vkCreateQueryPool - Create a new query pool object

Valid Usage (Implicit)

• device must be a valid Device handle

• pCreateInfo must be a valid pointer to a valid QueryPoolCreateInfo structure
• If pAllocator is not NULL, pAllocator must be a valid pointer to a valid AllocationCallbacks structure
• pQueryPool must be a valid pointer to a QueryPool handle

Return Codes

Success

• SUCCESS

Failure

• ERROR_OUT_OF_HOST_MEMORY
• ERROR_OUT_OF_DEVICE_MEMORY

See Also

VK_VERSION_1_0, AllocationCallbacks, Device, QueryPool, QueryPoolCreateInfo

A convenience wrapper to make a compatible pair of calls to createQueryPool and destroyQueryPool

To ensure that destroyQueryPool is always called: pass bracket (or the allocate function from your favourite resource management library) as the last argument. To just extract the pair pass (,) as the last argument.

vkDestroyQueryPool - Destroy a query pool object

Valid Usage

• All submitted commands that refer to queryPool must have completed execution

• If AllocationCallbacks were provided when queryPool was created, a compatible set of callbacks must be provided here
• If no AllocationCallbacks were provided when queryPool was created, pAllocator must be NULL

Note

Applications can verify that queryPool can be destroyed by checking that getQueryPoolResults() without the QUERY_RESULT_PARTIAL_BIT flag returns SUCCESS for all queries that are used in command buffers submitted for execution.

Valid Usage (Implicit)

• device must be a valid Device handle

• If queryPool is not NULL_HANDLE, queryPool must be a valid QueryPool handle
• If pAllocator is not NULL, pAllocator must be a valid pointer to a valid AllocationCallbacks structure
• If queryPool is a valid handle, it must have been created, allocated, or retrieved from device

Host Synchronization

• Host access to queryPool must be externally synchronized

See Also

VK_VERSION_1_0, AllocationCallbacks, Device, QueryPool

vkGetQueryPoolResults - Copy results of queries in a query pool to a host memory region

Description

Any results written for a query are written according to a layout dependent on the query type.

If no bits are set in flags, and all requested queries are in the available state, results are written as an array of 32-bit unsigned integer values. Behavior when not all queries are available is described below.

If QUERY_RESULT_WITH_AVAILABILITY_BIT is set, results for all queries in queryPool identified by firstQuery and queryCount are copied to pData, along with an extra availability or status value written directly after the results of each query and interpreted as an unsigned integer. A value of zero indicates that the results are not yet available, otherwise the query is complete and results are available. The size of the availability or status values is 64 bits if QUERY_RESULT_64_BIT is set in flags. Otherwise, it is 32 bits.

If VK_QUERY_RESULT_WITH_STATUS_BIT_KHR is set, results for all queries in queryPool identified by firstQuery and queryCount are copied to pData, along with an extra status value written directly after the results of each query and interpreted as a signed integer. A value of zero indicates that the results are not yet available. Positive values indicate that the operations within the query completed successfully, and the query results are valid. Negative values indicate that the operations within the query completed unsuccessfully.

VkQueryResultStatusKHR defines specific meaning for values returned here, though implementations are free to return other values.

Note

If QUERY_RESULT_WITH_AVAILABILITY_BIT or VK_QUERY_RESULT_WITH_STATUS_BIT_KHR is set, the layout of data in the buffer is a (result,availability) or (result,status) pair for each query returned, and stride is the stride between each pair.

Results for any available query written by this command are final and represent the final result of the query. If QUERY_RESULT_PARTIAL_BIT is set, then for any query that is unavailable, an intermediate result between zero and the final result value is written for that query. Otherwise, any result written by this command is undefined.

If QUERY_RESULT_64_BIT is set, results and, if returned, availability or status values for all queries are written as an array of 64-bit values. If the queryPool was created with QUERY_TYPE_PERFORMANCE_QUERY_KHR, results for each query are written as an array of the type indicated by PerformanceCounterKHR::storage for the counter being queried. Otherwise, results and availability or status values are written as an array of 32-bit values. If an unsigned integer query’s value overflows the result type, the value may either wrap or saturate. If a signed integer query’s value overflows the result type, the value is undefined. If a floating point query’s value is not representable as the result type, the value is undefined.

If QUERY_RESULT_WAIT_BIT is set, this command defines an execution dependency with any earlier commands that writes one of the identified queries. The first synchronization scope includes all instances of cmdEndQuery, cmdEndQueryIndexedEXT, cmdWriteTimestamp2, and cmdWriteTimestamp that reference any query in queryPool indicated by firstQuery and queryCount. The second synchronization scope includes the host operations of this command.

If QUERY_RESULT_WAIT_BIT is not set, getQueryPoolResults may return NOT_READY if there are queries in the unavailable state.

