Oilpan: move LiveNodeList collections 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 24 matching lines @@
 #include "wtf/PassOwnPtr.h"
 #include "wtf/text/AtomicString.h"
 #include "wtf/text/StringHash.h"
 
 namespace WebCore {
 
 class LabelsNodeList;
 class RadioNodeList;
 class TreeScope;
 
-class NodeListsNodeData {
-    WTF_MAKE_NONCOPYABLE(NodeListsNodeData); WTF_MAKE_FAST_ALLOCATED;
+class NodeListsNodeData FINAL : public NoBaseWillBeGarbageCollectedFinalized<NodeListsNodeData> {
+    WTF_MAKE_NONCOPYABLE(NodeListsNodeData);
+    WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED;
 public:
     void clearChildNodeListCache()
     {
         if (m_childNodeList && m_childNodeList->isChildNodeList())
             toChildNodeList(m_childNodeList)->invalidateCache();
     }
 
-    PassRefPtr<ChildNodeList> ensureChildNodeList(ContainerNode& node)
+    PassRefPtrWillBeRawPtr<ChildNodeList> ensureChildNodeList(ContainerNode& node)
     {
         if (m_childNodeList)
             return toChildNodeList(m_childNodeList);
-        RefPtr<ChildNodeList> list = ChildNodeList::create(node);
+        RefPtrWillBeRawPtr<ChildNodeList> list = ChildNodeList::create(node);
         m_childNodeList = list.get();
         return list.release();
     }
 
-    PassRefPtr<EmptyNodeList> ensureEmptyChildNodeList(Node& node)
+    PassRefPtrWillBeRawPtr<EmptyNodeList> ensureEmptyChildNodeList(Node& node)
     {
         if (m_childNodeList)
             return toEmptyNodeList(m_childNodeList);
-        RefPtr<EmptyNodeList> list = EmptyNodeList::create(node);
+        RefPtrWillBeRawPtr<EmptyNodeList> list = EmptyNodeList::create(node);
         m_childNodeList = list.get();
         return list.release();
     }
 
+#if !ENABLE(OILPAN)
     void removeChildNodeList(ChildNodeList* list)
     {
         ASSERT(m_childNodeList == list);
         if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(list->ownerNode()))
             return;
-        m_childNodeList = 0;
+        m_childNodeList = nullptr;
     }
 
     void removeEmptyChildNodeList(EmptyNodeList* list)
     {
         ASSERT(m_childNodeList == list);
         if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(list->ownerNode()))
             return;
-        m_childNodeList = 0;
+        m_childNodeList = nullptr;
     }
+#endif
 
     struct NodeListAtomicCacheMapEntryHash {
         static unsigned hash(const std::pair<unsigned char, StringImpl*>& entry)
         {
             return DefaultHash<StringImpl*>::Hash::hash(entry.second) + entry.first;
         }
         static bool equal(const std::pair<unsigned char, StringImpl*>& a, const std::pair<unsigned char, StringImpl*>& b) { return a == b; }
         static const bool safeToCompareToEmptyOrDeleted = DefaultHash<StringImpl*>::Hash::safeToCompareToEmptyOrDeleted;
     };
 
-    typedef HashMap<std::pair<unsigned char, StringImpl*>, LiveNodeListBase*, NodeListAtomicCacheMapEntryHash> NodeListAtomicNameCacheMap;
-    typedef HashMap<QualifiedName, TagCollection*> TagCollectionCacheNS;
+    // Oilpan: keep a weak reference to the collection objects.
+    // Explicit object unregistration in a non-Oilpan setting
+    // on object destruction is replaced by the garbage collector
+    // clearing out their weak reference.
+    typedef WillBeHeapHashMap<std::pair<unsigned char, StringImpl*>, RawPtrWillBeWeakMember<LiveNodeListBase>, NodeListAtomicCacheMapEntryHash> NodeListAtomicNameCacheMap;
+    typedef WillBeHeapHashMap<QualifiedName, RawPtrWillBeWeakMember<TagCollection> > TagCollectionCacheNS;
 
