vkCmdCopyQueryPoolResults(3)

# vkCmdCopyQueryPoolResults(3) Manual Page

## Name

vkCmdCopyQueryPoolResults - Copy the results of queries in a query pool to a buffer object

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## C Specification

To copy query statuses and numerical results directly to buffer memory, call:

    // Provided by VK_VERSION_1_0
    void vkCmdCopyQueryPoolResults(
        VkCommandBuffer                             commandBuffer,
        VkQueryPool                                 queryPool,
        uint32_t                                    firstQuery,
        uint32_t                                    queryCount,
        VkBuffer                                    dstBuffer,
        VkDeviceSize                                dstOffset,
        VkDeviceSize                                stride,
        VkQueryResultFlags                          flags);

## Parameters

- `commandBuffer` is the command buffer into which this command will be recorded.

- `queryPool` is the query pool managing the queries containing the desired results.

- `firstQuery` is the initial query index.

- `queryCount` is the number of queries. `firstQuery` and `queryCount` together define a range of queries.

- `dstBuffer` is a VkBuffer object that will receive the results of the copy command.

- `dstOffset` is an offset into `dstBuffer`.

- `stride` is the stride in bytes between results for individual queries within `dstBuffer`. The required size of the backing memory for `dstBuffer` is determined as described above for vkGetQueryPoolResults.

- `flags` is a bitmask of VkQueryResultFlagBits specifying how and when results are returned.

## Description

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

Results for any query in `queryPool` identified by `firstQuery` and `queryCount` that is available are copied to `dstBuffer`.

If `VK_QUERY_RESULT_WITH_AVAILABILITY_BIT` is set, results for all queries in `queryPool` identified by `firstQuery` and `queryCount` are copied to `dstBuffer`, along with an extra availability 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.

If `VK_QUERY_RESULT_WITH_STATUS_BIT_KHR` is set, results for all queries in `queryPool` identified by `firstQuery` and `queryCount` are copied to `dstBuffer`, 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.

If the status value written is negative, indicating that the operations within the query completed unsuccessfully, then all other results written by this command are undefined unless otherwise specified for any of the results of the used query type.

Results for any available query written by this command are final and represent the final result of the query. If `VK_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 `VK_QUERY_RESULT_64_BIT` is set, results and availability or status values for all queries are written as an array of 64-bit values. If the `queryPool` was created with `VK_QUERY_TYPE_PERFORMANCE_QUERY_KHR`, results for each query are written as an array of the type indicated by VkPerformanceCounterKHR::`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.

This command defines an execution dependency between other query commands that reference the same query.

The first synchronization scope includes all commands which reference the queries in `queryPool` indicated by `query` that occur earlier in submission order. If `flags` does not include `VK_QUERY_RESULT_WAIT_BIT`, vkCmdEndQueryIndexedEXT, vkCmdWriteTimestamp2, vkCmdEndQuery, and vkCmdWriteTimestamp are excluded from this scope.

The second synchronization scope includes all commands which reference the queries in `queryPool` indicated by `query` that occur later in submission order.

The operation of this command happens after the first scope and happens before the second scope.

`vkCmdCopyQueryPoolResults` is considered to be a transfer operation, and its writes to buffer memory must be synchronized using `VK_PIPELINE_STAGE_TRANSFER_BIT` and `VK_ACCESS_TRANSFER_WRITE_BIT` before using the results.

Valid Usage

- VUID-vkCmdCopyQueryPoolResults-firstQuery-09436
  `firstQuery` must be less than the number of queries in `queryPool`

- VUID-vkCmdCopyQueryPoolResults-firstQuery-09437
  The sum of `firstQuery` and `queryCount` must be less than or equal to the number of queries in `queryPool`

- VUID-vkCmdCopyQueryPoolResults-queryCount-09438
  If `queryCount` is greater than 1, `stride` must not be zero

- VUID-vkCmdCopyQueryPoolResults-queryType-09439
  If the `queryType` used to create `queryPool` was `VK_QUERY_TYPE_TIMESTAMP`, `flags` must not contain `VK_QUERY_RESULT_PARTIAL_BIT`

- VUID-vkCmdCopyQueryPoolResults-queryType-09440
  If the `queryType` used to create `queryPool` was `VK_QUERY_TYPE_PERFORMANCE_QUERY_KHR`, `flags` must not contain `VK_QUERY_RESULT_WITH_AVAILABILITY_BIT`, `VK_QUERY_RESULT_WITH_STATUS_BIT_KHR`, `VK_QUERY_RESULT_PARTIAL_BIT`, or `VK_QUERY_RESULT_64_BIT`

