Bug 283286 – [GTK][WPE][Skia] Add GPU synchronization primitives to NativeImage/ImageBuffer for Skia

• Component: WPE WebKit
• Status: RESOLVED FIXED

[Nikolas Zimmermann]

For the planned threaded GPU rendering mode we need a way to mark
a NativeImage/ImageBuffer "as done", to inject a fence in the GL
command stream, that we can wait on at a later point in time to
guarantee that all operations finished. Therefore I propose to
add Skia specific functions to ImageBuffer(Backend)/NativeImageBackend:
 
 - finishAcceleratedRenderingAndCreateFence()
 
   Used to notify the underlying SkSurface, that it should flush
   all pending rendering operations and submit the work to the GPU.
   Afterwards inject a fence into the GL command stream, so that we
   we can wait upon completion at a later point, before attempting
   to use the ImageBuffer/NativeImage.

 - waitForAcceleratedRenderingFenceCompletion()

   Performs a 'serverWait()' operation on the GLFence, previously
   created by finishAcceleratedRenderingAndCreateFence(). This
   instructs to GPU to await completion of the previous rendering.

finishAcceleratedRenderingAndCreateFence() will be used during
DisplayList recording, whenever an ImageBuffer/NativeImage resource
is used, upon entering the DisplayList::ResourceHeap cache.

waitForAcceleratedRenderingFenceCompletion() will be used during
DisplayList replaying, whenever an ImageBuffer/NativeImage resource
is extracted from the DisplayList::ResourceHeap cache.

[Nikolas Zimmermann]

Pull request: https://github.com/WebKit/WebKit/pull/36794

[EWS]

Committed 286767@main (774fd3dddd84): <https://commits.webkit.org/286767@main>

Reviewed commits have been landed. Closing PR #36794 and removing active labels.