Oilpan: Remove guardRef and guardDeref from TreeScope.

Source/core/dom/Node.cpp

Index: Source/core/dom/Node.cpp
diff --git a/Source/core/dom/Node.cpp b/Source/core/dom/Node.cpp
index edcac04a7e802c3106b53453088b9128102e179e..7a9ecd6b7200b6e7a738b44de704148170c28564 100644
--- a/Source/core/dom/Node.cpp
+++ b/Source/core/dom/Node.cpp
@@ -279,8 +279,10 @@ Node::~Node()
     if (m_next)
         m_next->setPreviousSibling(0);
 
+#if !ENABLE(OILPAN)
     if (m_treeScope)
         m_treeScope->guardDeref();
+#endif
 
     InspectorCounters::decrementCounter(InspectorCounters::NodeCounter);
 
@@ -290,6 +292,8 @@ Node::~Node()
 
 void Node::willBeDeletedFromDocument()
 {
+#if !ENABLE(OILPAN)
+    // With Oilpan all of this is handled with weak processing on the document.

[haraken, 2014/04/25 14:30:32]

I'd put #if !ENABLE(OILPAN) around Node::willBeDeletedFromDocument() and all
call sites of Node::willBeDeletedFromDocument().

[Mads Ager (chromium), 2014/04/28 09:45:21]

Thanks. That more clearly indicates what is going on. Done.

     if (!isTreeScopeInitialized())
         return;
 
@@ -305,6 +309,7 @@ void Node::willBeDeletedFromDocument()
         cache->remove(this);
 
     document.markers().removeMarkers(this);
+#endif
 }
 
 NodeRareData* Node::rareData() const
@@ -2029,12 +2034,17 @@ void Node::removeAllEventListenersRecursively()
     }
 }
 
-typedef HashMap<Node*, OwnPtr<EventTargetData> > EventTargetDataMap;
+typedef WillBeHeapHashMap<RawPtrWillBeWeakMember<Node>, OwnPtr<EventTargetData> > EventTargetDataMap;
 
 static EventTargetDataMap& eventTargetDataMap()
 {
+#if ENABLE(OILPAN)
+    DEFINE_STATIC_LOCAL(Persistent<EventTargetDataMap>, map, (new EventTargetDataMap()));
+    return *map;
+#else
     DEFINE_STATIC_LOCAL(EventTargetDataMap, map, ());
     return map;
+#endif
 }
 
 EventTargetData* Node::eventTargetData()
@@ -2354,6 +2364,12 @@ bool Node::willRespondToTouchEvents()
 }
 
 // This is here for inlining
+#if ENABLE(OILPAN)
+inline void TreeScope::removedLastRefToScope()

[haraken, 2014/04/25 14:30:32]

Just help me understand: How is removedLastRef working now (for TreeScope/Node)?
Given that the TreeScope/Node can be referenced via Members, the point where the
last RefPtr is gone is not the point where we should dispatch dispose().

[Mads Ager (chromium), 2014/04/28 09:45:21]

When the last ref is removed to the tree scope we always call dispose. Before,
dispose was called only if there was a guardRef and otherwise the treescope was
deleted right away (and therefore dispose was not needed because the treescope
was being deleted instead). Now, we never eagerly delete the document. Instead,
we call dispose when there are no more RefPtrs to the document.

In my next change where we start visiting everything and move away from the
TreeShared algorithms for destruction. We will have to explicitly dispatch
dispose. A document has well-defined life-time states. I think we need to
piggy-back on that and call dispose when the document moves to one of the later
stages (stopping? stopped?).

+{
+    dispose();
+}
+#else
 inline void TreeScope::removedLastRefToScope()
 {
     ASSERT_WITH_SECURITY_IMPLICATION(!deletionHasBegun());
@@ -2373,14 +2389,13 @@ inline void TreeScope::removedLastRefToScope()
 #if !ASSERT_DISABLED
         rootNode().m_inRemovedLastRefFunction = false;
 #endif
-#if !ENABLE(OILPAN)
 #if SECURITY_ASSERT_ENABLED
         beginDeletion();
 #endif
         delete this;
-#endif
     }
 }
+#endif
 
 // It's important not to inline removedLastRef, because we don't want to inline the code to
 // delete a Node at each deref call site.
@@ -2542,6 +2557,11 @@ void Node::setCustomElementState(CustomElementState newState)
         setNeedsStyleRecalc(SubtreeStyleChange); // :unresolved has changed
 }
 
+void Node::trace(Visitor* visitor)
+{
+    visitor->trace(m_treeScope);
+}
+
 } // namespace WebCore
 
 #ifndef NDEBUG