shaderInputAttachmentArrayNonUniformIndexingNative;
    VkBool32                             robustBufferAccessUpdateAfterBind;
    VkBool32                             quadDivergentImplicitLod;
    uint32_t                             maxPerStageDescriptorUpdateAfterBindSamplers;
    uint32_t                             maxPerStageDescriptorUpdateAfterBindUniformBuffers;
    uint32_t                             maxPerStageDescriptorUpdateAfterBindStorageBuffers;
    uint32_t                             maxPerStageDescriptorUpdateAfterBindSampledImages;
    uint32_t                             maxPerStageDescriptorUpdateAfterBindStorageImages;
    uint32_t                             maxPerStageDescriptorUpdateAfterBindInputAttachments;
    uint32_t                             maxPerStageUpdateAfterBindResources;
    uint32_t                             maxDescriptorSetUpdateAfterBindSamplers;
    uint32_t                             maxDescriptorSetUpdateAfterBindUniformBuffers;
    uint32_t                             maxDescriptorSetUpdateAfterBindUniformBuffersDynamic;
    uint32_t                             maxDescriptorSetUpdateAfterBindStorageBuffers;
    uint32_t                             maxDescriptorSetUpdateAfterBindStorageBuffersDynamic;
    uint32_t                             maxDescriptorSetUpdateAfterBindSampledImages;
    uint32_t                             maxDescriptorSetUpdateAfterBindStorageImages;
    uint32_t                             maxDescriptorSetUpdateAfterBindInputAttachments;
    VkResolveModeFlags                   supportedDepthResolveModes;
    VkResolveModeFlags                   supportedStencilResolveModes;
    VkBool32                             independentResolveNone;
    VkBool32                             independentResolve;
    VkBool32                             filterMinmaxSingleComponentFormats;
    VkBool32                             filterMinmaxImageComponentMapping;
    uint64_t                             maxTimelineSemaphoreValueDifference;
    VkSampleCountFlags                   framebufferIntegerColorSampleCounts;
} VkPhysicalDeviceVulkan12Properties;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • driverID is a unique identifier for the driver of the physical device.

  • driverName is an array of VK_MAX_DRIVER_NAME_SIZE char containing a null-terminated UTF-8 string which is the name of the driver.

  • driverInfo is an array of VK_MAX_DRIVER_INFO_SIZE char containing a null-terminated UTF-8 string with additional information about the driver.

  • conformanceVersion is the version of the Vulkan conformance test this driver is conformant against (see VkConformanceVersion).

  • denormBehaviorIndependence is a VkShaderFloatControlsIndependence value indicating whether, and how, denorm behavior can be set independently for different bit widths.

  • roundingModeIndependence is a VkShaderFloatControlsIndependence value indicating whether, and how, rounding modes can be set independently for different bit widths.

  • shaderSignedZeroInfNanPreserveFloat16 is a boolean value indicating whether sign of a zero, Nans and can be preserved in 16-bit floating-point computations. It also indicates whether the SignedZeroInfNanPreserve execution mode can be used for 16-bit floating-point types.

  • shaderSignedZeroInfNanPreserveFloat32 is a boolean value indicating whether sign of a zero, Nans and can be preserved in 32-bit floating-point computations. It also indicates whether the SignedZeroInfNanPreserve execution mode can be used for 32-bit floating-point types.

  • shaderSignedZeroInfNanPreserveFloat64 is a boolean value indicating whether sign of a zero, Nans and can be preserved in 64-bit floating-point computations. It also indicates whether the SignedZeroInfNanPreserve execution mode can be used for 64-bit floating-point types.

  • shaderDenormPreserveFloat16 is a boolean value indicating whether denormals can be preserved in 16-bit floating-point computations. It also indicates whether the DenormPreserve execution mode can be used for 16-bit floating-point types.

  • shaderDenormPreserveFloat32 is a boolean value indicating whether denormals can be preserved in 32-bit floating-point computations. It also indicates whether the DenormPreserve execution mode can be used for 32-bit floating-point types.

  • shaderDenormPreserveFloat64 is a boolean value indicating whether denormals can be preserved in 64-bit floating-point computations. It also indicates whether the DenormPreserve execution mode can be used for 64-bit floating-point types.

  • shaderDenormFlushToZeroFloat16 is a boolean value indicating whether denormals can be flushed to zero in 16-bit floating-point computations. It also indicates whether the DenormFlushToZero execution mode can be used for 16-bit floating-point types.

  • shaderDenormFlushToZeroFloat32 is a boolean value indicating whether denormals can be flushed to zero in 32-bit floating-point computations. It also indicates whether the DenormFlushToZero execution mode can be used for 32-bit floating-point types.

  • shaderDenormFlushToZeroFloat64 is a boolean value indicating whether denormals can be flushed to zero in 64-bit floating-point computations. It also indicates whether the DenormFlushToZero execution mode can be used for 64-bit floating-point types.

  • shaderRoundingModeRTEFloat16 is a boolean value indicating whether an implementation supports the round-to-nearest-even rounding mode for 16-bit floating-point arithmetic and conversion instructions. It also indicates whether the RoundingModeRTE execution mode can be used for 16-bit floating-point types.

  • shaderRoundingModeRTEFloat32 is a boolean value indicating whether an implementation supports the round-to-nearest-even rounding mode for 32-bit floating-point arithmetic and conversion instructions. It also indicates whether the RoundingModeRTE execution mode can be used for 32-bit floating-point types.

  • shaderRoundingModeRTEFloat64 is a boolean value indicating whether an implementation supports the round-to-nearest-even rounding mode for 64-bit floating-point arithmetic and conversion instructions. It also indicates whether the RoundingModeRTE execution mode can be used for 64-bit floating-point types.

  • shaderRoundingModeRTZFloat16 is a boolean value indicating whether an implementation supports the round-towards-zero rounding mode for 16-bit floating-point arithmetic and conversion instructions. It also indicates whether the RoundingModeRTZ execution mode can be used for 16-bit floating-point types.

  • shaderRoundingModeRTZFloat32 is a boolean value indicating whether an implementation supports the round-towards-zero rounding mode for 32-bit floating-point arithmetic and conversion instructions. It also indicates whether the RoundingModeRTZ execution mode can be used for 32-bit floating-point types.

  • shaderRoundingModeRTZFloat64 is a boolean value indicating whether an implementation supports the round-towards-zero rounding mode for 64-bit floating-point arithmetic and conversion instructions. It also indicates whether the RoundingModeRTZ execution mode can be used for 64-bit floating-point types.

  • maxUpdateAfterBindDescriptorsInAllPools is the maximum number of descriptors (summed over all descriptor types) that can be created across all pools that are created with the VK_DESCRIPTOR_POOL_CREATE_UPDATE_AFTER_BIND_BIT bit set. Pool creation may fail when this limit is exceeded, or when the space this limit represents is unable to satisfy a pool creation due to fragmentation.

  • shaderUniformBufferArrayNonUniformIndexingNative is a boolean value indicating whether uniform buffer descriptors natively support nonuniform indexing. If this is VK_FALSE, then a single dynamic instance of an instruction that nonuniformly indexes an array of uniform buffers may execute multiple times in order to access all the descriptors.

  • shaderSampledImageArrayNonUniformIndexingNative is a boolean value indicating whether sampler and image descriptors natively support nonuniform indexing. If this is VK_FALSE, then a single dynamic instance of an instruction that nonuniformly indexes an array of samplers or images may execute multiple times in order to access all the descriptors.

  • shaderStorageBufferArrayNonUniformIndexingNative is a boolean value indicating whether storage buffer descriptors natively support nonuniform indexing. If this is VK_FALSE, then a single dynamic instance of an instruction that nonuniformly indexes an array of storage buffers may execute multiple times in order to access all the descriptors.

  • shaderStorageImageArrayNonUniformIndexingNative is a boolean value indicating whether storage image descriptors natively support nonuniform indexing. If this is VK_FALSE, then a single dynamic instance of an instruction that nonuniformly indexes an array of storage images may execute multiple times in order to access all the descriptors.

  • shaderInputAttachmentArrayNonUniformIndexingNative is a boolean value indicating whether input attachment descriptors natively support nonuniform indexing. If this is VK_FALSE, then a single dynamic instance of an instruction that nonuniformly indexes an array of input attachments may execute multiple times in order to access all the descriptors.

  • robustBufferAccessUpdateAfterBind is a boolean value indicating whether robustBufferAccess can be enabled on a device simultaneously with descriptorBindingUniformBufferUpdateAfterBind, descriptorBindingStorageBufferUpdateAfterBind, descriptorBindingUniformTexelBufferUpdateAfterBind, and/or descriptorBindingStorageTexelBufferUpdateAfterBind. If this is VK_FALSE, then either robustBufferAccess must be disabled or all of these update-after-bind features must be disabled.

  • quadDivergentImplicitLod is a boolean value indicating whether implicit level of detail calculations for image operations have well-defined results when the image and/or sampler objects used for the instruction are not uniform within a quad. See Derivative Image Operations.

  • maxPerStageDescriptorUpdateAfterBindSamplers is similar to maxPerStageDescriptorSamplers but counts descriptors from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set.

  • maxPerStageDescriptorUpdateAfterBindUniformBuffers is similar to maxPerStageDescriptorUniformBuffers but counts descriptors from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set.

  • maxPerStageDescriptorUpdateAfterBindStorageBuffers is similar to maxPerStageDescriptorStorageBuffers but counts descriptors from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set.

  • maxPerStageDescriptorUpdateAfterBindSampledImages is similar to maxPerStageDescriptorSampledImages but counts descriptors from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set.

  • maxPerStageDescriptorUpdateAfterBindStorageImages is similar to maxPerStageDescriptorStorageImages but counts descriptors from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set.

  • maxPerStageDescriptorUpdateAfterBindInputAttachments is similar to maxPerStageDescriptorInputAttachments but counts descriptors from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set.

  • maxPerStageUpdateAfterBindResources is similar to maxPerStageResources but counts descriptors from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set.

  • maxDescriptorSetUpdateAfterBindSamplers is similar to maxDescriptorSetSamplers but counts descriptors from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set.

  • maxDescriptorSetUpdateAfterBindUniformBuffers is similar to maxDescriptorSetUniformBuffers but counts descriptors from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set.

  • maxDescriptorSetUpdateAfterBindUniformBuffersDynamic is similar to maxDescriptorSetUniformBuffersDynamic but counts descriptors from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set. While an application can allocate dynamic uniform buffer descriptors from a pool created with the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT, bindings for these descriptors must not be present in any descriptor set layout that includes bindings created with VK_DESCRIPTOR_BINDING_UPDATE_AFTER_BIND_BIT.

  • maxDescriptorSetUpdateAfterBindStorageBuffers is similar to maxDescriptorSetStorageBuffers but counts descriptors from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set.

  • maxDescriptorSetUpdateAfterBindStorageBuffersDynamic is similar to maxDescriptorSetStorageBuffersDynamic but counts descriptors from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set. While an application can allocate dynamic storage buffer descriptors from a pool created with the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT, bindings for these descriptors must not be present in any descriptor set layout that includes bindings created with VK_DESCRIPTOR_BINDING_UPDATE_AFTER_BIND_BIT.

  • maxDescriptorSetUpdateAfterBindSampledImages is similar to maxDescriptorSetSampledImages but counts descriptors from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set.

  • maxDescriptorSetUpdateAfterBindStorageImages is similar to maxDescriptorSetStorageImages but counts descriptors from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set.

  • maxDescriptorSetUpdateAfterBindInputAttachments is similar to maxDescriptorSetInputAttachments but counts descriptors from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set.

  • supportedDepthResolveModes is a bitmask of VkResolveModeFlagBits indicating the set of supported depth resolve modes. VK_RESOLVE_MODE_SAMPLE_ZERO_BIT must be included in the set but implementations may support additional modes.

  • supportedStencilResolveModes is a bitmask of VkResolveModeFlagBits indicating the set of supported stencil resolve modes. VK_RESOLVE_MODE_SAMPLE_ZERO_BIT must be included in the set but implementations may support additional modes. VK_RESOLVE_MODE_AVERAGE_BIT must not be included in the set.

  • independentResolveNone is VK_TRUE if the implementation supports setting the depth and stencil resolve modes to different values when one of those modes is VK_RESOLVE_MODE_NONE. Otherwise the implementation only supports setting both modes to the same value.

  • independentResolve is VK_TRUE if the implementation supports all combinations of the supported depth and stencil resolve modes, including setting either depth or stencil resolve mode to VK_RESOLVE_MODE_NONE. An implementation that supports independentResolve must also support independentResolveNone.

  • filterMinmaxSingleComponentFormats is a boolean value indicating whether a minimum set of required formats support min/max filtering.

  • filterMinmaxImageComponentMapping is a boolean value indicating whether the implementation supports non-identity component mapping of the image when doing min/max filtering.

  • maxTimelineSemaphoreValueDifference indicates the maximum difference allowed by the implementation between the current value of a timeline semaphore and any pending signal or wait operations.

  • framebufferIntegerColorSampleCounts is a bitmask of VkSampleCountFlagBits indicating the color sample counts that are supported for all framebuffer color attachments with integer formats.

If the VkPhysicalDeviceVulkan12Properties structure is included in the pNext chain of the VkPhysicalDeviceProperties2 structure passed to vkGetPhysicalDeviceProperties2, it is filled in with each corresponding implementation-dependent property.

These properties correspond to Vulkan 1.2 functionality.

The members of VkPhysicalDeviceVulkan12Properties must have the same values as the corresponding members of VkPhysicalDeviceDriverProperties, VkPhysicalDeviceFloatControlsProperties, VkPhysicalDeviceDescriptorIndexingProperties, VkPhysicalDeviceDepthStencilResolveProperties, VkPhysicalDeviceSamplerFilterMinmaxProperties, and VkPhysicalDeviceTimelineSemaphoreProperties.

Valid Usage (Implicit)

  • VUID-VkPhysicalDeviceVulkan12Properties-sType-sType
    sType must be VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_2_PROPERTIES

The VkPhysicalDeviceVulkan13Properties structure is defined as:

// Provided by VK_VERSION_1_3
typedef struct VkPhysicalDeviceVulkan13Properties {
    VkStructureType       sType;
    void*                 pNext;
    uint32_t              minSubgroupSize;
    uint32_t              maxSubgroupSize;
    uint32_t              maxComputeWorkgroupSubgroups;
    VkShaderStageFlags    requiredSubgroupSizeStages;
    uint32_t              maxInlineUniformBlockSize;
    uint32_t              maxPerStageDescriptorInlineUniformBlocks;
    uint32_t              maxPerStageDescriptorUpdateAfterBindInlineUniformBlocks;
    uint32_t              maxDescriptorSetInlineUniformBlocks;
    uint32_t              maxDescriptorSetUpdateAfterBindInlineUniformBlocks;
    uint32_t              maxInlineUniformTotalSize;
    VkBool32              integerDotProduct8BitUnsignedAccelerated;
    VkBool32              integerDotProduct8BitSignedAccelerated;
    VkBool32              integerDotProduct8BitMixedSignednessAccelerated;
    VkBool32              integerDotProduct4x8BitPackedUnsignedAccelerated;
    VkBool32              integerDotProduct4x8BitPackedSignedAccelerated;
    VkBool32              integerDotProduct4x8BitPackedMixedSignednessAccelerated;
    VkBool32              integerDotProduct16BitUnsignedAccelerated;
    VkBool32              integerDotProduct16BitSignedAccelerated;
    VkBool32              integerDotProduct16BitMixedSignednessAccelerated;
    VkBool32              integerDotProduct32BitUnsignedAccelerated;
    VkBool32              integerDotProduct32BitSignedAccelerated;
    VkBool32              integerDotProduct32BitMixedSignednessAccelerated;
    VkBool32              integerDotProduct64BitUnsignedAccelerated;
    VkBool32              integerDotProduct64BitSignedAccelerated;
    VkBool32              integerDotProduct64BitMixedSignednessAccelerated;
    VkBool32              integerDotProductAccumulatingSaturating8BitUnsignedAccelerated;
    VkBool32              integerDotProductAccumulatingSaturating8BitSignedAccelerated;
    VkBool32              integerDotProductAccumulatingSaturating8BitMixedSignednessAccelerated;
    VkBool32              integerDotProductAccumulatingSaturating4x8BitPackedUnsignedAccelerated;
    VkBool32              integerDotProductAccumulatingSaturating4x8BitPackedSignedAccelerated;
    VkBool32              integerDotProductAccumulatingSaturating4x8BitPackedMixedSignednessAccelerated;
    VkBool32              integerDotProductAccumulatingSaturating16BitUnsignedAccelerated;
    VkBool32              integerDotProductAccumulatingSaturating16BitSignedAccelerated;
    VkBool32              integerDotProductAccumulatingSaturating16BitMixedSignednessAccelerated;
    VkBool32              integerDotProductAccumulatingSaturating32BitUnsignedAccelerated;
    VkBool32              integerDotProductAccumulatingSaturating32BitSignedAccelerated;
    VkBool32              integerDotProductAccumulatingSaturating32BitMixedSignednessAccelerated;
    VkBool32              integerDotProductAccumulatingSaturating64BitUnsignedAccelerated;
    VkBool32              integerDotProductAccumulatingSaturating64BitSignedAccelerated;
    VkBool32              integerDotProductAccumulatingSaturating64BitMixedSignednessAccelerated;
    VkDeviceSize          storageTexelBufferOffsetAlignmentBytes;
    VkBool32              storageTexelBufferOffsetSingleTexelAlignment;
    VkDeviceSize          uniformTexelBufferOffsetAlignmentBytes;
    VkBool32              uniformTexelBufferOffsetSingleTexelAlignment;
    VkDeviceSize          maxBufferSize;
} VkPhysicalDeviceVulkan13Properties;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • minSubgroupSize is the minimum subgroup size supported by this device. minSubgroupSize is at least one if any of the physical device’s queues support VK_QUEUE_GRAPHICS_BIT or VK_QUEUE_COMPUTE_BIT. minSubgroupSize is a power-of-two. minSubgroupSize is less than or equal to maxSubgroupSize. minSubgroupSize is less than or equal to subgroupSize.

  • maxSubgroupSize is the maximum subgroup size supported by this device. maxSubgroupSize is at least one if any of the physical device’s queues support VK_QUEUE_GRAPHICS_BIT or VK_QUEUE_COMPUTE_BIT. maxSubgroupSize is a power-of-two. maxSubgroupSize is greater than or equal to minSubgroupSize. maxSubgroupSize is greater than or equal to subgroupSize.

  • maxComputeWorkgroupSubgroups is the maximum number of subgroups supported by the implementation within a workgroup.

  • requiredSubgroupSizeStages is a bitfield of what shader stages support having a required subgroup size specified.

  • maxInlineUniformBlockSize is the maximum size in bytes of an inline uniform block binding.

  • maxPerStageDescriptorInlineUniformBlock is the maximum number of inline uniform block bindings that can be accessible to a single shader stage in a pipeline layout. Descriptor bindings with a descriptor type of VK_DESCRIPTOR_TYPE_INLINE_UNIFORM_BLOCK count against this limit. Only descriptor bindings in descriptor set layouts created without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set count against this limit.

  • maxPerStageDescriptorUpdateAfterBindInlineUniformBlocks is similar to maxPerStageDescriptorInlineUniformBlocks but counts descriptor bindings from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set.

  • maxDescriptorSetInlineUniformBlocks is the maximum number of inline uniform block bindings that can be included in descriptor bindings in a pipeline layout across all pipeline shader stages and descriptor set numbers. Descriptor bindings with a descriptor type of VK_DESCRIPTOR_TYPE_INLINE_UNIFORM_BLOCK count against this limit. Only descriptor bindings in descriptor set layouts created without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set count against this limit.

  • maxDescriptorSetUpdateAfterBindInlineUniformBlocks is similar to maxDescriptorSetInlineUniformBlocks but counts descriptor bindings from descriptor sets created with or without the VK_DESCRIPTOR_SET_LAYOUT_CREATE_UPDATE_AFTER_BIND_POOL_BIT bit set.

  • maxInlineUniformTotalSize is the maximum total size in bytes of all inline uniform block bindings, across all pipeline shader stages and descriptor set numbers, that can be included in a pipeline layout. Descriptor bindings with a descriptor type of VK_DESCRIPTOR_TYPE_INLINE_UNIFORM_BLOCK count against this limit.

  • integerDotProduct8BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit unsigned dot product operations using the OpUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct8BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit signed dot product operations using the OpSDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct8BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 8-bit mixed signedness dot product operations using the OpSUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct4x8BitPackedUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit unsigned dot product operations from operands packed into 32-bit integers using the OpUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct4x8BitPackedSignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit signed dot product operations from operands packed into 32-bit integers using the OpSDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct4x8BitPackedMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 8-bit mixed signedness dot product operations from operands packed into 32-bit integers using the OpSUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct16BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 16-bit unsigned dot product operations using the OpUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct16BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 16-bit signed dot product operations using the OpSDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct16BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 16-bit mixed signedness dot product operations using the OpSUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct32BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 32-bit unsigned dot product operations using the OpUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct32BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 32-bit signed dot product operations using the OpSDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct32BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 32-bit mixed signedness dot product operations using the OpSUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct64BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 64-bit unsigned dot product operations using the OpUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct64BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 64-bit signed dot product operations using the OpSDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct64BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 64-bit mixed signedness dot product operations using the OpSUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating8BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit unsigned accumulating saturating dot product operations using the OpUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating8BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit signed accumulating saturating dot product operations using the OpSDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating8BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 8-bit mixed signedness accumulating saturating dot product operations using the OpSUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating4x8BitPackedUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit unsigned accumulating saturating dot product operations from operands packed into 32-bit integers using the OpUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating4x8BitPackedSignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit signed accumulating saturating dot product operations from operands packed into 32-bit integers using the OpSDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating4x8BitPackedMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 8-bit mixed signedness accumulating saturating dot product operations from operands packed into 32-bit integers using the OpSUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating16BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 16-bit unsigned accumulating saturating dot product operations using the OpUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating16BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 16-bit signed accumulating saturating dot product operations using the OpSDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating16BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 16-bit mixed signedness accumulating saturating dot product operations using the OpSUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating32BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 32-bit unsigned accumulating saturating dot product operations using the OpUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating32BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 32-bit signed accumulating saturating dot product operations using the OpSDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating32BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 32-bit mixed signedness accumulating saturating dot product operations using the OpSUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating64BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 64-bit unsigned accumulating saturating dot product operations using the OpUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating64BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 64-bit signed accumulating saturating dot product operations using the OpSDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating64BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 64-bit mixed signedness accumulating saturating dot product operations using the OpSUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • storageTexelBufferOffsetAlignmentBytes is a byte alignment that is sufficient for a storage texel buffer of any format. The value must be a power of two.

  • storageTexelBufferOffsetSingleTexelAlignment indicates whether single texel alignment is sufficient for a storage texel buffer of any format.

  • uniformTexelBufferOffsetAlignmentBytes is a byte alignment that is sufficient for a uniform texel buffer of any format. The value must be a power of two.

  • uniformTexelBufferOffsetSingleTexelAlignment indicates whether single texel alignment is sufficient for a uniform texel buffer of any format.

  • maxBufferSize is the maximum size VkBuffer that can be created.

If the VkPhysicalDeviceVulkan13Properties structure is included in the pNext chain of the VkPhysicalDeviceProperties2 structure passed to vkGetPhysicalDeviceProperties2, it is filled in with each corresponding implementation-dependent property.

These properties correspond to Vulkan 1.3 functionality.

The members of VkPhysicalDeviceVulkan13Properties must have the same values as the corresponding members of VkPhysicalDeviceInlineUniformBlockProperties and VkPhysicalDeviceSubgroupSizeControlProperties.

Valid Usage (Implicit)

  • VUID-VkPhysicalDeviceVulkan13Properties-sType-sType
    sType must be VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_VULKAN_1_3_PROPERTIES

The VkPhysicalDeviceIDProperties structure is defined as:

// Provided by VK_VERSION_1_1
typedef struct VkPhysicalDeviceIDProperties {
    VkStructureType    sType;
    void*              pNext;
    uint8_t            deviceUUID[VK_UUID_SIZE];
    uint8_t            driverUUID[VK_UUID_SIZE];
    uint8_t            deviceLUID[VK_LUID_SIZE];
    uint32_t           deviceNodeMask;
    VkBool32           deviceLUIDValid;
} VkPhysicalDeviceIDProperties;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • deviceUUID is an array of VK_UUID_SIZE uint8_t values representing a universally unique identifier for the device.

  • driverUUID is an array of VK_UUID_SIZE uint8_t values representing a universally unique identifier for the driver build in use by the device.

  • deviceLUID is an array of VK_LUID_SIZE uint8_t values representing a locally unique identifier for the device.

  • deviceNodeMask is a uint32_t bitfield identifying the node within a linked device adapter corresponding to the device.

  • deviceLUIDValid is a boolean value that will be VK_TRUE if deviceLUID contains a valid LUID and deviceNodeMask contains a valid node mask, and VK_FALSE if they do not.

If the VkPhysicalDeviceIDProperties structure is included in the pNext chain of the VkPhysicalDeviceProperties2 structure passed to vkGetPhysicalDeviceProperties2, it is filled in with each corresponding implementation-dependent property.

deviceUUID must be immutable for a given device across instances, processes, driver APIs, driver versions, and system reboots.

Applications can compare the driverUUID value across instance and process boundaries, and can make similar queries in external APIs to determine whether they are capable of sharing memory objects and resources using them with the device.

deviceUUID and/or driverUUID must be used to determine whether a particular external object can be shared between driver components, where such a restriction exists as defined in the compatibility table for the particular object type:

If deviceLUIDValid is VK_FALSE, the values of deviceLUID and deviceNodeMask are undefined. If deviceLUIDValid is VK_TRUE and Vulkan is running on the Windows operating system, the contents of deviceLUID can be cast to an LUID object and must be equal to the locally unique identifier of a IDXGIAdapter1 object that corresponds to physicalDevice. If deviceLUIDValid is VK_TRUE, deviceNodeMask must contain exactly one bit. If Vulkan is running on an operating system that supports the Direct3D 12 API and physicalDevice corresponds to an individual device in a linked device adapter, deviceNodeMask identifies the Direct3D 12 node corresponding to physicalDevice. Otherwise, deviceNodeMask must be 1.

Note

Although they have identical descriptions, VkPhysicalDeviceIDProperties::deviceUUID may differ from VkPhysicalDeviceProperties2::pipelineCacheUUID. The former is intended to identify and correlate devices across API and driver boundaries, while the latter is used to identify a compatible device and driver combination to use when serializing and de-serializing pipeline state.

Implementations should return deviceUUID values which are likely to be unique even in the presence of multiple Vulkan implementations (such as a GPU driver and a software renderer; two drivers for different GPUs; or the same Vulkan driver running on two logically different devices).

Khronos' conformance testing is unable to guarantee that deviceUUID values are actually unique, so implementors should make their own best efforts to ensure this. In particular, hard-coded deviceUUID values, especially all-0 bits, should never be used.

A combination of values unique to the vendor, the driver, and the hardware environment can be used to provide a deviceUUID which is unique to a high degree of certainty. Some possible inputs to such a computation are:

  • Information reported by vkGetPhysicalDeviceProperties

  • PCI device ID (if defined)

  • PCI bus ID, or similar system configuration information.

  • Driver binary checksums.
Note

While VkPhysicalDeviceIDProperties::deviceUUID is specified to remain consistent across driver versions and system reboots, it is not intended to be usable as a serializable persistent identifier for a device. It may change when a device is physically added to, removed from, or moved to a different connector in a system while that system is powered down. Further, there is no reasonable way to verify with conformance testing that a given device retains the same UUID in a given system across all driver versions supported in that system. While implementations should make every effort to report consistent device UUIDs across driver versions, applications should avoid relying on the persistence of this value for uses other than identifying compatible devices for external object sharing purposes.
Valid Usage (Implicit)

  • VUID-VkPhysicalDeviceIDProperties-sType-sType
    sType must be VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_ID_PROPERTIES

VK_UUID_SIZE is the length in uint8_t values of an array containing a universally unique device or driver build identifier, as returned in VkPhysicalDeviceIDProperties::deviceUUID and VkPhysicalDeviceIDProperties::driverUUID.

#define VK_UUID_SIZE                      16U

VK_LUID_SIZE is the length in uint8_t values of an array containing a locally unique device identifier, as returned in VkPhysicalDeviceIDProperties::deviceLUID.

#define VK_LUID_SIZE                      8U

The VkPhysicalDeviceDriverProperties structure is defined as:

// Provided by VK_VERSION_1_2
typedef struct VkPhysicalDeviceDriverProperties {
    VkStructureType         sType;
    void*                   pNext;
    VkDriverId              driverID;
    char                    driverName[VK_MAX_DRIVER_NAME_SIZE];
    char                    driverInfo[VK_MAX_DRIVER_INFO_SIZE];
    VkConformanceVersion    conformanceVersion;
} VkPhysicalDeviceDriverProperties;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • driverID is a unique identifier for the driver of the physical device.

  • driverName is an array of VK_MAX_DRIVER_NAME_SIZE char containing a null-terminated UTF-8 string which is the name of the driver.

  • driverInfo is an array of VK_MAX_DRIVER_INFO_SIZE char containing a null-terminated UTF-8 string with additional information about the driver.

  • conformanceVersion is the version of the Vulkan conformance test this driver is conformant against (see VkConformanceVersion).

If the VkPhysicalDeviceDriverProperties structure is included in the pNext chain of the VkPhysicalDeviceProperties2 structure passed to vkGetPhysicalDeviceProperties2, it is filled in with each corresponding implementation-dependent property.

These are properties of the driver corresponding to a physical device.

driverID must be immutable for a given driver across instances, processes, driver versions, and system reboots.

Valid Usage (Implicit)

  • VUID-VkPhysicalDeviceDriverProperties-sType-sType
    sType must be VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_DRIVER_PROPERTIES

Khronos driver IDs which may be returned in VkPhysicalDeviceDriverProperties::driverID are:

// Provided by VK_VERSION_1_2
typedef enum VkDriverId {
    VK_DRIVER_ID_AMD_PROPRIETARY = 1,
    VK_DRIVER_ID_AMD_OPEN_SOURCE = 2,
    VK_DRIVER_ID_MESA_RADV = 3,
    VK_DRIVER_ID_NVIDIA_PROPRIETARY = 4,
    VK_DRIVER_ID_INTEL_PROPRIETARY_WINDOWS = 5,
    VK_DRIVER_ID_INTEL_OPEN_SOURCE_MESA = 6,
    VK_DRIVER_ID_IMAGINATION_PROPRIETARY = 7,
    VK_DRIVER_ID_QUALCOMM_PROPRIETARY = 8,
    VK_DRIVER_ID_ARM_PROPRIETARY = 9,
    VK_DRIVER_ID_GOOGLE_SWIFTSHADER = 10,
    VK_DRIVER_ID_GGP_PROPRIETARY = 11,
    VK_DRIVER_ID_BROADCOM_PROPRIETARY = 12,
    VK_DRIVER_ID_MESA_LLVMPIPE = 13,
    VK_DRIVER_ID_MOLTENVK = 14,
    VK_DRIVER_ID_COREAVI_PROPRIETARY = 15,
    VK_DRIVER_ID_JUICE_PROPRIETARY = 16,
    VK_DRIVER_ID_VERISILICON_PROPRIETARY = 17,
    VK_DRIVER_ID_MESA_TURNIP = 18,
    VK_DRIVER_ID_MESA_V3DV = 19,
    VK_DRIVER_ID_MESA_PANVK = 20,
    VK_DRIVER_ID_SAMSUNG_PROPRIETARY = 21,
    VK_DRIVER_ID_MESA_VENUS = 22,
    VK_DRIVER_ID_MESA_DOZEN = 23,
    VK_DRIVER_ID_MESA_NVK = 24,
    VK_DRIVER_ID_IMAGINATION_OPEN_SOURCE_MESA = 25,
} VkDriverId;
Note

Khronos driver IDs may be allocated by vendors at any time. There may be multiple driver IDs for the same vendor, representing different drivers (for e.g. different platforms, proprietary or open source, etc.). Only the latest canonical versions of this Specification, of the corresponding vk.xml API Registry, and of the corresponding vulkan_core.h header file must contain all reserved Khronos driver IDs.

Only driver IDs registered with Khronos are given symbolic names. There may be unregistered driver IDs returned.

VK_MAX_DRIVER_NAME_SIZE is the length in char values of an array containing a driver name string, as returned in VkPhysicalDeviceDriverProperties::driverName.

#define VK_MAX_DRIVER_NAME_SIZE           256U

VK_MAX_DRIVER_INFO_SIZE is the length in char values of an array containing a driver information string, as returned in VkPhysicalDeviceDriverProperties::driverInfo.

#define VK_MAX_DRIVER_INFO_SIZE           256U

The conformance test suite version an implementation is compliant with is described with the VkConformanceVersion structure:

// Provided by VK_VERSION_1_2
typedef struct VkConformanceVersion {
    uint8_t    major;
    uint8_t    minor;
    uint8_t    subminor;
    uint8_t    patch;
} VkConformanceVersion;

  • major is the major version number of the conformance test suite.

  • minor is the minor version number of the conformance test suite.

  • subminor is the subminor version number of the conformance test suite.

  • patch is the patch version number of the conformance test suite.

