vkGetFenceFdKHR

To export a POSIX file descriptor representing the payload of a fence, call:

VkResult vkGetFenceFdKHR(
    VkDevice device,
    const VkFenceGetFdInfoKHR* pGetFdInfo,
    int* pFd);

• device is the logical device that created the fence being exported.
• pGetFdInfo is a pointer to a VkFenceGetFdInfoKHR structure containing parameters of the export operation.
• pFd will return the file descriptor representing the fence payload.

Each call to vkGetFenceFdKHR must create a new file descriptor and transfer ownership of it to the application. To avoid leaking resources, the application must release ownership of the file descriptor when it is no longer needed.

If pGetFdInfo→handleType is VK_EXTERNAL_FENCE_HANDLE_TYPE_SYNC_FD_BIT and the fence is signaled at the time vkGetFenceFdKHR is called, pFd may return the value -1 instead of a valid file descriptor.

Where supported by the operating system, the implementation must set the file descriptor to be closed automatically when an execve system call is made.

Exporting a file descriptor from a fence may have side effects depending on the transference of the specified handle type, as described in Importing Fence State.