C Specification

To request a timestamp and write the value to memory, call:

// Provided by VK_VERSION_1_3
void vkCmdWriteTimestamp2(
    VkCommandBuffer                             commandBuffer,
    VkPipelineStageFlags2                       stage,
    VkQueryPool                                 queryPool,
    uint32_t                                    query);

or the equivalent command

// Provided by VK_KHR_synchronization2
void vkCmdWriteTimestamp2KHR(
    VkCommandBuffer                             commandBuffer,
    VkPipelineStageFlags2                       stage,
    VkQueryPool                                 queryPool,
    uint32_t                                    query);

Parameters

  • commandBuffer is the command buffer into which the command will be recorded.

  • stage specifies a stage of the pipeline.

  • queryPool is the query pool that will manage the timestamp.

  • query is the query within the query pool that will contain the timestamp.

Description

When vkCmdWriteTimestamp2 is submitted to a queue, it defines an execution dependency on commands that were submitted before it, and writes a timestamp to a query pool.

The first synchronization scope includes all commands that occur earlier in submission order. The synchronization scope is limited to operations on the pipeline stage specified by stage.

The second synchronization scope includes only the timestamp write operation.

Note

Implementations may write the timestamp at any stage that is logically later than stage.

Any timestamp write that happens-after another timestamp write in the same submission must not have a lower value unless its value overflows the maximum supported integer bit width of the query. If VK_KHR_calibrated_timestamps or VK_EXT_calibrated_timestamps is enabled, this extends to timestamp writes across all submissions on the same logical device: any timestamp write that happens-after another must not have a lower value unless its value overflows the maximum supported integer bit width of the query. Timestamps written by this command must be in the VK_TIME_DOMAIN_DEVICE_KHR time domain. If an overflow occurs, the timestamp value must wrap back to zero.

Note

Comparisons between timestamps should be done between timestamps where they are guaranteed to not decrease. For example, subtracting an older timestamp from a newer one to determine the execution time of a sequence of commands is only a reliable measurement if the two timestamp writes were performed in the same submission, or if the writes were performed on the same logical device and VK_KHR_calibrated_timestamps or VK_EXT_calibrated_timestamps is enabled.

If vkCmdWriteTimestamp2 is called while executing a render pass instance that has multiview enabled, the timestamp uses N consecutive query indices in the query pool (starting at query) where N is the number of bits set in the view mask of the subpass the command is executed in. The resulting query values are determined by an implementation-dependent choice of one of the following behaviors:

  • The first query is a timestamp value and (if more than one bit is set in the view mask) zero is written to the remaining queries. If two timestamps are written in the same subpass, the sum of the execution time of all views between those commands is the difference between the first query written by each command.

  • All N queries are timestamp values. If two timestamps are written in the same subpass, the sum of the execution time of all views between those commands is the sum of the difference between corresponding queries written by each command. The difference between corresponding queries may be the execution time of a single view.

In either case, the application can sum the differences between all N queries to determine the total execution time.

Valid Usage
  • VUID-vkCmdWriteTimestamp2-stage-03929
    If the geometryShader feature is not enabled, stage must not contain VK_PIPELINE_STAGE_2_GEOMETRY_SHADER_BIT

  • VUID-vkCmdWriteTimestamp2-stage-03930
    If the tessellationShader feature is not enabled, stage must not contain VK_PIPELINE_STAGE_2_TESSELLATION_CONTROL_SHADER_BIT or VK_PIPELINE_STAGE_2_TESSELLATION_EVALUATION_SHADER_BIT

  • VUID-vkCmdWriteTimestamp2-stage-03931
    If the conditionalRendering feature is not enabled, stage must not contain VK_PIPELINE_STAGE_2_CONDITIONAL_RENDERING_BIT_EXT

  • VUID-vkCmdWriteTimestamp2-stage-03932
    If the fragmentDensityMap feature is not enabled, stage must not contain VK_PIPELINE_STAGE_2_FRAGMENT_DENSITY_PROCESS_BIT_EXT