Note

Applications must take care to ensure that use of the QUERY_RESULT_WAIT_BIT bit has the desired effect.

For example, if a query has been used previously and a command buffer records the commands cmdResetQueryPool, cmdBeginQuery, and cmdEndQuery for that query, then the query will remain in the available state until resetQueryPool is called or the cmdResetQueryPool command executes on a queue. Applications can use fences or events to ensure that a query has already been reset before checking for its results or availability status. Otherwise, a stale value could be returned from a previous use of the query.

The above also applies when QUERY_RESULT_WAIT_BIT is used in combination with QUERY_RESULT_WITH_AVAILABILITY_BIT. In this case, the returned availability status may reflect the result of a previous use of the query unless resetQueryPool is called or the cmdResetQueryPool command has been executed since the last use of the query.

A similar situation can arise with the VK_QUERY_RESULT_WITH_STATUS_BIT_KHR flag.

Note

Applications can double-buffer query pool usage, with a pool per frame, and reset queries at the end of the frame in which they are read.

Valid Usage

• All queries used by the command must not be uninitialized

• firstQuery must be less than the number of queries in queryPool
• If QUERY_RESULT_64_BIT is not set in flags and the queryType used to create queryPool was not QUERY_TYPE_PERFORMANCE_QUERY_KHR, then pData and stride must be multiples of 4
• If QUERY_RESULT_64_BIT is set in flags then pData and stride must be multiples of 8
• If QUERY_RESULT_WITH_AVAILABILITY_BIT is set, stride must be large enough to contain the unsigned integer representing availability or status in addition to the query result.
• If the queryType used to create queryPool was QUERY_TYPE_PERFORMANCE_QUERY_KHR, then pData and stride must be multiples of the size of PerformanceCounterResultKHR
• If the queryType used to create queryPool was QUERY_TYPE_PERFORMANCE_QUERY_KHR, then stride must be large enough to contain the QueryPoolPerformanceCreateInfoKHR::counterIndexCount used to create queryPool times the size of PerformanceCounterResultKHR
• The sum of firstQuery and queryCount must be less than or equal to the number of queries in queryPool
• dataSize must be large enough to contain the result of each query, as described here
• If the queryType used to create queryPool was QUERY_TYPE_TIMESTAMP, flags must not contain QUERY_RESULT_PARTIAL_BIT
• If the queryType used to create queryPool was QUERY_TYPE_PERFORMANCE_QUERY_KHR, flags must not contain QUERY_RESULT_WITH_AVAILABILITY_BIT, VK_QUERY_RESULT_WITH_STATUS_BIT_KHR, QUERY_RESULT_PARTIAL_BIT, or QUERY_RESULT_64_BIT
• If the queryType used to create queryPool was QUERY_TYPE_PERFORMANCE_QUERY_KHR, the queryPool must have been recorded once for each pass as retrieved via a call to getPhysicalDeviceQueueFamilyPerformanceQueryPassesKHR
• If the queryType used to create queryPool was VK_QUERY_TYPE_RESULT_STATUS_ONLY_KHR, then flags must include VK_QUERY_RESULT_WITH_STATUS_BIT_KHR
• If flags includes VK_QUERY_RESULT_WITH_STATUS_BIT_KHR, then it must not include QUERY_RESULT_WITH_AVAILABILITY_BIT

Valid Usage (Implicit)

• device must be a valid Device handle

• queryPool must be a valid QueryPool handle
• pData must be a valid pointer to an array of dataSize bytes
• flags must be a valid combination of QueryResultFlagBits values
• dataSize must be greater than 0
• queryPool must have been created, allocated, or retrieved from device

Return Codes

Success

• SUCCESS
• NOT_READY

Failure

• ERROR_OUT_OF_HOST_MEMORY
• ERROR_OUT_OF_DEVICE_MEMORY
• ERROR_DEVICE_LOST

See Also

VK_VERSION_1_0, Device, DeviceSize, QueryPool, QueryResultFlags

VkQueryPoolCreateInfo - Structure specifying parameters of a newly created query pool

Description

pipelineStatistics is ignored if queryType is not QUERY_TYPE_PIPELINE_STATISTICS.

