vkImportSemaphoreFdKHR(3)

# vkImportSemaphoreFdKHR(3) Manual Page

## Name

vkImportSemaphoreFdKHR - Import a semaphore from a POSIX file descriptor

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## C Specification

To import a semaphore payload from a POSIX file descriptor, call:

    // Provided by VK_KHR_external_semaphore_fd
    VkResult vkImportSemaphoreFdKHR(
        VkDevice                                    device,
        const VkImportSemaphoreFdInfoKHR*           pImportSemaphoreFdInfo);

## Parameters

- `device` is the logical device that created the semaphore.

- `pImportSemaphoreFdInfo` is a pointer to a VkImportSemaphoreFdInfoKHR structure specifying the semaphore and import parameters.

## Description

Importing a semaphore payload from a file descriptor transfers ownership of the file descriptor from the application to the Vulkan implementation. The application must not perform any operations on the file descriptor after a successful import.

Applications can import the same semaphore payload into multiple instances of Vulkan, into the same instance from which it was exported, and multiple times into a given Vulkan instance.

Valid Usage

- VUID-vkImportSemaphoreFdKHR-semaphore-01142
  `semaphore` must not be associated with any queue command that has not yet completed execution on that queue

Valid Usage (Implicit)

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

- VUID-vkImportSemaphoreFdKHR-pImportSemaphoreFdInfo-parameter
  `pImportSemaphoreFdInfo` must be a valid pointer to a valid VkImportSemaphoreFdInfoKHR structure

Return Codes

On success, this command returns

  - VK_SUCCESS

On failure, this command returns

  - VK_ERROR_INVALID_EXTERNAL_HANDLE

  - VK_ERROR_OUT_OF_HOST_MEMORY

  - VK_ERROR_UNKNOWN

  - VK_ERROR_VALIDATION_FAILED

## See Also

VK_KHR_external_semaphore_fd, VkDevice, VkImportSemaphoreFdInfoKHR

## 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 2014-2026 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0