Oilpan: Make the Node hierarchy RefCountedGarbageCollected instead of TreeShared.

Source/core/svg/SVGElementInstance.h

 /*
  * Copyright (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2011 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  *
  * 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 19 matching lines @@
 namespace Private {
 template<class GenericNode, class GenericNodeContainer>
 void addChildNodesToDeletionQueue(GenericNode*& head, GenericNode*& tail, GenericNodeContainer&);
 };
 
 class Document;
 class SVGElement;
 class SVGUseElement;
 
 // SVGElementInstance mimics Node, but without providing all its functionality
-class SVGElementInstance FINAL : public TreeShared<SVGElementInstance>, public EventTarget, public ScriptWrappable {
-    DEFINE_EVENT_TARGET_REFCOUNTING(TreeShared<SVGElementInstance>);
+class SVGElementInstance FINAL : public TreeSharedWillBeRefCountedGarbageCollected<SVGElementInstance>, public EventTarget, public ScriptWrappable {
+    DEFINE_EVENT_TARGET_REFCOUNTING(TreeSharedWillBeRefCountedGarbageCollected<SVGElementInstance>);
 public:
     static PassRefPtr<SVGElementInstance> create(SVGUseElement* correspondingUseElement, SVGUseElement* directUseElement, PassRefPtr<SVGElement> originalElement);
 
     virtual ~SVGElementInstance();
 
     void setParentOrShadowHostNode(SVGElementInstance* instance) { m_parentInstance = instance; }
 
     virtual const AtomicString& interfaceName() const OVERRIDE;
     virtual ExecutionContext* executionContext() const OVERRIDE;
 
     virtual bool addEventListener(const AtomicString& eventType, PassRefPtr<EventListener>, bool useCapture = false) OVERRIDE;
     virtual bool removeEventListener(const AtomicString& eventType, EventListener*, bool useCapture = false) OVERRIDE;
     virtual void removeAllEventListeners() OVERRIDE;
 
     using EventTarget::dispatchEvent;
     virtual bool dispatchEvent(PassRefPtrWillBeRawPtr<Event>) OVERRIDE;
 
     SVGElement* correspondingElement() const { return m_element.get(); }
     SVGUseElement* correspondingUseElement() const { return m_correspondingUseElement; }
     SVGUseElement* directUseElement() const { return m_directUseElement; }
     SVGElement* shadowTreeElement() const { return m_shadowTreeElement.get(); }
 
     void detach();

[haraken, 2014/05/06 15:59:42]

You can add !ENABLE(OILPAN) to this.

[Mads Ager (chromium), 2014/05/07 12:13:16]

It is still called via SVGUseElement at this point.

 
     SVGElementInstance* parentNode() const { return m_parentInstance; }
 
     SVGElementInstance* previousSibling() const { return m_previousSibling; }
     SVGElementInstance* nextSibling() const { return m_nextSibling; }
 
     SVGElementInstance* firstChild() const { return m_firstChild; }
     SVGElementInstance* lastChild() const { return m_lastChild; }
 
     inline Document* ownerDocument() const;
 
-    virtual void trace(Visitor*) { }
+    virtual void trace(Visitor*);
 
     // EventTarget API
     DECLARE_FORWARDING_ATTRIBUTE_EVENT_LISTENER(correspondingElement(), abort);
     DECLARE_FORWARDING_ATTRIBUTE_EVENT_LISTENER(correspondingElement(), blur);
     DECLARE_FORWARDING_ATTRIBUTE_EVENT_LISTENER(correspondingElement(), change);
     DECLARE_FORWARDING_ATTRIBUTE_EVENT_LISTENER(correspondingElement(), click);
     DECLARE_FORWARDING_ATTRIBUTE_EVENT_LISTENER(correspondingElement(), contextmenu);
     DECLARE_FORWARDING_ATTRIBUTE_EVENT_LISTENER(correspondingElement(), dblclick);
     DECLARE_FORWARDING_ATTRIBUTE_EVENT_LISTENER(correspondingElement(), error);
     DECLARE_FORWARDING_ATTRIBUTE_EVENT_LISTENER(correspondingElement(), focus);
@@ skipping 32 matching lines @@
     DECLARE_FORWARDING_ATTRIBUTE_EVENT_LISTENER(correspondingElement(), selectstart);
     DECLARE_FORWARDING_ATTRIBUTE_EVENT_LISTENER(correspondingElement(), submit);
     DECLARE_FORWARDING_ATTRIBUTE_EVENT_LISTENER(correspondingElement(), unload);
 
