Split out Members, Persistents and SelfKeepAlive in separate headers.

third_party/WebKit/Source/platform/heap/Handle.h

 /*
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 16 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef Handle_h
 #define Handle_h
 
 #include "platform/heap/Heap.h"
 #include "platform/heap/HeapAllocator.h"
 #include "platform/heap/InlinedGlobalMarkingVisitor.h"
-#include "platform/heap/PersistentNode.h"
+#include "platform/heap/Member.h"
+#include "platform/heap/Persistent.h"
 #include "platform/heap/ThreadState.h"
 #include "platform/heap/TraceTraits.h"
 #include "platform/heap/Visitor.h"
 #include "wtf/Allocator.h"
-#include "wtf/Atomics.h"
-#include "wtf/HashFunctions.h"
 
 #if defined(LEAK_SANITIZER)
 #include "wtf/LeakAnnotations.h"
 #endif
 
 namespace blink {
 
-// Marker used to annotate persistent objects and collections with,
-// so as to enable reliable testing for persistent references via
-// a type trait (see TypeTraits.h's IsPersistentReferenceType<>.)
-#define IS_PERSISTENT_REFERENCE_TYPE()               \
-    public:                                          \
-        using IsPersistentReferenceTypeMarker = int; \
-    private:
-
-enum WeaknessPersistentConfiguration {
-    NonWeakPersistentConfiguration,
-    WeakPersistentConfiguration
-};
-
-enum CrossThreadnessPersistentConfiguration {
-    SingleThreadPersistentConfiguration,
-    CrossThreadPersistentConfiguration
-};
-
-template<typename T, WeaknessPersistentConfiguration weaknessConfiguration, CrossThreadnessPersistentConfiguration crossThreadnessConfiguration>
-class PersistentBase {
-    USING_FAST_MALLOC(PersistentBase);
-    IS_PERSISTENT_REFERENCE_TYPE();
-public:
-    PersistentBase() : m_raw(nullptr)
-    {
-        initialize();
-    }
-
-    PersistentBase(std::nullptr_t) : m_raw(nullptr)
-    {
-        initialize();
-    }
-
-    PersistentBase(T* raw) : m_raw(raw)
-    {
-        initialize();
-        checkPointer();
-    }
-
-    PersistentBase(T& raw) : m_raw(&raw)
-    {
-        initialize();
-        checkPointer();
-    }
-
-    PersistentBase(const PersistentBase& other) : m_raw(other)
-    {
-        initialize();
-        checkPointer();
-    }
-
-    template<typename U>
-    PersistentBase(const PersistentBase<U, weaknessConfiguration, crossThreadnessConfiguration>& other) : m_raw(other)
-    {
-        initialize();
-        checkPointer();
-    }
-
-    template<typename U>
-    PersistentBase(const Member<U>& other) : m_raw(other)
-    {
-        initialize();
-        checkPointer();
-    }
-
-    ~PersistentBase()
-    {
-        uninitialize();
-        m_raw = nullptr;
-    }
-
-    template<typename VisitorDispatcher>
-    void trace(VisitorDispatcher visitor)
-    {
-        static_assert(sizeof(T), "T must be fully defined");
-        static_assert(IsGarbageCollectedType<T>::value, "T needs to be a garbage collected object");
-        if (weaknessConfiguration == WeakPersistentConfiguration) {
-            visitor->registerWeakCell(&m_raw);
-        } else {
-            visitor->mark(m_raw);
-        }
-    }
-
-    T* release()
-    {
-        T* result = m_raw;
-        assign(nullptr);
-        return result;
-    }
-
-    void clear() { assign(nullptr); }
-    T& operator*() const { return *m_raw; }
-    explicit operator bool() const { return m_raw; }
-    operator T*() const { return m_raw; }
-    T* operator->() const { return *this; }
-    T* get() const { return m_raw; }
-
-    template<typename U>
-    PersistentBase& operator=(U* other)
-    {
-        assign(other);
-        return *this;
-    }
-
-    PersistentBase& operator=(std::nullptr_t)
-    {
-        assign(nullptr);
-        return *this;
-    }
-
-    PersistentBase& operator=(const PersistentBase& other)
-    {
-        assign(other);
-        return *this;
-    }
-
-    template<typename U>
-    PersistentBase& operator=(const PersistentBase<U, weaknessConfiguration, crossThreadnessConfiguration>& other)
-    {
-        assign(other);
-        return *this;
-    }
-
-    template<typename U>
-    PersistentBase& operator=(const Member<U>& other)