The VkPhysicalDeviceShaderIntegerDotProductProperties structure is defined as:

// Provided by VK_VERSION_1_3
typedef struct VkPhysicalDeviceShaderIntegerDotProductProperties {
    VkStructureType    sType;
    void*              pNext;
    VkBool32           integerDotProduct8BitUnsignedAccelerated;
    VkBool32           integerDotProduct8BitSignedAccelerated;
    VkBool32           integerDotProduct8BitMixedSignednessAccelerated;
    VkBool32           integerDotProduct4x8BitPackedUnsignedAccelerated;
    VkBool32           integerDotProduct4x8BitPackedSignedAccelerated;
    VkBool32           integerDotProduct4x8BitPackedMixedSignednessAccelerated;
    VkBool32           integerDotProduct16BitUnsignedAccelerated;
    VkBool32           integerDotProduct16BitSignedAccelerated;
    VkBool32           integerDotProduct16BitMixedSignednessAccelerated;
    VkBool32           integerDotProduct32BitUnsignedAccelerated;
    VkBool32           integerDotProduct32BitSignedAccelerated;
    VkBool32           integerDotProduct32BitMixedSignednessAccelerated;
    VkBool32           integerDotProduct64BitUnsignedAccelerated;
    VkBool32           integerDotProduct64BitSignedAccelerated;
    VkBool32           integerDotProduct64BitMixedSignednessAccelerated;
    VkBool32           integerDotProductAccumulatingSaturating8BitUnsignedAccelerated;
    VkBool32           integerDotProductAccumulatingSaturating8BitSignedAccelerated;
    VkBool32           integerDotProductAccumulatingSaturating8BitMixedSignednessAccelerated;
    VkBool32           integerDotProductAccumulatingSaturating4x8BitPackedUnsignedAccelerated;
    VkBool32           integerDotProductAccumulatingSaturating4x8BitPackedSignedAccelerated;
    VkBool32           integerDotProductAccumulatingSaturating4x8BitPackedMixedSignednessAccelerated;
    VkBool32           integerDotProductAccumulatingSaturating16BitUnsignedAccelerated;
    VkBool32           integerDotProductAccumulatingSaturating16BitSignedAccelerated;
    VkBool32           integerDotProductAccumulatingSaturating16BitMixedSignednessAccelerated;
    VkBool32           integerDotProductAccumulatingSaturating32BitUnsignedAccelerated;
    VkBool32           integerDotProductAccumulatingSaturating32BitSignedAccelerated;
    VkBool32           integerDotProductAccumulatingSaturating32BitMixedSignednessAccelerated;
    VkBool32           integerDotProductAccumulatingSaturating64BitUnsignedAccelerated;
    VkBool32           integerDotProductAccumulatingSaturating64BitSignedAccelerated;
    VkBool32           integerDotProductAccumulatingSaturating64BitMixedSignednessAccelerated;
} VkPhysicalDeviceShaderIntegerDotProductProperties;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • integerDotProduct8BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit unsigned dot product operations using the OpUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct8BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit signed dot product operations using the OpSDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct8BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 8-bit mixed signedness dot product operations using the OpSUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct4x8BitPackedUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit unsigned dot product operations from operands packed into 32-bit integers using the OpUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct4x8BitPackedSignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit signed dot product operations from operands packed into 32-bit integers using the OpSDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct4x8BitPackedMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 8-bit mixed signedness dot product operations from operands packed into 32-bit integers using the OpSUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct16BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 16-bit unsigned dot product operations using the OpUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct16BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 16-bit signed dot product operations using the OpSDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct16BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 16-bit mixed signedness dot product operations using the OpSUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct32BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 32-bit unsigned dot product operations using the OpUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct32BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 32-bit signed dot product operations using the OpSDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct32BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 32-bit mixed signedness dot product operations using the OpSUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct64BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 64-bit unsigned dot product operations using the OpUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct64BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 64-bit signed dot product operations using the OpSDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProduct64BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 64-bit mixed signedness dot product operations using the OpSUDotKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating8BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit unsigned accumulating saturating dot product operations using the OpUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating8BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit signed accumulating saturating dot product operations using the OpSDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating8BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 8-bit mixed signedness accumulating saturating dot product operations using the OpSUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating4x8BitPackedUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit unsigned accumulating saturating dot product operations from operands packed into 32-bit integers using the OpUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating4x8BitPackedSignedAccelerated is a boolean that will be VK_TRUE if the support for 8-bit signed accumulating saturating dot product operations from operands packed into 32-bit integers using the OpSDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating4x8BitPackedMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 8-bit mixed signedness accumulating saturating dot product operations from operands packed into 32-bit integers using the OpSUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating16BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 16-bit unsigned accumulating saturating dot product operations using the OpUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating16BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 16-bit signed accumulating saturating dot product operations using the OpSDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating16BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 16-bit mixed signedness accumulating saturating dot product operations using the OpSUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating32BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 32-bit unsigned accumulating saturating dot product operations using the OpUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating32BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 32-bit signed accumulating saturating dot product operations using the OpSDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating32BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 32-bit mixed signedness accumulating saturating dot product operations using the OpSUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating64BitUnsignedAccelerated is a boolean that will be VK_TRUE if the support for 64-bit unsigned accumulating saturating dot product operations using the OpUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating64BitSignedAccelerated is a boolean that will be VK_TRUE if the support for 64-bit signed accumulating saturating dot product operations using the OpSDotAccSatKHR SPIR-V instruction is accelerated as defined below.

  • integerDotProductAccumulatingSaturating64BitMixedSignednessAccelerated is a boolean that will be VK_TRUE if the support for 64-bit mixed signedness accumulating saturating dot product operations using the OpSUDotAccSatKHR SPIR-V instruction is accelerated as defined below.

If the VkPhysicalDeviceShaderIntegerDotProductProperties structure is included in the pNext chain of the VkPhysicalDeviceProperties2 structure passed to vkGetPhysicalDeviceProperties2, it is filled in with each corresponding implementation-dependent property.

These are properties of the integer dot product acceleration information of a physical device.

Note

A dot product operation is deemed accelerated if its implementation provides a performance advantage over application-provided code composed from elementary instructions and/or other dot product instructions, either because the implementation uses optimized machine code sequences whose generation from application-provided code cannot be guaranteed or because it uses hardware features that cannot otherwise be targeted from application-provided code.
Valid Usage (Implicit)

  • VUID-VkPhysicalDeviceShaderIntegerDotProductProperties-sType-sType
    sType must be VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_SHADER_INTEGER_DOT_PRODUCT_PROPERTIES

To query properties of queues available on a physical device, call:

// Provided by VK_VERSION_1_0
void vkGetPhysicalDeviceQueueFamilyProperties(
    VkPhysicalDevice                            physicalDevice,
    uint32_t*                                   pQueueFamilyPropertyCount,
    VkQueueFamilyProperties*                    pQueueFamilyProperties);

  • physicalDevice is the handle to the physical device whose properties will be queried.

  • pQueueFamilyPropertyCount is a pointer to an integer related to the number of queue families available or queried, as described below.

  • pQueueFamilyProperties is either NULL or a pointer to an array of VkQueueFamilyProperties structures.

If pQueueFamilyProperties is NULL, then the number of queue families available is returned in pQueueFamilyPropertyCount. Implementations must support at least one queue family. Otherwise, pQueueFamilyPropertyCount must point to a variable set by the user to the number of elements in the pQueueFamilyProperties array, and on return the variable is overwritten with the number of structures actually written to pQueueFamilyProperties. If pQueueFamilyPropertyCount is less than the number of queue families available, at most pQueueFamilyPropertyCount structures will be written.

Valid Usage (Implicit)

  • VUID-vkGetPhysicalDeviceQueueFamilyProperties-physicalDevice-parameter
    physicalDevice must be a valid VkPhysicalDevice handle

  • VUID-vkGetPhysicalDeviceQueueFamilyProperties-pQueueFamilyPropertyCount-parameter
    pQueueFamilyPropertyCount must be a valid pointer to a uint32_t value

  • VUID-vkGetPhysicalDeviceQueueFamilyProperties-pQueueFamilyProperties-parameter
    If the value referenced by pQueueFamilyPropertyCount is not 0, and pQueueFamilyProperties is not NULL, pQueueFamilyProperties must be a valid pointer to an array of pQueueFamilyPropertyCount VkQueueFamilyProperties structures

The VkQueueFamilyProperties structure is defined as:

// Provided by VK_VERSION_1_0
typedef struct VkQueueFamilyProperties {
    VkQueueFlags    queueFlags;
    uint32_t        queueCount;
    uint32_t        timestampValidBits;
    VkExtent3D      minImageTransferGranularity;
} VkQueueFamilyProperties;

  • queueFlags is a bitmask of VkQueueFlagBits indicating capabilities of the queues in this queue family.

  • queueCount is the unsigned integer count of queues in this queue family. Each queue family must support at least one queue.

  • timestampValidBits is the unsigned integer count of meaningful bits in the timestamps written via vkCmdWriteTimestamp2 or vkCmdWriteTimestamp. The valid range for the count is 36 to 64 bits, or a value of 0, indicating no support for timestamps. Bits outside the valid range are guaranteed to be zeros.

  • minImageTransferGranularity is the minimum granularity supported for image transfer operations on the queues in this queue family.

The value returned in minImageTransferGranularity has a unit of compressed texel blocks for images having a block-compressed format, and a unit of texels otherwise.

Possible values of minImageTransferGranularity are:

  • (0,0,0) specifies that only whole mip levels must be transferred using the image transfer operations on the corresponding queues. In this case, the following restrictions apply to all offset and extent parameters of image transfer operations:

    • The x, y, and z members of a VkOffset3D parameter must always be zero.

    • The width, height, and depth members of a VkExtent3D parameter must always match the width, height, and depth of the image subresource corresponding to the parameter, respectively.

  • (Ax, Ay, Az) where Ax, Ay, and Az are all integer powers of two. In this case the following restrictions apply to all image transfer operations:

    • x, y, and z of a VkOffset3D parameter must be integer multiples of Ax, Ay, and Az, respectively.

    • width of a VkExtent3D parameter must be an integer multiple of Ax, or else x + width must equal the width of the image subresource corresponding to the parameter.

    • height of a VkExtent3D parameter must be an integer multiple of Ay, or else y + height must equal the height of the image subresource corresponding to the parameter.

    • depth of a VkExtent3D parameter must be an integer multiple of Az, or else z + depth must equal the depth of the image subresource corresponding to the parameter.

    • If the format of the image corresponding to the parameters is one of the block-compressed formats then for the purposes of the above calculations the granularity must be scaled up by the compressed texel block dimensions.

Queues supporting graphics and/or compute operations must report (1,1,1) in minImageTransferGranularity, meaning that there are no additional restrictions on the granularity of image transfer operations for these queues. Other queues supporting image transfer operations are only required to support whole mip level transfers, thus minImageTransferGranularity for queues belonging to such queue families may be (0,0,0).

The Device Memory section describes memory properties queried from the physical device.

For physical device feature queries see the Features chapter.

Bits which may be set in VkQueueFamilyProperties::queueFlags, indicating capabilities of queues in a queue family are:

// Provided by VK_VERSION_1_0
typedef enum VkQueueFlagBits {
    VK_QUEUE_GRAPHICS_BIT = 0x00000001,
    VK_QUEUE_COMPUTE_BIT = 0x00000002,
    VK_QUEUE_TRANSFER_BIT = 0x00000004,
    VK_QUEUE_SPARSE_BINDING_BIT = 0x00000008,
  // Provided by VK_VERSION_1_1
    VK_QUEUE_PROTECTED_BIT = 0x00000010,
} VkQueueFlagBits;

  • VK_QUEUE_GRAPHICS_BIT specifies that queues in this queue family support graphics operations.

  • VK_QUEUE_COMPUTE_BIT specifies that queues in this queue family support compute operations.

  • VK_QUEUE_TRANSFER_BIT specifies that queues in this queue family support transfer operations.

  • VK_QUEUE_SPARSE_BINDING_BIT specifies that queues in this queue family support sparse memory management operations (see Sparse Resources). If any of the sparse resource features are enabled, then at least one queue family must support this bit.

  • VK_QUEUE_PROTECTED_BIT specifies that queues in this queue family support the VK_DEVICE_QUEUE_CREATE_PROTECTED_BIT bit. (see Protected Memory). If the physical device supports the protectedMemory feature, at least one of its queue families must support this bit.

If an implementation exposes any queue family that supports graphics operations, at least one queue family of at least one physical device exposed by the implementation must support both graphics and compute operations.

Furthermore, if the protectedMemory physical device feature is supported, then at least one queue family of at least one physical device exposed by the implementation must support graphics operations, compute operations, and protected memory operations.

Note

All commands that are allowed on a queue that supports transfer operations are also allowed on a queue that supports either graphics or compute operations. Thus, if the capabilities of a queue family include VK_QUEUE_GRAPHICS_BIT or VK_QUEUE_COMPUTE_BIT, then reporting the VK_QUEUE_TRANSFER_BIT capability separately for that queue family is optional.

For further details see Queues.

// Provided by VK_VERSION_1_0
typedef VkFlags VkQueueFlags;

VkQueueFlags is a bitmask type for setting a mask of zero or more VkQueueFlagBits.

To query properties of queues available on a physical device, call:

// Provided by VK_VERSION_1_1
void vkGetPhysicalDeviceQueueFamilyProperties2(
    VkPhysicalDevice                            physicalDevice,
    uint32_t*                                   pQueueFamilyPropertyCount,
    VkQueueFamilyProperties2*                   pQueueFamilyProperties);

  • physicalDevice is the handle to the physical device whose properties will be queried.

  • pQueueFamilyPropertyCount is a pointer to an integer related to the number of queue families available or queried, as described in vkGetPhysicalDeviceQueueFamilyProperties.

  • pQueueFamilyProperties is either NULL or a pointer to an array of VkQueueFamilyProperties2 structures.

vkGetPhysicalDeviceQueueFamilyProperties2 behaves similarly to vkGetPhysicalDeviceQueueFamilyProperties, with the ability to return extended information in a pNext chain of output structures.

Valid Usage (Implicit)

  • VUID-vkGetPhysicalDeviceQueueFamilyProperties2-physicalDevice-parameter
    physicalDevice must be a valid VkPhysicalDevice handle

  • VUID-vkGetPhysicalDeviceQueueFamilyProperties2-pQueueFamilyPropertyCount-parameter
    pQueueFamilyPropertyCount must be a valid pointer to a uint32_t value

  • VUID-vkGetPhysicalDeviceQueueFamilyProperties2-pQueueFamilyProperties-parameter
    If the value referenced by pQueueFamilyPropertyCount is not 0, and pQueueFamilyProperties is not NULL, pQueueFamilyProperties must be a valid pointer to an array of pQueueFamilyPropertyCount VkQueueFamilyProperties2 structures

The VkQueueFamilyProperties2 structure is defined as:

// Provided by VK_VERSION_1_1
typedef struct VkQueueFamilyProperties2 {
    VkStructureType            sType;
    void*                      pNext;
    VkQueueFamilyProperties    queueFamilyProperties;
} VkQueueFamilyProperties2;
Valid Usage (Implicit)

  • VUID-VkQueueFamilyProperties2-sType-sType
    sType must be VK_STRUCTURE_TYPE_QUEUE_FAMILY_PROPERTIES_2

  • VUID-VkQueueFamilyProperties2-pNext-pNext
    pNext must be NULL

5.2. Devices

Device objects represent logical connections to physical devices. Each device exposes a number of queue families each having one or more queues. All queues in a queue family support the same operations.

As described in Physical Devices, a Vulkan application will first query for all physical devices in a system. Each physical device can then be queried for its capabilities, including its queue and queue family properties. Once an acceptable physical device is identified, an application will create a corresponding logical device. The created logical device is then the primary interface to the physical device.

How to enumerate the physical devices in a system and query those physical devices for their queue family properties is described in the Physical Device Enumeration section above.

A single logical device can be created from multiple physical devices, if those physical devices belong to the same device group. A device group is a set of physical devices that support accessing each other’s memory and recording a single command buffer that can be executed on all the physical devices. Device groups are enumerated by calling vkEnumeratePhysicalDeviceGroups, and a logical device is created from a subset of the physical devices in a device group by passing the physical devices through VkDeviceGroupDeviceCreateInfo. For two physical devices to be in the same device group, they must support identical extensions, features, and properties.

Note

Physical devices in the same device group must be so similar because there are no rules for how different features/properties would interact. They must return the same values for nearly every invariant vkGetPhysicalDevice* feature, property, capability, etc., but could potentially differ for certain queries based on things like having a different display connected, or a different compositor. The specification does not attempt to enumerate which state is in each category, because such a list would quickly become out of date.

To retrieve a list of the device groups present in the system, call:

// Provided by VK_VERSION_1_1
VkResult vkEnumeratePhysicalDeviceGroups(
    VkInstance                                  instance,
    uint32_t*                                   pPhysicalDeviceGroupCount,
    VkPhysicalDeviceGroupProperties*            pPhysicalDeviceGroupProperties);

  • instance is a handle to a Vulkan instance previously created with vkCreateInstance.

  • pPhysicalDeviceGroupCount is a pointer to an integer related to the number of device groups available or queried, as described below.

  • pPhysicalDeviceGroupProperties is either NULL or a pointer to an array of VkPhysicalDeviceGroupProperties structures.

If pPhysicalDeviceGroupProperties is NULL, then the number of device groups available is returned in pPhysicalDeviceGroupCount. Otherwise, pPhysicalDeviceGroupCount must point to a variable set by the user to the number of elements in the pPhysicalDeviceGroupProperties array, and on return the variable is overwritten with the number of structures actually written to pPhysicalDeviceGroupProperties. If pPhysicalDeviceGroupCount is less than the number of device groups available, at most pPhysicalDeviceGroupCount structures will be written, and VK_INCOMPLETE will be returned instead of VK_SUCCESS, to indicate that not all the available device groups were returned.

Every physical device must be in exactly one device group.

Valid Usage (Implicit)

  • VUID-vkEnumeratePhysicalDeviceGroups-instance-parameter
    instance must be a valid VkInstance handle

  • VUID-vkEnumeratePhysicalDeviceGroups-pPhysicalDeviceGroupCount-parameter
    pPhysicalDeviceGroupCount must be a valid pointer to a uint32_t value

  • VUID-vkEnumeratePhysicalDeviceGroups-pPhysicalDeviceGroupProperties-parameter
    If the value referenced by pPhysicalDeviceGroupCount is not 0, and pPhysicalDeviceGroupProperties is not NULL, pPhysicalDeviceGroupProperties must be a valid pointer to an array of pPhysicalDeviceGroupCount VkPhysicalDeviceGroupProperties structures

Return Codes
Success

  • VK_SUCCESS

  • VK_INCOMPLETE

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

  • VK_ERROR_INITIALIZATION_FAILED

The VkPhysicalDeviceGroupProperties structure is defined as:

// Provided by VK_VERSION_1_1
typedef struct VkPhysicalDeviceGroupProperties {
    VkStructureType     sType;
    void*               pNext;
    uint32_t            physicalDeviceCount;
    VkPhysicalDevice    physicalDevices[VK_MAX_DEVICE_GROUP_SIZE];
    VkBool32            subsetAllocation;
} VkPhysicalDeviceGroupProperties;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • physicalDeviceCount is the number of physical devices in the group.

  • physicalDevices is an array of VK_MAX_DEVICE_GROUP_SIZE VkPhysicalDevice handles representing all physical devices in the group. The first physicalDeviceCount elements of the array will be valid.

  • subsetAllocation specifies whether logical devices created from the group support allocating device memory on a subset of devices, via the deviceMask member of the VkMemoryAllocateFlagsInfo. If this is VK_FALSE, then all device memory allocations are made across all physical devices in the group. If physicalDeviceCount is 1, then subsetAllocation must be VK_FALSE.

Valid Usage (Implicit)

  • VUID-VkPhysicalDeviceGroupProperties-sType-sType
    sType must be VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_GROUP_PROPERTIES

  • VUID-VkPhysicalDeviceGroupProperties-pNext-pNext
    pNext must be NULL

VK_MAX_DEVICE_GROUP_SIZE is the length of an array containing VkPhysicalDevice handle values representing all physical devices in a group, as returned in VkPhysicalDeviceGroupProperties::physicalDevices.

#define VK_MAX_DEVICE_GROUP_SIZE          32U

5.2.1. Device Creation

Logical devices are represented by VkDevice handles:

// Provided by VK_VERSION_1_0
VK_DEFINE_HANDLE(VkDevice)

A logical device is created as a connection to a physical device. To create a logical device, call:

// Provided by VK_VERSION_1_0
VkResult vkCreateDevice(
    VkPhysicalDevice                            physicalDevice,
    const VkDeviceCreateInfo*                   pCreateInfo,
    const VkAllocationCallbacks*                pAllocator,
    VkDevice*                                   pDevice);

  • physicalDevice must be one of the device handles returned from a call to vkEnumeratePhysicalDevices (see Physical Device Enumeration).

  • pCreateInfo is a pointer to a VkDeviceCreateInfo structure containing information about how to create the device.

  • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

  • pDevice is a pointer to a handle in which the created VkDevice is returned.

vkCreateDevice verifies that extensions and features requested in the ppEnabledExtensionNames and pEnabledFeatures members of pCreateInfo, respectively, are supported by the implementation. If any requested extension is not supported, vkCreateDevice must return VK_ERROR_EXTENSION_NOT_PRESENT. If any requested feature is not supported, vkCreateDevice must return VK_ERROR_FEATURE_NOT_PRESENT. Support for extensions can be checked before creating a device by querying vkEnumerateDeviceExtensionProperties. Support for features can similarly be checked by querying vkGetPhysicalDeviceFeatures.

After verifying and enabling the extensions the VkDevice object is created and returned to the application.

Multiple logical devices can be created from the same physical device. Logical device creation may fail due to lack of device-specific resources (in addition to other errors). If that occurs, vkCreateDevice will return VK_ERROR_TOO_MANY_OBJECTS.

Valid Usage
Valid Usage (Implicit)

  • VUID-vkCreateDevice-physicalDevice-parameter
    physicalDevice must be a valid VkPhysicalDevice handle

  • VUID-vkCreateDevice-pCreateInfo-parameter
    pCreateInfo must be a valid pointer to a valid VkDeviceCreateInfo structure

  • VUID-vkCreateDevice-pAllocator-parameter
    If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

  • VUID-vkCreateDevice-pDevice-parameter
    pDevice must be a valid pointer to a VkDevice handle

Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

  • VK_ERROR_INITIALIZATION_FAILED

  • VK_ERROR_EXTENSION_NOT_PRESENT

  • VK_ERROR_FEATURE_NOT_PRESENT

  • VK_ERROR_TOO_MANY_OBJECTS

  • VK_ERROR_DEVICE_LOST

The VkDeviceCreateInfo structure is defined as:

// Provided by VK_VERSION_1_0
typedef struct VkDeviceCreateInfo {
    VkStructureType                    sType;
    const void*                        pNext;
    VkDeviceCreateFlags                flags;
    uint32_t                           queueCreateInfoCount;
    const VkDeviceQueueCreateInfo*     pQueueCreateInfos;
    uint32_t                           enabledLayerCount;
    const char* const*                 ppEnabledLayerNames;
    uint32_t                           enabledExtensionCount;
    const char* const*                 ppEnabledExtensionNames;
    const VkPhysicalDeviceFeatures*    pEnabledFeatures;
} VkDeviceCreateInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • flags is reserved for future use.

  • queueCreateInfoCount is the unsigned integer size of the pQueueCreateInfos array. Refer to the Queue Creation section below for further details.

  • pQueueCreateInfos is a pointer to an array of VkDeviceQueueCreateInfo structures describing the queues that are requested to be created along with the logical device. Refer to the Queue Creation section below for further details.

  • enabledLayerCount is deprecated and ignored.

  • ppEnabledLayerNames is deprecated and ignored. See Device Layer Deprecation.

  • enabledExtensionCount is the number of device extensions to enable.

  • ppEnabledExtensionNames is a pointer to an array of enabledExtensionCount null-terminated UTF-8 strings containing the names of extensions to enable for the created device. See the Extensions section for further details.

  • pEnabledFeatures is NULL or a pointer to a VkPhysicalDeviceFeatures structure containing boolean indicators of all the features to be enabled. Refer to the Features section for further details.

Valid Usage
Valid Usage (Implicit)
// Provided by VK_VERSION_1_0
typedef VkFlags VkDeviceCreateFlags;

VkDeviceCreateFlags is a bitmask type for setting a mask, but is currently reserved for future use.

A logical device can be created that connects to one or more physical devices by adding a VkDeviceGroupDeviceCreateInfo structure to the pNext chain of VkDeviceCreateInfo. The VkDeviceGroupDeviceCreateInfo structure is defined as:

// Provided by VK_VERSION_1_1
typedef struct VkDeviceGroupDeviceCreateInfo {
    VkStructureType            sType;
    const void*                pNext;
    uint32_t                   physicalDeviceCount;
    const VkPhysicalDevice*    pPhysicalDevices;
} VkDeviceGroupDeviceCreateInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • physicalDeviceCount is the number of elements in the pPhysicalDevices array.

  • pPhysicalDevices is a pointer to an array of physical device handles belonging to the same device group.

The elements of the pPhysicalDevices array are an ordered list of the physical devices that the logical device represents. These must be a subset of a single device group, and need not be in the same order as they were enumerated. The order of the physical devices in the pPhysicalDevices array determines the device index of each physical device, with element i being assigned a device index of i. Certain commands and structures refer to one or more physical devices by using device indices or device masks formed using device indices.

A logical device created without using VkDeviceGroupDeviceCreateInfo, or with physicalDeviceCount equal to zero, is equivalent to a physicalDeviceCount of one and pPhysicalDevices pointing to the physicalDevice parameter to vkCreateDevice. In particular, the device index of that physical device is zero.

Valid Usage

  • VUID-VkDeviceGroupDeviceCreateInfo-pPhysicalDevices-00375
    Each element of pPhysicalDevices must be unique

  • VUID-VkDeviceGroupDeviceCreateInfo-pPhysicalDevices-00376
    All elements of pPhysicalDevices must be in the same device group as enumerated by vkEnumeratePhysicalDeviceGroups

  • VUID-VkDeviceGroupDeviceCreateInfo-physicalDeviceCount-00377
    If physicalDeviceCount is not 0, the physicalDevice parameter of vkCreateDevice must be an element of pPhysicalDevices

Valid Usage (Implicit)

  • VUID-VkDeviceGroupDeviceCreateInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_DEVICE_GROUP_DEVICE_CREATE_INFO

  • VUID-VkDeviceGroupDeviceCreateInfo-pPhysicalDevices-parameter
    If physicalDeviceCount is not 0, pPhysicalDevices must be a valid pointer to an array of physicalDeviceCount valid VkPhysicalDevice handles

To reserve private data storage slots, add a VkDevicePrivateDataCreateInfo structure to the pNext chain of the VkDeviceCreateInfo structure. Reserving slots in this manner is not strictly necessary, but doing so may improve performance.

// Provided by VK_VERSION_1_3
typedef struct VkDevicePrivateDataCreateInfo {
    VkStructureType    sType;
    const void*        pNext;
    uint32_t           privateDataSlotRequestCount;
} VkDevicePrivateDataCreateInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • privateDataSlotRequestCount is the amount of slots to reserve.

Valid Usage (Implicit)

  • VUID-VkDevicePrivateDataCreateInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_DEVICE_PRIVATE_DATA_CREATE_INFO

5.2.2. Device Use

The following is a high-level list of VkDevice uses along with references on where to find more information:

5.2.3. Lost Device

A logical device may become lost for a number of implementation-specific reasons, indicating that pending and future command execution may fail and cause resources and backing memory to become undefined.

Note

Typical reasons for device loss will include things like execution timing out (to prevent denial of service), power management events, platform resource management, implementation errors.

Applications not adhering to valid usage may also result in device loss being reported, however this is not guaranteed. Even if device loss is reported, the system may be in an unrecoverable state, and further usage of the API is still considered invalid.

When this happens, certain commands will return VK_ERROR_DEVICE_LOST. After any such event, the logical device is considered lost. It is not possible to reset the logical device to a non-lost state, however the lost state is specific to a logical device (VkDevice), and the corresponding physical device (VkPhysicalDevice) may be otherwise unaffected.

In some cases, the physical device may also be lost, and attempting to create a new logical device will fail, returning VK_ERROR_DEVICE_LOST. This is usually indicative of a problem with the underlying implementation, or its connection to the host. If the physical device has not been lost, and a new logical device is successfully created from that physical device, it must be in the non-lost state.

Note

Whilst logical device loss may be recoverable, in the case of physical device loss, it is unlikely that an application will be able to recover unless additional, unaffected physical devices exist on the system. The error is largely informational and intended only to inform the user that a platform issue has occurred, and should be investigated further. For example, underlying hardware may have developed a fault or become physically disconnected from the rest of the system. In many cases, physical device loss may cause other more serious issues such as the operating system crashing; in which case it may not be reported via the Vulkan API.

When a device is lost, its child objects are not implicitly destroyed and their handles are still valid. Those objects must still be destroyed before their parents or the device can be destroyed (see the Object Lifetime section). The host address space corresponding to device memory mapped using vkMapMemory is still valid, and host memory accesses to these mapped regions are still valid, but the contents are undefined. It is still legal to call any API command on the device and child objects.

Once a device is lost, command execution may fail, and certain commands that return a VkResult may return VK_ERROR_DEVICE_LOST. These commands can be identified by the inclusion of VK_ERROR_DEVICE_LOST in the Return Codes section for each command. Commands that do not allow runtime errors must still operate correctly for valid usage and, if applicable, return valid data.

Commands that wait indefinitely for device execution (namely vkDeviceWaitIdle, vkQueueWaitIdle, vkWaitForFences with a maximum timeout, and vkGetQueryPoolResults with the VK_QUERY_RESULT_WAIT_BIT bit set in flags) must return in finite time even in the case of a lost device, and return either VK_SUCCESS or VK_ERROR_DEVICE_LOST. For any command that may return VK_ERROR_DEVICE_LOST, for the purpose of determining whether a command buffer is in the pending state, or whether resources are considered in-use by the device, a return value of VK_ERROR_DEVICE_LOST is equivalent to VK_SUCCESS.

The content of any external memory objects that have been exported from or imported to a lost device become undefined. Objects on other logical devices or in other APIs which are associated with the same underlying memory resource as the external memory objects on the lost device are unaffected other than their content becoming undefined. The layout of subresources of images on other logical devices that are bound to VkDeviceMemory objects associated with the same underlying memory resources as external memory objects on the lost device becomes VK_IMAGE_LAYOUT_UNDEFINED.

The state of VkSemaphore objects on other logical devices created by importing a semaphore payload with temporary permanence which was exported from the lost device is undefined. The state of VkSemaphore objects on other logical devices that permanently share a semaphore payload with a VkSemaphore object on the lost device is undefined, and remains undefined following any subsequent signal operations. Implementations must ensure pending and subsequently submitted wait operations on such semaphores behave as defined in Semaphore State Requirements For Wait Operations for external semaphores not in a valid state for a wait operation.

5.2.4. Device Destruction

To destroy a device, call:

// Provided by VK_VERSION_1_0
void vkDestroyDevice(
    VkDevice                                    device,
    const VkAllocationCallbacks*                pAllocator);

  • device is the logical device to destroy.

  • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

To ensure that no work is active on the device, vkDeviceWaitIdle can be used to gate the destruction of the device. Prior to destroying a device, an application is responsible for destroying/freeing any Vulkan objects that were created using that device as the first parameter of the corresponding vkCreate* or vkAllocate* command.

Note

The lifetime of each of these objects is bound by the lifetime of the VkDevice object. Therefore, to avoid resource leaks, it is critical that an application explicitly free all of these resources prior to calling vkDestroyDevice.
Valid Usage

  • VUID-vkDestroyDevice-device-00378
    All child objects created on device must have been destroyed prior to destroying device

  • VUID-vkDestroyDevice-device-00379
    If VkAllocationCallbacks were provided when device was created, a compatible set of callbacks must be provided here

  • VUID-vkDestroyDevice-device-00380
    If no VkAllocationCallbacks were provided when device was created, pAllocator must be NULL

Valid Usage (Implicit)

  • VUID-vkDestroyDevice-device-parameter
    If device is not NULL, device must be a valid VkDevice handle

  • VUID-vkDestroyDevice-pAllocator-parameter
    If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

Host Synchronization

  • Host access to device must be externally synchronized

  • Host access to all VkQueue objects created from device must be externally synchronized

5.3. Queues

5.3.1. Queue Family Properties

As discussed in the Physical Device Enumeration section above, the vkGetPhysicalDeviceQueueFamilyProperties command is used to retrieve details about the queue families and queues supported by a device.

Each index in the pQueueFamilyProperties array returned by vkGetPhysicalDeviceQueueFamilyProperties describes a unique queue family on that physical device. These indices are used when creating queues, and they correspond directly with the queueFamilyIndex that is passed to the vkCreateDevice command via the VkDeviceQueueCreateInfo structure as described in the Queue Creation section below.

Grouping of queue families within a physical device is implementation-dependent.

Note

The general expectation is that a physical device groups all queues of matching capabilities into a single family. However, while implementations should do this, it is possible that a physical device may return two separate queue families with the same capabilities.

Once an application has identified a physical device with the queue(s) that it desires to use, it will create those queues in conjunction with a logical device. This is described in the following section.

5.3.2. Queue Creation

Creating a logical device also creates the queues associated with that device. The queues to create are described by a set of VkDeviceQueueCreateInfo structures that are passed to vkCreateDevice in pQueueCreateInfos.

Queues are represented by VkQueue handles:

// Provided by VK_VERSION_1_0
VK_DEFINE_HANDLE(VkQueue)

The VkDeviceQueueCreateInfo structure is defined as:

// Provided by VK_VERSION_1_0
typedef struct VkDeviceQueueCreateInfo {
    VkStructureType             sType;
    const void*                 pNext;
    VkDeviceQueueCreateFlags    flags;
    uint32_t                    queueFamilyIndex;
    uint32_t                    queueCount;
    const float*                pQueuePriorities;
} VkDeviceQueueCreateInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • flags is a bitmask indicating behavior of the queues.

