VK_KHR_external_fence_win32

Other Extension Metadata

Last Modified Date

2017-05-08

IP Status

No known IP claims.

Contributors

• Jesse Hall, Google
• James Jones, NVIDIA
• Jeff Juliano, NVIDIA
• Cass Everitt, Oculus
• Contributors to VK_KHR_external_semaphore_win32

Description

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 Windows handles.

New Commands

• vkGetFenceWin32HandleKHR
• vkImportFenceWin32HandleKHR

New Structures

• VkFenceGetWin32HandleInfoKHR
• VkImportFenceWin32HandleInfoKHR
• Extending VkFenceCreateInfo:
  • VkExportFenceWin32HandleInfoKHR

New Enum Constants

• VK_KHR_EXTERNAL_FENCE_WIN32_EXTENSION_NAME
• VK_KHR_EXTERNAL_FENCE_WIN32_SPEC_VERSION
• Extending VkStructureType:
  • VK_STRUCTURE_TYPE_EXPORT_FENCE_WIN32_HANDLE_INFO_KHR
  • VK_STRUCTURE_TYPE_FENCE_GET_WIN32_HANDLE_INFO_KHR
  • VK_STRUCTURE_TYPE_IMPORT_FENCE_WIN32_HANDLE_INFO_KHR

Issues

This extension borrows concepts, semantics, and language from VK_KHR_external_semaphore_win32. That extension’s issues apply equally to this extension.

1) Should D3D12 fence handle types be supported, like they are for semaphores?

RESOLVED: No. Doing so would require extending the fence signal and wait operations to provide values to signal / wait for, like VkD3D12FenceSubmitInfoKHR does. A D3D12 fence can be signaled by importing it into a VkSemaphore instead of a VkFence, and applications can check status or wait on the D3D12 fence using non-Vulkan APIs. The convenience of being able to do these operations on VkFence objects does not justify the extra API complexity.

Version History

• Revision 1, 2017-05-08 (Jesse Hall)
  • Initial revision