-    {
-        assign(other);
-        return *this;
-    }
-
-    // Register the persistent node as a 'static reference',
-    // belonging to the current thread and a persistent that must
-    // be cleared when the ThreadState itself is cleared out and
-    // destructed.
-    //
-    // Static singletons arrange for this to happen, either to ensure
-    // clean LSan leak reports or to register a thread-local persistent
-    // needing to be cleared out before the thread is terminated.
-    PersistentBase* registerAsStaticReference()
-    {
-        if (m_persistentNode) {
-            ASSERT(ThreadState::current());
-            ThreadState::current()->registerStaticPersistentNode(m_persistentNode, nullptr);
-            LEAK_SANITIZER_IGNORE_OBJECT(this);
-        }
-        return this;
-    }
-
-protected:
-    T* atomicGet() { return reinterpret_cast<T*>(acquireLoad(reinterpret_cast<void* volatile*>(&m_raw))); }
-
-private:
-    NO_LAZY_SWEEP_SANITIZE_ADDRESS
-    void assign(T* ptr)
-    {
-        if (crossThreadnessConfiguration == CrossThreadPersistentConfiguration)
-            releaseStore(reinterpret_cast<void* volatile*>(&m_raw), ptr);
-        else
-            m_raw = ptr;
-        checkPointer();
-        if (m_raw) {
-            if (!m_persistentNode)
-                initialize();
-            return;
-        }
-        uninitialize();
-    }
-
-    NO_LAZY_SWEEP_SANITIZE_ADDRESS
-    void initialize()
-    {
-        ASSERT(!m_persistentNode);
-        if (!m_raw)
-            return;
-
-        TraceCallback traceCallback = TraceMethodDelegate<PersistentBase<T, weaknessConfiguration, crossThreadnessConfiguration>, &PersistentBase<T, weaknessConfiguration, crossThreadnessConfiguration>::trace>::trampoline;
-        if (crossThreadnessConfiguration == CrossThreadPersistentConfiguration) {
-            ProcessHeap::crossThreadPersistentRegion().allocatePersistentNode(m_persistentNode, this, traceCallback);
-            return;
-        }
-        ThreadState* state = ThreadStateFor<ThreadingTrait<T>::Affinity>::state();
-        ASSERT(state->checkThread());
-        m_persistentNode = state->getPersistentRegion()->allocatePersistentNode(this, traceCallback);
-#if ENABLE(ASSERT)
-        m_state = state;
-#endif
-    }
-
-    void uninitialize()
-    {
-        if (crossThreadnessConfiguration == CrossThreadPersistentConfiguration) {
-            if (acquireLoad(reinterpret_cast<void* volatile*>(&m_persistentNode)))
-                ProcessHeap::crossThreadPersistentRegion().freePersistentNode(m_persistentNode);
-            return;
-        }
-
-        if (!m_persistentNode)
-            return;
-        ThreadState* state = ThreadStateFor<ThreadingTrait<T>::Affinity>::state();
-        ASSERT(state->checkThread());
-        // Persistent handle must be created and destructed in the same thread.
-        ASSERT(m_state == state);
-        state->freePersistentNode(m_persistentNode);
-        m_persistentNode = nullptr;
-    }
-
-    void checkPointer()
-    {
-#if ENABLE(ASSERT) && defined(ADDRESS_SANITIZER)
-        if (!m_raw)
-            return;
-
-        // ThreadHeap::isHeapObjectAlive(m_raw) checks that m_raw is a traceable
-        // object. In other words, it checks that the pointer is either of:
-        //
-        //   (a) a pointer to the head of an on-heap object.
-        //   (b) a pointer to the head of an on-heap mixin object.
-        //
-        // Otherwise, ThreadHeap::isHeapObjectAlive will crash when it calls
-        // header->checkHeader().
-        ThreadHeap::isHeapObjectAlive(m_raw);
-#endif
-    }
-
-    // m_raw is accessed most, so put it at the first field.
-    T* m_raw;
-    PersistentNode* m_persistentNode = nullptr;
-#if ENABLE(ASSERT)
-    ThreadState* m_state = nullptr;
-#endif
-};
-
-// Persistent is a way to create a strong pointer from an off-heap object
-// to another on-heap object. As long as the Persistent handle is alive
-// the GC will keep the object pointed to alive. The Persistent handle is
-// always a GC root from the point of view of the GC.
-//
-// We have to construct and destruct Persistent in the same thread.