  • queueFamilyIndex is an unsigned integer indicating the index of the queue family in which to create the queues on this device. This index corresponds to the index of an element of the pQueueFamilyProperties array that was returned by vkGetPhysicalDeviceQueueFamilyProperties.

  • queueCount is an unsigned integer specifying the number of queues to create in the queue family indicated by queueFamilyIndex, and with the behavior specified by flags.

  • pQueuePriorities is a pointer to an array of queueCount normalized floating point values, specifying priorities of work that will be submitted to each created queue. See Queue Priority for more information.

Valid Usage

  • VUID-VkDeviceQueueCreateInfo-queueFamilyIndex-00381
    queueFamilyIndex must be less than pQueueFamilyPropertyCount returned by vkGetPhysicalDeviceQueueFamilyProperties

  • VUID-VkDeviceQueueCreateInfo-queueCount-00382
    queueCount must be less than or equal to the queueCount member of the VkQueueFamilyProperties structure, as returned by vkGetPhysicalDeviceQueueFamilyProperties in the pQueueFamilyProperties[queueFamilyIndex]

  • VUID-VkDeviceQueueCreateInfo-pQueuePriorities-00383
    Each element of pQueuePriorities must be between 0.0 and 1.0 inclusive

  • VUID-VkDeviceQueueCreateInfo-flags-02861
    If the protectedMemory feature is not enabled, the VK_DEVICE_QUEUE_CREATE_PROTECTED_BIT bit of flags must not be set

  • VUID-VkDeviceQueueCreateInfo-flags-06449
    If flags includes VK_DEVICE_QUEUE_CREATE_PROTECTED_BIT, queueFamilyIndex must be the index of a queue family that includes the VK_QUEUE_PROTECTED_BIT capability

Valid Usage (Implicit)

  • VUID-VkDeviceQueueCreateInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_DEVICE_QUEUE_CREATE_INFO

  • VUID-VkDeviceQueueCreateInfo-pNext-pNext
    pNext must be NULL

  • VUID-VkDeviceQueueCreateInfo-flags-parameter
    flags must be a valid combination of VkDeviceQueueCreateFlagBits values

  • VUID-VkDeviceQueueCreateInfo-pQueuePriorities-parameter
    pQueuePriorities must be a valid pointer to an array of queueCount float values

  • VUID-VkDeviceQueueCreateInfo-queueCount-arraylength
    queueCount must be greater than 0

Bits which can be set in VkDeviceQueueCreateInfo::flags, specifying usage behavior of a queue, are:

// Provided by VK_VERSION_1_1
typedef enum VkDeviceQueueCreateFlagBits {
  // Provided by VK_VERSION_1_1
    VK_DEVICE_QUEUE_CREATE_PROTECTED_BIT = 0x00000001,
} VkDeviceQueueCreateFlagBits;

  • VK_DEVICE_QUEUE_CREATE_PROTECTED_BIT specifies that the device queue is a protected-capable queue.

// Provided by VK_VERSION_1_0
typedef VkFlags VkDeviceQueueCreateFlags;

VkDeviceQueueCreateFlags is a bitmask type for setting a mask of zero or more VkDeviceQueueCreateFlagBits.

To retrieve a handle to a VkQueue object, call:

// Provided by VK_VERSION_1_0
void vkGetDeviceQueue(
    VkDevice                                    device,
    uint32_t                                    queueFamilyIndex,
    uint32_t                                    queueIndex,
    VkQueue*                                    pQueue);

  • device is the logical device that owns the queue.

  • queueFamilyIndex is the index of the queue family to which the queue belongs.

  • queueIndex is the index within this queue family of the queue to retrieve.

  • pQueue is a pointer to a VkQueue object that will be filled with the handle for the requested queue.

vkGetDeviceQueue must only be used to get queues that were created with the flags parameter of VkDeviceQueueCreateInfo set to zero. To get queues that were created with a non-zero flags parameter use vkGetDeviceQueue2.

Valid Usage

  • VUID-vkGetDeviceQueue-queueFamilyIndex-00384
    queueFamilyIndex must be one of the queue family indices specified when device was created, via the VkDeviceQueueCreateInfo structure

  • VUID-vkGetDeviceQueue-queueIndex-00385
    queueIndex must be less than the value of VkDeviceQueueCreateInfo::queueCount for the queue family indicated by queueFamilyIndex when device was created

  • VUID-vkGetDeviceQueue-flags-01841
    VkDeviceQueueCreateInfo::flags must have been set to zero when device was created

Valid Usage (Implicit)

  • VUID-vkGetDeviceQueue-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkGetDeviceQueue-pQueue-parameter
    pQueue must be a valid pointer to a VkQueue handle

To retrieve a handle to a VkQueue object with specific VkDeviceQueueCreateFlags creation flags, call:

// Provided by VK_VERSION_1_1
void vkGetDeviceQueue2(
    VkDevice                                    device,
    const VkDeviceQueueInfo2*                   pQueueInfo,
    VkQueue*                                    pQueue);

  • device is the logical device that owns the queue.

  • pQueueInfo is a pointer to a VkDeviceQueueInfo2 structure, describing parameters of the device queue to be retrieved.

  • pQueue is a pointer to a VkQueue object that will be filled with the handle for the requested queue.

Valid Usage (Implicit)

  • VUID-vkGetDeviceQueue2-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkGetDeviceQueue2-pQueueInfo-parameter
    pQueueInfo must be a valid pointer to a valid VkDeviceQueueInfo2 structure

  • VUID-vkGetDeviceQueue2-pQueue-parameter
    pQueue must be a valid pointer to a VkQueue handle

The VkDeviceQueueInfo2 structure is defined as:

// Provided by VK_VERSION_1_1
typedef struct VkDeviceQueueInfo2 {
    VkStructureType             sType;
    const void*                 pNext;
    VkDeviceQueueCreateFlags    flags;
    uint32_t                    queueFamilyIndex;
    uint32_t                    queueIndex;
} VkDeviceQueueInfo2;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure. The pNext chain of VkDeviceQueueInfo2 can be used to provide additional device queue parameters to vkGetDeviceQueue2.

  • flags is a VkDeviceQueueCreateFlags value indicating the flags used to create the device queue.

  • queueFamilyIndex is the index of the queue family to which the queue belongs.

  • queueIndex is the index of the queue to retrieve from within the set of queues that share both the queue family and flags specified.

The queue returned by vkGetDeviceQueue2 must have the same flags value from this structure as that used at device creation time in a VkDeviceQueueCreateInfo structure.

Note

Normally, if you create both protected-capable and non-protected-capable queues with the same family, they are treated as separate lists of queues and queueIndex is relative to the start of the list of queues specified by both queueFamilyIndex and flags. However, for historical reasons, some implementations may exhibit different behavior. These divergent implementations instead concatenate the lists of queues and treat queueIndex as relative to the start of the first list of queues with the given queueFamilyIndex. This only matters in cases where an application has created both protected-capable and non-protected-capable queues from the same queue family.

For such divergent implementations, the maximum value of queueIndex is equal to the sum of VkDeviceQueueCreateInfo::queueCount minus one, for all VkDeviceQueueCreateInfo structures that share a common queueFamilyIndex.

Such implementations will return NULL for either the protected or unprotected queues when calling vkGetDeviceQueue2 with queueIndex in the range zero to VkDeviceQueueCreateInfo::queueCount minus one. In cases where these implementations returned NULL, the corresponding queues are instead located in the extended range described in the preceding two paragraphs.

This behaviour will not be observed on any driver that has passed Vulkan conformance test suite version 1.3.3.0, or any subsequent version. This information can be found by querying VkPhysicalDeviceDriverProperties::conformanceVersion.
Valid Usage

  • VUID-VkDeviceQueueInfo2-queueFamilyIndex-01842
    queueFamilyIndex must be one of the queue family indices specified when device was created, via the VkDeviceQueueCreateInfo structure

  • VUID-VkDeviceQueueInfo2-flags-06225
    flags must be equal to VkDeviceQueueCreateInfo::flags for a VkDeviceQueueCreateInfo structure for the queue family indicated by queueFamilyIndex when device was created

  • VUID-VkDeviceQueueInfo2-queueIndex-01843
    queueIndex must be less than VkDeviceQueueCreateInfo::queueCount for the corresponding queue family and flags indicated by queueFamilyIndex and flags when device was created

Valid Usage (Implicit)

  • VUID-VkDeviceQueueInfo2-sType-sType
    sType must be VK_STRUCTURE_TYPE_DEVICE_QUEUE_INFO_2

  • VUID-VkDeviceQueueInfo2-pNext-pNext
    pNext must be NULL

  • VUID-VkDeviceQueueInfo2-flags-parameter
    flags must be a valid combination of VkDeviceQueueCreateFlagBits values

5.3.3. Queue Family Index

The queue family index is used in multiple places in Vulkan in order to tie operations to a specific family of queues.

When retrieving a handle to the queue via vkGetDeviceQueue, the queue family index is used to select which queue family to retrieve the VkQueue handle from as described in the previous section.

When creating a VkCommandPool object (see Command Pools), a queue family index is specified in the VkCommandPoolCreateInfo structure. Command buffers from this pool can only be submitted on queues corresponding to this queue family.

When creating VkImage (see Images) and VkBuffer (see Buffers) resources, a set of queue families is included in the VkImageCreateInfo and VkBufferCreateInfo structures to specify the queue families that can access the resource.

When inserting a VkBufferMemoryBarrier or VkImageMemoryBarrier (see Pipeline Barriers), a source and destination queue family index is specified to allow the ownership of a buffer or image to be transferred from one queue family to another. See the Resource Sharing section for details.

5.3.4. Queue Priority

Each queue is assigned a priority, as set in the VkDeviceQueueCreateInfo structures when creating the device. The priority of each queue is a normalized floating point value between 0.0 and 1.0, which is then translated to a discrete priority level by the implementation. Higher values indicate a higher priority, with 0.0 being the lowest priority and 1.0 being the highest.

Within the same device, queues with higher priority may be allotted more processing time than queues with lower priority. The implementation makes no guarantees with regards to ordering or scheduling among queues with the same priority, other than the constraints defined by any explicit synchronization primitives. The implementation makes no guarantees with regards to queues across different devices.

An implementation may allow a higher-priority queue to starve a lower-priority queue on the same VkDevice until the higher-priority queue has no further commands to execute. The relationship of queue priorities must not cause queues on one VkDevice to starve queues on another VkDevice.

No specific guarantees are made about higher priority queues receiving more processing time or better quality of service than lower priority queues.

5.3.5. Queue Submission

Work is submitted to a queue via queue submission commands such as vkQueueSubmit2 or vkQueueSubmit. Queue submission commands define a set of queue operations to be executed by the underlying physical device, including synchronization with semaphores and fences.

Submission commands take as parameters a target queue, zero or more batches of work, and an optional fence to signal upon completion. Each batch consists of three distinct parts:

  1. Zero or more semaphores to wait on before execution of the rest of the batch.

  2. Zero or more work items to execute.

    • If present, these describe a queue operation matching the work described.

  3. Zero or more semaphores to signal upon completion of the work items.

If a fence is present in a queue submission, it describes a fence signal operation.

All work described by a queue submission command must be submitted to the queue before the command returns.

Sparse Memory Binding

In Vulkan it is possible to sparsely bind memory to buffers and images as described in the Sparse Resource chapter. Sparse memory binding is a queue operation. A queue whose flags include the VK_QUEUE_SPARSE_BINDING_BIT must be able to support the mapping of a virtual address to a physical address on the device. This causes an update to the page table mappings on the device. This update must be synchronized on a queue to avoid corrupting page table mappings during execution of graphics commands. By binding the sparse memory resources on queues, all commands that are dependent on the updated bindings are synchronized to only execute after the binding is updated. See the Synchronization and Cache Control chapter for how this synchronization is accomplished.

5.3.6. Queue Destruction

Queues are created along with a logical device during vkCreateDevice. All queues associated with a logical device are destroyed when vkDestroyDevice is called on that device.

6. Command Buffers

Command buffers are objects used to record commands which can be subsequently submitted to a device queue for execution. There are two levels of command buffers - primary command buffers, which can execute secondary command buffers, and which are submitted to queues, and secondary command buffers, which can be executed by primary command buffers, and which are not directly submitted to queues.

Command buffers are represented by VkCommandBuffer handles:

// Provided by VK_VERSION_1_0
VK_DEFINE_HANDLE(VkCommandBuffer)

Recorded commands include commands to bind pipelines and descriptor sets to the command buffer, commands to modify dynamic state, commands to draw (for graphics rendering), commands to dispatch (for compute), commands to execute secondary command buffers (for primary command buffers only), commands to copy buffers and images, and other commands.

Each command buffer manages state independently of other command buffers. There is no inheritance of state across primary and secondary command buffers, or between secondary command buffers. When a command buffer begins recording, all state in that command buffer is undefined. When secondary command buffer(s) are recorded to execute on a primary command buffer, the secondary command buffer inherits no state from the primary command buffer, and all state of the primary command buffer is undefined after an execute secondary command buffer command is recorded. There is one exception to this rule - if the primary command buffer is inside a render pass instance, then the render pass and subpass state is not disturbed by executing secondary command buffers. For state dependent commands (such as draws and dispatches), any state consumed by those commands must not be undefined.

Unless otherwise specified, and without explicit synchronization, the various commands submitted to a queue via command buffers may execute in arbitrary order relative to each other, and/or concurrently. Also, the memory side effects of those commands may not be directly visible to other commands without explicit memory dependencies. This is true within a command buffer, and across command buffers submitted to a given queue. See the synchronization chapter for information on implicit and explicit synchronization between commands.

6.1. Command Buffer Lifecycle

Each command buffer is always in one of the following states:

Initial

When a command buffer is allocated, it is in the initial state. Some commands are able to reset a command buffer (or a set of command buffers) back to this state from any of the executable, recording or invalid state. Command buffers in the initial state can only be moved to the recording state, or freed.

Recording

vkBeginCommandBuffer changes the state of a command buffer from the initial state to the recording state. Once a command buffer is in the recording state, vkCmd* commands can be used to record to the command buffer.

Executable

vkEndCommandBuffer ends the recording of a command buffer, and moves it from the recording state to the executable state. Executable command buffers can be submitted, reset, or recorded to another command buffer.

Pending

Queue submission of a command buffer changes the state of a command buffer from the executable state to the pending state. Whilst in the pending state, applications must not attempt to modify the command buffer in any way - as the device may be processing the commands recorded to it. Once execution of a command buffer completes, the command buffer either reverts back to the executable state, or if it was recorded with VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT, it moves to the invalid state. A synchronization command should be used to detect when this occurs.

Invalid

Some operations, such as modifying or deleting a resource that was used in a command recorded to a command buffer, will transition the state of that command buffer into the invalid state. Command buffers in the invalid state can only be reset or freed.

image/svg+xml Initial Recording Pending Executable Invalid Allocate Begin End Submission Completion Completion withOne Time Submit Reset Reset Invalidate
Figure 1. Lifecycle of a command buffer

Any given command that operates on a command buffer has its own requirements on what state a command buffer must be in, which are detailed in the valid usage constraints for that command.

Resetting a command buffer is an operation that discards any previously recorded commands and puts a command buffer in the initial state. Resetting occurs as a result of vkResetCommandBuffer or vkResetCommandPool, or as part of vkBeginCommandBuffer (which additionally puts the command buffer in the recording state).

Secondary command buffers can be recorded to a primary command buffer via vkCmdExecuteCommands. This partially ties the lifecycle of the two command buffers together - if the primary is submitted to a queue, both the primary and any secondaries recorded to it move to the pending state. Once execution of the primary completes, so it does for any secondary recorded within it. After all executions of each command buffer complete, they each move to their appropriate completion state (either to the executable state or the invalid state, as specified above).

If a secondary moves to the invalid state or the initial state, then all primary buffers it is recorded in move to the invalid state. A primary moving to any other state does not affect the state of a secondary recorded in it.

Note

Resetting or freeing a primary command buffer removes the lifecycle linkage to all secondary command buffers that were recorded into it.

6.2. Command Pools

Command pools are opaque objects that command buffer memory is allocated from, and which allow the implementation to amortize the cost of resource creation across multiple command buffers. Command pools are externally synchronized, meaning that a command pool must not be used concurrently in multiple threads. That includes use via recording commands on any command buffers allocated from the pool, as well as operations that allocate, free, and reset command buffers or the pool itself.

Command pools are represented by VkCommandPool handles:

// Provided by VK_VERSION_1_0
VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkCommandPool)

To create a command pool, call:

// Provided by VK_VERSION_1_0
VkResult vkCreateCommandPool(
    VkDevice                                    device,
    const VkCommandPoolCreateInfo*              pCreateInfo,
    const VkAllocationCallbacks*                pAllocator,
    VkCommandPool*                              pCommandPool);

  • device is the logical device that creates the command pool.

  • pCreateInfo is a pointer to a VkCommandPoolCreateInfo structure specifying the state of the command pool object.

  • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

  • pCommandPool is a pointer to a VkCommandPool handle in which the created pool is returned.

Valid Usage

  • VUID-vkCreateCommandPool-queueFamilyIndex-01937
    pCreateInfo->queueFamilyIndex must be the index of a queue family available in the logical device device

Valid Usage (Implicit)

  • VUID-vkCreateCommandPool-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkCreateCommandPool-pCreateInfo-parameter
    pCreateInfo must be a valid pointer to a valid VkCommandPoolCreateInfo structure

  • VUID-vkCreateCommandPool-pAllocator-parameter
    If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

  • VUID-vkCreateCommandPool-pCommandPool-parameter
    pCommandPool must be a valid pointer to a VkCommandPool handle

Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

The VkCommandPoolCreateInfo structure is defined as:

// Provided by VK_VERSION_1_0
typedef struct VkCommandPoolCreateInfo {
    VkStructureType             sType;
    const void*                 pNext;
    VkCommandPoolCreateFlags    flags;
    uint32_t                    queueFamilyIndex;
} VkCommandPoolCreateInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • flags is a bitmask of VkCommandPoolCreateFlagBits indicating usage behavior for the pool and command buffers allocated from it.

  • queueFamilyIndex designates a queue family as described in section Queue Family Properties. All command buffers allocated from this command pool must be submitted on queues from the same queue family.

Valid Usage

  • VUID-VkCommandPoolCreateInfo-flags-02860
    If the protectedMemory feature is not enabled, the VK_COMMAND_POOL_CREATE_PROTECTED_BIT bit of flags must not be set

Valid Usage (Implicit)

  • VUID-VkCommandPoolCreateInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_COMMAND_POOL_CREATE_INFO

  • VUID-VkCommandPoolCreateInfo-pNext-pNext
    pNext must be NULL

  • VUID-VkCommandPoolCreateInfo-flags-parameter
    flags must be a valid combination of VkCommandPoolCreateFlagBits values

Bits which can be set in VkCommandPoolCreateInfo::flags, specifying usage behavior for a command pool, are:

// Provided by VK_VERSION_1_0
typedef enum VkCommandPoolCreateFlagBits {
    VK_COMMAND_POOL_CREATE_TRANSIENT_BIT = 0x00000001,
    VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT = 0x00000002,
  // Provided by VK_VERSION_1_1
    VK_COMMAND_POOL_CREATE_PROTECTED_BIT = 0x00000004,
} VkCommandPoolCreateFlagBits;

  • VK_COMMAND_POOL_CREATE_TRANSIENT_BIT specifies that command buffers allocated from the pool will be short-lived, meaning that they will be reset or freed in a relatively short timeframe. This flag may be used by the implementation to control memory allocation behavior within the pool.

  • VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT allows any command buffer allocated from a pool to be individually reset to the initial state; either by calling vkResetCommandBuffer, or via the implicit reset when calling vkBeginCommandBuffer. If this flag is not set on a pool, then vkResetCommandBuffer must not be called for any command buffer allocated from that pool.

  • VK_COMMAND_POOL_CREATE_PROTECTED_BIT specifies that command buffers allocated from the pool are protected command buffers.

// Provided by VK_VERSION_1_0
typedef VkFlags VkCommandPoolCreateFlags;

VkCommandPoolCreateFlags is a bitmask type for setting a mask of zero or more VkCommandPoolCreateFlagBits.

To trim a command pool, call:

// Provided by VK_VERSION_1_1
void vkTrimCommandPool(
    VkDevice                                    device,
    VkCommandPool                               commandPool,
    VkCommandPoolTrimFlags                      flags);

  • device is the logical device that owns the command pool.

  • commandPool is the command pool to trim.

  • flags is reserved for future use.

Trimming a command pool recycles unused memory from the command pool back to the system. Command buffers allocated from the pool are not affected by the command.

Note

This command provides applications with some control over the internal memory allocations used by command pools.

Unused memory normally arises from command buffers that have been recorded and later reset, such that they are no longer using the memory. On reset, a command buffer can return memory to its command pool, but the only way to release memory from a command pool to the system requires calling vkResetCommandPool, which cannot be executed while any command buffers from that pool are still in use. Subsequent recording operations into command buffers will re-use this memory but since total memory requirements fluctuate over time, unused memory can accumulate.

In this situation, trimming a command pool may be useful to return unused memory back to the system, returning the total outstanding memory allocated by the pool back to a more “average” value.

Implementations utilize many internal allocation strategies that make it impossible to guarantee that all unused memory is released back to the system. For instance, an implementation of a command pool may involve allocating memory in bulk from the system and sub-allocating from that memory. In such an implementation any live command buffer that holds a reference to a bulk allocation would prevent that allocation from being freed, even if only a small proportion of the bulk allocation is in use.

In most cases trimming will result in a reduction in allocated but unused memory, but it does not guarantee the “ideal” behavior.

Trimming may be an expensive operation, and should not be called frequently. Trimming should be treated as a way to relieve memory pressure after application-known points when there exists enough unused memory that the cost of trimming is “worth” it.
Valid Usage (Implicit)

  • VUID-vkTrimCommandPool-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkTrimCommandPool-commandPool-parameter
    commandPool must be a valid VkCommandPool handle

  • VUID-vkTrimCommandPool-flags-zerobitmask
    flags must be 0

  • VUID-vkTrimCommandPool-commandPool-parent
    commandPool must have been created, allocated, or retrieved from device

Host Synchronization

  • Host access to commandPool must be externally synchronized

// Provided by VK_VERSION_1_1
typedef VkFlags VkCommandPoolTrimFlags;

VkCommandPoolTrimFlags is a bitmask type for setting a mask, but is currently reserved for future use.

To reset a command pool, call:

// Provided by VK_VERSION_1_0
VkResult vkResetCommandPool(
    VkDevice                                    device,
    VkCommandPool                               commandPool,
    VkCommandPoolResetFlags                     flags);

  • device is the logical device that owns the command pool.

  • commandPool is the command pool to reset.

  • flags is a bitmask of VkCommandPoolResetFlagBits controlling the reset operation.

Resetting a command pool recycles all of the resources from all of the command buffers allocated from the command pool back to the command pool. All command buffers that have been allocated from the command pool are put in the initial state.

Any primary command buffer allocated from another VkCommandPool that is in the recording or executable state and has a secondary command buffer allocated from commandPool recorded into it, becomes invalid.

Valid Usage

  • VUID-vkResetCommandPool-commandPool-00040
    All VkCommandBuffer objects allocated from commandPool must not be in the pending state

Valid Usage (Implicit)

  • VUID-vkResetCommandPool-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkResetCommandPool-commandPool-parameter
    commandPool must be a valid VkCommandPool handle

  • VUID-vkResetCommandPool-flags-parameter
    flags must be a valid combination of VkCommandPoolResetFlagBits values

  • VUID-vkResetCommandPool-commandPool-parent
    commandPool must have been created, allocated, or retrieved from device

Host Synchronization

  • Host access to commandPool must be externally synchronized

Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

Bits which can be set in vkResetCommandPool::flags, controlling the reset operation, are:

// Provided by VK_VERSION_1_0
typedef enum VkCommandPoolResetFlagBits {
    VK_COMMAND_POOL_RESET_RELEASE_RESOURCES_BIT = 0x00000001,
} VkCommandPoolResetFlagBits;

  • VK_COMMAND_POOL_RESET_RELEASE_RESOURCES_BIT specifies that resetting a command pool recycles all of the resources from the command pool back to the system.

// Provided by VK_VERSION_1_0
typedef VkFlags VkCommandPoolResetFlags;

VkCommandPoolResetFlags is a bitmask type for setting a mask of zero or more VkCommandPoolResetFlagBits.

To destroy a command pool, call:

// Provided by VK_VERSION_1_0
void vkDestroyCommandPool(
    VkDevice                                    device,
    VkCommandPool                               commandPool,
    const VkAllocationCallbacks*                pAllocator);

  • device is the logical device that destroys the command pool.

  • commandPool is the handle of the command pool to destroy.

  • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

When a pool is destroyed, all command buffers allocated from the pool are freed.

Any primary command buffer allocated from another VkCommandPool that is in the recording or executable state and has a secondary command buffer allocated from commandPool recorded into it, becomes invalid.

Valid Usage

  • VUID-vkDestroyCommandPool-commandPool-00041
    All VkCommandBuffer objects allocated from commandPool must not be in the pending state

  • VUID-vkDestroyCommandPool-commandPool-00042
    If VkAllocationCallbacks were provided when commandPool was created, a compatible set of callbacks must be provided here

  • VUID-vkDestroyCommandPool-commandPool-00043
    If no VkAllocationCallbacks were provided when commandPool was created, pAllocator must be NULL

Valid Usage (Implicit)

  • VUID-vkDestroyCommandPool-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkDestroyCommandPool-commandPool-parameter
    If commandPool is not VK_NULL_HANDLE, commandPool must be a valid VkCommandPool handle

  • VUID-vkDestroyCommandPool-pAllocator-parameter
    If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

  • VUID-vkDestroyCommandPool-commandPool-parent
    If commandPool is a valid handle, it must have been created, allocated, or retrieved from device

Host Synchronization

  • Host access to commandPool must be externally synchronized

6.3. Command Buffer Allocation and Management

To allocate command buffers, call:

// Provided by VK_VERSION_1_0
VkResult vkAllocateCommandBuffers(
    VkDevice                                    device,
    const VkCommandBufferAllocateInfo*          pAllocateInfo,
    VkCommandBuffer*                            pCommandBuffers);

  • device is the logical device that owns the command pool.

  • pAllocateInfo is a pointer to a VkCommandBufferAllocateInfo structure describing parameters of the allocation.

  • pCommandBuffers is a pointer to an array of VkCommandBuffer handles in which the resulting command buffer objects are returned. The array must be at least the length specified by the commandBufferCount member of pAllocateInfo. Each allocated command buffer begins in the initial state.

vkAllocateCommandBuffers can be used to allocate multiple command buffers. If the allocation of any of those command buffers fails, the implementation must free all successfully allocated command buffer objects from this command, set all entries of the pCommandBuffers array to NULL and return the error.

Note

Filling pCommandBuffers with NULL values on failure is an exception to the default error behavior that output parameters will have undefined contents.

When command buffers are first allocated, they are in the initial state.

Valid Usage (Implicit)

  • VUID-vkAllocateCommandBuffers-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkAllocateCommandBuffers-pAllocateInfo-parameter
    pAllocateInfo must be a valid pointer to a valid VkCommandBufferAllocateInfo structure

  • VUID-vkAllocateCommandBuffers-pCommandBuffers-parameter
    pCommandBuffers must be a valid pointer to an array of pAllocateInfo->commandBufferCount VkCommandBuffer handles

  • VUID-vkAllocateCommandBuffers-pAllocateInfo::commandBufferCount-arraylength
    pAllocateInfo->commandBufferCount must be greater than 0

Host Synchronization

  • Host access to pAllocateInfo->commandPool must be externally synchronized

Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

The VkCommandBufferAllocateInfo structure is defined as:

// Provided by VK_VERSION_1_0
typedef struct VkCommandBufferAllocateInfo {
    VkStructureType         sType;
    const void*             pNext;
    VkCommandPool           commandPool;
    VkCommandBufferLevel    level;
    uint32_t                commandBufferCount;
} VkCommandBufferAllocateInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • commandPool is the command pool from which the command buffers are allocated.

  • level is a VkCommandBufferLevel value specifying the command buffer level.

  • commandBufferCount is the number of command buffers to allocate from the pool.

Valid Usage (Implicit)

  • VUID-VkCommandBufferAllocateInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_COMMAND_BUFFER_ALLOCATE_INFO

  • VUID-VkCommandBufferAllocateInfo-pNext-pNext
    pNext must be NULL

  • VUID-VkCommandBufferAllocateInfo-commandPool-parameter
    commandPool must be a valid VkCommandPool handle

  • VUID-VkCommandBufferAllocateInfo-level-parameter
    level must be a valid VkCommandBufferLevel value

Possible values of VkCommandBufferAllocateInfo::level, specifying the command buffer level, are:

// Provided by VK_VERSION_1_0
typedef enum VkCommandBufferLevel {
    VK_COMMAND_BUFFER_LEVEL_PRIMARY = 0,
    VK_COMMAND_BUFFER_LEVEL_SECONDARY = 1,
} VkCommandBufferLevel;

  • VK_COMMAND_BUFFER_LEVEL_PRIMARY specifies a primary command buffer.

  • VK_COMMAND_BUFFER_LEVEL_SECONDARY specifies a secondary command buffer.

To reset a command buffer, call:

// Provided by VK_VERSION_1_0
VkResult vkResetCommandBuffer(
    VkCommandBuffer                             commandBuffer,
    VkCommandBufferResetFlags                   flags);

Any primary command buffer that is in the recording or executable state and has commandBuffer recorded into it, becomes invalid.

Valid Usage

  • VUID-vkResetCommandBuffer-commandBuffer-00045
    commandBuffer must not be in the pending state

  • VUID-vkResetCommandBuffer-commandBuffer-00046
    commandBuffer must have been allocated from a pool that was created with the VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT

Valid Usage (Implicit)

  • VUID-vkResetCommandBuffer-commandBuffer-parameter
    commandBuffer must be a valid VkCommandBuffer handle

  • VUID-vkResetCommandBuffer-flags-parameter
    flags must be a valid combination of VkCommandBufferResetFlagBits values

Host Synchronization

  • Host access to commandBuffer must be externally synchronized

  • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

Bits which can be set in vkResetCommandBuffer::flags, controlling the reset operation, are:

// Provided by VK_VERSION_1_0
typedef enum VkCommandBufferResetFlagBits {
    VK_COMMAND_BUFFER_RESET_RELEASE_RESOURCES_BIT = 0x00000001,
} VkCommandBufferResetFlagBits;

  • VK_COMMAND_BUFFER_RESET_RELEASE_RESOURCES_BIT specifies that most or all memory resources currently owned by the command buffer should be returned to the parent command pool. If this flag is not set, then the command buffer may hold onto memory resources and reuse them when recording commands. commandBuffer is moved to the initial state.

// Provided by VK_VERSION_1_0
typedef VkFlags VkCommandBufferResetFlags;

VkCommandBufferResetFlags is a bitmask type for setting a mask of zero or more VkCommandBufferResetFlagBits.

To free command buffers, call:

// Provided by VK_VERSION_1_0
void vkFreeCommandBuffers(
    VkDevice                                    device,
    VkCommandPool                               commandPool,
    uint32_t                                    commandBufferCount,
    const VkCommandBuffer*                      pCommandBuffers);

  • device is the logical device that owns the command pool.

  • commandPool is the command pool from which the command buffers were allocated.

  • commandBufferCount is the length of the pCommandBuffers array.

  • pCommandBuffers is a pointer to an array of handles of command buffers to free.

Any primary command buffer that is in the recording or executable state and has any element of pCommandBuffers recorded into it, becomes invalid.

Valid Usage

  • VUID-vkFreeCommandBuffers-pCommandBuffers-00047
    All elements of pCommandBuffers must not be in the pending state

  • VUID-vkFreeCommandBuffers-pCommandBuffers-00048
    pCommandBuffers must be a valid pointer to an array of commandBufferCount VkCommandBuffer handles, each element of which must either be a valid handle or NULL

Valid Usage (Implicit)

  • VUID-vkFreeCommandBuffers-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkFreeCommandBuffers-commandPool-parameter
    commandPool must be a valid VkCommandPool handle

  • VUID-vkFreeCommandBuffers-commandBufferCount-arraylength
    commandBufferCount must be greater than 0

  • VUID-vkFreeCommandBuffers-commandPool-parent
    commandPool must have been created, allocated, or retrieved from device

  • VUID-vkFreeCommandBuffers-pCommandBuffers-parent
    Each element of pCommandBuffers that is a valid handle must have been created, allocated, or retrieved from commandPool

Host Synchronization

  • Host access to commandPool must be externally synchronized

  • Host access to each member of pCommandBuffers must be externally synchronized

6.4. Command Buffer Recording

To begin recording a command buffer, call:

// Provided by VK_VERSION_1_0
VkResult vkBeginCommandBuffer(
    VkCommandBuffer                             commandBuffer,
    const VkCommandBufferBeginInfo*             pBeginInfo);

  • commandBuffer is the handle of the command buffer which is to be put in the recording state.

  • pBeginInfo is a pointer to a VkCommandBufferBeginInfo structure defining additional information about how the command buffer begins recording.

