Safe Haskell	None
Language	Haskell2010

Vulkan.Extensions.VK_KHR_external_semaphore

Description

Name

VK_KHR_external_semaphore - device extension

VK_KHR_external_semaphore

Name String: VK_KHR_external_semaphore

Extension Type

Device extension

Registered Extension Number

78

Revision

1

Extension and Version Dependencies

Requires Vulkan 1.0
Requires VK_KHR_external_semaphore_capabilities

Deprecation state

Promoted to Vulkan 1.1

Contact

James Jones https://github.com/KhronosGroup/Vulkan-Docs/issues/new?title=VK_KHR_external_semaphore:%20&body=@cubanismo%20

Other Extension Metadata

Last Modified Date: 2016-10-21

IP Status

No known IP claims.

Interactions and External Dependencies

Promoted to Vulkan 1.1 Core

Contributors

Jason Ekstrand, Intel
Jesse Hall, Google
Tobias Hector, Imagination Technologies
James Jones, NVIDIA
Jeff Juliano, NVIDIA
Matthew Netsch, Qualcomm Technologies, Inc.
Ray Smith, ARM
Chad Versace, Google

Description

An application using external memory may wish to synchronize access to that memory using semaphores. This extension enables an application to create semaphores from which non-Vulkan handles that reference the underlying synchronization primitive can be exported.

Promotion to Vulkan 1.1

All functionality in this extension is included in core Vulkan 1.1, with the KHR suffix omitted. The original type, enum and command names are still available as aliases of the core functionality.

New Structures

Extending SemaphoreCreateInfo:
- ExportSemaphoreCreateInfoKHR

New Enums

SemaphoreImportFlagBitsKHR

New Bitmasks

SemaphoreImportFlagsKHR

New Enum Constants

KHR_EXTERNAL_SEMAPHORE_EXTENSION_NAME

KHR_EXTERNAL_SEMAPHORE_SPEC_VERSION
Extending SemaphoreImportFlagBits:
- SEMAPHORE_IMPORT_TEMPORARY_BIT_KHR
Extending StructureType:
- STRUCTURE_TYPE_EXPORT_SEMAPHORE_CREATE_INFO_KHR

Issues

1) Should there be restrictions on what side effects can occur when waiting on imported semaphores that are in an invalid state?

RESOLVED: Yes. Normally, validating such state would be the responsibility of the application, and the implementation would be free to enter an undefined state if valid usage rules were violated. However, this could cause security concerns when using imported semaphores, as it would require the importing application to trust the exporting application to ensure the state is valid. Requiring this level of trust is undesirable for many potential use cases.

2) Must implementations validate external handles the application provides as input to semaphore state import operations?

RESOLVED: Implementations must return an error to the application if the provided semaphore state handle cannot be used to complete the requested import operation. However, implementations need not validate handles are of the exact type specified by the application.