Changeset 248445 in webkit

Timestamp:

Aug 8, 2019, 3:10:36 PM (7 years ago)

Author:

Chris Dumez

Message:

ScrollingStateNode is not ThreadSafeRefCounted but is ref'd / deref'd from several threads
​https://bugs.webkit.org/show_bug.cgi?id=200545

Reviewed by Antti Koivisto.

The ScrollingStateTree and its ScrollingStateNodes are being passed to the scrolling thread.
ScrollingStateNode is not ThreadSafeRefCounted, which is potentially unsafe. Make it
ThreadSafeRefCounted for safety in this patch given that using RefCounted here is either
wrong or fragile.

• page/scrolling/ScrollingStateNode.h:

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• page/scrolling/ScrollingStateNode.cpp (modified) (1 diff)
• page/scrolling/ScrollingStateNode.h (modified) (3 diffs)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2019-08-08  Chris Dumez  <cdumez@apple.com>
+
+        ScrollingStateNode is not ThreadSafeRefCounted but is ref'd / deref'd from several threads
+        https://bugs.webkit.org/show_bug.cgi?id=200545
+
+        Reviewed by Antti Koivisto.
+
+        The ScrollingStateTree and its ScrollingStateNodes are being passed to the scrolling thread.
+        ScrollingStateNode is not ThreadSafeRefCounted, which is potentially unsafe. Make it
+        ThreadSafeRefCounted for safety in this patch given that using RefCounted here is either
+        wrong or fragile.
+
+        * page/scrolling/ScrollingStateNode.h:
+
 2019-08-08  Brent Fulgham  <bfulgham@apple.com>
 

trunk/Source/WebCore/page/scrolling/ScrollingStateNode.cpp

@@ -55 +55 @@
         setLayer(stateNode.layer().toRepresentation(adoptiveTree.preferredLayerRepresentation()));
 
-    relaxAdoptionRequirement();
     scrollingStateTree().addNode(*this);
 }

trunk/Source/WebCore/page/scrolling/ScrollingStateNode.h

@@ -31 +31 @@
 #include "ScrollingCoordinator.h"
 #include <stdint.h>
-#include <wtf/RefCounted.h>
+#include <wtf/ThreadSafeRefCounted.h>
 #include <wtf/TypeCasts.h>
 #include <wtf/Vector.h>
@@ -181 +181 @@
 };
 
-class ScrollingStateNode : public RefCounted<ScrollingStateNode> {
+class ScrollingStateNode : public ThreadSafeRefCounted<ScrollingStateNode> {
     WTF_MAKE_FAST_ALLOCATED;
 public:
-    ScrollingStateNode(ScrollingNodeType, ScrollingStateTree&, ScrollingNodeID);
     virtual ~ScrollingStateNode();
     
@@ -249 +248 @@
 protected:
     ScrollingStateNode(const ScrollingStateNode&, ScrollingStateTree&);
+    ScrollingStateNode(ScrollingNodeType, ScrollingStateTree&, ScrollingNodeID);
 
     virtual void dumpProperties(WTF::TextStream&, ScrollingStateTreeAsTextBehavior) const;