Valid Usage

  • VUID-vkBeginCommandBuffer-commandBuffer-00049
    commandBuffer must not be in the recording or pending state

  • VUID-vkBeginCommandBuffer-commandBuffer-00050
    If commandBuffer was allocated from a VkCommandPool which did not have the VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT flag set, commandBuffer must be in the initial state

  • VUID-vkBeginCommandBuffer-commandBuffer-00051
    If commandBuffer is a secondary command buffer, the pInheritanceInfo member of pBeginInfo must be a valid VkCommandBufferInheritanceInfo structure

  • VUID-vkBeginCommandBuffer-commandBuffer-00052
    If commandBuffer is a secondary command buffer and either the occlusionQueryEnable member of the pInheritanceInfo member of pBeginInfo is VK_FALSE, or the occlusionQueryPrecise feature is not enabled, then pBeginInfo->pInheritanceInfo->queryFlags must not contain VK_QUERY_CONTROL_PRECISE_BIT

  • VUID-vkBeginCommandBuffer-commandBuffer-02840
    If commandBuffer is a primary command buffer, then pBeginInfo->flags must not set both the VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT and the VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT flags

Valid Usage (Implicit)

  • VUID-vkBeginCommandBuffer-commandBuffer-parameter
    commandBuffer must be a valid VkCommandBuffer handle

  • VUID-vkBeginCommandBuffer-pBeginInfo-parameter
    pBeginInfo must be a valid pointer to a valid VkCommandBufferBeginInfo structure

Host Synchronization

  • Host access to commandBuffer must be externally synchronized

  • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

The VkCommandBufferBeginInfo structure is defined as:

// Provided by VK_VERSION_1_0
typedef struct VkCommandBufferBeginInfo {
    VkStructureType                          sType;
    const void*                              pNext;
    VkCommandBufferUsageFlags                flags;
    const VkCommandBufferInheritanceInfo*    pInheritanceInfo;
} VkCommandBufferBeginInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • flags is a bitmask of VkCommandBufferUsageFlagBits specifying usage behavior for the command buffer.

  • pInheritanceInfo is a pointer to a VkCommandBufferInheritanceInfo structure, used if commandBuffer is a secondary command buffer. If this is a primary command buffer, then this value is ignored.

Valid Usage

  • VUID-VkCommandBufferBeginInfo-flags-00055
    If flags contains VK_COMMAND_BUFFER_USAGE_RENDER_PASS_CONTINUE_BIT, the framebuffer member of pInheritanceInfo must be either VK_NULL_HANDLE, or a valid VkFramebuffer that is compatible with the renderPass member of pInheritanceInfo

  • VUID-VkCommandBufferBeginInfo-flags-06000
    If flags contains VK_COMMAND_BUFFER_USAGE_RENDER_PASS_CONTINUE_BIT and the renderPass member of pInheritanceInfo is not VK_NULL_HANDLE, renderPass must be a valid VkRenderPass

  • VUID-VkCommandBufferBeginInfo-flags-06001
    If flags contains VK_COMMAND_BUFFER_USAGE_RENDER_PASS_CONTINUE_BIT and the renderPass member of pInheritanceInfo is not VK_NULL_HANDLE, the subpass member of pInheritanceInfo must be a valid subpass index within the renderPass member of pInheritanceInfo

  • VUID-VkCommandBufferBeginInfo-flags-06002
    If flags contains VK_COMMAND_BUFFER_USAGE_RENDER_PASS_CONTINUE_BIT and the renderPass member of pInheritanceInfo is VK_NULL_HANDLE, the pNext chain of pInheritanceInfo must include a VkCommandBufferInheritanceRenderingInfo structure

Valid Usage (Implicit)

  • VUID-VkCommandBufferBeginInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_COMMAND_BUFFER_BEGIN_INFO

  • VUID-VkCommandBufferBeginInfo-pNext-pNext
    pNext must be NULL or a pointer to a valid instance of VkDeviceGroupCommandBufferBeginInfo

  • VUID-VkCommandBufferBeginInfo-sType-unique
    The sType value of each struct in the pNext chain must be unique

  • VUID-VkCommandBufferBeginInfo-flags-parameter
    flags must be a valid combination of VkCommandBufferUsageFlagBits values

Bits which can be set in VkCommandBufferBeginInfo::flags, specifying usage behavior for a command buffer, are:

// Provided by VK_VERSION_1_0
typedef enum VkCommandBufferUsageFlagBits {
    VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT = 0x00000001,
    VK_COMMAND_BUFFER_USAGE_RENDER_PASS_CONTINUE_BIT = 0x00000002,
    VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT = 0x00000004,
} VkCommandBufferUsageFlagBits;

  • VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT specifies that each recording of the command buffer will only be submitted once, and the command buffer will be reset and recorded again between each submission.

  • VK_COMMAND_BUFFER_USAGE_RENDER_PASS_CONTINUE_BIT specifies that a secondary command buffer is considered to be entirely inside a render pass. If this is a primary command buffer, then this bit is ignored.

  • VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT specifies that a command buffer can be resubmitted to a queue while it is in the pending state, and recorded into multiple primary command buffers.

// Provided by VK_VERSION_1_0
typedef VkFlags VkCommandBufferUsageFlags;

VkCommandBufferUsageFlags is a bitmask type for setting a mask of zero or more VkCommandBufferUsageFlagBits.

If the command buffer is a secondary command buffer, then the VkCommandBufferInheritanceInfo structure defines any state that will be inherited from the primary command buffer:

// Provided by VK_VERSION_1_0
typedef struct VkCommandBufferInheritanceInfo {
    VkStructureType                  sType;
    const void*                      pNext;
    VkRenderPass                     renderPass;
    uint32_t                         subpass;
    VkFramebuffer                    framebuffer;
    VkBool32                         occlusionQueryEnable;
    VkQueryControlFlags              queryFlags;
    VkQueryPipelineStatisticFlags    pipelineStatistics;
} VkCommandBufferInheritanceInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • renderPass is a VkRenderPass object defining which render passes the VkCommandBuffer will be compatible with and can be executed within.

  • subpass is the index of the subpass within the render pass instance that the VkCommandBuffer will be executed within.

  • framebuffer can refer to the VkFramebuffer object that the VkCommandBuffer will be rendering to if it is executed within a render pass instance. It can be VK_NULL_HANDLE if the framebuffer is not known.

    Note

    Specifying the exact framebuffer that the secondary command buffer will be executed with may result in better performance at command buffer execution time.

  • occlusionQueryEnable specifies whether the command buffer can be executed while an occlusion query is active in the primary command buffer. If this is VK_TRUE, then this command buffer can be executed whether the primary command buffer has an occlusion query active or not. If this is VK_FALSE, then the primary command buffer must not have an occlusion query active.

  • queryFlags specifies the query flags that can be used by an active occlusion query in the primary command buffer when this secondary command buffer is executed. If this value includes the VK_QUERY_CONTROL_PRECISE_BIT bit, then the active query can return boolean results or actual sample counts. If this bit is not set, then the active query must not use the VK_QUERY_CONTROL_PRECISE_BIT bit.

  • pipelineStatistics is a bitmask of VkQueryPipelineStatisticFlagBits specifying the set of pipeline statistics that can be counted by an active query in the primary command buffer when this secondary command buffer is executed. If this value includes a given bit, then this command buffer can be executed whether the primary command buffer has a pipeline statistics query active that includes this bit or not. If this value excludes a given bit, then the active pipeline statistics query must not be from a query pool that counts that statistic.

If the VkCommandBuffer will not be executed within a render pass instance, or if the render pass instance was begun with vkCmdBeginRendering, renderPass, subpass, and framebuffer are ignored.

Valid Usage

  • VUID-VkCommandBufferInheritanceInfo-occlusionQueryEnable-00056
    If the inheritedQueries feature is not enabled, occlusionQueryEnable must be VK_FALSE

  • VUID-VkCommandBufferInheritanceInfo-queryFlags-00057
    If the inheritedQueries feature is enabled, queryFlags must be a valid combination of VkQueryControlFlagBits values

  • VUID-VkCommandBufferInheritanceInfo-queryFlags-02788
    If the inheritedQueries feature is not enabled, queryFlags must be 0

  • VUID-VkCommandBufferInheritanceInfo-pipelineStatistics-02789
    If the pipelineStatisticsQuery feature is enabled, pipelineStatistics must be a valid combination of VkQueryPipelineStatisticFlagBits values

  • VUID-VkCommandBufferInheritanceInfo-pipelineStatistics-00058
    If the pipelineStatisticsQuery feature is not enabled, pipelineStatistics must be 0

Valid Usage (Implicit)

  • VUID-VkCommandBufferInheritanceInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_COMMAND_BUFFER_INHERITANCE_INFO

  • VUID-VkCommandBufferInheritanceInfo-pNext-pNext
    pNext must be NULL or a pointer to a valid instance of VkCommandBufferInheritanceRenderingInfo

  • VUID-VkCommandBufferInheritanceInfo-sType-unique
    The sType value of each struct in the pNext chain must be unique

  • VUID-VkCommandBufferInheritanceInfo-commonparent
    Both of framebuffer, and renderPass that are valid handles of non-ignored parameters must have been created, allocated, or retrieved from the same VkDevice

Note

On some implementations, not using the VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT bit enables command buffers to be patched in-place if needed, rather than creating a copy of the command buffer.

If a command buffer is in the invalid, or executable state, and the command buffer was allocated from a command pool with the VK_COMMAND_POOL_CREATE_RESET_COMMAND_BUFFER_BIT flag set, then vkBeginCommandBuffer implicitly resets the command buffer, behaving as if vkResetCommandBuffer had been called with VK_COMMAND_BUFFER_RESET_RELEASE_RESOURCES_BIT not set. After the implicit reset, commandBuffer is moved to the recording state.

The VkCommandBufferInheritanceRenderingInfo structure is defined as:

// Provided by VK_VERSION_1_3
typedef struct VkCommandBufferInheritanceRenderingInfo {
    VkStructureType          sType;
    const void*              pNext;
    VkRenderingFlags         flags;
    uint32_t                 viewMask;
    uint32_t                 colorAttachmentCount;
    const VkFormat*          pColorAttachmentFormats;
    VkFormat                 depthAttachmentFormat;
    VkFormat                 stencilAttachmentFormat;
    VkSampleCountFlagBits    rasterizationSamples;
} VkCommandBufferInheritanceRenderingInfo;

  • sType is the type of this structure

  • pNext is NULL or a pointer to a structure extending this structure

  • flags is a bitmask of VkRenderingFlagBits used by the render pass instance.

  • viewMask is the view mask used for rendering.

  • colorAttachmentCount is the number of color attachments specified in the render pass instance.

  • pColorAttachmentFormats is a pointer to an array of VkFormat values defining the format of color attachments.

  • depthAttachmentFormat is a VkFormat value defining the format of the depth attachment.

  • stencilAttachmentFormat is a VkFormat value defining the format of the stencil attachment.

  • rasterizationSamples is a VkSampleCountFlagBits specifying the number of samples used in rasterization.

If the pNext chain of VkCommandBufferInheritanceInfo includes a VkCommandBufferInheritanceRenderingInfo structure, then that structure controls parameters of dynamic render pass instances that the VkCommandBuffer can be executed within. If VkCommandBufferInheritanceInfo::renderPass is not VK_NULL_HANDLE, or VK_COMMAND_BUFFER_USAGE_RENDER_PASS_CONTINUE_BIT is not specified in VkCommandBufferBeginInfo::flags, parameters of this structure are ignored.

If colorAttachmentCount is 0 and the variableMultisampleRate feature is enabled, rasterizationSamples is ignored.

If depthAttachmentFormat, stencilAttachmentFormat, or any element of pColorAttachmentFormats is VK_FORMAT_UNDEFINED, it indicates that the corresponding attachment is unused within the render pass.

Valid Usage

  • VUID-VkCommandBufferInheritanceRenderingInfo-colorAttachmentCount-06004
    If colorAttachmentCount is not 0, rasterizationSamples must be a valid VkSampleCountFlagBits value

  • VUID-VkCommandBufferInheritanceRenderingInfo-variableMultisampleRate-06005
    If the variableMultisampleRate feature is not enabled, rasterizationSamples must be a valid VkSampleCountFlagBits value

  • VUID-VkCommandBufferInheritanceRenderingInfo-pColorAttachmentFormats-06006
    If any element of pColorAttachmentFormats is not VK_FORMAT_UNDEFINED, it must be a format with potential format features that include VK_FORMAT_FEATURE_COLOR_ATTACHMENT_BIT

  • VUID-VkCommandBufferInheritanceRenderingInfo-depthAttachmentFormat-06540
    If depthAttachmentFormat is not VK_FORMAT_UNDEFINED, it must be a format that includes a depth component

  • VUID-VkCommandBufferInheritanceRenderingInfo-depthAttachmentFormat-06007
    If depthAttachmentFormat is not VK_FORMAT_UNDEFINED, it must be a format with potential format features that include VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT

  • VUID-VkCommandBufferInheritanceRenderingInfo-stencilAttachmentFormat-06541
    If stencilAttachmentFormat is not VK_FORMAT_UNDEFINED, it must be a format that includes a stencil aspect

  • VUID-VkCommandBufferInheritanceRenderingInfo-stencilAttachmentFormat-06199
    If stencilAttachmentFormat is not VK_FORMAT_UNDEFINED, it must be a format with potential format features that include VK_FORMAT_FEATURE_DEPTH_STENCIL_ATTACHMENT_BIT

  • VUID-VkCommandBufferInheritanceRenderingInfo-depthAttachmentFormat-06200
    If depthAttachmentFormat is not VK_FORMAT_UNDEFINED and stencilAttachmentFormat is not VK_FORMAT_UNDEFINED, depthAttachmentFormat must equal stencilAttachmentFormat

  • VUID-VkCommandBufferInheritanceRenderingInfo-multiview-06008
    If the multiview feature is not enabled, viewMask must be 0

  • VUID-VkCommandBufferInheritanceRenderingInfo-viewMask-06009
    The index of the most significant bit in viewMask must be less than maxMultiviewViewCount

Valid Usage (Implicit)

  • VUID-VkCommandBufferInheritanceRenderingInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_COMMAND_BUFFER_INHERITANCE_RENDERING_INFO

  • VUID-VkCommandBufferInheritanceRenderingInfo-flags-parameter
    flags must be a valid combination of VkRenderingFlagBits values

  • VUID-VkCommandBufferInheritanceRenderingInfo-pColorAttachmentFormats-parameter
    If colorAttachmentCount is not 0, pColorAttachmentFormats must be a valid pointer to an array of colorAttachmentCount valid VkFormat values

  • VUID-VkCommandBufferInheritanceRenderingInfo-depthAttachmentFormat-parameter
    depthAttachmentFormat must be a valid VkFormat value

  • VUID-VkCommandBufferInheritanceRenderingInfo-stencilAttachmentFormat-parameter
    stencilAttachmentFormat must be a valid VkFormat value

  • VUID-VkCommandBufferInheritanceRenderingInfo-rasterizationSamples-parameter
    If rasterizationSamples is not 0, rasterizationSamples must be a valid VkSampleCountFlagBits value

Once recording starts, an application records a sequence of commands (vkCmd*) to set state in the command buffer, draw, dispatch, and other commands.

To complete recording of a command buffer, call:

// Provided by VK_VERSION_1_0
VkResult vkEndCommandBuffer(
    VkCommandBuffer                             commandBuffer);

  • commandBuffer is the command buffer to complete recording.

If there was an error during recording, the application will be notified by an unsuccessful return code returned by vkEndCommandBuffer. If the application wishes to further use the command buffer, the command buffer must be reset.

The command buffer must have been in the recording state, and is moved to the executable state.

Valid Usage

  • VUID-vkEndCommandBuffer-commandBuffer-00059
    commandBuffer must be in the recording state

  • VUID-vkEndCommandBuffer-commandBuffer-00060
    If commandBuffer is a primary command buffer, there must not be an active render pass instance

  • VUID-vkEndCommandBuffer-commandBuffer-00061
    All queries made active during the recording of commandBuffer must have been made inactive

Valid Usage (Implicit)

  • VUID-vkEndCommandBuffer-commandBuffer-parameter
    commandBuffer must be a valid VkCommandBuffer handle

Host Synchronization

  • Host access to commandBuffer must be externally synchronized

  • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

When a command buffer is in the executable state, it can be submitted to a queue for execution.

6.5. Command Buffer Submission

Note

Submission can be a high overhead operation, and applications should attempt to batch work together into as few calls to vkQueueSubmit or vkQueueSubmit2 as possible.

To submit command buffers to a queue, call:

// Provided by VK_VERSION_1_3
VkResult vkQueueSubmit2(
    VkQueue                                     queue,
    uint32_t                                    submitCount,
    const VkSubmitInfo2*                        pSubmits,
    VkFence                                     fence);

  • queue is the queue that the command buffers will be submitted to.

  • submitCount is the number of elements in the pSubmits array.

  • pSubmits is a pointer to an array of VkSubmitInfo2 structures, each specifying a command buffer submission batch.

  • fence is an optional handle to a fence to be signaled once all submitted command buffers have completed execution. If fence is not VK_NULL_HANDLE, it defines a fence signal operation.

vkQueueSubmit2 is a queue submission command, with each batch defined by an element of pSubmits.

Semaphore operations submitted with vkQueueSubmit2 have additional ordering constraints compared to other submission commands, with dependencies involving previous and subsequent queue operations. Information about these additional constraints can be found in the semaphore section of the synchronization chapter.

If any command buffer submitted to this queue is in the executable state, it is moved to the pending state. Once execution of all submissions of a command buffer complete, it moves from the pending state, back to the executable state. If a command buffer was recorded with the VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT flag, it instead moves back to the invalid state.

If vkQueueSubmit2 fails, it may return VK_ERROR_OUT_OF_HOST_MEMORY or VK_ERROR_OUT_OF_DEVICE_MEMORY. If it does, the implementation must ensure that the state and contents of any resources or synchronization primitives referenced by the submitted command buffers and any semaphores referenced by pSubmits is unaffected by the call or its failure. If vkQueueSubmit2 fails in such a way that the implementation is unable to make that guarantee, the implementation must return VK_ERROR_DEVICE_LOST. See Lost Device.

Valid Usage

  • VUID-vkQueueSubmit2-fence-04894
    If fence is not VK_NULL_HANDLE, fence must be unsignaled

  • VUID-vkQueueSubmit2-fence-04895
    If fence is not VK_NULL_HANDLE, fence must not be associated with any other queue command that has not yet completed execution on that queue

  • VUID-vkQueueSubmit2-synchronization2-03866
    The synchronization2 feature must be enabled

  • VUID-vkQueueSubmit2-commandBuffer-03867
    If a command recorded into the commandBuffer member of any element of the pCommandBufferInfos member of any element of pSubmits referenced an VkEvent, that event must not be referenced by a command that has been submitted to another queue and is still in the pending state

  • VUID-vkQueueSubmit2-semaphore-03868
    The semaphore member of any binary semaphore element of the pSignalSemaphoreInfos member of any element of pSubmits must be unsignaled when the semaphore signal operation it defines is executed on the device

  • VUID-vkQueueSubmit2-stageMask-03869
    The stageMask member of any element of the pSignalSemaphoreInfos member of any element of pSubmits must only include pipeline stages that are supported by the queue family which queue belongs to

  • VUID-vkQueueSubmit2-stageMask-03870
    The stageMask member of any element of the pWaitSemaphoreInfos member of any element of pSubmits must only include pipeline stages that are supported by the queue family which queue belongs to

  • VUID-vkQueueSubmit2-semaphore-03871
    When a semaphore wait operation for a binary semaphore is executed, as defined by the semaphore member of any element of the pWaitSemaphoreInfos member of any element of pSubmits, there must be no other queues waiting on the same semaphore

  • VUID-vkQueueSubmit2-semaphore-03872
    The semaphore member of any element of the pWaitSemaphoreInfos member of any element of pSubmits must be semaphores that are signaled, or have semaphore signal operations previously submitted for execution

  • VUID-vkQueueSubmit2-commandBuffer-03874
    The commandBuffer member of any element of the pCommandBufferInfos member of any element of pSubmits must be in the pending or executable state

  • VUID-vkQueueSubmit2-commandBuffer-03875
    If a command recorded into the commandBuffer member of any element of the pCommandBufferInfos member of any element of pSubmits was not recorded with the VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT, it must not be in the pending state

  • VUID-vkQueueSubmit2-commandBuffer-03876
    Any secondary command buffers recorded into the commandBuffer member of any element of the pCommandBufferInfos member of any element of pSubmits must be in the pending or executable state

  • VUID-vkQueueSubmit2-commandBuffer-03877
    If any secondary command buffers recorded into the commandBuffer member of any element of the pCommandBufferInfos member of any element of pSubmits was not recorded with the VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT, it must not be in the pending state

  • VUID-vkQueueSubmit2-commandBuffer-03878
    The commandBuffer member of any element of the pCommandBufferInfos member of any element of pSubmits must have been allocated from a VkCommandPool that was created for the same queue family queue belongs to

  • VUID-vkQueueSubmit2-commandBuffer-03879
    If a command recorded into the commandBuffer member of any element of the pCommandBufferInfos member of any element of pSubmits includes a Queue Family Transfer Acquire Operation, there must exist a previously submitted Queue Family Transfer Release Operation on a queue in the queue family identified by the acquire operation, with parameters matching the acquire operation as defined in the definition of such acquire operations, and which happens before the acquire operation

  • VUID-vkQueueSubmit2-queue-06447
    If queue was not created with VK_DEVICE_QUEUE_CREATE_PROTECTED_BIT, the flags member of any element of pSubmits must not include VK_SUBMIT_PROTECTED_BIT_KHR

Valid Usage (Implicit)

  • VUID-vkQueueSubmit2-queue-parameter
    queue must be a valid VkQueue handle

  • VUID-vkQueueSubmit2-pSubmits-parameter
    If submitCount is not 0, pSubmits must be a valid pointer to an array of submitCount valid VkSubmitInfo2 structures

  • VUID-vkQueueSubmit2-fence-parameter
    If fence is not VK_NULL_HANDLE, fence must be a valid VkFence handle

  • VUID-vkQueueSubmit2-commonparent
    Both of fence, and queue that are valid handles of non-ignored parameters must have been created, allocated, or retrieved from the same VkDevice

Host Synchronization

  • Host access to queue must be externally synchronized

  • Host access to fence must be externally synchronized

Command Properties
Command Buffer Levels Render Pass Scope Supported Queue Types Command Type
Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

  • VK_ERROR_DEVICE_LOST

The VkSubmitInfo2 structure is defined as:

// Provided by VK_VERSION_1_3
typedef struct VkSubmitInfo2 {
    VkStructureType                     sType;
    const void*                         pNext;
    VkSubmitFlags                       flags;
    uint32_t                            waitSemaphoreInfoCount;
    const VkSemaphoreSubmitInfo*        pWaitSemaphoreInfos;
    uint32_t                            commandBufferInfoCount;
    const VkCommandBufferSubmitInfo*    pCommandBufferInfos;
    uint32_t                            signalSemaphoreInfoCount;
    const VkSemaphoreSubmitInfo*        pSignalSemaphoreInfos;
} VkSubmitInfo2;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • flags is a bitmask of VkSubmitFlagBits.

  • waitSemaphoreInfoCount is the number of elements in pWaitSemaphoreInfos.

  • pWaitSemaphoreInfos is a pointer to an array of VkSemaphoreSubmitInfo structures defining semaphore wait operations.

  • commandBufferInfoCount is the number of elements in pCommandBufferInfos and the number of command buffers to execute in the batch.

  • pCommandBufferInfos is a pointer to an array of VkCommandBufferSubmitInfo structures describing command buffers to execute in the batch.

  • signalSemaphoreInfoCount is the number of elements in pSignalSemaphoreInfos.

  • pSignalSemaphoreInfos is a pointer to an array of VkSemaphoreSubmitInfo describing semaphore signal operations.

Valid Usage

  • VUID-VkSubmitInfo2-flags-03886
    If flags includes VK_SUBMIT_PROTECTED_BIT, all elements of pCommandBuffers must be protected command buffers

  • VUID-VkSubmitInfo2-flags-03887
    If flags does not include VK_SUBMIT_PROTECTED_BIT, each element of pCommandBuffers must not be a protected command buffer

  • VUID-VkSubmitInfo2KHR-commandBuffer-06192
    If any commandBuffer member of an element of pCommandBufferInfos contains any resumed render pass instances, they must be suspended by a render pass instance earlier in submission order within pCommandBufferInfos

  • VUID-VkSubmitInfo2KHR-commandBuffer-06010
    If any commandBuffer member of an element of pCommandBufferInfos contains any suspended render pass instances, they must be resumed by a render pass instance later in submission order within pCommandBufferInfos

  • VUID-VkSubmitInfo2KHR-commandBuffer-06011
    If any commandBuffer member of an element of pCommandBufferInfos contains any suspended render pass instances, there must be no action or synchronization commands between that render pass instance and the render pass instance that resumes it

  • VUID-VkSubmitInfo2KHR-commandBuffer-06012
    If any commandBuffer member of an element of pCommandBufferInfos contains any suspended render pass instances, there must be no render pass instances between that render pass instance and the render pass instance that resumes it

Valid Usage (Implicit)

  • VUID-VkSubmitInfo2-sType-sType
    sType must be VK_STRUCTURE_TYPE_SUBMIT_INFO_2

  • VUID-VkSubmitInfo2-pNext-pNext
    pNext must be NULL

  • VUID-VkSubmitInfo2-flags-parameter
    flags must be a valid combination of VkSubmitFlagBits values

  • VUID-VkSubmitInfo2-pWaitSemaphoreInfos-parameter
    If waitSemaphoreInfoCount is not 0, pWaitSemaphoreInfos must be a valid pointer to an array of waitSemaphoreInfoCount valid VkSemaphoreSubmitInfo structures

  • VUID-VkSubmitInfo2-pCommandBufferInfos-parameter
    If commandBufferInfoCount is not 0, pCommandBufferInfos must be a valid pointer to an array of commandBufferInfoCount valid VkCommandBufferSubmitInfo structures

  • VUID-VkSubmitInfo2-pSignalSemaphoreInfos-parameter
    If signalSemaphoreInfoCount is not 0, pSignalSemaphoreInfos must be a valid pointer to an array of signalSemaphoreInfoCount valid VkSemaphoreSubmitInfo structures

Bits which can be set in VkSubmitInfo2::flags, specifying submission behavior, are:

// Provided by VK_VERSION_1_3
typedef enum VkSubmitFlagBits {
    VK_SUBMIT_PROTECTED_BIT = 0x00000001,
    VK_SUBMIT_PROTECTED_BIT_KHR = VK_SUBMIT_PROTECTED_BIT,
} VkSubmitFlagBits;

  • VK_SUBMIT_PROTECTED_BIT specifies that this batch is a protected submission.

// Provided by VK_VERSION_1_3
typedef VkFlags VkSubmitFlags;

VkSubmitFlags is a bitmask type for setting a mask of zero or more VkSubmitFlagBits.

The VkSemaphoreSubmitInfo structure is defined as:

// Provided by VK_VERSION_1_3
typedef struct VkSemaphoreSubmitInfo {
    VkStructureType          sType;
    const void*              pNext;
    VkSemaphore              semaphore;
    uint64_t                 value;
    VkPipelineStageFlags2    stageMask;
    uint32_t                 deviceIndex;
} VkSemaphoreSubmitInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • semaphore is a VkSemaphore affected by this operation.

  • value is ignored.

  • stageMask is a VkPipelineStageFlags2 mask of pipeline stages which limit the first synchronization scope of a semaphore signal operation, or second synchronization scope of a semaphore wait operation as described in the semaphore wait operation and semaphore signal operation sections of the synchronization chapter.

  • deviceIndex is the index of the device within a device group that executes the semaphore wait or signal operation.

Whether this structure defines a semaphore wait or signal operation is defined by how it is used.

Valid Usage

  • VUID-VkSemaphoreSubmitInfo-stageMask-03929
    If the geometryShader feature is not enabled, stageMask must not contain VK_PIPELINE_STAGE_2_GEOMETRY_SHADER_BIT

  • VUID-VkSemaphoreSubmitInfo-stageMask-03930
    If the tessellationShader feature is not enabled, stageMask must not contain VK_PIPELINE_STAGE_2_TESSELLATION_CONTROL_SHADER_BIT or VK_PIPELINE_STAGE_2_TESSELLATION_EVALUATION_SHADER_BIT

  • VUID-VkSemaphoreSubmitInfo-device-03888
    If the device that semaphore was created on is not a device group, deviceIndex must be 0

  • VUID-VkSemaphoreSubmitInfo-device-03889
    If the device that semaphore was created on is a device group, deviceIndex must be a valid device index

Valid Usage (Implicit)

  • VUID-VkSemaphoreSubmitInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_SEMAPHORE_SUBMIT_INFO

  • VUID-VkSemaphoreSubmitInfo-pNext-pNext
    pNext must be NULL

  • VUID-VkSemaphoreSubmitInfo-semaphore-parameter
    semaphore must be a valid VkSemaphore handle

  • VUID-VkSemaphoreSubmitInfo-stageMask-parameter
    stageMask must be a valid combination of VkPipelineStageFlagBits2 values

The VkCommandBufferSubmitInfo structure is defined as:

// Provided by VK_VERSION_1_3
typedef struct VkCommandBufferSubmitInfo {
    VkStructureType    sType;
    const void*        pNext;
    VkCommandBuffer    commandBuffer;
    uint32_t           deviceMask;
} VkCommandBufferSubmitInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • commandBuffer is a VkCommandBuffer to be submitted for execution.

  • deviceMask is a bitmask indicating which devices in a device group execute the command buffer. A deviceMask of 0 is equivalent to setting all bits corresponding to valid devices in the group to 1.

Valid Usage

  • VUID-VkCommandBufferSubmitInfo-commandBuffer-03890
    commandBuffer must not have been allocated with VK_COMMAND_BUFFER_LEVEL_SECONDARY

  • VUID-VkCommandBufferSubmitInfo-deviceMask-03891
    If deviceMask is not 0, it must be a valid device mask

Valid Usage (Implicit)

  • VUID-VkCommandBufferSubmitInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_COMMAND_BUFFER_SUBMIT_INFO

  • VUID-VkCommandBufferSubmitInfo-pNext-pNext
    pNext must be NULL

  • VUID-VkCommandBufferSubmitInfo-commandBuffer-parameter
    commandBuffer must be a valid VkCommandBuffer handle

To submit command buffers to a queue, call:

// Provided by VK_VERSION_1_0
VkResult vkQueueSubmit(
    VkQueue                                     queue,
    uint32_t                                    submitCount,
    const VkSubmitInfo*                         pSubmits,
    VkFence                                     fence);

  • queue is the queue that the command buffers will be submitted to.

  • submitCount is the number of elements in the pSubmits array.

  • pSubmits is a pointer to an array of VkSubmitInfo structures, each specifying a command buffer submission batch.

  • fence is an optional handle to a fence to be signaled once all submitted command buffers have completed execution. If fence is not VK_NULL_HANDLE, it defines a fence signal operation.

vkQueueSubmit is a queue submission command, with each batch defined by an element of pSubmits. Batches begin execution in the order they appear in pSubmits, but may complete out of order.

Fence and semaphore operations submitted with vkQueueSubmit have additional ordering constraints compared to other submission commands, with dependencies involving previous and subsequent queue operations. Information about these additional constraints can be found in the semaphore and fence sections of the synchronization chapter.

Details on the interaction of pWaitDstStageMask with synchronization are described in the semaphore wait operation section of the synchronization chapter.

The order that batches appear in pSubmits is used to determine submission order, and thus all the implicit ordering guarantees that respect it. Other than these implicit ordering guarantees and any explicit synchronization primitives, these batches may overlap or otherwise execute out of order.

If any command buffer submitted to this queue is in the executable state, it is moved to the pending state. Once execution of all submissions of a command buffer complete, it moves from the pending state, back to the executable state. If a command buffer was recorded with the VK_COMMAND_BUFFER_USAGE_ONE_TIME_SUBMIT_BIT flag, it instead moves to the invalid state.

If vkQueueSubmit fails, it may return VK_ERROR_OUT_OF_HOST_MEMORY or VK_ERROR_OUT_OF_DEVICE_MEMORY. If it does, the implementation must ensure that the state and contents of any resources or synchronization primitives referenced by the submitted command buffers and any semaphores referenced by pSubmits is unaffected by the call or its failure. If vkQueueSubmit fails in such a way that the implementation is unable to make that guarantee, the implementation must return VK_ERROR_DEVICE_LOST. See Lost Device.

