VK_KHR_external_semaphore_fd

Other Extension Metadata

Last Modified Date

2016-10-21

IP Status

No known IP claims.

Contributors

• Jesse Hall, Google
• James Jones, NVIDIA
• Jeff Juliano, NVIDIA
• Carsten Rohde, NVIDIA

Description

An application using external memory may wish to synchronize access to that memory using semaphores. This extension enables an application to export semaphore payload to and import semaphore payload from POSIX file descriptors.

New Commands

• vkGetSemaphoreFdKHR
• vkImportSemaphoreFdKHR

New Structures

• VkImportSemaphoreFdInfoKHR
• VkSemaphoreGetFdInfoKHR

New Enum Constants

• VK_KHR_EXTERNAL_SEMAPHORE_FD_EXTENSION_NAME
• VK_KHR_EXTERNAL_SEMAPHORE_FD_SPEC_VERSION
• Extending VkStructureType:
  • VK_STRUCTURE_TYPE_IMPORT_SEMAPHORE_FD_INFO_KHR
  • VK_STRUCTURE_TYPE_SEMAPHORE_GET_FD_INFO_KHR

Issues

1) Does the application need to close the file descriptor returned by vkGetSemaphoreFdKHR?

RESOLVED: Yes, unless it is passed back in to a driver instance to import the semaphore. A successful get call transfers ownership of the file descriptor to the application, and a successful import transfers it back to the driver. Destroying the original semaphore object will not close the file descriptor or remove its reference to the underlying semaphore resource associated with it.

Version History

• Revision 1, 2016-10-21 (Jesse Hall)
  • Initial revision