vkCmdWriteTimestamp(3)

C Specification

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

// Provided by VK_VERSION_1_0
void vkCmdWriteTimestamp(
    VkCommandBuffer                             commandBuffer,
    VkPipelineStageFlagBits                     pipelineStage,
    VkQueryPool                                 queryPool,
    uint32_t                                    query);

Parameters

commandBuffer is the command buffer into which the command will be recorded.
pipelineStage is a VkPipelineStageFlagBits value, specifying 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 vkCmdWriteTimestamp 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 pipelineStage.

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 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.

If vkCmdWriteTimestamp 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.
All N queries are timestamp values.

Either way, if two timestamps are written in the same subpass with multiview enabled, each of the N consecutive queries written for a timestamp must not have a lower value than the queries with corresponding indices written by the timestamp that happens-before unless the value overflows the maximum supported integer bit width of the query.

Valid Usage

VUID-vkCmdWriteTimestamp-pipelineStage-04074
pipelineStage must be a valid stage for the queue family that was used to create the command pool that commandBuffer was allocated from
VUID-vkCmdWriteTimestamp-pipelineStage-04075
If the geometryShader feature is not enabled, pipelineStage must not be VK_PIPELINE_STAGE_GEOMETRY_SHADER_BIT
VUID-vkCmdWriteTimestamp-pipelineStage-04076
If the tessellationShader feature is not enabled, pipelineStage must not be VK_PIPELINE_STAGE_TESSELLATION_CONTROL_SHADER_BIT or VK_PIPELINE_STAGE_TESSELLATION_EVALUATION_SHADER_BIT
VUID-vkCmdWriteTimestamp-fragmentShadingRate-07315
If the attachmentFragmentShadingRate feature is not enabled, pipelineStage must not be VK_PIPELINE_STAGE_FRAGMENT_SHADING_RATE_ATTACHMENT_BIT_KHR
VUID-vkCmdWriteTimestamp-synchronization2-06489
If the synchronization2 feature is not enabled, pipelineStage must not be VK_PIPELINE_STAGE_NONE
VUID-vkCmdWriteTimestamp-queryPool-01416
queryPool must have been created with a queryType of VK_QUERY_TYPE_TIMESTAMP
VUID-vkCmdWriteTimestamp-timestampValidBits-00829
The command pool’s queue family must support a non-zero timestampValidBits
VUID-vkCmdWriteTimestamp-query-04904
query must be less than the number of queries in queryPool
VUID-vkCmdWriteTimestamp-None-00830
All queries used by the command must be unavailable
VUID-vkCmdWriteTimestamp-query-00831
If vkCmdWriteTimestamp 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-vkCmdWriteTimestamp-commandBuffer-parameter
commandBuffer must be a valid VkCommandBuffer handle
VUID-vkCmdWriteTimestamp-pipelineStage-parameter
pipelineStage must be a valid VkPipelineStageFlagBits value
VUID-vkCmdWriteTimestamp-queryPool-parameter
queryPool must be a valid VkQueryPool handle
VUID-vkCmdWriteTimestamp-commandBuffer-recording
commandBuffer must be in the recording state
VUID-vkCmdWriteTimestamp-commandBuffer-cmdpool
The VkCommandPool that commandBuffer was allocated from must support VK_QUEUE_COMPUTE_BIT, VK_QUEUE_GRAPHICS_BIT, or VK_QUEUE_TRANSFER_BIT operations
VUID-vkCmdWriteTimestamp-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