Valid Usage

  • VUID-vkQueueSubmit-fence-00063
    If fence is not VK_NULL_HANDLE, fence must be unsignaled

  • VUID-vkQueueSubmit-fence-00064
    If fence is not VK_NULL_HANDLE, fence must not be associated with any other queue command that has not yet completed execution on that queue

  • VUID-vkQueueSubmit-pCommandBuffers-00065
    Any calls to vkCmdSetEvent, vkCmdResetEvent or vkCmdWaitEvents that have been recorded into any of the command buffer elements of the pCommandBuffers member of any element of pSubmits, must not reference any VkEvent that is referenced by any of those commands in a command buffer that has been submitted to another queue and is still in the pending state

  • VUID-vkQueueSubmit-pWaitDstStageMask-00066
    Any stage flag included in any element of the pWaitDstStageMask member of any element of pSubmits must be a pipeline stage supported by one of the capabilities of queue, as specified in the table of supported pipeline stages

  • VUID-vkQueueSubmit-pSignalSemaphores-00067
    Each binary semaphore element of the pSignalSemaphores member of any element of pSubmits must be unsignaled when the semaphore signal operation it defines is executed on the device

  • VUID-vkQueueSubmit-pWaitSemaphores-00068
    When a semaphore wait operation referring to a binary semaphore defined by any element of the pWaitSemaphores member of any element of pSubmits executes on queue, there must be no other queues waiting on the same semaphore

  • VUID-vkQueueSubmit-pWaitSemaphores-00069
    All elements of the pWaitSemaphores member of all elements of pSubmits must be semaphores that are signaled, or have semaphore signal operations previously submitted for execution

  • VUID-vkQueueSubmit-pWaitSemaphores-03238
    All elements of the pWaitSemaphores member of all elements of pSubmits created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_BINARY must reference a semaphore signal operation that has been submitted for execution and any semaphore signal operations on which it depends (if any) must have also been submitted for execution

  • VUID-vkQueueSubmit-pCommandBuffers-00070
    Each element of the pCommandBuffers member of each element of pSubmits must be in the pending or executable state

  • VUID-vkQueueSubmit-pCommandBuffers-00071
    If any element of the pCommandBuffers member of any element of pSubmits was not recorded with the VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT, it must not be in the pending state

  • VUID-vkQueueSubmit-pCommandBuffers-00072
    Any secondary command buffers recorded into any element of the pCommandBuffers member of any element of pSubmits must be in the pending or executable state

  • VUID-vkQueueSubmit-pCommandBuffers-00073
    If any secondary command buffers recorded into any element of the pCommandBuffers member of any element of pSubmits was not recorded with the VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT, it must not be in the pending state

  • VUID-vkQueueSubmit-pCommandBuffers-00074
    Each element of the pCommandBuffers member of each element of pSubmits must have been allocated from a VkCommandPool that was created for the same queue family queue belongs to

  • VUID-vkQueueSubmit-pSubmits-02207
    If any element of pSubmits->pCommandBuffers includes a Queue Family Transfer Acquire Operation, there must exist a previously submitted Queue Family Transfer Release Operation on a queue in the queue family identified by the acquire operation, with parameters matching the acquire operation as defined in the definition of such acquire operations, and which happens-before the acquire operation

  • VUID-vkQueueSubmit-pSubmits-02808
    Any resource created with VK_SHARING_MODE_EXCLUSIVE that is read by an operation specified by pSubmits must not be owned by any queue family other than the one which queue belongs to, at the time it is executed

  • VUID-vkQueueSubmit-pSubmits-04626
    Any resource created with VK_SHARING_MODE_CONCURRENT that is accessed by an operation specified by pSubmits must have included the queue family of queue at resource creation time

  • VUID-vkQueueSubmit-queue-06448
    If queue was not created with VK_DEVICE_QUEUE_CREATE_PROTECTED_BIT, there must be no element of pSubmits that includes an VkProtectedSubmitInfo structure in its pNext chain with protectedSubmit equal to VK_TRUE

Valid Usage (Implicit)

  • VUID-vkQueueSubmit-queue-parameter
    queue must be a valid VkQueue handle

  • VUID-vkQueueSubmit-pSubmits-parameter
    If submitCount is not 0, pSubmits must be a valid pointer to an array of submitCount valid VkSubmitInfo structures

  • VUID-vkQueueSubmit-fence-parameter
    If fence is not VK_NULL_HANDLE, fence must be a valid VkFence handle

  • VUID-vkQueueSubmit-commonparent
    Both of fence, and queue that are valid handles of non-ignored parameters must have been created, allocated, or retrieved from the same VkDevice

Host Synchronization

  • Host access to queue must be externally synchronized

  • Host access to fence must be externally synchronized

Command Properties
Command Buffer Levels Render Pass Scope Supported Queue Types Command Type
Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

  • VK_ERROR_DEVICE_LOST

The VkSubmitInfo structure is defined as:

// Provided by VK_VERSION_1_0
typedef struct VkSubmitInfo {
    VkStructureType                sType;
    const void*                    pNext;
    uint32_t                       waitSemaphoreCount;
    const VkSemaphore*             pWaitSemaphores;
    const VkPipelineStageFlags*    pWaitDstStageMask;
    uint32_t                       commandBufferCount;
    const VkCommandBuffer*         pCommandBuffers;
    uint32_t                       signalSemaphoreCount;
    const VkSemaphore*             pSignalSemaphores;
} VkSubmitInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • waitSemaphoreCount is the number of semaphores upon which to wait before executing the command buffers for the batch.

  • pWaitSemaphores is a pointer to an array of VkSemaphore handles upon which to wait before the command buffers for this batch begin execution. If semaphores to wait on are provided, they define a semaphore wait operation.

  • pWaitDstStageMask is a pointer to an array of pipeline stages at which each corresponding semaphore wait will occur.

  • commandBufferCount is the number of command buffers to execute in the batch.

  • pCommandBuffers is a pointer to an array of VkCommandBuffer handles to execute in the batch.

  • signalSemaphoreCount is the number of semaphores to be signaled once the commands specified in pCommandBuffers have completed execution.

  • pSignalSemaphores is a pointer to an array of VkSemaphore handles which will be signaled when the command buffers for this batch have completed execution. If semaphores to be signaled are provided, they define a semaphore signal operation.

The order that command buffers appear in pCommandBuffers is used to determine submission order, and thus all the implicit ordering guarantees that respect it. Other than these implicit ordering guarantees and any explicit synchronization primitives, these command buffers may overlap or otherwise execute out of order.

Valid Usage

  • VUID-VkSubmitInfo-pWaitDstStageMask-04090
    If the geometryShader feature is not enabled, pWaitDstStageMask must not contain VK_PIPELINE_STAGE_GEOMETRY_SHADER_BIT

  • VUID-VkSubmitInfo-pWaitDstStageMask-04091
    If the tessellationShader feature is not enabled, pWaitDstStageMask must not contain VK_PIPELINE_STAGE_TESSELLATION_CONTROL_SHADER_BIT or VK_PIPELINE_STAGE_TESSELLATION_EVALUATION_SHADER_BIT

  • VUID-VkSubmitInfo-pWaitDstStageMask-03937
    If the synchronization2 feature is not enabled, pWaitDstStageMask must not be 0

  • VUID-VkSubmitInfo-pCommandBuffers-00075
    Each element of pCommandBuffers must not have been allocated with VK_COMMAND_BUFFER_LEVEL_SECONDARY

  • VUID-VkSubmitInfo-pWaitDstStageMask-00078
    Each element of pWaitDstStageMask must not include VK_PIPELINE_STAGE_HOST_BIT

  • VUID-VkSubmitInfo-pWaitSemaphores-03239
    If any element of pWaitSemaphores or pSignalSemaphores was created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE, then the pNext chain must include a VkTimelineSemaphoreSubmitInfo structure

  • VUID-VkSubmitInfo-pNext-03240
    If the pNext chain of this structure includes a VkTimelineSemaphoreSubmitInfo structure and any element of pWaitSemaphores was created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE, then its waitSemaphoreValueCount member must equal waitSemaphoreCount

  • VUID-VkSubmitInfo-pNext-03241
    If the pNext chain of this structure includes a VkTimelineSemaphoreSubmitInfo structure and any element of pSignalSemaphores was created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE, then its signalSemaphoreValueCount member must equal signalSemaphoreCount

  • VUID-VkSubmitInfo-pSignalSemaphores-03242
    For each element of pSignalSemaphores created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE the corresponding element of VkTimelineSemaphoreSubmitInfo::pSignalSemaphoreValues must have a value greater than the current value of the semaphore when the semaphore signal operation is executed

  • VUID-VkSubmitInfo-pWaitSemaphores-03243
    For each element of pWaitSemaphores created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE the corresponding element of VkTimelineSemaphoreSubmitInfo::pWaitSemaphoreValues must have a value which does not differ from the current value of the semaphore or the value of any outstanding semaphore wait or signal operation on that semaphore by more than maxTimelineSemaphoreValueDifference

  • VUID-VkSubmitInfo-pSignalSemaphores-03244
    For each element of pSignalSemaphores created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE the corresponding element of VkTimelineSemaphoreSubmitInfo::pSignalSemaphoreValues must have a value which does not differ from the current value of the semaphore or the value of any outstanding semaphore wait or signal operation on that semaphore by more than maxTimelineSemaphoreValueDifference

  • VUID-VkSubmitInfo-pNext-04120
    If the pNext chain of this structure does not include a VkProtectedSubmitInfo structure with protectedSubmit set to VK_TRUE, then each element of the pCommandBuffers array must be an unprotected command buffer

  • VUID-VkSubmitInfo-pNext-04148
    If the pNext chain of this structure includes a VkProtectedSubmitInfo structure with protectedSubmit set to VK_TRUE, then each element of the pCommandBuffers array must be a protected command buffer

  • VUID-VkSubmitInfo-pCommandBuffers-06193
    If pCommandBuffers contains any resumed render pass instances, they must be suspended by a render pass instance earlier in submission order within pCommandBuffers

  • VUID-VkSubmitInfo-pCommandBuffers-06014
    If pCommandBuffers contains any suspended render pass instances, they must be resumed by a render pass instance later in submission order within pCommandBuffers

  • VUID-VkSubmitInfo-pCommandBuffers-06015
    If pCommandBuffers contains any suspended render pass instances, there must be no action or synchronization commands executed in a primary or secondary command buffer between that render pass instance and the render pass instance that resumes it

  • VUID-VkSubmitInfo-pCommandBuffers-06016
    If pCommandBuffers contains any suspended render pass instances, there must be no render pass instances between that render pass instance and the render pass instance that resumes it

Valid Usage (Implicit)

  • VUID-VkSubmitInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_SUBMIT_INFO

  • VUID-VkSubmitInfo-pNext-pNext
    Each pNext member of any structure (including this one) in the pNext chain must be either NULL or a pointer to a valid instance of VkDeviceGroupSubmitInfo, VkProtectedSubmitInfo, or VkTimelineSemaphoreSubmitInfo

  • VUID-VkSubmitInfo-sType-unique
    The sType value of each struct in the pNext chain must be unique

  • VUID-VkSubmitInfo-pWaitSemaphores-parameter
    If waitSemaphoreCount is not 0, pWaitSemaphores must be a valid pointer to an array of waitSemaphoreCount valid VkSemaphore handles

  • VUID-VkSubmitInfo-pWaitDstStageMask-parameter
    If waitSemaphoreCount is not 0, pWaitDstStageMask must be a valid pointer to an array of waitSemaphoreCount valid combinations of VkPipelineStageFlagBits values

  • VUID-VkSubmitInfo-pCommandBuffers-parameter
    If commandBufferCount is not 0, pCommandBuffers must be a valid pointer to an array of commandBufferCount valid VkCommandBuffer handles

  • VUID-VkSubmitInfo-pSignalSemaphores-parameter
    If signalSemaphoreCount is not 0, pSignalSemaphores must be a valid pointer to an array of signalSemaphoreCount valid VkSemaphore handles

  • VUID-VkSubmitInfo-commonparent
    Each of the elements of pCommandBuffers, the elements of pSignalSemaphores, and the elements of pWaitSemaphores that are valid handles of non-ignored parameters must have been created, allocated, or retrieved from the same VkDevice

To specify the values to use when waiting for and signaling semaphores created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE, add a VkTimelineSemaphoreSubmitInfo structure to the pNext chain of the VkSubmitInfo structure when using vkQueueSubmit or the VkBindSparseInfo structure when using vkQueueBindSparse. The VkTimelineSemaphoreSubmitInfo structure is defined as:

// Provided by VK_VERSION_1_2
typedef struct VkTimelineSemaphoreSubmitInfo {
    VkStructureType    sType;
    const void*        pNext;
    uint32_t           waitSemaphoreValueCount;
    const uint64_t*    pWaitSemaphoreValues;
    uint32_t           signalSemaphoreValueCount;
    const uint64_t*    pSignalSemaphoreValues;
} VkTimelineSemaphoreSubmitInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • waitSemaphoreValueCount is the number of semaphore wait values specified in pWaitSemaphoreValues.

  • pWaitSemaphoreValues is a pointer to an array of waitSemaphoreValueCount values for the corresponding semaphores in VkSubmitInfo::pWaitSemaphores to wait for.

  • signalSemaphoreValueCount is the number of semaphore signal values specified in pSignalSemaphoreValues.

  • pSignalSemaphoreValues is a pointer to an array signalSemaphoreValueCount values for the corresponding semaphores in VkSubmitInfo::pSignalSemaphores to set when signaled.

If the semaphore in VkSubmitInfo::pWaitSemaphores or VkSubmitInfo::pSignalSemaphores corresponding to an entry in pWaitSemaphoreValues or pSignalSemaphoreValues respectively was not created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE, the implementation must ignore the value in the pWaitSemaphoreValues or pSignalSemaphoreValues entry.

Valid Usage (Implicit)

  • VUID-VkTimelineSemaphoreSubmitInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_TIMELINE_SEMAPHORE_SUBMIT_INFO

  • VUID-VkTimelineSemaphoreSubmitInfo-pWaitSemaphoreValues-parameter
    If waitSemaphoreValueCount is not 0, and pWaitSemaphoreValues is not NULL, pWaitSemaphoreValues must be a valid pointer to an array of waitSemaphoreValueCount uint64_t values

  • VUID-VkTimelineSemaphoreSubmitInfo-pSignalSemaphoreValues-parameter
    If signalSemaphoreValueCount is not 0, and pSignalSemaphoreValues is not NULL, pSignalSemaphoreValues must be a valid pointer to an array of signalSemaphoreValueCount uint64_t values

If the pNext chain of VkSubmitInfo includes a VkProtectedSubmitInfo structure, then the structure indicates whether the batch is protected. The VkProtectedSubmitInfo structure is defined as:

// Provided by VK_VERSION_1_1
typedef struct VkProtectedSubmitInfo {
    VkStructureType    sType;
    const void*        pNext;
    VkBool32           protectedSubmit;
} VkProtectedSubmitInfo;

  • protectedSubmit specifies whether the batch is protected. If protectedSubmit is VK_TRUE, the batch is protected. If protectedSubmit is VK_FALSE, the batch is unprotected. If the VkSubmitInfo::pNext chain does not include this structure, the batch is unprotected.

Valid Usage (Implicit)

  • VUID-VkProtectedSubmitInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_PROTECTED_SUBMIT_INFO

If the pNext chain of VkSubmitInfo includes a VkDeviceGroupSubmitInfo structure, then that structure includes device indices and masks specifying which physical devices execute semaphore operations and command buffers.

The VkDeviceGroupSubmitInfo structure is defined as:

// Provided by VK_VERSION_1_1
typedef struct VkDeviceGroupSubmitInfo {
    VkStructureType    sType;
    const void*        pNext;
    uint32_t           waitSemaphoreCount;
    const uint32_t*    pWaitSemaphoreDeviceIndices;
    uint32_t           commandBufferCount;
    const uint32_t*    pCommandBufferDeviceMasks;
    uint32_t           signalSemaphoreCount;
    const uint32_t*    pSignalSemaphoreDeviceIndices;
} VkDeviceGroupSubmitInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • waitSemaphoreCount is the number of elements in the pWaitSemaphoreDeviceIndices array.

  • pWaitSemaphoreDeviceIndices is a pointer to an array of waitSemaphoreCount device indices indicating which physical device executes the semaphore wait operation in the corresponding element of VkSubmitInfo::pWaitSemaphores.

  • commandBufferCount is the number of elements in the pCommandBufferDeviceMasks array.

  • pCommandBufferDeviceMasks is a pointer to an array of commandBufferCount device masks indicating which physical devices execute the command buffer in the corresponding element of VkSubmitInfo::pCommandBuffers. A physical device executes the command buffer if the corresponding bit is set in the mask.

  • signalSemaphoreCount is the number of elements in the pSignalSemaphoreDeviceIndices array.

  • pSignalSemaphoreDeviceIndices is a pointer to an array of signalSemaphoreCount device indices indicating which physical device executes the semaphore signal operation in the corresponding element of VkSubmitInfo::pSignalSemaphores.

If this structure is not present, semaphore operations and command buffers execute on device index zero.

Valid Usage

  • VUID-VkDeviceGroupSubmitInfo-waitSemaphoreCount-00082
    waitSemaphoreCount must equal VkSubmitInfo::waitSemaphoreCount

  • VUID-VkDeviceGroupSubmitInfo-commandBufferCount-00083
    commandBufferCount must equal VkSubmitInfo::commandBufferCount

  • VUID-VkDeviceGroupSubmitInfo-signalSemaphoreCount-00084
    signalSemaphoreCount must equal VkSubmitInfo::signalSemaphoreCount

  • VUID-VkDeviceGroupSubmitInfo-pWaitSemaphoreDeviceIndices-00085
    All elements of pWaitSemaphoreDeviceIndices and pSignalSemaphoreDeviceIndices must be valid device indices

  • VUID-VkDeviceGroupSubmitInfo-pCommandBufferDeviceMasks-00086
    All elements of pCommandBufferDeviceMasks must be valid device masks

Valid Usage (Implicit)

  • VUID-VkDeviceGroupSubmitInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_DEVICE_GROUP_SUBMIT_INFO

  • VUID-VkDeviceGroupSubmitInfo-pWaitSemaphoreDeviceIndices-parameter
    If waitSemaphoreCount is not 0, pWaitSemaphoreDeviceIndices must be a valid pointer to an array of waitSemaphoreCount uint32_t values

  • VUID-VkDeviceGroupSubmitInfo-pCommandBufferDeviceMasks-parameter
    If commandBufferCount is not 0, pCommandBufferDeviceMasks must be a valid pointer to an array of commandBufferCount uint32_t values

  • VUID-VkDeviceGroupSubmitInfo-pSignalSemaphoreDeviceIndices-parameter
    If signalSemaphoreCount is not 0, pSignalSemaphoreDeviceIndices must be a valid pointer to an array of signalSemaphoreCount uint32_t values

6.6. Queue Forward Progress

When using binary semaphores, the application must ensure that command buffer submissions will be able to complete without any subsequent operations by the application on any queue. After any call to vkQueueSubmit (or other queue operation), for every queued wait on a semaphore created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_BINARY there must be a prior signal of that semaphore that will not be consumed by a different wait on the semaphore.

When using timeline semaphores, wait-before-signal behavior is well-defined and applications can submit work via vkQueueSubmit defining a timeline semaphore wait operation before submitting a corresponding semaphore signal operation. For each timeline semaphore wait operation defined by a call to vkQueueSubmit, the application must ensure that a corresponding semaphore signal operation is executed before forward progress can be made.

If a command buffer submission waits for any events to be signaled, the application must ensure that command buffer submissions will be able to complete without any subsequent operations by the application. Events signaled by the host must be signaled before the command buffer waits on those events.

Note

The ability for commands to wait on the host to set an events was originally added to allow low-latency updates to resources between host and device. However, to ensure quality of service, implementations would necessarily detect extended stalls in execution and timeout after a short period. As this period is not defined in the Vulkan specification, it is impossible to correctly validate any application with any wait period. Since the original users of this functionality were highly limited and platform-specific, this functionality is now considered defunct and should not be used.

6.7. Secondary Command Buffer Execution

A secondary command buffer must not be directly submitted to a queue. Instead, secondary command buffers are recorded to execute as part of a primary command buffer with the command:

// Provided by VK_VERSION_1_0
void vkCmdExecuteCommands(
    VkCommandBuffer                             commandBuffer,
    uint32_t                                    commandBufferCount,
    const VkCommandBuffer*                      pCommandBuffers);

  • commandBuffer is a handle to a primary command buffer that the secondary command buffers are executed in.

  • commandBufferCount is the length of the pCommandBuffers array.

  • pCommandBuffers is a pointer to an array of commandBufferCount secondary command buffer handles, which are recorded to execute in the primary command buffer in the order they are listed in the array.

If any element of pCommandBuffers was not recorded with the VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT flag, and it was recorded into any other primary command buffer which is currently in the executable or recording state, that primary command buffer becomes invalid.

Valid Usage

  • VUID-vkCmdExecuteCommands-pCommandBuffers-00088
    Each element of pCommandBuffers must have been allocated with a level of VK_COMMAND_BUFFER_LEVEL_SECONDARY

  • VUID-vkCmdExecuteCommands-pCommandBuffers-00089
    Each element of pCommandBuffers must be in the pending or executable state

  • VUID-vkCmdExecuteCommands-pCommandBuffers-00091
    If any element of pCommandBuffers was not recorded with the VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT flag, it must not be in the pending state

  • VUID-vkCmdExecuteCommands-pCommandBuffers-00092
    If any element of pCommandBuffers was not recorded with the VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT flag, it must not have already been recorded to commandBuffer

  • VUID-vkCmdExecuteCommands-pCommandBuffers-00093
    If any element of pCommandBuffers was not recorded with the VK_COMMAND_BUFFER_USAGE_SIMULTANEOUS_USE_BIT flag, it must not appear more than once in pCommandBuffers

  • VUID-vkCmdExecuteCommands-pCommandBuffers-00094
    Each element of pCommandBuffers must have been allocated from a VkCommandPool that was created for the same queue family as the VkCommandPool from which commandBuffer was allocated

  • VUID-vkCmdExecuteCommands-pCommandBuffers-00096
    If vkCmdExecuteCommands is being called within a render pass instance, each element of pCommandBuffers must have been recorded with the VK_COMMAND_BUFFER_USAGE_RENDER_PASS_CONTINUE_BIT

  • VUID-vkCmdExecuteCommands-pCommandBuffers-00099
    If vkCmdExecuteCommands is being called within a render pass instance, and any element of pCommandBuffers was recorded with VkCommandBufferInheritanceInfo::framebuffer not equal to VK_NULL_HANDLE, that VkFramebuffer must match the VkFramebuffer used in the current render pass instance

  • VUID-vkCmdExecuteCommands-contents-06018
    If vkCmdExecuteCommands is being called within a render pass instance begun with vkCmdBeginRenderPass, its contents parameter must have been set to VK_SUBPASS_CONTENTS_SECONDARY_COMMAND_BUFFERS

  • VUID-vkCmdExecuteCommands-pCommandBuffers-06019
    If vkCmdExecuteCommands is being called within a render pass instance begun with vkCmdBeginRenderPass, each element of pCommandBuffers must have been recorded with VkCommandBufferInheritanceInfo::subpass set to the index of the subpass which the given command buffer will be executed in

  • VUID-vkCmdExecuteCommands-pBeginInfo-06020
    If vkCmdExecuteCommands is being called within a render pass instance begun with vkCmdBeginRenderPass, the render passes specified in the pBeginInfo->pInheritanceInfo->renderPass members of the vkBeginCommandBuffer commands used to begin recording each element of pCommandBuffers must be compatible with the current render pass

  • VUID-vkCmdExecuteCommands-pCommandBuffers-00100
    If vkCmdExecuteCommands is not being called within a render pass instance, each element of pCommandBuffers must not have been recorded with the VK_COMMAND_BUFFER_USAGE_RENDER_PASS_CONTINUE_BIT

  • VUID-vkCmdExecuteCommands-commandBuffer-00101
    If the inheritedQueries feature is not enabled, commandBuffer must not have any queries active

  • VUID-vkCmdExecuteCommands-commandBuffer-00102
    If commandBuffer has a VK_QUERY_TYPE_OCCLUSION query active, then each element of pCommandBuffers must have been recorded with VkCommandBufferInheritanceInfo::occlusionQueryEnable set to VK_TRUE

  • VUID-vkCmdExecuteCommands-commandBuffer-00103
    If commandBuffer has a VK_QUERY_TYPE_OCCLUSION query active, then each element of pCommandBuffers must have been recorded with VkCommandBufferInheritanceInfo::queryFlags having all bits set that are set for the query

  • VUID-vkCmdExecuteCommands-commandBuffer-00104
    If commandBuffer has a VK_QUERY_TYPE_PIPELINE_STATISTICS query active, then each element of pCommandBuffers must have been recorded with VkCommandBufferInheritanceInfo::pipelineStatistics having all bits set that are set in the VkQueryPool the query uses

  • VUID-vkCmdExecuteCommands-pCommandBuffers-00105
    Each element of pCommandBuffers must not begin any query types that are active in commandBuffer

  • VUID-vkCmdExecuteCommands-commandBuffer-07594
    commandBuffer must not have any queries other than VK_QUERY_TYPE_OCCLUSION and VK_QUERY_TYPE_PIPELINE_STATISTICS active

  • VUID-vkCmdExecuteCommands-commandBuffer-01820
    If commandBuffer is a protected command buffer and protectedNoFault is not supported, each element of pCommandBuffers must be a protected command buffer

  • VUID-vkCmdExecuteCommands-commandBuffer-01821
    If commandBuffer is an unprotected command buffer and protectedNoFault is not supported, each element of pCommandBuffers must be an unprotected command buffer

  • VUID-vkCmdExecuteCommands-commandBuffer-06533
    If vkCmdExecuteCommands is being called within a render pass instance and any recorded command in commandBuffer in the current subpass will write to an image subresource as an attachment, commands recorded in elements of pCommandBuffers must not read from the memory backing that image subresource in any other way

  • VUID-vkCmdExecuteCommands-commandBuffer-06534
    If vkCmdExecuteCommands is being called within a render pass instance and any recorded command in commandBuffer in the current subpass will read from an image subresource used as an attachment in any way other than as an attachment, commands recorded in elements of pCommandBuffers must not write to that image subresource as an attachment

  • VUID-vkCmdExecuteCommands-pCommandBuffers-06535
    If vkCmdExecuteCommands is being called within a render pass instance and any recorded command in a given element of pCommandBuffers will write to an image subresource as an attachment, commands recorded in elements of pCommandBuffers at a higher index must not read from the memory backing that image subresource in any other way

  • VUID-vkCmdExecuteCommands-pCommandBuffers-06536
    If vkCmdExecuteCommands is being called within a render pass instance and any recorded command in a given element of pCommandBuffers will read from an image subresource used as an attachment in any way other than as an attachment, commands recorded in elements of pCommandBuffers at a higher index must not write to that image subresource as an attachment

  • VUID-vkCmdExecuteCommands-pCommandBuffers-06021
    If pCommandBuffers contains any suspended render pass instances, there must be no action or synchronization commands between that render pass instance and any render pass instance that resumes it

  • VUID-vkCmdExecuteCommands-pCommandBuffers-06022
    If pCommandBuffers contains any suspended render pass instances, there must be no render pass instances between that render pass instance and any render pass instance that resumes it

  • VUID-vkCmdExecuteCommands-flags-06024
    If vkCmdExecuteCommands is being called within a render pass instance begun with vkCmdBeginRendering, its VkRenderingInfo::flags parameter must have included VK_RENDERING_CONTENTS_SECONDARY_COMMAND_BUFFERS_BIT

  • VUID-vkCmdExecuteCommands-pBeginInfo-06025
    If vkCmdExecuteCommands is being called within a render pass instance begun with vkCmdBeginRendering, the render passes specified in the pBeginInfo->pInheritanceInfo->renderPass members of the vkBeginCommandBuffer commands used to begin recording each element of pCommandBuffers must be VK_NULL_HANDLE

  • VUID-vkCmdExecuteCommands-flags-06026
    If vkCmdExecuteCommands is being called within a render pass instance begun with vkCmdBeginRendering, the flags member of the VkCommandBufferInheritanceRenderingInfo structure included in the pNext chain of VkCommandBufferBeginInfo::pInheritanceInfo used to begin recording each element of pCommandBuffers must be equal to the VkRenderingInfo::flags parameter to vkCmdBeginRendering, excluding VK_RENDERING_CONTENTS_SECONDARY_COMMAND_BUFFERS_BIT

  • VUID-vkCmdExecuteCommands-colorAttachmentCount-06027
    If vkCmdExecuteCommands is being called within a render pass instance begun with vkCmdBeginRendering, the colorAttachmentCount member of the VkCommandBufferInheritanceRenderingInfo structure included in the pNext chain of VkCommandBufferBeginInfo::pInheritanceInfo used to begin recording each element of pCommandBuffers must be equal to the VkRenderingInfo::colorAttachmentCount parameter to vkCmdBeginRendering

  • VUID-vkCmdExecuteCommands-imageView-06028
    If vkCmdExecuteCommands is being called within a render pass instance begun with vkCmdBeginRendering, if the imageView member of an element of the VkRenderingInfo::pColorAttachments parameter to vkCmdBeginRendering is not VK_NULL_HANDLE, the corresponding element of the pColorAttachmentFormats member of the VkCommandBufferInheritanceRenderingInfo structure included in the pNext chain of VkCommandBufferBeginInfo::pInheritanceInfo used to begin recording each element of pCommandBuffers must be equal to the format used to create that image view

  • VUID-vkCmdExecuteCommands-imageView-07606
    If vkCmdExecuteCommands is being called within a render pass instance begun with vkCmdBeginRendering, if the imageView member of an element of the VkRenderingInfo::pColorAttachments parameter to vkCmdBeginRendering is VK_NULL_HANDLE, the corresponding element of the pColorAttachmentFormats member of the VkCommandBufferInheritanceRenderingInfo structure included in the pNext chain of VkCommandBufferBeginInfo::pInheritanceInfo used to begin recording each element of pCommandBuffers must be VK_FORMAT_UNDEFINED

  • VUID-vkCmdExecuteCommands-pDepthAttachment-06029
    If vkCmdExecuteCommands is being called within a render pass instance begun with vkCmdBeginRendering, if the VkRenderingInfo::pDepthAttachment->imageView parameter to vkCmdBeginRendering is not VK_NULL_HANDLE, the value of the depthAttachmentFormat member of the VkCommandBufferInheritanceRenderingInfo structure included in the pNext chain of VkCommandBufferBeginInfo::pInheritanceInfo used to begin recording each element of pCommandBuffers must be equal to the format used to create that image view

  • VUID-vkCmdExecuteCommands-pStencilAttachment-06030
    If vkCmdExecuteCommands is being called within a render pass instance begun with vkCmdBeginRendering, if the VkRenderingInfo::pStencilAttachment->imageView parameter to vkCmdBeginRendering is not VK_NULL_HANDLE, the value of the stencilAttachmentFormat member of the VkCommandBufferInheritanceRenderingInfo structure included in the pNext chain of VkCommandBufferBeginInfo::pInheritanceInfo used to begin recording each element of pCommandBuffers must be equal to the format used to create that image view

  • VUID-vkCmdExecuteCommands-pDepthAttachment-06774
    If vkCmdExecuteCommands is being called within a render pass instance begun with vkCmdBeginRendering and the VkRenderingInfo::pDepthAttachment->imageView parameter to vkCmdBeginRendering was VK_NULL_HANDLE, the value of the depthAttachmentFormat member of the VkCommandBufferInheritanceRenderingInfo structure included in the pNext chain of VkCommandBufferBeginInfo::pInheritanceInfo used to begin recording each element of pCommandBuffers must be VK_FORMAT_UNDEFINED

  • VUID-vkCmdExecuteCommands-pStencilAttachment-06775
    If vkCmdExecuteCommands is being called within a render pass instance begun with vkCmdBeginRendering and the VkRenderingInfo::pStencilAttachment->imageView parameter to vkCmdBeginRendering was VK_NULL_HANDLE, the value of the stencilAttachmentFormat member of the VkCommandBufferInheritanceRenderingInfo structure included in the pNext chain of VkCommandBufferBeginInfo::pInheritanceInfo used to begin recording each element of pCommandBuffers must be VK_FORMAT_UNDEFINED

  • VUID-vkCmdExecuteCommands-viewMask-06031
    If vkCmdExecuteCommands is being called within a render pass instance begun with vkCmdBeginRendering, the viewMask member of the VkCommandBufferInheritanceRenderingInfo structure included in the pNext chain of VkCommandBufferBeginInfo::pInheritanceInfo used to begin recording each element of pCommandBuffers must be equal to the VkRenderingInfo::viewMask parameter to vkCmdBeginRendering

Valid Usage (Implicit)

  • VUID-vkCmdExecuteCommands-commandBuffer-parameter
    commandBuffer must be a valid VkCommandBuffer handle

  • VUID-vkCmdExecuteCommands-pCommandBuffers-parameter
    pCommandBuffers must be a valid pointer to an array of commandBufferCount valid VkCommandBuffer handles

  • VUID-vkCmdExecuteCommands-commandBuffer-recording
    commandBuffer must be in the recording state

  • VUID-vkCmdExecuteCommands-commandBuffer-cmdpool
    The VkCommandPool that commandBuffer was allocated from must support transfer, graphics, or compute operations

  • VUID-vkCmdExecuteCommands-bufferlevel
    commandBuffer must be a primary VkCommandBuffer

  • VUID-vkCmdExecuteCommands-commandBufferCount-arraylength
    commandBufferCount must be greater than 0

  • VUID-vkCmdExecuteCommands-commonparent
    Both of commandBuffer, and the elements of pCommandBuffers must have been created, allocated, or retrieved from the same VkDevice

Host Synchronization

  • Host access to commandBuffer must be externally synchronized

  • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

Command Properties
Command Buffer Levels Render Pass Scope Supported Queue Types Command Type

Primary

Both

Transfer
Graphics
Compute

Indirection

6.8. Command Buffer Device Mask

Each command buffer has a piece of state storing the current device mask of the command buffer. This mask controls which physical devices within the logical device all subsequent commands will execute on, including state-setting commands, action commands, and synchronization commands.

Scissor and viewport state (excluding the count of each) can be set to different values on each physical device (only when set as dynamic state), and each physical device will render using its local copy of the state. Other state is shared between physical devices, such that all physical devices use the most recently set values for the state. However, when recording an action command that uses a piece of state, the most recent command that set that state must have included all physical devices that execute the action command in its current device mask.

The command buffer’s device mask is orthogonal to the pCommandBufferDeviceMasks member of VkDeviceGroupSubmitInfo. Commands only execute on a physical device if the device index is set in both device masks.

If the pNext chain of VkCommandBufferBeginInfo includes a VkDeviceGroupCommandBufferBeginInfo structure, then that structure includes an initial device mask for the command buffer.

The VkDeviceGroupCommandBufferBeginInfo structure is defined as:

// Provided by VK_VERSION_1_1
typedef struct VkDeviceGroupCommandBufferBeginInfo {
    VkStructureType    sType;
    const void*        pNext;
    uint32_t           deviceMask;
} VkDeviceGroupCommandBufferBeginInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • deviceMask is the initial value of the command buffer’s device mask.

The initial device mask also acts as an upper bound on the set of devices that can ever be in the device mask in the command buffer.

If this structure is not present, the initial value of a command buffer’s device mask is set to include all physical devices in the logical device when the command buffer begins recording.

Valid Usage

  • VUID-VkDeviceGroupCommandBufferBeginInfo-deviceMask-00106
    deviceMask must be a valid device mask value

  • VUID-VkDeviceGroupCommandBufferBeginInfo-deviceMask-00107
    deviceMask must not be zero

Valid Usage (Implicit)

  • VUID-VkDeviceGroupCommandBufferBeginInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_DEVICE_GROUP_COMMAND_BUFFER_BEGIN_INFO

To update the current device mask of a command buffer, call:

// Provided by VK_VERSION_1_1
void vkCmdSetDeviceMask(
    VkCommandBuffer                             commandBuffer,
    uint32_t                                    deviceMask);

  • commandBuffer is command buffer whose current device mask is modified.

