C Specification

To export a Zircon event handle representing the payload of a semaphore, call:

// Provided by VK_FUCHSIA_external_semaphore
VkResult vkGetSemaphoreZirconHandleFUCHSIA(
    VkDevice                                    device,
    const VkSemaphoreGetZirconHandleInfoFUCHSIA* pGetZirconHandleInfo,
    zx_handle_t*                                pZirconHandle);


  • device is the logical device that created the semaphore being exported.

  • pGetZirconHandleInfo is a pointer to a VkSemaphoreGetZirconHandleInfoFUCHSIA structure containing parameters of the export operation.

  • pZirconHandle will return the Zircon event handle representing the semaphore payload.


Each call to vkGetSemaphoreZirconHandleFUCHSIA must create a Zircon event handle and transfer ownership of it to the application. To avoid leaking resources, the application must release ownership of the Zircon event handle when it is no longer needed.


Ownership can be released in many ways. For example, the application can call zx_handle_close() on the file descriptor, or transfer ownership back to Vulkan by using the file descriptor to import a semaphore payload.

Exporting a Zircon event handle from a semaphore may have side effects depending on the transference of the specified handle type, as described in Importing Semaphore State.

Valid Usage (Implicit)
  • VUID-vkGetSemaphoreZirconHandleFUCHSIA-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkGetSemaphoreZirconHandleFUCHSIA-pGetZirconHandleInfo-parameter
    pGetZirconHandleInfo must be a valid pointer to a valid VkSemaphoreGetZirconHandleInfoFUCHSIA structure

  • VUID-vkGetSemaphoreZirconHandleFUCHSIA-pZirconHandle-parameter
    pZirconHandle must be a valid pointer to a zx_handle_t value

Return Codes
On success, this command returns

On failure, this command returns


See Also

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.

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SPDX-License-Identifier: CC-BY-4.0