[webkit-changes] [WebKit/WebKit] a59adc: MachSendRights can release their IOSurface use-cou...

[mattwoodrow]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: a59adccf52b4786fae9c819ae50dfdb39e98a06f
      https://github.com/WebKit/WebKit/commit/a59adccf52b4786fae9c819ae50dfdb39e98a06f
  Author: Matt Woodrow <mattwoodrow at apple.com>
  Date:   2023-05-26 (Fri, 26 May 2023)

  Changed paths:
    M Source/WebKit/UIProcess/RemoteLayerTree/RemoteLayerTreeDrawingAreaProxy.mm

  Log Message:
  -----------
  MachSendRights can release their IOSurface use-counts before CA adds a new ones.
https://bugs.webkit.org/show_bug.cgi?id=257173
<rdar://problem/109687766>

Reviewed by Dean Jackson.

CoreAnimation doesn't add a new use-count to CAIOSurfaces until the transaction is committed, which is after the MachSendRight (inside LayerTreeTransaction/RemoteLayerBackingStoreProperties) is destroyed.

We should run an explicit CATransaction for layer tree commits to ensure that we always have a use-count added.

* Source/WebKit/UIProcess/RemoteLayerTree/RemoteLayerTreeDrawingAreaProxy.mm:
(WebKit::RemoteLayerTreeDrawingAreaProxy::commitLayerTree):

Canonical link: https://commits.webkit.org/264617@main