  • deviceMask is the new value of the current device mask.

deviceMask is used to filter out subsequent commands from executing on all physical devices whose bit indices are not set in the mask, except commands beginning a render pass instance, commands transitioning to the next subpass in the render pass instance, and commands ending a render pass instance, which always execute on the set of physical devices whose bit indices are included in the deviceMask member of the VkDeviceGroupRenderPassBeginInfo structure passed to the command beginning the corresponding render pass instance.

Valid Usage

  • VUID-vkCmdSetDeviceMask-deviceMask-00108
    deviceMask must be a valid device mask value

  • VUID-vkCmdSetDeviceMask-deviceMask-00109
    deviceMask must not be zero

  • VUID-vkCmdSetDeviceMask-deviceMask-00110
    deviceMask must not include any set bits that were not in the VkDeviceGroupCommandBufferBeginInfo::deviceMask value when the command buffer began recording

  • VUID-vkCmdSetDeviceMask-deviceMask-00111
    If vkCmdSetDeviceMask is called inside a render pass instance, deviceMask must not include any set bits that were not in the VkDeviceGroupRenderPassBeginInfo::deviceMask value when the render pass instance began recording

Valid Usage (Implicit)

  • VUID-vkCmdSetDeviceMask-commandBuffer-parameter
    commandBuffer must be a valid VkCommandBuffer handle

  • VUID-vkCmdSetDeviceMask-commandBuffer-recording
    commandBuffer must be in the recording state

  • VUID-vkCmdSetDeviceMask-commandBuffer-cmdpool
    The VkCommandPool that commandBuffer was allocated from must support graphics, compute, or transfer operations

Host Synchronization

  • Host access to commandBuffer must be externally synchronized

  • Host access to the VkCommandPool that commandBuffer was allocated from must be externally synchronized

Command Properties
Command Buffer Levels Render Pass Scope Supported Queue Types Command Type

Primary
Secondary

Both

Graphics
Compute
Transfer

State

7. Synchronization and Cache Control

Synchronization of access to resources is primarily the responsibility of the application in Vulkan. The order of execution of commands with respect to the host and other commands on the device has few implicit guarantees, and needs to be explicitly specified. Memory caches and other optimizations are also explicitly managed, requiring that the flow of data through the system is largely under application control.

Whilst some implicit guarantees exist between commands, five explicit synchronization mechanisms are exposed by Vulkan:

Fences

Fences can be used to communicate to the host that execution of some task on the device has completed, controlling resource access between host and device.

Semaphores

Semaphores can be used to control resource access across multiple queues.

Events

Events provide a fine-grained synchronization primitive which can be signaled either within a command buffer or by the host, and can be waited upon within a command buffer or queried on the host. Events can be used to control resource access within a single queue.

Pipeline Barriers

Pipeline barriers also provide synchronization control within a command buffer, but at a single point, rather than with separate signal and wait operations. Pipeline barriers can be used to control resource access within a single queue.

Render Passes

Render passes provide a useful synchronization framework for most rendering tasks, built upon the concepts in this chapter. Many cases that would otherwise need an application to use other synchronization primitives can be expressed more efficiently as part of a render pass. Render pass objects can be used to control resource access within a single queue.

7.1. Execution and Memory Dependencies

An operation is an arbitrary amount of work to be executed on the host, a device, or an external entity such as a presentation engine. Synchronization commands introduce explicit execution dependencies, and memory dependencies between two sets of operations defined by the command’s two synchronization scopes.

The synchronization scopes define which other operations a synchronization command is able to create execution dependencies with. Any type of operation that is not in a synchronization command’s synchronization scopes will not be included in the resulting dependency. For example, for many synchronization commands, the synchronization scopes can be limited to just operations executing in specific pipeline stages, which allows other pipeline stages to be excluded from a dependency. Other scoping options are possible, depending on the particular command.

An execution dependency is a guarantee that for two sets of operations, the first set must happen-before the second set. If an operation happens-before another operation, then the first operation must complete before the second operation is initiated. More precisely:

  • Let Ops1 and Ops2 be separate sets of operations.

  • Let Sync be a synchronization command.

  • Let Scope1st and Scope2nd be the synchronization scopes of Sync.

  • Let ScopedOps1 be the intersection of sets Ops1 and Scope1st.

  • Let ScopedOps2 be the intersection of sets Ops2 and Scope2nd.

  • Submitting Ops1, Sync and Ops2 for execution, in that order, will result in execution dependency ExeDep between ScopedOps1 and ScopedOps2.

  • Execution dependency ExeDep guarantees that ScopedOps1 happen-before ScopedOps2.

An execution dependency chain is a sequence of execution dependencies that form a happens-before relation between the first dependency’s ScopedOps1 and the final dependency’s ScopedOps2. For each consecutive pair of execution dependencies, a chain exists if the intersection of Scope2nd in the first dependency and Scope1st in the second dependency is not an empty set. The formation of a single execution dependency from an execution dependency chain can be described by substituting the following in the description of execution dependencies:

  • Let Sync be a set of synchronization commands that generate an execution dependency chain.

  • Let Scope1st be the first synchronization scope of the first command in Sync.

  • Let Scope2nd be the second synchronization scope of the last command in Sync.

Execution dependencies alone are not sufficient to guarantee that values resulting from writes in one set of operations can be read from another set of operations.

Three additional types of operations are used to control memory access. Availability operations cause the values generated by specified memory write accesses to become available to a memory domain for future access. Any available value remains available until a subsequent write to the same memory location occurs (whether it is made available or not) or the memory is freed. Memory domain operations cause writes that are available to a source memory domain to become available to a destination memory domain (an example of this is making writes available to the host domain available to the device domain). Visibility operations cause values available to a memory domain to become visible to specified memory accesses.

Availability, visibility, memory domains, and memory domain operations are formally defined in the Availability and Visibility section of the Memory Model chapter. Which API operations perform each of these operations is defined in Availability, Visibility, and Domain Operations.

A memory dependency is an execution dependency which includes availability and visibility operations such that:

  • The first set of operations happens-before the availability operation.

  • The availability operation happens-before the visibility operation.

  • The visibility operation happens-before the second set of operations.

Once written values are made visible to a particular type of memory access, they can be read or written by that type of memory access. Most synchronization commands in Vulkan define a memory dependency.

The specific memory accesses that are made available and visible are defined by the access scopes of a memory dependency. Any type of access that is in a memory dependency’s first access scope and occurs in ScopedOps1 is made available. Any type of access that is in a memory dependency’s second access scope and occurs in ScopedOps2 has any available writes made visible to it. Any type of operation that is not in a synchronization command’s access scopes will not be included in the resulting dependency.

A memory dependency enforces availability and visibility of memory accesses and execution order between two sets of operations. Adding to the description of execution dependency chains:

  • Let MemOps1 be the set of memory accesses performed by ScopedOps1.

  • Let MemOps2 be the set of memory accesses performed by ScopedOps2.

  • Let AccessScope1st be the first access scope of the first command in the Sync chain.

  • Let AccessScope2nd be the second access scope of the last command in the Sync chain.

  • Let ScopedMemOps1 be the intersection of sets MemOps1 and AccessScope1st.

  • Let ScopedMemOps2 be the intersection of sets MemOps2 and AccessScope2nd.

  • Submitting Ops1, Sync, and Ops2 for execution, in that order, will result in a memory dependency MemDep between ScopedOps1 and ScopedOps2.

  • Memory dependency MemDep guarantees that:

    • Memory writes in ScopedMemOps1 are made available.

    • Available memory writes, including those from ScopedMemOps1, are made visible to ScopedMemOps2.

Note

Execution and memory dependencies are used to solve data hazards, i.e. to ensure that read and write operations occur in a well-defined order. Write-after-read hazards can be solved with just an execution dependency, but read-after-write and write-after-write hazards need appropriate memory dependencies to be included between them. If an application does not include dependencies to solve these hazards, the results and execution orders of memory accesses are undefined.

7.1.1. Image Layout Transitions

Image subresources can be transitioned from one layout to another as part of a memory dependency (e.g. by using an image memory barrier). When a layout transition is specified in a memory dependency, it happens-after the availability operations in the memory dependency, and happens-before the visibility operations. Image layout transitions may perform read and write accesses on all memory bound to the image subresource range, so applications must ensure that all memory writes have been made available before a layout transition is executed. Available memory is automatically made visible to a layout transition, and writes performed by a layout transition are automatically made available.

Layout transitions always apply to a particular image subresource range, and specify both an old layout and new layout. The old layout must either be VK_IMAGE_LAYOUT_UNDEFINED, or match the current layout of the image subresource range. If the old layout matches the current layout of the image subresource range, the transition preserves the contents of that range. If the old layout is VK_IMAGE_LAYOUT_UNDEFINED, the contents of that range may be discarded.

As image layout transitions may perform read and write accesses on the memory bound to the image, if the image subresource affected by the layout transition is bound to peer memory for any device in the current device mask then the memory heap the bound memory comes from must support the VK_PEER_MEMORY_FEATURE_GENERIC_SRC_BIT and VK_PEER_MEMORY_FEATURE_GENERIC_DST_BIT capabilities as returned by vkGetDeviceGroupPeerMemoryFeatures.

Note

Applications must ensure that layout transitions happen-after all operations accessing the image with the old layout, and happen-before any operations that will access the image with the new layout. Layout transitions are potentially read/write operations, so not defining appropriate memory dependencies to guarantee this will result in a data race.

Image layout transitions interact with memory aliasing.

Layout transitions that are performed via image memory barriers execute in their entirety in submission order, relative to other image layout transitions submitted to the same queue, including those performed by render passes. In effect there is an implicit execution dependency from each such layout transition to all layout transitions previously submitted to the same queue.

7.1.2. Pipeline Stages

The work performed by an action or synchronization command consists of multiple operations, which are performed as a sequence of logically independent steps known as pipeline stages. The exact pipeline stages executed depend on the particular command that is used, and current command buffer state when the command was recorded. Drawing commands, dispatching commands, copy commands, clear commands, and synchronization commands all execute in different sets of pipeline stages. Synchronization commands do not execute in a defined pipeline stage.

Note

Operations performed by synchronization commands (e.g. availability and visibility operations) are not executed by a defined pipeline stage. However other commands can still synchronize with them by using the synchronization scopes to create a dependency chain.

Execution of operations across pipeline stages must adhere to implicit ordering guarantees, particularly including pipeline stage order. Otherwise, execution across pipeline stages may overlap or execute out of order with regards to other stages, unless otherwise enforced by an execution dependency.

Several of the synchronization commands include pipeline stage parameters, restricting the synchronization scopes for that command to just those stages. This allows fine grained control over the exact execution dependencies and accesses performed by action commands. Implementations should use these pipeline stages to avoid unnecessary stalls or cache flushing.

Bits which can be set in a VkPipelineStageFlags2 mask, specifying stages of execution, are:

// Provided by VK_VERSION_1_3
// Flag bits for VkPipelineStageFlagBits2
typedef VkFlags64 VkPipelineStageFlagBits2;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_NONE = 0ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_NONE_KHR = 0ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_TOP_OF_PIPE_BIT = 0x00000001ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_TOP_OF_PIPE_BIT_KHR = 0x00000001ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_DRAW_INDIRECT_BIT = 0x00000002ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_DRAW_INDIRECT_BIT_KHR = 0x00000002ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_VERTEX_INPUT_BIT = 0x00000004ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_VERTEX_INPUT_BIT_KHR = 0x00000004ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_VERTEX_SHADER_BIT = 0x00000008ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_VERTEX_SHADER_BIT_KHR = 0x00000008ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_TESSELLATION_CONTROL_SHADER_BIT = 0x00000010ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_TESSELLATION_CONTROL_SHADER_BIT_KHR = 0x00000010ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_TESSELLATION_EVALUATION_SHADER_BIT = 0x00000020ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_TESSELLATION_EVALUATION_SHADER_BIT_KHR = 0x00000020ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_GEOMETRY_SHADER_BIT = 0x00000040ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_GEOMETRY_SHADER_BIT_KHR = 0x00000040ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_FRAGMENT_SHADER_BIT = 0x00000080ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_FRAGMENT_SHADER_BIT_KHR = 0x00000080ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_EARLY_FRAGMENT_TESTS_BIT = 0x00000100ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_EARLY_FRAGMENT_TESTS_BIT_KHR = 0x00000100ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_LATE_FRAGMENT_TESTS_BIT = 0x00000200ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_LATE_FRAGMENT_TESTS_BIT_KHR = 0x00000200ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_COLOR_ATTACHMENT_OUTPUT_BIT = 0x00000400ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_COLOR_ATTACHMENT_OUTPUT_BIT_KHR = 0x00000400ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_COMPUTE_SHADER_BIT = 0x00000800ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_COMPUTE_SHADER_BIT_KHR = 0x00000800ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_ALL_TRANSFER_BIT = 0x00001000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_ALL_TRANSFER_BIT_KHR = 0x00001000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_TRANSFER_BIT = 0x00001000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_TRANSFER_BIT_KHR = 0x00001000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_BOTTOM_OF_PIPE_BIT = 0x00002000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_BOTTOM_OF_PIPE_BIT_KHR = 0x00002000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_HOST_BIT = 0x00004000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_HOST_BIT_KHR = 0x00004000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_ALL_GRAPHICS_BIT = 0x00008000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_ALL_GRAPHICS_BIT_KHR = 0x00008000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_ALL_COMMANDS_BIT = 0x00010000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_ALL_COMMANDS_BIT_KHR = 0x00010000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_COPY_BIT = 0x100000000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_COPY_BIT_KHR = 0x100000000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_RESOLVE_BIT = 0x200000000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_RESOLVE_BIT_KHR = 0x200000000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_BLIT_BIT = 0x400000000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_BLIT_BIT_KHR = 0x400000000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_CLEAR_BIT = 0x800000000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_CLEAR_BIT_KHR = 0x800000000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_INDEX_INPUT_BIT = 0x1000000000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_INDEX_INPUT_BIT_KHR = 0x1000000000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_VERTEX_ATTRIBUTE_INPUT_BIT = 0x2000000000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_VERTEX_ATTRIBUTE_INPUT_BIT_KHR = 0x2000000000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_PRE_RASTERIZATION_SHADERS_BIT = 0x4000000000ULL;
static const VkPipelineStageFlagBits2 VK_PIPELINE_STAGE_2_PRE_RASTERIZATION_SHADERS_BIT_KHR = 0x4000000000ULL;

  • VK_PIPELINE_STAGE_2_NONE specifies no stages of execution.

  • VK_PIPELINE_STAGE_2_DRAW_INDIRECT_BIT specifies the stage of the pipeline where indirect command parameters are consumed.

  • VK_PIPELINE_STAGE_2_INDEX_INPUT_BIT specifies the stage of the pipeline where index buffers are consumed.

  • VK_PIPELINE_STAGE_2_VERTEX_ATTRIBUTE_INPUT_BIT specifies the stage of the pipeline where vertex buffers are consumed.

  • VK_PIPELINE_STAGE_2_VERTEX_INPUT_BIT is equivalent to the logical OR of:

    • VK_PIPELINE_STAGE_2_INDEX_INPUT_BIT

    • VK_PIPELINE_STAGE_2_VERTEX_ATTRIBUTE_INPUT_BIT

  • VK_PIPELINE_STAGE_2_VERTEX_SHADER_BIT specifies the vertex shader stage.

  • VK_PIPELINE_STAGE_2_TESSELLATION_CONTROL_SHADER_BIT specifies the tessellation control shader stage.

  • VK_PIPELINE_STAGE_2_TESSELLATION_EVALUATION_SHADER_BIT specifies the tessellation evaluation shader stage.

  • VK_PIPELINE_STAGE_2_GEOMETRY_SHADER_BIT specifies the geometry shader stage.

  • VK_PIPELINE_STAGE_2_PRE_RASTERIZATION_SHADERS_BIT is equivalent to specifying all supported pre-rasterization shader stages:

    • VK_PIPELINE_STAGE_2_VERTEX_SHADER_BIT

    • VK_PIPELINE_STAGE_2_TESSELLATION_CONTROL_SHADER_BIT

    • VK_PIPELINE_STAGE_2_TESSELLATION_EVALUATION_SHADER_BIT

    • VK_PIPELINE_STAGE_2_GEOMETRY_SHADER_BIT

  • VK_PIPELINE_STAGE_2_FRAGMENT_SHADER_BIT specifies the fragment shader stage.

  • VK_PIPELINE_STAGE_2_EARLY_FRAGMENT_TESTS_BIT specifies the stage of the pipeline where early fragment tests (depth and stencil tests before fragment shading) are performed. This stage also includes subpass load operations for framebuffer attachments with a depth/stencil format.

  • VK_PIPELINE_STAGE_2_LATE_FRAGMENT_TESTS_BIT specifies the stage of the pipeline where late fragment tests (depth and stencil tests after fragment shading) are performed. This stage also includes subpass store operations for framebuffer attachments with a depth/stencil format.

  • VK_PIPELINE_STAGE_2_COLOR_ATTACHMENT_OUTPUT_BIT specifies the stage of the pipeline where final color values are output from the pipeline. This stage includes blending, logic operations, subpass load and store operations, multisample resolve operations for framebuffer attachments with a color or depth/stencil format, and vkCmdClearAttachments.

  • VK_PIPELINE_STAGE_2_COMPUTE_SHADER_BIT specifies the compute shader stage.

  • VK_PIPELINE_STAGE_2_HOST_BIT specifies a pseudo-stage indicating execution on the host of reads/writes of device memory. This stage is not invoked by any commands recorded in a command buffer.

  • VK_PIPELINE_STAGE_2_COPY_BIT specifies the execution of all copy commands, including vkCmdCopyQueryPoolResults.

  • VK_PIPELINE_STAGE_2_BLIT_BIT specifies the execution of vkCmdBlitImage.

  • VK_PIPELINE_STAGE_2_RESOLVE_BIT specifies the execution of vkCmdResolveImage.

  • VK_PIPELINE_STAGE_2_CLEAR_BIT specifies the execution of clear commands, with the exception of vkCmdClearAttachments.

  • VK_PIPELINE_STAGE_2_ALL_TRANSFER_BIT is equivalent to specifying all of:

    • VK_PIPELINE_STAGE_2_COPY_BIT

    • VK_PIPELINE_STAGE_2_BLIT_BIT

    • VK_PIPELINE_STAGE_2_RESOLVE_BIT

    • VK_PIPELINE_STAGE_2_CLEAR_BIT

  • VK_PIPELINE_STAGE_2_ALL_GRAPHICS_BIT specifies the execution of all graphics pipeline stages, and is equivalent to the logical OR of:

    • VK_PIPELINE_STAGE_2_DRAW_INDIRECT_BIT

    • VK_PIPELINE_STAGE_2_VERTEX_INPUT_BIT

    • VK_PIPELINE_STAGE_2_VERTEX_SHADER_BIT

    • VK_PIPELINE_STAGE_2_TESSELLATION_CONTROL_SHADER_BIT

    • VK_PIPELINE_STAGE_2_TESSELLATION_EVALUATION_SHADER_BIT

    • VK_PIPELINE_STAGE_2_GEOMETRY_SHADER_BIT

    • VK_PIPELINE_STAGE_2_FRAGMENT_SHADER_BIT

    • VK_PIPELINE_STAGE_2_EARLY_FRAGMENT_TESTS_BIT

    • VK_PIPELINE_STAGE_2_LATE_FRAGMENT_TESTS_BIT

    • VK_PIPELINE_STAGE_2_COLOR_ATTACHMENT_OUTPUT_BIT

  • VK_PIPELINE_STAGE_2_ALL_COMMANDS_BIT specifies all operations performed by all commands supported on the queue it is used with.

  • VK_PIPELINE_STAGE_2_TOP_OF_PIPE_BIT is equivalent to VK_PIPELINE_STAGE_2_ALL_COMMANDS_BIT with VkAccessFlags2 set to 0 when specified in the second synchronization scope, but equivalent to VK_PIPELINE_STAGE_2_NONE in the first scope.

  • VK_PIPELINE_STAGE_2_BOTTOM_OF_PIPE_BIT is equivalent to VK_PIPELINE_STAGE_2_ALL_COMMANDS_BIT with VkAccessFlags2 set to 0 when specified in the first synchronization scope, but equivalent to VK_PIPELINE_STAGE_2_NONE in the second scope.

Note

The TOP and BOTTOM pipeline stages are deprecated, and applications should prefer VK_PIPELINE_STAGE_2_ALL_COMMANDS_BIT and VK_PIPELINE_STAGE_2_NONE.
Note

The VkPipelineStageFlags2 bitmask goes beyond the 31 individual bit flags allowable within a C99 enum, which is how VkPipelineStageFlagBits is defined. The first 31 values are common to both, and are interchangeable.

VkPipelineStageFlags2 is a bitmask type for setting a mask of zero or more VkPipelineStageFlagBits2 flags:

// Provided by VK_VERSION_1_3
typedef VkFlags64 VkPipelineStageFlags2;

Bits which can be set in a VkPipelineStageFlags mask, specifying stages of execution, are:

// Provided by VK_VERSION_1_0
typedef enum VkPipelineStageFlagBits {
    VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT = 0x00000001,
    VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT = 0x00000002,
    VK_PIPELINE_STAGE_VERTEX_INPUT_BIT = 0x00000004,
    VK_PIPELINE_STAGE_VERTEX_SHADER_BIT = 0x00000008,
    VK_PIPELINE_STAGE_TESSELLATION_CONTROL_SHADER_BIT = 0x00000010,
    VK_PIPELINE_STAGE_TESSELLATION_EVALUATION_SHADER_BIT = 0x00000020,
    VK_PIPELINE_STAGE_GEOMETRY_SHADER_BIT = 0x00000040,
    VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT = 0x00000080,
    VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT = 0x00000100,
    VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT = 0x00000200,
    VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT = 0x00000400,
    VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT = 0x00000800,
    VK_PIPELINE_STAGE_TRANSFER_BIT = 0x00001000,
    VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT = 0x00002000,
    VK_PIPELINE_STAGE_HOST_BIT = 0x00004000,
    VK_PIPELINE_STAGE_ALL_GRAPHICS_BIT = 0x00008000,
    VK_PIPELINE_STAGE_ALL_COMMANDS_BIT = 0x00010000,
  // Provided by VK_VERSION_1_3
    VK_PIPELINE_STAGE_NONE = 0,
} VkPipelineStageFlagBits;

These values all have the same meaning as the equivalently named values for VkPipelineStageFlags2.

  • VK_PIPELINE_STAGE_NONE specifies no stages of execution.

  • VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT specifies the stage of the pipeline where VkDrawIndirect* / VkDispatchIndirect* / VkTraceRaysIndirect* data structures are consumed.

  • VK_PIPELINE_STAGE_VERTEX_INPUT_BIT specifies the stage of the pipeline where vertex and index buffers are consumed.

  • VK_PIPELINE_STAGE_VERTEX_SHADER_BIT specifies the vertex shader stage.

  • VK_PIPELINE_STAGE_TESSELLATION_CONTROL_SHADER_BIT specifies the tessellation control shader stage.

  • VK_PIPELINE_STAGE_TESSELLATION_EVALUATION_SHADER_BIT specifies the tessellation evaluation shader stage.

  • VK_PIPELINE_STAGE_GEOMETRY_SHADER_BIT specifies the geometry shader stage.

  • VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT specifies the fragment shader stage.

  • VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT specifies the stage of the pipeline where early fragment tests (depth and stencil tests before fragment shading) are performed. This stage also includes subpass load operations for framebuffer attachments with a depth/stencil format.

  • VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT specifies the stage of the pipeline where late fragment tests (depth and stencil tests after fragment shading) are performed. This stage also includes subpass store operations for framebuffer attachments with a depth/stencil format.

  • VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT specifies the stage of the pipeline after blending where the final color values are output from the pipeline. This stage also includes subpass load and store operations, multisample resolve operations for framebuffer attachments with a color or depth/stencil format, and vkCmdClearAttachments.

  • VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT specifies the execution of a compute shader.

  • VK_PIPELINE_STAGE_TRANSFER_BIT specifies the following commands:

  • VK_PIPELINE_STAGE_HOST_BIT specifies a pseudo-stage indicating execution on the host of reads/writes of device memory. This stage is not invoked by any commands recorded in a command buffer.

  • VK_PIPELINE_STAGE_ALL_GRAPHICS_BIT specifies the execution of all graphics pipeline stages, and is equivalent to the logical OR of:

    • VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT

    • VK_PIPELINE_STAGE_VERTEX_INPUT_BIT

    • VK_PIPELINE_STAGE_VERTEX_SHADER_BIT

    • VK_PIPELINE_STAGE_TESSELLATION_CONTROL_SHADER_BIT

    • VK_PIPELINE_STAGE_TESSELLATION_EVALUATION_SHADER_BIT

    • VK_PIPELINE_STAGE_GEOMETRY_SHADER_BIT

    • VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT

    • VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT

    • VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT

    • VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT

  • VK_PIPELINE_STAGE_ALL_COMMANDS_BIT specifies all operations performed by all commands supported on the queue it is used with.

  • VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT is equivalent to VK_PIPELINE_STAGE_ALL_COMMANDS_BIT with VkAccessFlags set to 0 when specified in the second synchronization scope, but specifies no stage of execution when specified in the first scope.

  • VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT is equivalent to VK_PIPELINE_STAGE_ALL_COMMANDS_BIT with VkAccessFlags set to 0 when specified in the first synchronization scope, but specifies no stage of execution when specified in the second scope.

// Provided by VK_VERSION_1_0
typedef VkFlags VkPipelineStageFlags;

VkPipelineStageFlags is a bitmask type for setting a mask of zero or more VkPipelineStageFlagBits.

If a synchronization command includes a source stage mask, its first synchronization scope only includes execution of the pipeline stages specified in that mask and any logically earlier stages. Its first access scope only includes memory accesses performed by pipeline stages explicitly specified in the source stage mask.

If a synchronization command includes a destination stage mask, its second synchronization scope only includes execution of the pipeline stages specified in that mask and any logically later stages. Its second access scope only includes memory accesses performed by pipeline stages explicitly specified in the destination stage mask.

Note

Note that access scopes do not interact with the logically earlier or later stages for either scope - only the stages the app specifies are considered part of each access scope.

Certain pipeline stages are only available on queues that support a particular set of operations. The following table lists, for each pipeline stage flag, which queue capability flag must be supported by the queue. When multiple flags are enumerated in the second column of the table, it means that the pipeline stage is supported on the queue if it supports any of the listed capability flags. For further details on queue capabilities see Physical Device Enumeration and Queues.

Table 3. Supported pipeline stage flags
Pipeline stage flag Required queue capability flag

VK_PIPELINE_STAGE_NONE

None required

VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT

VK_QUEUE_GRAPHICS_BIT or VK_QUEUE_COMPUTE_BIT

VK_PIPELINE_STAGE_2_PRE_RASTERIZATION_SHADERS_BIT
      VK_PIPELINE_STAGE_VERTEX_SHADER_BIT
      VK_PIPELINE_STAGE_TESSELLATION_CONTROL_SHADER_BIT
      VK_PIPELINE_STAGE_TESSELLATION_EVALUATION_SHADER_BIT
      VK_PIPELINE_STAGE_GEOMETRY_SHADER_BIT

VK_QUEUE_GRAPHICS_BIT

VK_PIPELINE_STAGE_2_VERTEX_INPUT_BIT
      VK_PIPELINE_STAGE_2_INDEX_INPUT_BIT
      VK_PIPELINE_STAGE_2_VERTEX_ATTRIBUTE_INPUT_BIT

VK_QUEUE_GRAPHICS_BIT

VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT

VK_QUEUE_GRAPHICS_BIT

VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT

VK_QUEUE_GRAPHICS_BIT

VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT

VK_QUEUE_GRAPHICS_BIT

VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT

VK_QUEUE_GRAPHICS_BIT

VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT

VK_QUEUE_COMPUTE_BIT

VK_PIPELINE_STAGE_HOST_BIT

None required

VK_PIPELINE_STAGE_2_ALL_TRANSFER_BIT
(VK_PIPELINE_STAGE_TRANSFER_BIT)
      VK_PIPELINE_STAGE_2_COPY_BIT
      VK_PIPELINE_STAGE_2_BLIT_BIT
      VK_PIPELINE_STAGE_2_RESOLVE_BIT
      VK_PIPELINE_STAGE_2_CLEAR_BIT
      VK_PIPELINE_STAGE_2_ACCELERATION_STRUCTURE_COPY_BIT_KHR

VK_QUEUE_GRAPHICS_BIT, VK_QUEUE_COMPUTE_BIT or VK_QUEUE_TRANSFER_BIT

VK_PIPELINE_STAGE_ALL_GRAPHICS_BIT

VK_QUEUE_GRAPHICS_BIT

VK_PIPELINE_STAGE_ALL_COMMANDS_BIT

None required

VK_PIPELINE_STAGE_TOP_OF_PIPE_BIT

None required

VK_PIPELINE_STAGE_BOTTOM_OF_PIPE_BIT

None required

Pipeline stages that execute as a result of a command logically complete execution in a specific order, such that completion of a logically later pipeline stage must not happen-before completion of a logically earlier stage. This means that including any stage in the source stage mask for a particular synchronization command also implies that any logically earlier stages are included in Scope1st for that command.

Similarly, initiation of a logically earlier pipeline stage must not happen-after initiation of a logically later pipeline stage. Including any given stage in the destination stage mask for a particular synchronization command also implies that any logically later stages are included in Scope2nd for that command.

Note

Implementations may not support synchronization at every pipeline stage for every synchronization operation. If a pipeline stage that an implementation does not support synchronization for appears in a source stage mask, it may substitute any logically later stage in its place for the first synchronization scope. If a pipeline stage that an implementation does not support synchronization for appears in a destination stage mask, it may substitute any logically earlier stage in its place for the second synchronization scope.

For example, if an implementation is unable to signal an event immediately after vertex shader execution is complete, it may instead signal the event after color attachment output has completed.

If an implementation makes such a substitution, it must not affect the semantics of execution or memory dependencies or image and buffer memory barriers.

Graphics pipelines are executable on queues supporting VK_QUEUE_GRAPHICS_BIT. Stages executed by graphics pipelines can only be specified in commands recorded for queues supporting VK_QUEUE_GRAPHICS_BIT.

The graphics pipeline executes the following stages, with the logical ordering of the stages matching the order specified here:

  • VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT

  • VK_PIPELINE_STAGE_2_INDEX_INPUT_BIT

  • VK_PIPELINE_STAGE_2_VERTEX_ATTRIBUTE_INPUT_BIT

  • VK_PIPELINE_STAGE_VERTEX_SHADER_BIT

  • VK_PIPELINE_STAGE_TESSELLATION_CONTROL_SHADER_BIT

  • VK_PIPELINE_STAGE_TESSELLATION_EVALUATION_SHADER_BIT

  • VK_PIPELINE_STAGE_GEOMETRY_SHADER_BIT

  • VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT

  • VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT

  • VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT

  • VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT

For the compute pipeline, the following stages occur in this order:

  • VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT

  • VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT

For the transfer pipeline, the following stages occur in this order:

  • VK_PIPELINE_STAGE_TRANSFER_BIT

For host operations, only one pipeline stage occurs, so no order is guaranteed:

  • VK_PIPELINE_STAGE_HOST_BIT

7.1.3. Access Types

Memory in Vulkan can be accessed from within shader invocations and via some fixed-function stages of the pipeline. The access type is a function of the descriptor type used, or how a fixed-function stage accesses memory.

Some synchronization commands take sets of access types as parameters to define the access scopes of a memory dependency. If a synchronization command includes a source access mask, its first access scope only includes accesses via the access types specified in that mask. Similarly, if a synchronization command includes a destination access mask, its second access scope only includes accesses via the access types specified in that mask.

Bits which can be set in the srcAccessMask and dstAccessMask members of VkMemoryBarrier2KHR, VkImageMemoryBarrier2KHR, and VkBufferMemoryBarrier2KHR, specifying access behavior, are:

// Provided by VK_VERSION_1_3
// Flag bits for VkAccessFlagBits2
typedef VkFlags64 VkAccessFlagBits2;
static const VkAccessFlagBits2 VK_ACCESS_2_NONE = 0ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_NONE_KHR = 0ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_INDIRECT_COMMAND_READ_BIT = 0x00000001ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_INDIRECT_COMMAND_READ_BIT_KHR = 0x00000001ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_INDEX_READ_BIT = 0x00000002ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_INDEX_READ_BIT_KHR = 0x00000002ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_VERTEX_ATTRIBUTE_READ_BIT = 0x00000004ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_VERTEX_ATTRIBUTE_READ_BIT_KHR = 0x00000004ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_UNIFORM_READ_BIT = 0x00000008ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_UNIFORM_READ_BIT_KHR = 0x00000008ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_INPUT_ATTACHMENT_READ_BIT = 0x00000010ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_INPUT_ATTACHMENT_READ_BIT_KHR = 0x00000010ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_SHADER_READ_BIT = 0x00000020ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_SHADER_READ_BIT_KHR = 0x00000020ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_SHADER_WRITE_BIT = 0x00000040ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_SHADER_WRITE_BIT_KHR = 0x00000040ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_COLOR_ATTACHMENT_READ_BIT = 0x00000080ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_COLOR_ATTACHMENT_READ_BIT_KHR = 0x00000080ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_COLOR_ATTACHMENT_WRITE_BIT = 0x00000100ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_COLOR_ATTACHMENT_WRITE_BIT_KHR = 0x00000100ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_DEPTH_STENCIL_ATTACHMENT_READ_BIT = 0x00000200ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_DEPTH_STENCIL_ATTACHMENT_READ_BIT_KHR = 0x00000200ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT = 0x00000400ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT_KHR = 0x00000400ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_TRANSFER_READ_BIT = 0x00000800ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_TRANSFER_READ_BIT_KHR = 0x00000800ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_TRANSFER_WRITE_BIT = 0x00001000ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_TRANSFER_WRITE_BIT_KHR = 0x00001000ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_HOST_READ_BIT = 0x00002000ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_HOST_READ_BIT_KHR = 0x00002000ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_HOST_WRITE_BIT = 0x00004000ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_HOST_WRITE_BIT_KHR = 0x00004000ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_MEMORY_READ_BIT = 0x00008000ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_MEMORY_READ_BIT_KHR = 0x00008000ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_MEMORY_WRITE_BIT = 0x00010000ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_MEMORY_WRITE_BIT_KHR = 0x00010000ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_SHADER_SAMPLED_READ_BIT = 0x100000000ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_SHADER_SAMPLED_READ_BIT_KHR = 0x100000000ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_SHADER_STORAGE_READ_BIT = 0x200000000ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_SHADER_STORAGE_READ_BIT_KHR = 0x200000000ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_SHADER_STORAGE_WRITE_BIT = 0x400000000ULL;
static const VkAccessFlagBits2 VK_ACCESS_2_SHADER_STORAGE_WRITE_BIT_KHR = 0x400000000ULL;

  • VK_ACCESS_2_NONE specifies no accesses.

