Changeset 82633 in webkit

Timestamp:

Mar 31, 2011 4:15:52 PM (13 years ago)

Author:

Adam Roben

Message:

Don't ref CACFLayerTreeHosts when telling them to flush layer changes

LayerChangesFlusher was reffing CACFLayerTreeHosts before calling out to them. This would
have protected us if calling out to one CACFLayerTreeHost could cause a different
CACFLayerTreeHost to be destroyed. But that isn't possible; each CACFLayerTreeHost is
associated with its own page, and flushing layer changes doesn't touch any other page. So it
isn't possible for a CACFLayerTreeHost to be deleted while another one is flushing layer
changes.

One benefit of this change is that it will make it easier to make LayerChangesFlusher
interact with a forthcoming abstract base class, rather than with CACFLayerTreeHost itself.

This should cause no change in behavior.

Fixes <​http://webkit.org/b/57590> LayerChangesFlusher unnecessarily refs CACFLayerTreeHost
before calling out to it

Reviewed by Darin Adler.

• platform/graphics/ca/win/LayerChangesFlusher.cpp:

(WebCore::LayerChangesFlusher::hookFired): Just store bare pointers to the
CACFLayerTreeHosts.

Location:

trunk/Source/WebCore

Files:

• ChangeLog (modified) (1 diff)
• platform/graphics/ca/win/LayerChangesFlusher.cpp (modified) (1 diff)

trunk/Source/WebCore/ChangeLog

@@ +1 @@
+2011-03-31  Adam Roben  <aroben@apple.com>
+
+        Don't ref CACFLayerTreeHosts when telling them to flush layer changes
+
+        LayerChangesFlusher was reffing CACFLayerTreeHosts before calling out to them. This would
+        have protected us if calling out to one CACFLayerTreeHost could cause a different
+        CACFLayerTreeHost to be destroyed. But that isn't possible; each CACFLayerTreeHost is
+        associated with its own page, and flushing layer changes doesn't touch any other page. So it
+        isn't possible for a CACFLayerTreeHost to be deleted while another one is flushing layer
+        changes.
+
+        One benefit of this change is that it will make it easier to make LayerChangesFlusher
+        interact with a forthcoming abstract base class, rather than with CACFLayerTreeHost itself.
+
+        This should cause no change in behavior.
+
+        Fixes <http://webkit.org/b/57590> LayerChangesFlusher unnecessarily refs CACFLayerTreeHost
+        before calling out to it
+
+        Reviewed by Darin Adler.
+
+        * platform/graphics/ca/win/LayerChangesFlusher.cpp:
+        (WebCore::LayerChangesFlusher::hookFired): Just store bare pointers to the
+        CACFLayerTreeHosts.
+
 2011-03-31  Antti Koivisto  <antti@apple.com>
 

trunk/Source/WebCore/platform/graphics/ca/win/LayerChangesFlusher.cpp

@@ -81 +81 @@
 
     // Calling out to the hosts can cause m_hostsWithChangesToFlush to be modified, so we copy it
-    // into a Vector first. We have to hold a reference to them because otherwise they could be
-    // destroyed while we're calling out to them.
-    Vector<RefPtr<CACFLayerTreeHost> > hosts;
+    // into a Vector first.
+    Vector<CACFLayerTreeHost*> hosts;
     copyToVector(m_hostsWithChangesToFlush, hosts);
     m_hostsWithChangesToFlush.clear();