vkEnumeratePhysicalDeviceQueueFamilyPerformanceQueryCountersKHR(3)

# vkEnumeratePhysicalDeviceQueueFamilyPerformanceQueryCountersKHR(3) Manual Page

## Name

vkEnumeratePhysicalDeviceQueueFamilyPerformanceQueryCountersKHR - Reports properties of the performance query counters available on a queue family of a device

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## C Specification

To enumerate the performance query counters available on a queue family of a physical device, call:

    // Provided by VK_KHR_performance_query
    VkResult vkEnumeratePhysicalDeviceQueueFamilyPerformanceQueryCountersKHR(
        VkPhysicalDevice                            physicalDevice,
        uint32_t                                    queueFamilyIndex,
        uint32_t*                                   pCounterCount,
        VkPerformanceCounterKHR*                    pCounters,
        VkPerformanceCounterDescriptionKHR*         pCounterDescriptions);

## Parameters

- `physicalDevice` is the handle to the physical device whose queue family performance query counter properties will be queried.

- `queueFamilyIndex` is the index into the queue family of the physical device we want to get properties for.

- `pCounterCount` is a pointer to an integer related to the number of counters available or queried, as described below.

- `pCounters` is either `NULL` or a pointer to an array of VkPerformanceCounterKHR structures.

- `pCounterDescriptions` is either `NULL` or a pointer to an array of VkPerformanceCounterDescriptionKHR structures.

## Description

If `pCounters` is `NULL` and `pCounterDescriptions` is `NULL`, then the number of counters available is returned in `pCounterCount`. Otherwise, `pCounterCount` must point to a variable set by the user to the number of elements in the `pCounters`, `pCounterDescriptions`, or both arrays and on return the variable is overwritten with the number of structures actually written out. If `pCounterCount` is less than the number of counters available, at most `pCounterCount` structures will be written and `VK_INCOMPLETE` will be returned instead of `VK_SUCCESS`.

Valid Usage (Implicit)

- `physicalDevice` must be a valid VkPhysicalDevice handle

- `pCounterCount` must be a valid pointer to a `uint32_t` value

- If the value referenced by `pCounterCount` is not `0`, and `pCounters` is not `NULL`, `pCounters` must be a valid pointer to an array of `pCounterCount` VkPerformanceCounterKHR structures

- If the value referenced by `pCounterCount` is not `0`, and `pCounterDescriptions` is not `NULL`, `pCounterDescriptions` must be a valid pointer to an array of `pCounterCount` VkPerformanceCounterDescriptionKHR structures

Return Codes

On success, this command returns

  - `VK_SUCCESS`

  - `VK_INCOMPLETE`

On failure, this command returns

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

  - `VK_ERROR_OUT_OF_DEVICE_MEMORY`

  - `VK_ERROR_INITIALIZATION_FAILED`

## See Also

VkPerformanceCounterDescriptionKHR, VkPerformanceCounterKHR, VkPhysicalDevice

## 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 (c) 2014-2020 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0