  • VK_ACCESS_2_MEMORY_READ_BIT specifies all read accesses. It is always valid in any access mask, and is treated as equivalent to setting all READ access flags that are valid where it is used.

  • VK_ACCESS_2_MEMORY_WRITE_BIT specifies all write accesses. It is always valid in any access mask, and is treated as equivalent to setting all WRITE access flags that are valid where it is used.

  • VK_ACCESS_2_INDIRECT_COMMAND_READ_BIT specifies read access to command data read from indirect buffers as part of an indirect drawing or dispatch command. Such access occurs in the VK_PIPELINE_STAGE_2_DRAW_INDIRECT_BIT pipeline stage.

  • VK_ACCESS_2_INDEX_READ_BIT specifies read access to an index buffer as part of an indexed drawing command, bound by vkCmdBindIndexBuffer. Such access occurs in the VK_PIPELINE_STAGE_2_INDEX_INPUT_BIT pipeline stage.

  • VK_ACCESS_2_VERTEX_ATTRIBUTE_READ_BIT specifies read access to a vertex buffer as part of a drawing command, bound by vkCmdBindVertexBuffers. Such access occurs in the VK_PIPELINE_STAGE_2_VERTEX_ATTRIBUTE_INPUT_BIT pipeline stage.

  • VK_ACCESS_2_UNIFORM_READ_BIT specifies read access to a uniform buffer in any shader pipeline stage.

  • VK_ACCESS_2_INPUT_ATTACHMENT_READ_BIT specifies read access to an input attachment within a render pass during fragment shading. Such access occurs in the VK_PIPELINE_STAGE_2_FRAGMENT_SHADER_BIT pipeline stage.

  • VK_ACCESS_2_SHADER_SAMPLED_READ_BIT specifies read access to a uniform texel buffer or sampled image in any shader pipeline stage.

  • VK_ACCESS_2_SHADER_STORAGE_READ_BIT specifies read access to a storage buffer, physical storage buffer, storage texel buffer, or storage image in any shader pipeline stage.

  • VK_ACCESS_2_SHADER_READ_BIT is equivalent to the logical OR of:

    • VK_ACCESS_2_UNIFORM_READ_BIT

    • VK_ACCESS_2_SHADER_SAMPLED_READ_BIT

    • VK_ACCESS_2_SHADER_STORAGE_READ_BIT

  • VK_ACCESS_2_SHADER_STORAGE_WRITE_BIT specifies write access to a storage buffer, physical storage buffer, storage texel buffer, or storage image in any shader pipeline stage.

  • VK_ACCESS_2_SHADER_WRITE_BIT is equivalent to VK_ACCESS_2_SHADER_STORAGE_WRITE_BIT.

  • VK_ACCESS_2_COLOR_ATTACHMENT_READ_BIT specifies read access to a color attachment, such as via blending, logic operations, or certain subpass load operations. Such access occurs in the VK_PIPELINE_STAGE_2_COLOR_ATTACHMENT_OUTPUT_BIT pipeline stage.

  • VK_ACCESS_2_COLOR_ATTACHMENT_WRITE_BIT specifies write access to a color, resolve, or depth/stencil resolve attachment during a render pass or via certain subpass load and store operations. Such access occurs in the VK_PIPELINE_STAGE_2_COLOR_ATTACHMENT_OUTPUT_BIT pipeline stage.

  • VK_ACCESS_2_DEPTH_STENCIL_ATTACHMENT_READ_BIT specifies read access to a depth/stencil attachment, via depth or stencil operations or certain subpass load operations. Such access occurs in the VK_PIPELINE_STAGE_2_EARLY_FRAGMENT_TESTS_BIT or VK_PIPELINE_STAGE_2_LATE_FRAGMENT_TESTS_BIT pipeline stages.

  • VK_ACCESS_2_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT specifies write access to a depth/stencil attachment, via depth or stencil operations or certain subpass load and store operations. Such access occurs in the VK_PIPELINE_STAGE_2_EARLY_FRAGMENT_TESTS_BIT or VK_PIPELINE_STAGE_2_LATE_FRAGMENT_TESTS_BIT pipeline stages.

  • VK_ACCESS_2_TRANSFER_READ_BIT specifies read access to an image or buffer in a copy operation. Such access occurs in the VK_PIPELINE_STAGE_2_COPY_BIT, VK_PIPELINE_STAGE_2_BLIT_BIT, or VK_PIPELINE_STAGE_2_RESOLVE_BIT pipeline stages.

  • VK_ACCESS_2_TRANSFER_WRITE_BIT specifies write access to an image or buffer in a clear or copy operation. Such access occurs in the VK_PIPELINE_STAGE_2_COPY_BIT, VK_PIPELINE_STAGE_2_BLIT_BIT, VK_PIPELINE_STAGE_2_CLEAR_BIT, or VK_PIPELINE_STAGE_2_RESOLVE_BIT pipeline stages.

  • VK_ACCESS_2_HOST_READ_BIT specifies read access by a host operation. Accesses of this type are not performed through a resource, but directly on memory. Such access occurs in the VK_PIPELINE_STAGE_2_HOST_BIT pipeline stage.

  • VK_ACCESS_2_HOST_WRITE_BIT specifies write access by a host operation. Accesses of this type are not performed through a resource, but directly on memory. Such access occurs in the VK_PIPELINE_STAGE_2_HOST_BIT pipeline stage.

Note

In situations where an application wishes to select all access types for a given set of pipeline stages, VK_ACCESS_2_MEMORY_READ_BIT or VK_ACCESS_2_MEMORY_WRITE_BIT can be used. This is particularly useful when specifying stages that only have a single access type.
Note

The VkAccessFlags2 bitmask goes beyond the 31 individual bit flags allowable within a C99 enum, which is how VkAccessFlagBits is defined. The first 31 values are common to both, and are interchangeable.

VkAccessFlags2 is a bitmask type for setting a mask of zero or more VkAccessFlagBits2:

// Provided by VK_VERSION_1_3
typedef VkFlags64 VkAccessFlags2;

Bits which can be set in the srcAccessMask and dstAccessMask members of VkSubpassDependency, VkMemoryBarrier, VkBufferMemoryBarrier, and VkImageMemoryBarrier, specifying access behavior, are:

// Provided by VK_VERSION_1_0
typedef enum VkAccessFlagBits {
    VK_ACCESS_INDIRECT_COMMAND_READ_BIT = 0x00000001,
    VK_ACCESS_INDEX_READ_BIT = 0x00000002,
    VK_ACCESS_VERTEX_ATTRIBUTE_READ_BIT = 0x00000004,
    VK_ACCESS_UNIFORM_READ_BIT = 0x00000008,
    VK_ACCESS_INPUT_ATTACHMENT_READ_BIT = 0x00000010,
    VK_ACCESS_SHADER_READ_BIT = 0x00000020,
    VK_ACCESS_SHADER_WRITE_BIT = 0x00000040,
    VK_ACCESS_COLOR_ATTACHMENT_READ_BIT = 0x00000080,
    VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT = 0x00000100,
    VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_READ_BIT = 0x00000200,
    VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT = 0x00000400,
    VK_ACCESS_TRANSFER_READ_BIT = 0x00000800,
    VK_ACCESS_TRANSFER_WRITE_BIT = 0x00001000,
    VK_ACCESS_HOST_READ_BIT = 0x00002000,
    VK_ACCESS_HOST_WRITE_BIT = 0x00004000,
    VK_ACCESS_MEMORY_READ_BIT = 0x00008000,
    VK_ACCESS_MEMORY_WRITE_BIT = 0x00010000,
  // Provided by VK_VERSION_1_3
    VK_ACCESS_NONE = 0,
} VkAccessFlagBits;

These values all have the same meaning as the equivalently named values for VkAccessFlags2.

  • VK_ACCESS_NONE specifies no accesses.

  • VK_ACCESS_MEMORY_READ_BIT specifies all read accesses. It is always valid in any access mask, and is treated as equivalent to setting all READ access flags that are valid where it is used.

  • VK_ACCESS_MEMORY_WRITE_BIT specifies all write accesses. It is always valid in any access mask, and is treated as equivalent to setting all WRITE access flags that are valid where it is used.

  • VK_ACCESS_INDIRECT_COMMAND_READ_BIT specifies read access to indirect command data read as part of an indirect drawing or dispatching command. Such access occurs in the VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT pipeline stage.

  • VK_ACCESS_INDEX_READ_BIT specifies read access to an index buffer as part of an indexed drawing command, bound by vkCmdBindIndexBuffer. Such access occurs in the VK_PIPELINE_STAGE_VERTEX_INPUT_BIT pipeline stage.

  • VK_ACCESS_VERTEX_ATTRIBUTE_READ_BIT specifies read access to a vertex buffer as part of a drawing command, bound by vkCmdBindVertexBuffers. Such access occurs in the VK_PIPELINE_STAGE_VERTEX_INPUT_BIT pipeline stage.

  • VK_ACCESS_UNIFORM_READ_BIT specifies read access to a uniform buffer in any shader pipeline stage.

  • VK_ACCESS_INPUT_ATTACHMENT_READ_BIT specifies read access to an input attachment within a render pass during fragment shading. Such access occurs in the VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT pipeline stage.

  • VK_ACCESS_SHADER_READ_BIT specifies read access to a uniform buffer, uniform texel buffer, sampled image, storage buffer, physical storage buffer, storage texel buffer, or storage image in any shader pipeline stage.

  • VK_ACCESS_SHADER_WRITE_BIT specifies write access to a storage buffer, physical storage buffer, storage texel buffer, or storage image in any shader pipeline stage.

  • VK_ACCESS_COLOR_ATTACHMENT_READ_BIT specifies read access to a color attachment, such as via blending, logic operations, or certain subpass load operations.

  • VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT specifies write access to a color, resolve, or depth/stencil resolve attachment during a render pass or via certain subpass load and store operations. Such access occurs in the VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT pipeline stage.

  • VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_READ_BIT specifies read access to a depth/stencil attachment, via depth or stencil operations or certain subpass load operations. Such access occurs in the VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT or VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT pipeline stages.

  • VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT specifies write access to a depth/stencil attachment, via depth or stencil operations or certain subpass load and store operations. Such access occurs in the VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT or VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT pipeline stages.

  • VK_ACCESS_TRANSFER_READ_BIT specifies read access to an image or buffer in a copy operation. Such access occurs in the VK_PIPELINE_STAGE_2_ALL_TRANSFER_BIT pipeline stage.

  • VK_ACCESS_TRANSFER_WRITE_BIT specifies write access to an image or buffer in a clear or copy operation. Such access occurs in the VK_PIPELINE_STAGE_2_ALL_TRANSFER_BIT pipeline stage.

  • VK_ACCESS_HOST_READ_BIT specifies read access by a host operation. Accesses of this type are not performed through a resource, but directly on memory. Such access occurs in the VK_PIPELINE_STAGE_HOST_BIT pipeline stage.

  • VK_ACCESS_HOST_WRITE_BIT specifies write access by a host operation. Accesses of this type are not performed through a resource, but directly on memory. Such access occurs in the VK_PIPELINE_STAGE_HOST_BIT pipeline stage.

Certain access types are only performed by a subset of pipeline stages. Any synchronization command that takes both stage masks and access masks uses both to define the access scopes - only the specified access types performed by the specified stages are included in the access scope. An application must not specify an access flag in a synchronization command if it does not include a pipeline stage in the corresponding stage mask that is able to perform accesses of that type. The following table lists, for each access flag, which pipeline stages can perform that type of access.

Table 4. Supported access types
Access flag Supported pipeline stages

VK_ACCESS_INDIRECT_COMMAND_READ_BIT

VK_PIPELINE_STAGE_DRAW_INDIRECT_BIT

VK_ACCESS_INDEX_READ_BIT

VK_PIPELINE_STAGE_VERTEX_INPUT_BIT

VK_ACCESS_VERTEX_ATTRIBUTE_READ_BIT

VK_PIPELINE_STAGE_VERTEX_INPUT_BIT

VK_ACCESS_UNIFORM_READ_BIT

VK_PIPELINE_STAGE_VERTEX_SHADER_BIT, VK_PIPELINE_STAGE_TESSELLATION_CONTROL_SHADER_BIT, VK_PIPELINE_STAGE_TESSELLATION_EVALUATION_SHADER_BIT, VK_PIPELINE_STAGE_GEOMETRY_SHADER_BIT, VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT, or VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT

VK_ACCESS_SHADER_READ_BIT

VK_PIPELINE_STAGE_VERTEX_SHADER_BIT, VK_PIPELINE_STAGE_TESSELLATION_CONTROL_SHADER_BIT, VK_PIPELINE_STAGE_TESSELLATION_EVALUATION_SHADER_BIT, VK_PIPELINE_STAGE_GEOMETRY_SHADER_BIT, VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT, or VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT

VK_ACCESS_SHADER_WRITE_BIT

VK_PIPELINE_STAGE_VERTEX_SHADER_BIT, VK_PIPELINE_STAGE_TESSELLATION_CONTROL_SHADER_BIT, VK_PIPELINE_STAGE_TESSELLATION_EVALUATION_SHADER_BIT, VK_PIPELINE_STAGE_GEOMETRY_SHADER_BIT, VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT, or VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT

VK_ACCESS_INPUT_ATTACHMENT_READ_BIT

VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT

VK_ACCESS_COLOR_ATTACHMENT_READ_BIT

VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT

VK_ACCESS_COLOR_ATTACHMENT_WRITE_BIT

VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT

VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_READ_BIT

VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT, or VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT

VK_ACCESS_DEPTH_STENCIL_ATTACHMENT_WRITE_BIT

VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT, or VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT

VK_ACCESS_TRANSFER_READ_BIT

VK_PIPELINE_STAGE_TRANSFER_BIT

VK_ACCESS_TRANSFER_WRITE_BIT

VK_PIPELINE_STAGE_TRANSFER_BIT

VK_ACCESS_HOST_READ_BIT

VK_PIPELINE_STAGE_HOST_BIT

VK_ACCESS_HOST_WRITE_BIT

VK_PIPELINE_STAGE_HOST_BIT

VK_ACCESS_MEMORY_READ_BIT

Any

VK_ACCESS_MEMORY_WRITE_BIT

Any

 
// Provided by VK_VERSION_1_0
typedef VkFlags VkAccessFlags;

VkAccessFlags is a bitmask type for setting a mask of zero or more VkAccessFlagBits.

If a memory object does not have the VK_MEMORY_PROPERTY_HOST_COHERENT_BIT property, then vkFlushMappedMemoryRanges must be called in order to guarantee that writes to the memory object from the host are made available to the host domain, where they can be further made available to the device domain via a domain operation. Similarly, vkInvalidateMappedMemoryRanges must be called to guarantee that writes which are available to the host domain are made visible to host operations.

If the memory object does have the VK_MEMORY_PROPERTY_HOST_COHERENT_BIT property flag, writes to the memory object from the host are automatically made available to the host domain. Similarly, writes made available to the host domain are automatically made visible to the host.

Note

Queue submission commands automatically perform a domain operation from host to device for all writes performed before the command executes, so in most cases an explicit memory barrier is not needed for this case. In the few circumstances where a submit does not occur between the host write and the device read access, writes can be made available by using an explicit memory barrier.

7.1.4. Framebuffer Region Dependencies

Pipeline stages that operate on, or with respect to, the framebuffer are collectively the framebuffer-space pipeline stages. These stages are:

  • VK_PIPELINE_STAGE_FRAGMENT_SHADER_BIT

  • VK_PIPELINE_STAGE_EARLY_FRAGMENT_TESTS_BIT

  • VK_PIPELINE_STAGE_LATE_FRAGMENT_TESTS_BIT

  • VK_PIPELINE_STAGE_COLOR_ATTACHMENT_OUTPUT_BIT

For these pipeline stages, an execution or memory dependency from the first set of operations to the second set can either be a single framebuffer-global dependency, or split into multiple framebuffer-local dependencies. A dependency with non-framebuffer-space pipeline stages is neither framebuffer-global nor framebuffer-local.

A framebuffer region is a set of sample (x, y, layer, sample) coordinates that is a subset of the entire framebuffer.

Both synchronization scopes of a framebuffer-local dependency include only the operations performed within corresponding framebuffer regions (as defined below). No ordering guarantees are made between different framebuffer regions for a framebuffer-local dependency.

Both synchronization scopes of a framebuffer-global dependency include operations on all framebuffer-regions.

If the first synchronization scope includes operations on pixels/fragments with N samples and the second synchronization scope includes operations on pixels/fragments with M samples, where N does not equal M, then a framebuffer region containing all samples at a given (x, y, layer) coordinate in the first synchronization scope corresponds to a region containing all samples at the same coordinate in the second synchronization scope. In other words, it is a pixel granularity dependency. If N equals M, then a framebuffer region containing a single (x, y, layer, sample) coordinate in the first synchronization scope corresponds to a region containing the same sample at the same coordinate in the second synchronization scope. In other words, it is a sample granularity dependency.

Note

Since fragment shader invocations are not specified to run in any particular groupings, the size of a framebuffer region is implementation-dependent, not known to the application, and must be assumed to be no larger than specified above.
Note

Practically, the pixel vs. sample granularity dependency means that if an input attachment has a different number of samples than the pipeline’s rasterizationSamples, then a fragment can access any sample in the input attachment’s pixel even if it only uses framebuffer-local dependencies. If the input attachment has the same number of samples, then the fragment can only access the covered samples in its input SampleMask (i.e. the fragment operations happen-after a framebuffer-local dependency for each sample the fragment covers). To access samples that are not covered, a framebuffer-global dependency is required.

If a synchronization command includes a dependencyFlags parameter, and specifies the VK_DEPENDENCY_BY_REGION_BIT flag, then it defines framebuffer-local dependencies for the framebuffer-space pipeline stages in that synchronization command, for all framebuffer regions. If no dependencyFlags parameter is included, or the VK_DEPENDENCY_BY_REGION_BIT flag is not specified, then a framebuffer-global dependency is specified for those stages. The VK_DEPENDENCY_BY_REGION_BIT flag does not affect the dependencies between non-framebuffer-space pipeline stages, nor does it affect the dependencies between framebuffer-space and non-framebuffer-space pipeline stages.

Note

Framebuffer-local dependencies are more efficient for most architectures; particularly tile-based architectures - which can keep framebuffer-regions entirely in on-chip registers and thus avoid external bandwidth across such a dependency. Including a framebuffer-global dependency in your rendering will usually force all implementations to flush data to memory, or to a higher level cache, breaking any potential locality optimizations.

7.1.5. View-Local Dependencies

In a render pass instance that has multiview enabled, dependencies can be either view-local or view-global.

A view-local dependency only includes operations from a single source view from the source subpass in the first synchronization scope, and only includes operations from a single destination view from the destination subpass in the second synchronization scope. A view-global dependency includes all views in the view mask of the source and destination subpasses in the corresponding synchronization scopes.

If a synchronization command includes a dependencyFlags parameter and specifies the VK_DEPENDENCY_VIEW_LOCAL_BIT flag, then it defines view-local dependencies for that synchronization command, for all views. If no dependencyFlags parameter is included or the VK_DEPENDENCY_VIEW_LOCAL_BIT flag is not specified, then a view-global dependency is specified.

7.1.6. Device-Local Dependencies

Dependencies can be either device-local or non-device-local. A device-local dependency acts as multiple separate dependencies, one for each physical device that executes the synchronization command, where each dependency only includes operations from that physical device in both synchronization scopes. A non-device-local dependency is a single dependency where both synchronization scopes include operations from all physical devices that participate in the synchronization command. For subpass dependencies, all physical devices in the VkDeviceGroupRenderPassBeginInfo::deviceMask participate in the dependency, and for pipeline barriers all physical devices that are set in the command buffer’s current device mask participate in the dependency.

If a synchronization command includes a dependencyFlags parameter and specifies the VK_DEPENDENCY_DEVICE_GROUP_BIT flag, then it defines a non-device-local dependency for that synchronization command. If no dependencyFlags parameter is included or the VK_DEPENDENCY_DEVICE_GROUP_BIT flag is not specified, then it defines device-local dependencies for that synchronization command, for all participating physical devices.

Semaphore and event dependencies are device-local and only execute on the one physical device that performs the dependency.

7.2. Implicit Synchronization Guarantees

A small number of implicit ordering guarantees are provided by Vulkan, ensuring that the order in which commands are submitted is meaningful, and avoiding unnecessary complexity in common operations.

Submission order is a fundamental ordering in Vulkan, giving meaning to the order in which action and synchronization commands are recorded and submitted to a single queue. Explicit and implicit ordering guarantees between commands in Vulkan all work on the premise that this ordering is meaningful. This order does not itself define any execution or memory dependencies; synchronization commands and other orderings within the API use this ordering to define their scopes.

Submission order for any given set of commands is based on the order in which they were recorded to command buffers and then submitted. This order is determined as follows:

  1. The initial order is determined by the order in which vkQueueSubmit and vkQueueSubmit2 commands are executed on the host, for a single queue, from first to last.

  2. The order in which VkSubmitInfo structures are specified in the pSubmits parameter of vkQueueSubmit, or in which VkSubmitInfo2 structures are specified in the pSubmits parameter of vkQueueSubmit2, from lowest index to highest.

  3. The order in which command buffers are specified in the pCommandBuffers member of VkSubmitInfo or VkSubmitInfo2 from lowest index to highest.

  4. The order in which commands were recorded to a command buffer on the host, from first to last:

    • For commands recorded outside a render pass, this includes all other commands recorded outside a render pass, including vkCmdBeginRenderPass and vkCmdEndRenderPass commands; it does not directly include commands inside a render pass.

    • For commands recorded inside a render pass, this includes all other commands recorded inside the same subpass, including the vkCmdBeginRenderPass and vkCmdEndRenderPass commands that delimit the same render pass instance; it does not include commands recorded to other subpasses. State commands do not execute any operations on the device, instead they set the state of the command buffer when they execute on the host, in the order that they are recorded. Action commands consume the current state of the command buffer when they are recorded, and will execute state changes on the device as required to match the recorded state.

The order of primitives passing through the graphics pipeline and image layout transitions as part of an image memory barrier provide additional guarantees based on submission order.

Execution of pipeline stages within a given command also has a loose ordering, dependent only on a single command.

Signal operation order is a fundamental ordering in Vulkan, giving meaning to the order in which semaphore and fence signal operations occur when submitted to a single queue. The signal operation order for queue operations is determined as follows:

  1. The initial order is determined by the order in which vkQueueSubmit and vkQueueSubmit2 commands are executed on the host, for a single queue, from first to last.

  2. The order in which VkSubmitInfo structures are specified in the pSubmits parameter of vkQueueSubmit, or in which VkSubmitInfo2 structures are specified in the pSubmits parameter of vkQueueSubmit2, from lowest index to highest.

  3. The fence signal operation defined by the fence parameter of a vkQueueSubmit, vkQueueSubmit2, or vkQueueBindSparse command is ordered after all semaphore signal operations defined by that command.

Semaphore signal operations defined by a single VkSubmitInfo, VkSubmitInfo2, or VkBindSparseInfo structure are unordered with respect to other semaphore signal operations defined within the same structure.

The vkSignalSemaphore command does not execute on a queue but instead performs the signal operation from the host. The semaphore signal operation defined by executing a vkSignalSemaphore command happens-after the vkSignalSemaphore command is invoked and happens-before the command returns.

Note

When signaling timeline semaphores, it is the responsibility of the application to ensure that they are ordered such that the semaphore value is strictly increasing. Because the first synchronization scope for a semaphore signal operation contains all semaphore signal operations which occur earlier in submission order, all semaphore signal operations contained in any given batch are guaranteed to happen-after all semaphore signal operations contained in any previous batches. However, no ordering guarantee is provided between the semaphore signal operations defined within a single batch. This, combined with the requirement that timeline semaphore values strictly increase, means that it is invalid to signal the same timeline semaphore twice within a single batch.

If an application wishes to ensure that some semaphore signal operation happens-after some other semaphore signal operation, it can submit a separate batch containing only semaphore signal operations, which will happen-after the semaphore signal operations in any earlier batches.

When signaling a semaphore from the host, the only ordering guarantee is that the signal operation happens-after when vkSignalSemaphore is called and happens-before it returns. Therefore, it is invalid to call vkSignalSemaphore while there are any outstanding signal operations on that semaphore from any queue submissions unless those queue submissions have some dependency which ensures that they happen-after the host signal operation. One example of this would be if the pending signal operation is, itself, waiting on the same semaphore at a lower value and the call to vkSignalSemaphore signals that lower value. Furthermore, if there are two or more processes or threads signaling the same timeline semaphore from the host, the application must ensure that the vkSignalSemaphore with the lower semaphore value returns before vkSignalSemaphore is called with the higher value.

7.3. Fences

Fences are a synchronization primitive that can be used to insert a dependency from a queue to the host. Fences have two states - signaled and unsignaled. A fence can be signaled as part of the execution of a queue submission command. Fences can be unsignaled on the host with vkResetFences. Fences can be waited on by the host with the vkWaitForFences command, and the current state can be queried with vkGetFenceStatus.

The internal data of a fence may include a reference to any resources and pending work associated with signal or unsignal operations performed on that fence object, collectively referred to as the fence’s payload. Mechanisms to import and export that internal data to and from fences are provided below. These mechanisms indirectly enable applications to share fence state between two or more fences and other synchronization primitives across process and API boundaries.

Fences are represented by VkFence handles:

// Provided by VK_VERSION_1_0
VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkFence)

To create a fence, call:

// Provided by VK_VERSION_1_0
VkResult vkCreateFence(
    VkDevice                                    device,
    const VkFenceCreateInfo*                    pCreateInfo,
    const VkAllocationCallbacks*                pAllocator,
    VkFence*                                    pFence);

  • device is the logical device that creates the fence.

  • pCreateInfo is a pointer to a VkFenceCreateInfo structure containing information about how the fence is to be created.

  • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

  • pFence is a pointer to a handle in which the resulting fence object is returned.

Valid Usage (Implicit)

  • VUID-vkCreateFence-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkCreateFence-pCreateInfo-parameter
    pCreateInfo must be a valid pointer to a valid VkFenceCreateInfo structure

  • VUID-vkCreateFence-pAllocator-parameter
    If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

  • VUID-vkCreateFence-pFence-parameter
    pFence must be a valid pointer to a VkFence handle

Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

The VkFenceCreateInfo structure is defined as:

// Provided by VK_VERSION_1_0
typedef struct VkFenceCreateInfo {
    VkStructureType       sType;
    const void*           pNext;
    VkFenceCreateFlags    flags;
} VkFenceCreateInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • flags is a bitmask of VkFenceCreateFlagBits specifying the initial state and behavior of the fence.

Valid Usage (Implicit)

  • VUID-VkFenceCreateInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_FENCE_CREATE_INFO

  • VUID-VkFenceCreateInfo-pNext-pNext
    pNext must be NULL or a pointer to a valid instance of VkExportFenceCreateInfo

  • VUID-VkFenceCreateInfo-sType-unique
    The sType value of each struct in the pNext chain must be unique

  • VUID-VkFenceCreateInfo-flags-parameter
    flags must be a valid combination of VkFenceCreateFlagBits values

// Provided by VK_VERSION_1_0
typedef enum VkFenceCreateFlagBits {
    VK_FENCE_CREATE_SIGNALED_BIT = 0x00000001,
} VkFenceCreateFlagBits;

  • VK_FENCE_CREATE_SIGNALED_BIT specifies that the fence object is created in the signaled state. Otherwise, it is created in the unsignaled state.

// Provided by VK_VERSION_1_0
typedef VkFlags VkFenceCreateFlags;

VkFenceCreateFlags is a bitmask type for setting a mask of zero or more VkFenceCreateFlagBits.

To create a fence whose payload can be exported to external handles, add a VkExportFenceCreateInfo structure to the pNext chain of the VkFenceCreateInfo structure. The VkExportFenceCreateInfo structure is defined as:

// Provided by VK_VERSION_1_1
typedef struct VkExportFenceCreateInfo {
    VkStructureType                   sType;
    const void*                       pNext;
    VkExternalFenceHandleTypeFlags    handleTypes;
} VkExportFenceCreateInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • handleTypes is a bitmask of VkExternalFenceHandleTypeFlagBits specifying one or more fence handle types the application can export from the resulting fence. The application can request multiple handle types for the same fence.

Valid Usage

  • VUID-VkExportFenceCreateInfo-handleTypes-01446
    The bits in handleTypes must be supported and compatible, as reported by VkExternalFenceProperties

Valid Usage (Implicit)

  • VUID-VkExportFenceCreateInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_EXPORT_FENCE_CREATE_INFO

  • VUID-VkExportFenceCreateInfo-handleTypes-parameter
    handleTypes must be a valid combination of VkExternalFenceHandleTypeFlagBits values

To destroy a fence, call:

// Provided by VK_VERSION_1_0
void vkDestroyFence(
    VkDevice                                    device,
    VkFence                                     fence,
    const VkAllocationCallbacks*                pAllocator);

  • device is the logical device that destroys the fence.

  • fence is the handle of the fence to destroy.

  • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

Valid Usage

  • VUID-vkDestroyFence-fence-01120
    All queue submission commands that refer to fence must have completed execution

  • VUID-vkDestroyFence-fence-01121
    If VkAllocationCallbacks were provided when fence was created, a compatible set of callbacks must be provided here

  • VUID-vkDestroyFence-fence-01122
    If no VkAllocationCallbacks were provided when fence was created, pAllocator must be NULL

Valid Usage (Implicit)

  • VUID-vkDestroyFence-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkDestroyFence-fence-parameter
    If fence is not VK_NULL_HANDLE, fence must be a valid VkFence handle

  • VUID-vkDestroyFence-pAllocator-parameter
    If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

  • VUID-vkDestroyFence-fence-parent
    If fence is a valid handle, it must have been created, allocated, or retrieved from device

Host Synchronization

  • Host access to fence must be externally synchronized

To query the status of a fence from the host, call:

// Provided by VK_VERSION_1_0
VkResult vkGetFenceStatus(
    VkDevice                                    device,
    VkFence                                     fence);

  • device is the logical device that owns the fence.

  • fence is the handle of the fence to query.

Upon success, vkGetFenceStatus returns the status of the fence object, with the following return codes:

Table 5. Fence Object Status Codes
Status Meaning

VK_SUCCESS

The fence specified by fence is signaled.

VK_NOT_READY

The fence specified by fence is unsignaled.

VK_ERROR_DEVICE_LOST

The device has been lost. See Lost Device.

If a queue submission command is pending execution, then the value returned by this command may immediately be out of date.

If the device has been lost (see Lost Device), vkGetFenceStatus may return any of the above status codes. If the device has been lost and vkGetFenceStatus is called repeatedly, it will eventually return either VK_SUCCESS or VK_ERROR_DEVICE_LOST.

Valid Usage (Implicit)

  • VUID-vkGetFenceStatus-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkGetFenceStatus-fence-parameter
    fence must be a valid VkFence handle

  • VUID-vkGetFenceStatus-fence-parent
    fence must have been created, allocated, or retrieved from device

Return Codes
Success

  • VK_SUCCESS

  • VK_NOT_READY

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

  • VK_ERROR_DEVICE_LOST

To set the state of fences to unsignaled from the host, call:

// Provided by VK_VERSION_1_0
VkResult vkResetFences(
    VkDevice                                    device,
    uint32_t                                    fenceCount,
    const VkFence*                              pFences);

  • device is the logical device that owns the fences.

  • fenceCount is the number of fences to reset.

  • pFences is a pointer to an array of fence handles to reset.

If any member of pFences currently has its payload imported with temporary permanence, that fence’s prior permanent payload is first restored. The remaining operations described therefore operate on the restored payload.

When vkResetFences is executed on the host, it defines a fence unsignal operation for each fence, which resets the fence to the unsignaled state.

If any member of pFences is already in the unsignaled state when vkResetFences is executed, then vkResetFences has no effect on that fence.

Valid Usage

  • VUID-vkResetFences-pFences-01123
    Each element of pFences must not be currently associated with any queue command that has not yet completed execution on that queue

Valid Usage (Implicit)

  • VUID-vkResetFences-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkResetFences-pFences-parameter
    pFences must be a valid pointer to an array of fenceCount valid VkFence handles

  • VUID-vkResetFences-fenceCount-arraylength
    fenceCount must be greater than 0

  • VUID-vkResetFences-pFences-parent
    Each element of pFences must have been created, allocated, or retrieved from device

Host Synchronization

  • Host access to each member of pFences must be externally synchronized

Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

When a fence is submitted to a queue as part of a queue submission command, it defines a memory dependency on the batches that were submitted as part of that command, and defines a fence signal operation which sets the fence to the signaled state.