     template<typename T>
-    PassRefPtr<T> addCache(ContainerNode& node, CollectionType collectionType, const AtomicString& name)
+    PassRefPtrWillBeRawPtr<T> addCache(ContainerNode& node, CollectionType collectionType, const AtomicString& name)
     {
-        NodeListAtomicNameCacheMap::AddResult result = m_atomicNameCaches.add(namedNodeListKey(collectionType, name), 0);
+        NodeListAtomicNameCacheMap::AddResult result = m_atomicNameCaches.add(namedNodeListKey(collectionType, name), nullptr);
         if (!result.isNewEntry)
-            return static_cast<T*>(result.storedValue->value);
+            return static_cast<T*>(result.storedValue->value.get());
 
-        RefPtr<T> list = T::create(node, collectionType, name);
+        RefPtrWillBeRawPtr<T> list = T::create(node, collectionType, name);
         result.storedValue->value = list.get();
         return list.release();
     }
 
     template<typename T>
-    PassRefPtr<T> addCache(ContainerNode& node, CollectionType collectionType)
+    PassRefPtrWillBeRawPtr<T> addCache(ContainerNode& node, CollectionType collectionType)
     {
-        NodeListAtomicNameCacheMap::AddResult result = m_atomicNameCaches.add(namedNodeListKey(collectionType, starAtom), 0);
+        NodeListAtomicNameCacheMap::AddResult result = m_atomicNameCaches.add(namedNodeListKey(collectionType, starAtom), nullptr);
         if (!result.isNewEntry)
-            return static_cast<T*>(result.storedValue->value);
+            return static_cast<T*>(result.storedValue->value.get());
 
-        RefPtr<T> list = T::create(node, collectionType);
+        RefPtrWillBeRawPtr<T> list = T::create(node, collectionType);
         result.storedValue->value = list.get();
         return list.release();
     }
 
     template<typename T>
     T* cached(CollectionType collectionType)
     {
+#if ENABLE(OILPAN)
+        // FIXME: Oilpan: unify, if possible. The lookup resolves to a T& with Oilpan,
+        // whereas non-Oilpan resolves to RawPtr<T>.
         return static_cast<T*>(m_atomicNameCaches.get(namedNodeListKey(collectionType, starAtom)));
+#else
+        return static_cast<T*>(m_atomicNameCaches.get(namedNodeListKey(collectionType, starAtom)).get());
+#endif
     }
 
-    PassRefPtr<TagCollection> addCache(ContainerNode& node, const AtomicString& namespaceURI, const AtomicString& localName)
+    PassRefPtrWillBeRawPtr<TagCollection> addCache(ContainerNode& node, const AtomicString& namespaceURI, const AtomicString& localName)
     {
         QualifiedName name(nullAtom, localName, namespaceURI);
-        TagCollectionCacheNS::AddResult result = m_tagCollectionCacheNS.add(name, 0);
+        TagCollectionCacheNS::AddResult result = m_tagCollectionCacheNS.add(name, nullptr);
         if (!result.isNewEntry)
             return result.storedValue->value;
 
-        RefPtr<TagCollection> list = TagCollection::create(node, namespaceURI, localName);
+        RefPtrWillBeRawPtr<TagCollection> list = TagCollection::create(node, namespaceURI, localName);
         result.storedValue->value = list.get();
         return list.release();
     }
 
+#if !ENABLE(OILPAN)
     void removeCache(LiveNodeListBase* list, CollectionType collectionType, const AtomicString& name = starAtom)
     {
         ASSERT(list == m_atomicNameCaches.get(namedNodeListKey(collectionType, name)));
         if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(list->ownerNode()))
             return;
         m_atomicNameCaches.remove(namedNodeListKey(collectionType, name));
     }
 
     void removeCache(LiveNodeListBase* list, const AtomicString& namespaceURI, const AtomicString& localName)
     {
         QualifiedName name(nullAtom, localName, namespaceURI);
         ASSERT(list == m_tagCollectionCacheNS.get(name));
         if (deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(list->ownerNode()))
             return;
         m_tagCollectionCacheNS.remove(name);
     }
+#endif
 
