Class KHRExternalFenceFd

  • public class KHRExternalFenceFd
    extends java.lang.Object
    An application using external memory may wish to synchronize access to that memory using fences. This extension enables an application to export fence payload to and import fence payload from POSIX file descriptors.
    Name String
    Extension Type
    Device extension
    Registered Extension Number
    Extension and Version Dependencies
    Last Modified Date
    IP Status
    No known IP claims.
    • Method Detail

      • nvkImportFenceFdKHR

        public static int nvkImportFenceFdKHR​(VkDevice device,
                                              long pImportFenceFdInfo)
        Unsafe version of: ImportFenceFdKHR
      • vkImportFenceFdKHR

        public static int vkImportFenceFdKHR​(VkDevice device,
                                             VkImportFenceFdInfoKHR pImportFenceFdInfo)
        Import a fence from a POSIX file descriptor.
        C Specification

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

         VkResult vkImportFenceFdKHR(
             VkDevice                                    device,
             const VkImportFenceFdInfoKHR*               pImportFenceFdInfo);

        Importing a fence 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 fence 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
        • fence must not be associated with any queue command that has not yet completed execution on that queue
        Valid Usage (Implicit)
        • device must be a valid VkDevice handle
        • pImportFenceFdInfo must be a valid pointer to a valid VkImportFenceFdInfoKHR structure
        Return Codes
        On success, this command returns
        On failure, this command returns
        See Also


        device - the logical device that created the fence.
        pImportFenceFdInfo - points to a VkImportFenceFdInfoKHR structure specifying the fence and import parameters.
      • nvkGetFenceFdKHR

        public static int nvkGetFenceFdKHR​(VkDevice device,
                                           long pGetFdInfo,
                                           long pFd)
        Unsafe version of: GetFenceFdKHR
      • vkGetFenceFdKHR

        public static int vkGetFenceFdKHR​(VkDevice device,
                                          VkFenceGetFdInfoKHR pGetFdInfo,
                                          java.nio.IntBuffer pFd)
        Get a POSIX file descriptor handle for a fence.
        C Specification

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

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

        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.


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

        If pGetFdInfo->handleType is 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.

        Valid Usage (Implicit)
        • device must be a valid VkDevice handle
        • pGetFdInfo must be a valid pointer to a valid VkFenceGetFdInfoKHR structure
        • pFd must be a valid pointer to an int value
        Return Codes
        On success, this command returns
        On failure, this command returns
        See Also


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