# vkGetPhysicalDeviceQueueFamilyProperties(3) Manual Page

## Name

vkGetPhysicalDeviceQueueFamilyProperties - Reports properties of the queues of the specified physical device

## C Specification

To query properties of queues available on a physical device, call:

    void vkGetPhysicalDeviceQueueFamilyProperties(
        VkPhysicalDevice                            physicalDevice,
        uint32_t*                                   pQueueFamilyPropertyCount,
        VkQueueFamilyProperties*                    pQueueFamilyProperties);

## Parameters

- `physicalDevice` is the handle to the physical device whose properties will be queried.

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

- `pQueueFamilyProperties` is either `NULL` or a pointer to an array of VkQueueFamilyProperties structures.

## Description

If `pQueueFamilyProperties` is `NULL`, then the number of queue families available is returned in `pQueueFamilyPropertyCount`. Implementations must support at least one queue family. Otherwise, `pQueueFamilyPropertyCount` must point to a variable set by the user to the number of elements in the `pQueueFamilyProperties` array, and on return the variable is overwritten with the number of structures actually written to `pQueueFamilyProperties`. If `pQueueFamilyPropertyCount` is less than the number of queue families available, at most `pQueueFamilyPropertyCount` structures will be written.

Valid Usage (Implicit)

- `physicalDevice` must be a valid VkPhysicalDevice handle

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

- If the value referenced by `pQueueFamilyPropertyCount` is not `0`, and `pQueueFamilyProperties` is not `NULL`, `pQueueFamilyProperties` must be a valid pointer to an array of `pQueueFamilyPropertyCount` VkQueueFamilyProperties structures

## See Also

VkPhysicalDevice, VkQueueFamilyProperties

## 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 Khronos Group. This work is licensed under a Creative Commons Attribution 4.0 International License.