-    static PassOwnPtr<NodeListsNodeData> create()
+    static PassOwnPtrWillBeRawPtr<NodeListsNodeData> create()
     {
-        return adoptPtr(new NodeListsNodeData);
+        return adoptPtrWillBeNoop(new NodeListsNodeData);
     }
 
     void invalidateCaches(const QualifiedName* attrName = 0);
     bool isEmpty() const
     {
         return m_atomicNameCaches.isEmpty() && m_tagCollectionCacheNS.isEmpty();
     }
 
     void adoptTreeScope()
     {
@@ skipping 11 matching lines @@
         }
 
         TagCollectionCacheNS::const_iterator tagEnd = m_tagCollectionCacheNS.end();
         for (TagCollectionCacheNS::const_iterator it = m_tagCollectionCacheNS.begin(); it != tagEnd; ++it) {
             LiveNodeListBase* list = it->value;
             ASSERT(!list->isRootedAtDocument());
             list->didMoveToDocument(oldDocument, newDocument);
         }
     }
 
+    void trace(Visitor* visitor)
+    {
+        visitor->trace(m_childNodeList);
+        visitor->trace(m_atomicNameCaches);
+        visitor->trace(m_tagCollectionCacheNS);
+    }
+
 private:
     NodeListsNodeData()
-        : m_childNodeList(0)
+        : m_childNodeList(nullptr)
     { }
 
     std::pair<unsigned char, StringImpl*> namedNodeListKey(CollectionType type, const AtomicString& name)
     {
         // Holding the raw StringImpl is safe because |name| is retained by the NodeList and the NodeList
         // is reponsible for removing itself from the cache on deletion.
         return std::pair<unsigned char, StringImpl*>(type, name.impl());
     }
 
+#if !ENABLE(OILPAN)
     bool deleteThisAndUpdateNodeRareDataIfAboutToRemoveLastList(Node&);
+#endif
 
     // Can be a ChildNodeList or an EmptyNodeList.
-    NodeList* m_childNodeList;
+    RawPtrWillBeMember<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;
@@ skipping 63 matching lines @@
     enum {
         ConnectedFrameCountBits = 10, // Must fit Page::maxNumberOfFrames.
     };
 
     void trace(Visitor*);
 
     void traceAfterDispatch(Visitor*);
     void finalizeGarbageCollectedObject();
 
 protected:
     NodeRareData(RenderObject* renderer)

[haraken, 2014/05/12 12:04:13]

Add explicit.

[sof, 2014/05/15 22:15:57]

Done.

         : NodeRareDataBase(renderer)
         , m_connectedFrameCount(0)
         , m_elementFlags(0)
         , m_restyleFlags(0)
         , m_isElementRareData(false)
     { }
 
 private:
-    OwnPtr<NodeListsNodeData> m_nodeLists;
+    OwnPtrWillBeMember<NodeListsNodeData> m_nodeLists;
     OwnPtrWillBeMember<NodeMutationObserverData> m_mutationObserverData;
 
     unsigned m_connectedFrameCount : ConnectedFrameCountBits;
     unsigned m_elementFlags : NumberOfElementFlags;
     unsigned m_restyleFlags : NumberOfDynamicRestyleFlags;
 protected:
     unsigned m_isElementRareData : 1;
 };
 
+#if !ENABLE(OILPAN)
 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();

[haraken, 2014/05/12 12:04:13]

When the last cached list is removed from the Node, we need to discard the
NodeListsNodeData (to save memory). How is this logic implemented in oilpan?

I guess that some weak processing is necessary to implement the logic.

     return true;
 }
+#endif
 
 } // namespace WebCore
 
 #endif // NodeRareData_h