- VUID-vkCmdCopyQueryPoolResults-queryType-09441
  If the `queryType` used to create `queryPool` was `VK_QUERY_TYPE_PERFORMANCE_QUERY_KHR`, the `queryPool` must have been recorded once for each pass as retrieved via a call to vkGetPhysicalDeviceQueueFamilyPerformanceQueryPassesKHR

- VUID-vkCmdCopyQueryPoolResults-queryType-09442
  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`

- VUID-vkCmdCopyQueryPoolResults-flags-09443
  If `flags` includes `VK_QUERY_RESULT_WITH_STATUS_BIT_KHR`, then it must not include `VK_QUERY_RESULT_WITH_AVAILABILITY_BIT`

- VUID-vkCmdCopyQueryPoolResults-None-09402
  All queries used by the command must not be uninitialized when the command is executed

- VUID-vkCmdCopyQueryPoolResults-dstOffset-00819
  `dstOffset` must be less than the size of `dstBuffer`

- VUID-vkCmdCopyQueryPoolResults-flags-00822
  If `VK_QUERY_RESULT_64_BIT` is not set in `flags` then `dstOffset` and `stride` must be multiples of `4`

- VUID-vkCmdCopyQueryPoolResults-flags-00823
  If `VK_QUERY_RESULT_64_BIT` is set in `flags` then `dstOffset` and `stride` must be multiples of `8`

- VUID-vkCmdCopyQueryPoolResults-dstBuffer-00824
  `dstBuffer` must have enough storage, from `dstOffset`, to contain the result of each query, as described here

- VUID-vkCmdCopyQueryPoolResults-dstBuffer-00825
  `dstBuffer` must have been created with `VK_BUFFER_USAGE_TRANSFER_DST_BIT` usage flag

- VUID-vkCmdCopyQueryPoolResults-dstBuffer-00826
  If `dstBuffer` is non-sparse then it must be bound completely and contiguously to a single `VkDeviceMemory` object

- VUID-vkCmdCopyQueryPoolResults-queryType-03232
  If the `queryType` used to create `queryPool` was `VK_QUERY_TYPE_PERFORMANCE_QUERY_KHR`, VkPhysicalDevicePerformanceQueryPropertiesKHR::`allowCommandBufferQueryCopies` must be `VK_TRUE`

- VUID-vkCmdCopyQueryPoolResults-queryType-02734
  vkCmdCopyQueryPoolResults must not be called if the `queryType` used to create `queryPool` was `VK_QUERY_TYPE_PERFORMANCE_QUERY_INTEL`

- VUID-vkCmdCopyQueryPoolResults-None-07429
  All queries used by the command must not be active

- VUID-vkCmdCopyQueryPoolResults-None-08752
  All queries used by the command must have been made available by prior executed commands

Valid Usage (Implicit)

- VUID-vkCmdCopyQueryPoolResults-commandBuffer-parameter
  `commandBuffer` must be a valid VkCommandBuffer handle

- VUID-vkCmdCopyQueryPoolResults-queryPool-parameter
  `queryPool` must be a valid VkQueryPool handle

- VUID-vkCmdCopyQueryPoolResults-dstBuffer-parameter
  `dstBuffer` must be a valid VkBuffer handle

- VUID-vkCmdCopyQueryPoolResults-flags-parameter
  `flags` must be a valid combination of VkQueryResultFlagBits values

- VUID-vkCmdCopyQueryPoolResults-commandBuffer-recording
  `commandBuffer` must be in the recording state

- VUID-vkCmdCopyQueryPoolResults-commandBuffer-cmdpool
  The `VkCommandPool` that `commandBuffer` was allocated from must support graphics, or compute operations

- VUID-vkCmdCopyQueryPoolResults-renderpass
  This command must only be called outside of a render pass instance

- VUID-vkCmdCopyQueryPoolResults-videocoding
  This command must only be called outside of a video coding scope

- VUID-vkCmdCopyQueryPoolResults-commonparent
  Each of `commandBuffer`, `dstBuffer`, 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 | Outside | Outside | Graphics Compute | Action

## See Also

VK_VERSION_1_0, VkBuffer, VkCommandBuffer, VkDeviceSize, VkQueryPool, VkQueryResultFlags

## 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

Copyright 2014-2023 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0