[webkit-changes] [WebKit/WebKit] 7a6e06: AX: Make AXGeometryManager thread safe.

[AndresGonzalezApple]

  Branch: refs/heads/main
  Home:   https://github.com/WebKit/WebKit
  Commit: 7a6e0627e073356842e414b20b5b005c4a17baa1
      https://github.com/WebKit/WebKit/commit/7a6e0627e073356842e414b20b5b005c4a17baa1
  Author: Andres Gonzalez <andresg_22 at apple.com>
  Date:   2023-05-11 (Thu, 11 May 2023)

  Changed paths:
    M Source/WebCore/accessibility/AXGeometryManager.cpp
    M Source/WebCore/accessibility/AXGeometryManager.h
    M Source/WebCore/accessibility/AXObjectCache.cpp
    M Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.cpp
    M Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.cpp
    M Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.h
    M Source/WebCore/accessibility/isolatedtree/mac/AXIsolatedObjectMac.mm

  Log Message:
  -----------
  AX: Make AXGeometryManager thread safe.
https://bugs.webkit.org/show_bug.cgi?id=256625
<rdar://problem/109185522>

Reviewed by Tyler Wilcock.

There were several thread safety issues related to AXGeometryManager:
- Since AXIsolatedTree holds a reference to it, when the AXObjectCache goes away, the AXGeometryManager was kept alive and its Timer could fire causing random crashes. Now, the AXIsolatedTree releases its reference to the AXGeometryManager when the AXObjectCache is about to be destroyed, allowing the AXGeometryManager to be destroyed on the main thread.
- The destructor of AXGeometryManager now stops the Timer.
- The member m_primaryScreenRect is now guarded by a Lock since it is accessed in both threads.
- The initialization of m_primaryScreenRect is done later, right before it is needed instead of at construction time.

* Source/WebCore/accessibility/AXGeometryManager.cpp:
(WebCore::AXGeometryManager::AXGeometryManager):
(WebCore::AXGeometryManager::~AXGeometryManager):
(WebCore::AXGeometryManager::scheduleRenderingUpdate):
(WebCore::AXGeometryManager::initializePrimaryScreenRect):
(WebCore::AXGeometryManager::primaryScreenRect):
(WebCore::AXGeometryManager::primaryScreenRect const): Deleted.
* Source/WebCore/accessibility/AXGeometryManager.h:

* Source/WebCore/accessibility/AXObjectCache.cpp:
(WebCore::AXObjectCache::getOrCreateIsolatedTree):
* Source/WebCore/accessibility/isolatedtree/AXIsolatedObject.cpp:
(WebCore::AXIsolatedObject::initializeProperties):
* Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.cpp:
(WebCore::AXIsolatedTree::AXIsolatedTree):
(WebCore::AXIsolatedTree::removeTreeForPageID):
* Source/WebCore/accessibility/isolatedtree/AXIsolatedTree.h:
(WebCore::AXIsolatedTree::geometryManager const):
* Source/WebCore/accessibility/isolatedtree/mac/AXIsolatedObjectMac.mm:
(WebCore::AXIsolatedObject::primaryScreenRect const):

Canonical link: https://commits.webkit.org/263970@main