  • VUID-vkCmdWriteTimestamp2-stage-03933
    If the transformFeedback feature is not enabled, stage must not contain VK_PIPELINE_STAGE_2_TRANSFORM_FEEDBACK_BIT_EXT

  • VUID-vkCmdWriteTimestamp2-stage-03934
    If the meshShader feature is not enabled, stage must not contain VK_PIPELINE_STAGE_2_MESH_SHADER_BIT_EXT

  • VUID-vkCmdWriteTimestamp2-stage-03935
    If the taskShader feature is not enabled, stage must not contain VK_PIPELINE_STAGE_2_TASK_SHADER_BIT_EXT

  • VUID-vkCmdWriteTimestamp2-stage-07316
    If neither the shadingRateImage or attachmentFragmentShadingRate are enabled, stage must not contain VK_PIPELINE_STAGE_2_FRAGMENT_SHADING_RATE_ATTACHMENT_BIT_KHR

  • VUID-vkCmdWriteTimestamp2-stage-04957
    If the subpassShading feature is not enabled, stage must not contain VK_PIPELINE_STAGE_2_SUBPASS_SHADER_BIT_HUAWEI

  • VUID-vkCmdWriteTimestamp2-stage-04995
    If the invocationMask feature is not enabled, stage must not contain VK_PIPELINE_STAGE_2_INVOCATION_MASK_BIT_HUAWEI

  • VUID-vkCmdWriteTimestamp2-stage-07946
    If neither the VK_NV_ray_tracing extension or rayTracingPipeline feature are enabled, stage must not contain VK_PIPELINE_STAGE_2_RAY_TRACING_SHADER_BIT_KHR

  • VUID-vkCmdWriteTimestamp2-synchronization2-03858
    The synchronization2 feature must be enabled

  • VUID-vkCmdWriteTimestamp2-stage-03859
    stage must only include a single pipeline stage

  • VUID-vkCmdWriteTimestamp2-stage-03860
    stage must only include stages valid for the queue family that was used to create the command pool that commandBuffer was allocated from

  • VUID-vkCmdWriteTimestamp2-queryPool-03861
    queryPool must have been created with a queryType of VK_QUERY_TYPE_TIMESTAMP

  • VUID-vkCmdWriteTimestamp2-timestampValidBits-03863
    The command pool’s queue family must support a non-zero timestampValidBits

  • VUID-vkCmdWriteTimestamp2-query-04903
    query must be less than the number of queries in queryPool

  • VUID-vkCmdWriteTimestamp2-None-03864
    All queries used by the command must be unavailable

  • VUID-vkCmdWriteTimestamp2-query-03865
    If vkCmdWriteTimestamp2 is called within a render pass instance, the sum of query and the number of bits set in the current subpass’s view mask must be less than or equal to the number of queries in queryPool

Valid Usage (Implicit)
  • VUID-vkCmdWriteTimestamp2-commandBuffer-parameter
    commandBuffer must be a valid VkCommandBuffer handle

  • VUID-vkCmdWriteTimestamp2-stage-parameter
    stage must be a valid combination of VkPipelineStageFlagBits2 values

  • VUID-vkCmdWriteTimestamp2-queryPool-parameter
    queryPool must be a valid VkQueryPool handle

  • VUID-vkCmdWriteTimestamp2-commandBuffer-recording
    commandBuffer must be in the recording state

  • VUID-vkCmdWriteTimestamp2-commandBuffer-cmdpool
    The VkCommandPool that commandBuffer was allocated from must support transfer, graphics, compute, decode, or encode operations

  • VUID-vkCmdWriteTimestamp2-commonparent
    Both of commandBuffer, and queryPool 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 Video Coding Scope Supported Queue Types Command Type

Primary
Secondary

Both

Both

Transfer
Graphics
Compute
Decode
Encode

Action

See Also

Document Notes

For more information, see the Vulkan Specification

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.

Copyright 2014-2024 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0