Valid Usage

• If the pipelineStatisticsQuery feature is not enabled, queryType must not be QUERY_TYPE_PIPELINE_STATISTICS

• If the meshShaderQueries feature is not enabled, queryType must not be QUERY_TYPE_MESH_PRIMITIVES_GENERATED_EXT
• If the meshShaderQueries feature is not enabled, and queryType is QUERY_TYPE_PIPELINE_STATISTICS, pipelineStatistics must not contain QUERY_PIPELINE_STATISTIC_TASK_SHADER_INVOCATIONS_BIT_EXT or QUERY_PIPELINE_STATISTIC_MESH_SHADER_INVOCATIONS_BIT_EXT
• If queryType is QUERY_TYPE_PIPELINE_STATISTICS, pipelineStatistics must be a valid combination of QueryPipelineStatisticFlagBits values
• If queryType is QUERY_TYPE_PERFORMANCE_QUERY_KHR, the pNext chain must include a QueryPoolPerformanceCreateInfoKHR structure
• queryCount must be greater than 0
• If queryType is VK_QUERY_TYPE_VIDEO_ENCODE_FEEDBACK_KHR, then the pNext chain must include a VkVideoProfileInfoKHR structure with videoCodecOperation specifying an encode operation
• If queryType is VK_QUERY_TYPE_VIDEO_ENCODE_FEEDBACK_KHR, then the pNext chain must include a VkQueryPoolVideoEncodeFeedbackCreateInfoKHR structure
• If queryType is VK_QUERY_TYPE_VIDEO_ENCODE_FEEDBACK_KHR, and the pNext chain includes a VkVideoProfileInfoKHR structure and a VkQueryPoolVideoEncodeFeedbackCreateInfoKHR structure, then VkQueryPoolVideoEncodeFeedbackCreateInfoKHR::encodeFeedbackFlags must not contain any bits that are not set in VkVideoEncodeCapabilitiesKHR::supportedEncodeFeedbackFlags, as returned by vkGetPhysicalDeviceVideoCapabilitiesKHR for the video profile described by VkVideoProfileInfoKHR and its pNext chain

Valid Usage (Implicit)

• sType must be STRUCTURE_TYPE_QUERY_POOL_CREATE_INFO

• 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 QueryPoolPerformanceCreateInfoKHR, QueryPoolPerformanceQueryCreateInfoINTEL, VkQueryPoolVideoEncodeFeedbackCreateInfoKHR, VkVideoDecodeH264ProfileInfoKHR, VkVideoDecodeH265ProfileInfoKHR, VkVideoDecodeUsageInfoKHR, VkVideoEncodeH264ProfileInfoEXT, VkVideoEncodeH265ProfileInfoEXT, VkVideoEncodeUsageInfoKHR, or VkVideoProfileInfoKHR
• The sType value of each struct in the pNext chain must be unique
• flags must be 0
• queryType must be a valid QueryType value

See Also

VK_VERSION_1_0, QueryPipelineStatisticFlags, QueryPoolCreateFlags, QueryType, StructureType, createQueryPool

VkQueryPool - Opaque handle to a query pool object

See Also

VK_VERSION_1_0, cmdBeginQuery, cmdBeginQueryIndexedEXT, cmdCopyQueryPoolResults, cmdEndQuery, cmdEndQueryIndexedEXT, cmdResetQueryPool, cmdWriteAccelerationStructuresPropertiesKHR, cmdWriteAccelerationStructuresPropertiesNV, cmdWriteMicromapsPropertiesEXT, cmdWriteTimestamp, cmdWriteTimestamp2, cmdWriteTimestamp2KHR, createQueryPool, destroyQueryPool, getQueryPoolResults, resetQueryPool, resetQueryPoolEXT

VkQueryPoolCreateFlags - Reserved for future use

Description

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

See Also

VK_VERSION_1_0, QueryPoolCreateInfo

VkQueryType - Specify the type of queries managed by a query pool

See Also

VK_VERSION_1_0, QueryPoolCreateInfo, cmdWriteAccelerationStructuresPropertiesKHR, cmdWriteAccelerationStructuresPropertiesNV, cmdWriteMicromapsPropertiesEXT, writeAccelerationStructuresPropertiesKHR, writeMicromapsPropertiesEXT

VkQueryResultFlagBits - Bitmask specifying how and when query results are returned

See Also

VK_VERSION_1_0, QueryResultFlags

VkQueryPipelineStatisticFlagBits - Bitmask specifying queried pipeline statistics

Description

These values are intended to measure relative statistics on one implementation. Various device architectures will count these values differently. Any or all counters may be affected by the issues described in Query Operation.

This counting difference is especially true if the pipeline contains mesh or task shaders, which may affect several of the counters in unexpected ways.

Note

For example, tile-based rendering devices may need to replay the scene multiple times, affecting some of the counts.

If a pipeline has rasterizerDiscardEnable enabled, implementations may discard primitives after the final pre-rasterization shader stage. As a result, if rasterizerDiscardEnable is enabled, the clipping input and output primitives counters may not be incremented.

When a pipeline statistics query finishes, the result for that query is marked as available. The application can copy the result to a buffer (via cmdCopyQueryPoolResults), or request it be put into host memory (via getQueryPoolResults).

See Also

VK_VERSION_1_0, QueryPipelineStatisticFlags