The first synchronization scope includes every batch submitted in the same queue submission command. Fence signal operations that are defined by vkQueueSubmit or vkQueueSubmit2 additionally include in the first synchronization scope all commands that occur earlier in submission order. Fence signal operations that are defined by vkQueueSubmit , vkQueueSubmit2 or vkQueueBindSparse additionally include in the first synchronization scope any semaphore and fence signal operations that occur earlier in signal operation order.

The second synchronization scope only includes the fence signal operation.

The first access scope includes all memory access performed by the device.

The second access scope is empty.

To wait for one or more fences to enter the signaled state on the host, call:

// Provided by VK_VERSION_1_0
VkResult vkWaitForFences(
    VkDevice                                    device,
    uint32_t                                    fenceCount,
    const VkFence*                              pFences,
    VkBool32                                    waitAll,
    uint64_t                                    timeout);

  • device is the logical device that owns the fences.

  • fenceCount is the number of fences to wait on.

  • pFences is a pointer to an array of fenceCount fence handles.

  • waitAll is the condition that must be satisfied to successfully unblock the wait. If waitAll is VK_TRUE, then the condition is that all fences in pFences are signaled. Otherwise, the condition is that at least one fence in pFences is signaled.

  • timeout is the timeout period in units of nanoseconds. timeout is adjusted to the closest value allowed by the implementation-dependent timeout accuracy, which may be substantially longer than one nanosecond, and may be longer than the requested period.

If the condition is satisfied when vkWaitForFences is called, then vkWaitForFences returns immediately. If the condition is not satisfied at the time vkWaitForFences is called, then vkWaitForFences will block and wait until the condition is satisfied or the timeout has expired, whichever is sooner.

If timeout is zero, then vkWaitForFences does not wait, but simply returns the current state of the fences. VK_TIMEOUT will be returned in this case if the condition is not satisfied, even though no actual wait was performed.

If the condition is satisfied before the timeout has expired, vkWaitForFences returns VK_SUCCESS. Otherwise, vkWaitForFences returns VK_TIMEOUT after the timeout has expired.

If device loss occurs (see Lost Device) before the timeout has expired, vkWaitForFences must return in finite time with either VK_SUCCESS or VK_ERROR_DEVICE_LOST.

Note

While we guarantee that vkWaitForFences must return in finite time, no guarantees are made that it returns immediately upon device loss. However, the client can reasonably expect that the delay will be on the order of seconds and that calling vkWaitForFences will not result in a permanently (or seemingly permanently) dead process.
Valid Usage (Implicit)

  • VUID-vkWaitForFences-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkWaitForFences-pFences-parameter
    pFences must be a valid pointer to an array of fenceCount valid VkFence handles

  • VUID-vkWaitForFences-fenceCount-arraylength
    fenceCount must be greater than 0

  • VUID-vkWaitForFences-pFences-parent
    Each element of pFences must have been created, allocated, or retrieved from device

Return Codes
Success

  • VK_SUCCESS

  • VK_TIMEOUT

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

  • VK_ERROR_DEVICE_LOST

An execution dependency is defined by waiting for a fence to become signaled, either via vkWaitForFences or by polling on vkGetFenceStatus.

The first synchronization scope includes only the fence signal operation.

The second synchronization scope includes the host operations of vkWaitForFences or vkGetFenceStatus indicating that the fence has become signaled.

Note

Signaling a fence and waiting on the host does not guarantee that the results of memory accesses will be visible to the host, as the access scope of a memory dependency defined by a fence only includes device access. A memory barrier or other memory dependency must be used to guarantee this. See the description of host access types for more information.

7.3.1. Importing Fence Payloads

Applications can import a fence payload into an existing fence using an external fence handle. The effects of the import operation will be either temporary or permanent, as specified by the application. If the import is temporary, the fence will be restored to its permanent state the next time that fence is passed to vkResetFences.

Note

Restoring a fence to its prior permanent payload is a distinct operation from resetting a fence payload. See vkResetFences for more detail.

Performing a subsequent temporary import on a fence before resetting it has no effect on this requirement; the next unsignal of the fence must still restore its last permanent state. A permanent payload import behaves as if the target fence was destroyed, and a new fence was created with the same handle but the imported payload. Because importing a fence payload temporarily or permanently detaches the existing payload from a fence, similar usage restrictions to those applied to vkDestroyFence are applied to any command that imports a fence payload. Which of these import types is used is referred to as the import operation’s permanence. Each handle type supports either one or both types of permanence.

The implementation must perform the import operation by either referencing or copying the payload referred to by the specified external fence handle, depending on the handle’s type. The import method used is referred to as the handle type’s transference. When using handle types with reference transference, importing a payload to a fence adds the fence to the set of all fences sharing that payload. This set includes the fence from which the payload was exported. Fence signaling, waiting, and resetting operations performed on any fence in the set must behave as if the set were a single fence. Importing a payload using handle types with copy transference creates a duplicate copy of the payload at the time of import, but makes no further reference to it. Fence signaling, waiting, and resetting operations performed on the target of copy imports must not affect any other fence or payload.

Export operations have the same transference as the specified handle type’s import operations. Additionally, exporting a fence payload to a handle with copy transference has the same side effects on the source fence’s payload as executing a fence reset operation. If the fence was using a temporarily imported payload, the fence’s prior permanent payload will be restored.

External synchronization allows implementations to modify an object’s internal state, i.e. payload, without internal synchronization. However, for fences sharing a payload across processes, satisfying the external synchronization requirements of VkFence parameters as if all fences in the set were the same object is sometimes infeasible. Satisfying valid usage constraints on the state of a fence would similarly require impractical coordination or levels of trust between processes. Therefore, these constraints only apply to a specific fence handle, not to its payload. For distinct fence objects which share a payload:

  • If multiple commands which queue a signal operation, or which unsignal a fence, are called concurrently, behavior will be as if the commands were called in an arbitrary sequential order.

  • If a queue submission command is called with a fence that is sharing a payload, and the payload is already associated with another queue command that has not yet completed execution, either one or both of the commands will cause the fence to become signaled when they complete execution.

  • If a fence payload is reset while it is associated with a queue command that has not yet completed execution, the payload will become unsignaled, but may become signaled again when the command completes execution.

  • In the preceding cases, any of the devices associated with the fences sharing the payload may be lost, or any of the queue submission or fence reset commands may return VK_ERROR_INITIALIZATION_FAILED.

Other than these non-deterministic results, behavior is well defined. In particular:

  • The implementation must not crash or enter an internally inconsistent state where future valid Vulkan commands might cause undefined results,

  • Timeouts on future wait commands on fences sharing the payload must be effective.

Note

These rules allow processes to synchronize access to shared memory without trusting each other. However, such processes must still be cautious not to use the shared fence for more than synchronizing access to the shared memory. For example, a process should not use a fence with shared payload to tell when commands it submitted to a queue have completed and objects used by those commands may be destroyed, since the other process can accidentally or maliciously cause the fence to signal before the commands actually complete.

When a fence is using an imported payload, its VkExportFenceCreateInfo::handleTypes value is specified when creating the fence from which the payload was exported, rather than specified when creating the fence. Additionally, VkExternalFenceProperties::exportFromImportedHandleTypes restricts which handle types can be exported from such a fence based on the specific handle type used to import the current payload.

When importing a fence payload, it is the responsibility of the application to ensure the external handles meet all valid usage requirements. However, implementations must perform sufficient validation of external handles to ensure that the operation results in a valid fence which will not cause program termination, device loss, queue stalls, host thread stalls, or corruption of other resources when used as allowed according to its import parameters. If the external handle provided does not meet these requirements, the implementation must fail the fence payload import operation with the error code VK_ERROR_INVALID_EXTERNAL_HANDLE.

7.4. Semaphores

Semaphores are a synchronization primitive that can be used to insert a dependency between queue operations or between a queue operation and the host. Binary semaphores have two states - signaled and unsignaled. Timeline semaphores have a strictly increasing 64-bit unsigned integer payload and are signaled with respect to a particular reference value. A semaphore can be signaled after execution of a queue operation is completed, and a queue operation can wait for a semaphore to become signaled before it begins execution. A timeline semaphore can additionally be signaled from the host with the vkSignalSemaphore command and waited on from the host with the vkWaitSemaphores command.

The internal data of a semaphore may include a reference to any resources and pending work associated with signal or unsignal operations performed on that semaphore object, collectively referred to as the semaphore’s payload. Mechanisms to import and export that internal data to and from semaphores are provided below. These mechanisms indirectly enable applications to share semaphore state between two or more semaphores and other synchronization primitives across process and API boundaries.

Semaphores are represented by VkSemaphore handles:

// Provided by VK_VERSION_1_0
VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkSemaphore)

To create a semaphore, call:

// Provided by VK_VERSION_1_0
VkResult vkCreateSemaphore(
    VkDevice                                    device,
    const VkSemaphoreCreateInfo*                pCreateInfo,
    const VkAllocationCallbacks*                pAllocator,
    VkSemaphore*                                pSemaphore);

  • device is the logical device that creates the semaphore.

  • pCreateInfo is a pointer to a VkSemaphoreCreateInfo structure containing information about how the semaphore is to be created.

  • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

  • pSemaphore is a pointer to a handle in which the resulting semaphore object is returned.

Valid Usage (Implicit)

  • VUID-vkCreateSemaphore-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkCreateSemaphore-pCreateInfo-parameter
    pCreateInfo must be a valid pointer to a valid VkSemaphoreCreateInfo structure

  • VUID-vkCreateSemaphore-pAllocator-parameter
    If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

  • VUID-vkCreateSemaphore-pSemaphore-parameter
    pSemaphore must be a valid pointer to a VkSemaphore handle

Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

The VkSemaphoreCreateInfo structure is defined as:

// Provided by VK_VERSION_1_0
typedef struct VkSemaphoreCreateInfo {
    VkStructureType           sType;
    const void*               pNext;
    VkSemaphoreCreateFlags    flags;
} VkSemaphoreCreateInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • flags is reserved for future use.

Valid Usage (Implicit)

  • VUID-VkSemaphoreCreateInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_SEMAPHORE_CREATE_INFO

  • VUID-VkSemaphoreCreateInfo-pNext-pNext
    Each pNext member of any structure (including this one) in the pNext chain must be either NULL or a pointer to a valid instance of VkExportSemaphoreCreateInfo or VkSemaphoreTypeCreateInfo

  • VUID-VkSemaphoreCreateInfo-sType-unique
    The sType value of each struct in the pNext chain must be unique

  • VUID-VkSemaphoreCreateInfo-flags-zerobitmask
    flags must be 0

// Provided by VK_VERSION_1_0
typedef VkFlags VkSemaphoreCreateFlags;

VkSemaphoreCreateFlags is a bitmask type for setting a mask, but is currently reserved for future use.

The VkSemaphoreTypeCreateInfo structure is defined as:

// Provided by VK_VERSION_1_2
typedef struct VkSemaphoreTypeCreateInfo {
    VkStructureType    sType;
    const void*        pNext;
    VkSemaphoreType    semaphoreType;
    uint64_t           initialValue;
} VkSemaphoreTypeCreateInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • semaphoreType is a VkSemaphoreType value specifying the type of the semaphore.

  • initialValue is the initial payload value if semaphoreType is VK_SEMAPHORE_TYPE_TIMELINE.

To create a semaphore of a specific type, add a VkSemaphoreTypeCreateInfo structure to the VkSemaphoreCreateInfo::pNext chain.

If no VkSemaphoreTypeCreateInfo structure is included in the pNext chain of VkSemaphoreCreateInfo, then the created semaphore will have a default VkSemaphoreType of VK_SEMAPHORE_TYPE_BINARY.

Valid Usage

  • VUID-VkSemaphoreTypeCreateInfo-timelineSemaphore-03252
    If the timelineSemaphore feature is not enabled, semaphoreType must not equal VK_SEMAPHORE_TYPE_TIMELINE

  • VUID-VkSemaphoreTypeCreateInfo-semaphoreType-03279
    If semaphoreType is VK_SEMAPHORE_TYPE_BINARY, initialValue must be zero

Valid Usage (Implicit)

  • VUID-VkSemaphoreTypeCreateInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_SEMAPHORE_TYPE_CREATE_INFO

  • VUID-VkSemaphoreTypeCreateInfo-semaphoreType-parameter
    semaphoreType must be a valid VkSemaphoreType value

Possible values of VkSemaphoreTypeCreateInfo::semaphoreType, specifying the type of a semaphore, are:

// Provided by VK_VERSION_1_2
typedef enum VkSemaphoreType {
    VK_SEMAPHORE_TYPE_BINARY = 0,
    VK_SEMAPHORE_TYPE_TIMELINE = 1,
} VkSemaphoreType;

  • VK_SEMAPHORE_TYPE_BINARY specifies a binary semaphore type that has a boolean payload indicating whether the semaphore is currently signaled or unsignaled. When created, the semaphore is in the unsignaled state.

  • VK_SEMAPHORE_TYPE_TIMELINE specifies a timeline semaphore type that has a strictly increasing 64-bit unsigned integer payload indicating whether the semaphore is signaled with respect to a particular reference value. When created, the semaphore payload has the value given by the initialValue field of VkSemaphoreTypeCreateInfo.

To create a semaphore whose payload can be exported to external handles, add a VkExportSemaphoreCreateInfo structure to the pNext chain of the VkSemaphoreCreateInfo structure. The VkExportSemaphoreCreateInfo structure is defined as:

// Provided by VK_VERSION_1_1
typedef struct VkExportSemaphoreCreateInfo {
    VkStructureType                       sType;
    const void*                           pNext;
    VkExternalSemaphoreHandleTypeFlags    handleTypes;
} VkExportSemaphoreCreateInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • handleTypes is a bitmask of VkExternalSemaphoreHandleTypeFlagBits specifying one or more semaphore handle types the application can export from the resulting semaphore. The application can request multiple handle types for the same semaphore.

Valid Usage

  • VUID-VkExportSemaphoreCreateInfo-handleTypes-01124
    The bits in handleTypes must be supported and compatible, as reported by VkExternalSemaphoreProperties

Valid Usage (Implicit)

  • VUID-VkExportSemaphoreCreateInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_EXPORT_SEMAPHORE_CREATE_INFO

  • VUID-VkExportSemaphoreCreateInfo-handleTypes-parameter
    handleTypes must be a valid combination of VkExternalSemaphoreHandleTypeFlagBits values

To destroy a semaphore, call:

// Provided by VK_VERSION_1_0
void vkDestroySemaphore(
    VkDevice                                    device,
    VkSemaphore                                 semaphore,
    const VkAllocationCallbacks*                pAllocator);

  • device is the logical device that destroys the semaphore.

  • semaphore is the handle of the semaphore to destroy.

  • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

Valid Usage

  • VUID-vkDestroySemaphore-semaphore-01137
    All submitted batches that refer to semaphore must have completed execution

  • VUID-vkDestroySemaphore-semaphore-01138
    If VkAllocationCallbacks were provided when semaphore was created, a compatible set of callbacks must be provided here

  • VUID-vkDestroySemaphore-semaphore-01139
    If no VkAllocationCallbacks were provided when semaphore was created, pAllocator must be NULL

Valid Usage (Implicit)

  • VUID-vkDestroySemaphore-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkDestroySemaphore-semaphore-parameter
    If semaphore is not VK_NULL_HANDLE, semaphore must be a valid VkSemaphore handle

  • VUID-vkDestroySemaphore-pAllocator-parameter
    If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

  • VUID-vkDestroySemaphore-semaphore-parent
    If semaphore is a valid handle, it must have been created, allocated, or retrieved from device

Host Synchronization

  • Host access to semaphore must be externally synchronized

7.4.1. Semaphore Signaling

When a batch is submitted to a queue via a queue submission, and it includes semaphores to be signaled, it defines a memory dependency on the batch, and defines semaphore signal operations which set the semaphores to the signaled state.

In case of semaphores created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE the semaphore is considered signaled with respect to the counter value set to be signaled as specified in VkTimelineSemaphoreSubmitInfo or VkSemaphoreSignalInfo.

The first synchronization scope includes every command submitted in the same batch. In the case of vkQueueSubmit2, the first synchronization scope is limited to the pipeline stage specified by VkSemaphoreSubmitInfo::stageMask. Semaphore signal operations that are defined by vkQueueSubmit or vkQueueSubmit2 additionally include all commands that occur earlier in submission order. Semaphore signal operations that are defined by vkQueueSubmit , vkQueueSubmit2 or vkQueueBindSparse additionally include in the first synchronization scope any semaphore and fence signal operations that occur earlier in signal operation order.

The second synchronization scope includes only the semaphore signal operation.

The first access scope includes all memory access performed by the device.

The second access scope is empty.

7.4.2. Semaphore Waiting

When a batch is submitted to a queue via a queue submission, and it includes semaphores to be waited on, it defines a memory dependency between prior semaphore signal operations and the batch, and defines semaphore wait operations.

Such semaphore wait operations set the semaphores created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_BINARY to the unsignaled state. In case of semaphores created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE a prior semaphore signal operation defines a memory dependency with a semaphore wait operation if the value the semaphore is signaled with is greater than or equal to the value the semaphore is waited with, thus the semaphore will continue to be considered signaled with respect to the counter value waited on as specified in VkTimelineSemaphoreSubmitInfo.

The first synchronization scope includes all semaphore signal operations that operate on semaphores waited on in the same batch, and that happen-before the wait completes.

The second synchronization scope includes every command submitted in the same batch. In the case of vkQueueSubmit, the second synchronization scope is limited to operations on the pipeline stages determined by the destination stage mask specified by the corresponding element of pWaitDstStageMask. In the case of vkQueueSubmit2, the second synchronization scope is limited to the pipeline stage specified by VkSemaphoreSubmitInfo::stageMask. Also, in the case of either vkQueueSubmit2 or vkQueueSubmit, the second synchronization scope additionally includes all commands that occur later in submission order.

The first access scope is empty.

The second access scope includes all memory access performed by the device.

The semaphore wait operation happens-after the first set of operations in the execution dependency, and happens-before the second set of operations in the execution dependency.

Note

Unlike timeline semaphores, fences or events, the act of waiting for a binary semaphore also unsignals that semaphore. Applications must ensure that between two such wait operations, the semaphore is signaled again, with execution dependencies used to ensure these occur in order. Binary semaphore waits and signals should thus occur in discrete 1:1 pairs.

7.4.3. Semaphore State Requirements For Wait Operations

Before waiting on a semaphore, the application must ensure the semaphore is in a valid state for a wait operation. Specifically, when a semaphore wait operation is submitted to a queue:

  • A binary semaphore must be signaled, or have an associated semaphore signal operation that is pending execution.

  • Any semaphore signal operations on which the pending binary semaphore signal operation depends must also be completed or pending execution.

  • There must be no other queue waiting on the same binary semaphore when the operation executes.

7.4.4. Host Operations on Semaphores

In addition to semaphore signal operations and semaphore wait operations submitted to device queues, timeline semaphores support the following host operations:

  • Query the current counter value of the semaphore using the vkGetSemaphoreCounterValue command.

  • Wait for a set of semaphores to reach particular counter values using the vkWaitSemaphores command.

  • Signal the semaphore with a particular counter value from the host using the vkSignalSemaphore command.

To query the current counter value of a semaphore created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE from the host, call:

// Provided by VK_VERSION_1_2
VkResult vkGetSemaphoreCounterValue(
    VkDevice                                    device,
    VkSemaphore                                 semaphore,
    uint64_t*                                   pValue);

  • device is the logical device that owns the semaphore.

  • semaphore is the handle of the semaphore to query.

  • pValue is a pointer to a 64-bit integer value in which the current counter value of the semaphore is returned.

Note

If a queue submission command is pending execution, then the value returned by this command may immediately be out of date.
Valid Usage

  • VUID-vkGetSemaphoreCounterValue-semaphore-03255
    semaphore must have been created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE

Valid Usage (Implicit)

  • VUID-vkGetSemaphoreCounterValue-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkGetSemaphoreCounterValue-semaphore-parameter
    semaphore must be a valid VkSemaphore handle

  • VUID-vkGetSemaphoreCounterValue-pValue-parameter
    pValue must be a valid pointer to a uint64_t value

  • VUID-vkGetSemaphoreCounterValue-semaphore-parent
    semaphore must have been created, allocated, or retrieved from device

Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

  • VK_ERROR_DEVICE_LOST

To wait for a set of semaphores created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE to reach particular counter values on the host, call:

// Provided by VK_VERSION_1_2
VkResult vkWaitSemaphores(
    VkDevice                                    device,
    const VkSemaphoreWaitInfo*                  pWaitInfo,
    uint64_t                                    timeout);

  • device is the logical device that owns the semaphores.

  • pWaitInfo is a pointer to a VkSemaphoreWaitInfo structure containing information about the wait condition.

  • timeout is the timeout period in units of nanoseconds. timeout is adjusted to the closest value allowed by the implementation-dependent timeout accuracy, which may be substantially longer than one nanosecond, and may be longer than the requested period.

If the condition is satisfied when vkWaitSemaphores is called, then vkWaitSemaphores returns immediately. If the condition is not satisfied at the time vkWaitSemaphores is called, then vkWaitSemaphores will block and wait until the condition is satisfied or the timeout has expired, whichever is sooner.

If timeout is zero, then vkWaitSemaphores does not wait, but simply returns information about the current state of the semaphores. VK_TIMEOUT will be returned in this case if the condition is not satisfied, even though no actual wait was performed.

If the condition is satisfied before the timeout has expired, vkWaitSemaphores returns VK_SUCCESS. Otherwise, vkWaitSemaphores returns VK_TIMEOUT after the timeout has expired.

If device loss occurs (see Lost Device) before the timeout has expired, vkWaitSemaphores must return in finite time with either VK_SUCCESS or VK_ERROR_DEVICE_LOST.

Valid Usage (Implicit)

  • VUID-vkWaitSemaphores-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkWaitSemaphores-pWaitInfo-parameter
    pWaitInfo must be a valid pointer to a valid VkSemaphoreWaitInfo structure

Return Codes
Success

  • VK_SUCCESS

  • VK_TIMEOUT

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

  • VK_ERROR_DEVICE_LOST

The VkSemaphoreWaitInfo structure is defined as:

// Provided by VK_VERSION_1_2
typedef struct VkSemaphoreWaitInfo {
    VkStructureType         sType;
    const void*             pNext;
    VkSemaphoreWaitFlags    flags;
    uint32_t                semaphoreCount;
    const VkSemaphore*      pSemaphores;
    const uint64_t*         pValues;
} VkSemaphoreWaitInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • flags is a bitmask of VkSemaphoreWaitFlagBits specifying additional parameters for the semaphore wait operation.

  • semaphoreCount is the number of semaphores to wait on.

  • pSemaphores is a pointer to an array of semaphoreCount semaphore handles to wait on.

  • pValues is a pointer to an array of semaphoreCount timeline semaphore values.

Valid Usage

  • VUID-VkSemaphoreWaitInfo-pSemaphores-03256
    All of the elements of pSemaphores must reference a semaphore that was created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE

Valid Usage (Implicit)

  • VUID-VkSemaphoreWaitInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_SEMAPHORE_WAIT_INFO

  • VUID-VkSemaphoreWaitInfo-pNext-pNext
    pNext must be NULL

  • VUID-VkSemaphoreWaitInfo-flags-parameter
    flags must be a valid combination of VkSemaphoreWaitFlagBits values

  • VUID-VkSemaphoreWaitInfo-pSemaphores-parameter
    pSemaphores must be a valid pointer to an array of semaphoreCount valid VkSemaphore handles

  • VUID-VkSemaphoreWaitInfo-pValues-parameter
    pValues must be a valid pointer to an array of semaphoreCount uint64_t values

  • VUID-VkSemaphoreWaitInfo-semaphoreCount-arraylength
    semaphoreCount must be greater than 0

Bits which can be set in VkSemaphoreWaitInfo::flags, specifying additional parameters of a semaphore wait operation, are:

// Provided by VK_VERSION_1_2
typedef enum VkSemaphoreWaitFlagBits {
    VK_SEMAPHORE_WAIT_ANY_BIT = 0x00000001,
} VkSemaphoreWaitFlagBits;

  • VK_SEMAPHORE_WAIT_ANY_BIT specifies that the semaphore wait condition is that at least one of the semaphores in VkSemaphoreWaitInfo::pSemaphores has reached the value specified by the corresponding element of VkSemaphoreWaitInfo::pValues. If VK_SEMAPHORE_WAIT_ANY_BIT is not set, the semaphore wait condition is that all of the semaphores in VkSemaphoreWaitInfo::pSemaphores have reached the value specified by the corresponding element of VkSemaphoreWaitInfo::pValues.

// Provided by VK_VERSION_1_2
typedef VkFlags VkSemaphoreWaitFlags;

VkSemaphoreWaitFlags is a bitmask type for setting a mask of zero or more VkSemaphoreWaitFlagBits.

To signal a semaphore created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE with a particular counter value, on the host, call:

// Provided by VK_VERSION_1_2
VkResult vkSignalSemaphore(
    VkDevice                                    device,
    const VkSemaphoreSignalInfo*                pSignalInfo);

  • device is the logical device that owns the semaphore.

  • pSignalInfo is a pointer to a VkSemaphoreSignalInfo structure containing information about the signal operation.

When vkSignalSemaphore is executed on the host, it defines and immediately executes a semaphore signal operation which sets the timeline semaphore to the given value.

The first synchronization scope is defined by the host execution model, but includes execution of vkSignalSemaphore on the host and anything that happened-before it.

The second synchronization scope is empty.

Valid Usage (Implicit)

  • VUID-vkSignalSemaphore-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkSignalSemaphore-pSignalInfo-parameter
    pSignalInfo must be a valid pointer to a valid VkSemaphoreSignalInfo structure

Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OUT_OF_HOST_MEMORY

  • VK_ERROR_OUT_OF_DEVICE_MEMORY

The VkSemaphoreSignalInfo structure is defined as:

// Provided by VK_VERSION_1_2
typedef struct VkSemaphoreSignalInfo {
    VkStructureType    sType;
    const void*        pNext;
    VkSemaphore        semaphore;
    uint64_t           value;
} VkSemaphoreSignalInfo;

  • sType is the type of this structure.

  • pNext is NULL or a pointer to a structure extending this structure.

  • semaphore is the handle of the semaphore to signal.

  • value is the value to signal.

Valid Usage

  • VUID-VkSemaphoreSignalInfo-semaphore-03257
    semaphore must have been created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE

  • VUID-VkSemaphoreSignalInfo-value-03258
    value must have a value greater than the current value of the semaphore

  • VUID-VkSemaphoreSignalInfo-value-03259
    value must be less than the value of any pending semaphore signal operations

  • VUID-VkSemaphoreSignalInfo-value-03260
    value must have a value which does not differ from the current value of the semaphore or the value of any outstanding semaphore wait or signal operation on semaphore by more than maxTimelineSemaphoreValueDifference

Valid Usage (Implicit)

  • VUID-VkSemaphoreSignalInfo-sType-sType
    sType must be VK_STRUCTURE_TYPE_SEMAPHORE_SIGNAL_INFO

  • VUID-VkSemaphoreSignalInfo-pNext-pNext
    pNext must be NULL

  • VUID-VkSemaphoreSignalInfo-semaphore-parameter
    semaphore must be a valid VkSemaphore handle

7.4.5. Importing Semaphore Payloads

Applications can import a semaphore payload into an existing semaphore using an external semaphore handle. The effects of the import operation will be either temporary or permanent, as specified by the application. If the import is temporary, the implementation must restore the semaphore to its prior permanent state after submitting the next semaphore wait operation. Performing a subsequent temporary import on a semaphore before performing a semaphore wait has no effect on this requirement; the next wait submitted on the semaphore must still restore its last permanent state. A permanent payload import behaves as if the target semaphore was destroyed, and a new semaphore was created with the same handle but the imported payload. Because importing a semaphore payload temporarily or permanently detaches the existing payload from a semaphore, similar usage restrictions to those applied to vkDestroySemaphore are applied to any command that imports a semaphore payload. Which of these import types is used is referred to as the import operation’s permanence. Each handle type supports either one or both types of permanence.

The implementation must perform the import operation by either referencing or copying the payload referred to by the specified external semaphore handle, depending on the handle’s type. The import method used is referred to as the handle type’s transference. When using handle types with reference transference, importing a payload to a semaphore adds the semaphore to the set of all semaphores sharing that payload. This set includes the semaphore from which the payload was exported. Semaphore signaling and waiting operations performed on any semaphore in the set must behave as if the set were a single semaphore. Importing a payload using handle types with copy transference creates a duplicate copy of the payload at the time of import, but makes no further reference to it. Semaphore signaling and waiting operations performed on the target of copy imports must not affect any other semaphore or payload.

Export operations have the same transference as the specified handle type’s import operations. Additionally, exporting a semaphore payload to a handle with copy transference has the same side effects on the source semaphore’s payload as executing a semaphore wait operation. If the semaphore was using a temporarily imported payload, the semaphore’s prior permanent payload will be restored.

External synchronization allows implementations to modify an object’s internal state, i.e. payload, without internal synchronization. However, for semaphores sharing a payload across processes, satisfying the external synchronization requirements of VkSemaphore parameters as if all semaphores in the set were the same object is sometimes infeasible. Satisfying the wait operation state requirements would similarly require impractical coordination or levels of trust between processes. Therefore, these constraints only apply to a specific semaphore handle, not to its payload. For distinct semaphore objects which share a payload, if the semaphores are passed to separate queue submission commands concurrently, behavior will be as if the commands were called in an arbitrary sequential order. If the wait operation state requirements are violated for the shared payload by a queue submission command, or if a signal operation is queued for a shared payload that is already signaled or has a pending signal operation, effects must be limited to one or more of the following:

  • Returning VK_ERROR_INITIALIZATION_FAILED from the command which resulted in the violation.

  • Losing the logical device on which the violation occurred immediately or at a future time, resulting in a VK_ERROR_DEVICE_LOST error from subsequent commands, including the one causing the violation.

  • Continuing execution of the violating command or operation as if the semaphore wait completed successfully after an implementation-dependent timeout. In this case, the state of the payload becomes undefined, and future operations on semaphores sharing the payload will be subject to these same rules. The semaphore must be destroyed or have its payload replaced by an import operation to again have a well-defined state.

Note

These rules allow processes to synchronize access to shared memory without trusting each other. However, such processes must still be cautious not to use the shared semaphore for more than synchronizing access to the shared memory. For example, a process should not use a shared semaphore as part of an execution dependency chain that, when complete, leads to objects being destroyed, if it does not trust other processes sharing the semaphore payload.

When a semaphore is using an imported payload, its VkExportSemaphoreCreateInfo::handleTypes value is specified when creating the semaphore from which the payload was exported, rather than specified when creating the semaphore. Additionally, VkExternalSemaphoreProperties::exportFromImportedHandleTypes restricts which handle types can be exported from such a semaphore based on the specific handle type used to import the current payload.

When importing a semaphore payload, it is the responsibility of the application to ensure the external handles meet all valid usage requirements. However, implementations must perform sufficient validation of external handles to ensure that the operation results in a valid semaphore which will not cause program termination, device loss, queue stalls, or corruption of other resources when used as allowed according to its import parameters, and excepting those side effects allowed for violations of the valid semaphore state for wait operations rules. If the external handle provided does not meet these requirements, the implementation must fail the semaphore payload import operation with the error code VK_ERROR_INVALID_EXTERNAL_HANDLE.

In addition, when importing a semaphore payload that is not compatible with the payload type corresponding to the VkSemaphoreType the semaphore was created with, the implementation may fail the semaphore payload import operation with the error code VK_ERROR_INVALID_EXTERNAL_HANDLE.

Note

As the introduction of the external semaphore handle type VK_EXTERNAL_SEMAPHORE_HANDLE_TYPE_D3D12_FENCE_BIT predates that of timeline semaphores, support for importing semaphore payloads from external handles of that type into semaphores created (implicitly or explicitly) with a VkSemaphoreType of VK_SEMAPHORE_TYPE_BINARY is preserved for backwards compatibility. However, applications should prefer importing such handle types into semaphores created with a VkSemaphoreType of VK_SEMAPHORE_TYPE_TIMELINE.

7.5. Events

Events are a synchronization primitive that can be used to insert a fine-grained dependency between commands submitted to the same queue, or between the host and a queue. Events must not be used to insert a dependency between commands submitted to different queues. Events have two states - signaled and unsignaled. An application can signal or unsignal an event either on the host or on the device. A device can be made to wait for an event to become signaled before executing further operations. No command exists to wait for an event to become signaled on the host, but the current state of an event can be queried.

Events are represented by VkEvent handles:

// Provided by VK_VERSION_1_0
VK_DEFINE_NON_DISPATCHABLE_HANDLE(VkEvent)

To create an event, call:

// Provided by VK_VERSION_1_0
VkResult vkCreateEvent(
    VkDevice                                    device,
    const VkEventCreateInfo*                    pCreateInfo,
    const VkAllocationCallbacks*                pAllocator,
    VkEvent*                                    pEvent);

  • device is the logical device that creates the event.

  • pCreateInfo is a pointer to a VkEventCreateInfo structure containing information about how the event is to be created.

  • pAllocator controls host memory allocation as described in the Memory Allocation chapter.

  • pEvent is a pointer to a handle in which the resulting event object is returned.

When created, the event object is in the unsignaled state.

Valid Usage (Implicit)

  • VUID-vkCreateEvent-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkCreateEvent-pCreateInfo-parameter
    pCreateInfo must be a valid pointer to a valid VkEventCreateInfo structure

  • VUID-vkCreateEvent-pAllocator-parameter
    If pAllocator is not NULL, pAllocator must be a valid pointer to a valid VkAllocationCallbacks structure

  • VUID-vkCreateEvent-pEvent-parameter
    pEvent must be a valid pointer to a VkEvent handle

Return Codes
Success

  • VK_SUCCESS

Failure

  • VK_ERROR_OU