Oilpan: move node/element rare data objects to the heap.

Source/core/dom/NodeRareData.h

 /*
  * Copyright (C) 2008, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2008 David Smith <catfish.man@gmail.com>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 197 matching lines @@
     NodeList* m_childNodeList;
     NodeListAtomicNameCacheMap m_atomicNameCaches;
     TagCollectionCacheNS m_tagCollectionCacheNS;
 };
 
 class NodeMutationObserverData FINAL : public NoBaseWillBeGarbageCollected<NodeMutationObserverData> {
     WTF_MAKE_NONCOPYABLE(NodeMutationObserverData);
     WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
     WillBeHeapVector<OwnPtrWillBeMember<MutationObserverRegistration> > registry;
     WillBeHeapHashSet<RawPtrWillBeMember<MutationObserverRegistration> > transientRegistry;

[haraken, 2014/05/07 02:10:26]

Just to double-confirm: transientRegistry is really a strong pointer, right? It
seems that:

- NodeMutationObserverData outlives MutationObserverRegistrations in the
transientRegistry.
- transientRegistry just keeps a back pointer to MutationObserverRegistration.
- These facts imply that transientRegistry is a weak pointer.

However, I don't think I'm understanding the MutationObserver relationship very
well, so I'll let the decision to Erik and you instead of asking you a repeated
question :)

 
     static PassOwnPtrWillBeRawPtr<NodeMutationObserverData> create()
     {
         return adoptPtrWillBeNoop(new NodeMutationObserverData);
     }
 
     void trace(Visitor* visitor)
     {
         visitor->trace(registry);
         visitor->trace(transientRegistry);
     }
 
 private:
     NodeMutationObserverData() { }
 };
 
-class NodeRareData : public NodeRareDataBase {
-    WTF_MAKE_NONCOPYABLE(NodeRareData); WTF_MAKE_FAST_ALLOCATED;
+class NodeRareData : public NoBaseWillBeGarbageCollectedFinalized<NodeRareData>, public NodeRareDataBase {
+    WTF_MAKE_NONCOPYABLE(NodeRareData);
+    WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
-    static PassOwnPtr<NodeRareData> create(RenderObject* renderer)
+    static RawPtr<NodeRareData> create(RenderObject* renderer)

[haraken, 2014/05/07 02:10:26]

This could be NodeRareData*.

     {
-        return adoptPtr(new NodeRareData(renderer));
+        return new NodeRareData(renderer);
     }
 
-    void dispose();
-
     void clearNodeLists() { m_nodeLists.clear(); }
     NodeListsNodeData* nodeLists() const { return m_nodeLists.get(); }
     NodeListsNodeData& ensureNodeLists()
     {
         if (!m_nodeLists)
             m_nodeLists = NodeListsNodeData::create();
         return *m_nodeLists;
     }
 
     NodeMutationObserverData* mutationObserverData() { return m_mutationObserverData.get(); }
@@ skipping 22 matching lines @@
 
     bool hasRestyleFlag(DynamicRestyleFlags mask) const { return m_restyleFlags & mask; }
     void setRestyleFlag(DynamicRestyleFlags mask) { m_restyleFlags |= mask; RELEASE_ASSERT(m_restyleFlags); }
     bool hasRestyleFlags() const { return m_restyleFlags; }
     void clearRestyleFlags() { m_restyleFlags = 0; }
 
     enum {
         ConnectedFrameCountBits = 10, // Must fit Page::maxNumberOfFrames.
     };
 
+    void trace(Visitor*);
+
+    void traceAfterDispatch(Visitor*);
+    void finalizeGarbageCollectedObject();
+
 protected:
     NodeRareData(RenderObject* renderer)
         : NodeRareDataBase(renderer)
         , m_connectedFrameCount(0)
         , m_elementFlags(0)
         , m_restyleFlags(0)
+        , m_isElementRareData(false)
     { }
 
 private:
     OwnPtr<NodeListsNodeData> m_nodeLists;
-    OwnPtrWillBePersistent<NodeMutationObserverData> m_mutationObserverData;
+    OwnPtrWillBeMember<NodeMutationObserverData> m_mutationObserverData;
 
     unsigned m_connectedFrameCount : ConnectedFrameCountBits;
     unsigned m_elementFlags : NumberOfElementFlags;
     unsigned m_restyleFlags : NumberOfDynamicRestyleFlags;
+protected:
+    unsigned m_isElementRareData : 1;
 };
 
 inline bool NodeListsNodeData::deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(Node& ownerNode)
 {
     ASSERT(ownerNode.nodeLists() == this);
     if ((m_childNodeList ? 1 : 0) + m_atomicNameCaches.size() + m_tagCollectionCacheNS.size() != 1)
         return false;
     ownerNode.clearNodeLists();
     return true;
 }
 
 } // namespace WebCore
 
 #endif // NodeRareData_h