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

Source/core/dom/Node.cpp

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 248 matching lines @@
 Node::~Node()
 {
 #ifndef NDEBUG
     nodeCounter.decrement();
 #endif
 
 #if DUMP_NODE_STATISTICS
     liveNodeSet.remove(this);
 #endif
 
+#if !ENABLE(OILPAN)
     if (hasRareData())
         clearRareData();
 
     RELEASE_ASSERT(!renderer());
 
-#if !ENABLE(OILPAN)
     if (!isContainerNode())
         willBeDeletedFromDocument();
+#else
+    // With Oilpan, the rare data finalizer also asserts for
+    // this condition (we cannot directly access it here.)
+    RELEASE_ASSERT(hasRareData() || !renderer());
 #endif
 
     if (m_previous)
         m_previous->setNextSibling(0);
     if (m_next)
         m_next->setPreviousSibling(0);
 
 #if !ENABLE(OILPAN)
     if (m_treeScope)
         m_treeScope->guardDeref();
@@ skipping 32 matching lines @@
 {
     ASSERT_WITH_SECURITY_IMPLICATION(hasRareData());
     return static_cast<NodeRareData*>(m_data.m_rareData);
 }
 
 NodeRareData& Node::ensureRareData()
 {
     if (hasRareData())
         return *rareData();
 
-    NodeRareData* data;
+    OwnPtrWillBeRawPtr<NodeRareData> data;

[Erik Corry, 2014/05/05 09:31:27]

I can't see the point of this OwnPtr.  Things would be simpler if this was just
a raw pointer, and you just immediately leakPtr after create. If RawPtr had a
leakPtr method you could avid the ifdef completely, otherwise you have to move
it to the create() calls.

[sof, 2014/05/05 09:41:38]

It minimized the #if'ery required, but I'll take another look.

[sof, 2014/05/05 13:38:58]

Jumped ahead a bit and made the create() return a raw pointer (in the form of a
RawPtr<>) to avoid the #if's here, which is its only call site.

Acceptable type for create() to have in a non-Oilpan setting?

     if (isElementNode())
-        data = ElementRareData::create(m_data.m_renderer).leakPtr();
+        data = ElementRareData::create(m_data.m_renderer);
     else
-        data = NodeRareData::create(m_data.m_renderer).leakPtr();
+        data = NodeRareData::create(m_data.m_renderer);
+
     ASSERT(data);
 
+#if ENABLE(OILPAN)
     m_data.m_rareData = data;
+#else
+    m_data.m_rareData = data.leakPtr();
+#endif
     setFlag(HasRareDataFlag);
-    return *data;
+    return *rareData();
 }
 
+#if !ENABLE(OILPAN)
 void Node::clearRareData()
 {
     ASSERT(hasRareData());
     ASSERT(!transientMutationObserverRegistry() || transientMutationObserverRegistry()->isEmpty());
 
     RenderObject* renderer = m_data.m_rareData->renderer();
-    if (isElementNode()) {
-        ElementRareData* rareData = static_cast<ElementRareData*>(m_data.m_rareData);
-        rareData->dispose();
-        delete rareData;
-    } else {
-        NodeRareData* rareData = static_cast<NodeRareData*>(m_data.m_rareData);
-        rareData->dispose();
-        delete rareData;
-    }
+    if (isElementNode())
+        delete static_cast<ElementRareData*>(m_data.m_rareData);
+    else
+        delete static_cast<NodeRareData*>(m_data.m_rareData);
     m_data.m_renderer = renderer;
     clearFlag(HasRareDataFlag);
 }
+#endif
 
 Node* Node::toNode()
 {
     return this;
 }
 
 short Node::tabIndex() const
 {
     return 0;
 }
@@ skipping 2195 matching lines @@
     ASSERT(isHTMLElement() || isSVGElement());
     setFlag(CustomElementFlag);
     setFlag(newState == Upgraded, CustomElementUpgradedFlag);
 
     if (oldState == NotCustomElement || newState == Upgraded)
         setNeedsStyleRecalc(SubtreeStyleChange); // :unresolved has changed
 }
 
 void Node::trace(Visitor* visitor)
 {
+    if (hasRareData())
+        visitor->trace(rareData());
+
     visitor->trace(m_treeScope);
 }
 
 } // namespace WebCore
 
 #ifndef NDEBUG
 
 void showNode(const WebCore::Node* node)
 {
     if (node)
         node->showNode("");
 }
 
 void showTree(const WebCore::Node* node)
 {
     if (node)
         node->showTreeForThis();
 }
 
 void showNodePath(const WebCore::Node* node)
 {
     if (node)
         node->showNodePathForThis();
 }
 
 #endif