# vkGetMemoryFdKHR(3) Manual Page

## Name

vkGetMemoryFdKHR - Get a POSIX file descriptor for a memory object

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## C Specification

To export a POSIX file descriptor referencing the payload of a Vulkan device memory object, call:

    // Provided by VK_KHR_external_memory_fd
    VkResult vkGetMemoryFdKHR(
        VkDevice                                    device,
        const VkMemoryGetFdInfoKHR*                 pGetFdInfo,
        int*                                        pFd);

## Parameters

- `device` is the logical device that created the device memory being exported.

- `pGetFdInfo` is a pointer to a VkMemoryGetFdInfoKHR structure containing parameters of the export operation.

- `pFd` will return a file descriptor referencing the payload of the device memory object.

## Description

Each call to `vkGetMemoryFdKHR` must create a new file descriptor holding a reference to the memory object’s payload and transfer ownership of the file descriptor to the application. To avoid leaking resources, the application must release ownership of the file descriptor using the `close` system call when it is no longer needed, or by importing a Vulkan memory object from it. Where supported by the operating system, the implementation must set the file descriptor to be closed automatically when an `execve` system call is made.

Valid Usage (Implicit)

- VUID-vkGetMemoryFdKHR-device-parameter
  `device` must be a valid VkDevice handle

- VUID-vkGetMemoryFdKHR-pGetFdInfo-parameter
  `pGetFdInfo` must be a valid pointer to a valid VkMemoryGetFdInfoKHR structure

- VUID-vkGetMemoryFdKHR-pFd-parameter
  `pFd` must be a valid pointer to an `int` value

Return Codes

On success, this command returns

  - `VK_SUCCESS`

On failure, this command returns

  - `VK_ERROR_TOO_MANY_OBJECTS`

  - `VK_ERROR_OUT_OF_HOST_MEMORY`

## See Also

VK_KHR_external_memory_fd, VkDevice, VkMemoryGetFdInfoKHR

## 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 2014-2025 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0