 private:
     friend class SVGUseElement;
     friend class TreeShared<SVGElementInstance>;
 
     SVGElementInstance(SVGUseElement*, SVGUseElement*, PassRefPtr<SVGElement> originalElement);
 
     void removedLastRef();

[haraken, 2014/05/06 15:59:42]

Can we add !ENABLE(OILPAN) to this?

[Mads Ager (chromium), 2014/05/07 12:13:16]

Yes, we should be able to do that.

     bool hasTreeSharedParent() const { return !!m_parentInstance; }
 
     virtual Node* toNode() OVERRIDE;
 
     void appendChild(PassRefPtr<SVGElementInstance> child);
     void setShadowTreeElement(SVGElement*);
 
     template<class GenericNode, class GenericNodeContainer>
     friend void appendChildToContainer(GenericNode& child, GenericNodeContainer&);
 
     template<class GenericNode, class GenericNodeContainer>
     friend void removeDetachedChildrenInContainer(GenericNodeContainer&);

[haraken, 2014/05/06 15:59:42]

You can add !ENABLE(OILPAN) to this (but it won't be that helpful).

[Mads Ager (chromium), 2014/05/07 12:13:16]

Done.

 
     template<class GenericNode, class GenericNodeContainer>
     friend void Private::addChildNodesToDeletionQueue(GenericNode*& head, GenericNode*& tail, GenericNodeContainer&);
 
     bool hasChildren() const { return m_firstChild; }
 
     void setFirstChild(SVGElementInstance* child) { m_firstChild = child; }
     void setLastChild(SVGElementInstance* child) { m_lastChild = child; }
 
     void setNextSibling(SVGElementInstance* sibling) { m_nextSibling = sibling; }
     void setPreviousSibling(SVGElementInstance* sibling) { m_previousSibling = sibling; }
 
     virtual EventTargetData* eventTargetData() OVERRIDE;
     virtual EventTargetData& ensureEventTargetData() OVERRIDE;
 
-    SVGElementInstance* m_parentInstance;
+    RawPtrWillBeMember<SVGElementInstance> m_parentInstance;
 
     SVGUseElement* m_correspondingUseElement;
     SVGUseElement* m_directUseElement;

[kouhei (in TOK), 2014/05/07 01:43:13]

RawPtrWillBeMember?

[Mads Ager (chromium), 2014/05/07 12:13:16]

Yes, and I replace the RefPtr from SVGElementInstance to SVGUseElement with a
Member as well so that they will live and die together when they are connected.

-    RefPtr<SVGElement> m_element;
-    RefPtr<SVGElement> m_shadowTreeElement;
+    RefPtrWillBeMember<SVGElement> m_element;
+    RefPtrWillBeMember<SVGElement> m_shadowTreeElement;
 
-    SVGElementInstance* m_previousSibling;
-    SVGElementInstance* m_nextSibling;
+    RawPtrWillBeMember<SVGElementInstance> m_previousSibling;
+    RawPtrWillBeMember<SVGElementInstance> m_nextSibling;
 
-    SVGElementInstance* m_firstChild;
-    SVGElementInstance* m_lastChild;
+    RawPtrWillBeMember<SVGElementInstance> m_firstChild;
+    RawPtrWillBeMember<SVGElementInstance> m_lastChild;
 };
 
 } // namespace WebCore
 
 #endif