-template<typename T>
-class Persistent : public PersistentBase<T, NonWeakPersistentConfiguration, SingleThreadPersistentConfiguration> {
-    typedef PersistentBase<T, NonWeakPersistentConfiguration, SingleThreadPersistentConfiguration> Parent;
-public:
-    Persistent() : Parent() { }
-    Persistent(std::nullptr_t) : Parent(nullptr) { }
-    Persistent(T* raw) : Parent(raw) { }
-    Persistent(T& raw) : Parent(raw) { }
-    Persistent(const Persistent& other) : Parent(other) { }
-    template<typename U>
-    Persistent(const Persistent<U>& other) : Parent(other) { }
-    template<typename U>
-    Persistent(const Member<U>& other) : Parent(other) { }
-
-    template<typename U>
-    Persistent& operator=(U* other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-
-    Persistent& operator=(std::nullptr_t)
-    {
-        Parent::operator=(nullptr);
-        return *this;
-    }
-
-    Persistent& operator=(const Persistent& other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-
-    template<typename U>
-    Persistent& operator=(const Persistent<U>& other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-
-    template<typename U>
-    Persistent& operator=(const Member<U>& other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-};
-
-// WeakPersistent is a way to create a weak pointer from an off-heap object
-// to an on-heap object. The m_raw is automatically cleared when the pointee
-// gets collected.
-//
-// We have to construct and destruct WeakPersistent in the same thread.
-//
-// Note that collections of WeakPersistents are not supported. Use a persistent
-// collection of WeakMembers instead.
-//
-//   HashSet<WeakPersistent<T>> m_set; // wrong
-//   PersistentHeapHashSet<WeakMember<T>> m_set; // correct
-template<typename T>
-class WeakPersistent : public PersistentBase<T, WeakPersistentConfiguration, SingleThreadPersistentConfiguration> {
-    typedef PersistentBase<T, WeakPersistentConfiguration, SingleThreadPersistentConfiguration> Parent;
-public:
-    WeakPersistent() : Parent() { }
-    WeakPersistent(std::nullptr_t) : Parent(nullptr) { }
-    WeakPersistent(T* raw) : Parent(raw) { }
-    WeakPersistent(T& raw) : Parent(raw) { }
-    WeakPersistent(const WeakPersistent& other) : Parent(other) { }
-    template<typename U>
-    WeakPersistent(const WeakPersistent<U>& other) : Parent(other) { }
-    template<typename U>
-    WeakPersistent(const Member<U>& other) : Parent(other) { }
-
-    template<typename U>
-    WeakPersistent& operator=(U* other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-
-    WeakPersistent& operator=(std::nullptr_t)
-    {
-        Parent::operator=(nullptr);
-        return *this;
-    }
-
-    WeakPersistent& operator=(const WeakPersistent& other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-
-    template<typename U>
-    WeakPersistent& operator=(const WeakPersistent<U>& other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-
-    template<typename U>
-    WeakPersistent& operator=(const Member<U>& other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-};
-
-// Unlike Persistent, we can destruct a CrossThreadPersistent in a thread
-// different from the construction thread.
-template<typename T>
-class CrossThreadPersistent : public PersistentBase<T, NonWeakPersistentConfiguration, CrossThreadPersistentConfiguration> {
-    typedef PersistentBase<T, NonWeakPersistentConfiguration, CrossThreadPersistentConfiguration> Parent;
-public:
-    CrossThreadPersistent() : Parent() { }
-    CrossThreadPersistent(std::nullptr_t) : Parent(nullptr) { }
-    CrossThreadPersistent(T* raw) : Parent(raw) { }
-    CrossThreadPersistent(T& raw) : Parent(raw) { }
-    CrossThreadPersistent(const CrossThreadPersistent& other) : Parent(other) { }
-    template<typename U>
-    CrossThreadPersistent(const CrossThreadPersistent<U>& other) : Parent(other) { }
-    template<typename U>
-    CrossThreadPersistent(const Member<U>& other) : Parent(other) { }
-
-    T* atomicGet() { return Parent::atomicGet(); }
-
-    template<typename U>
-    CrossThreadPersistent& operator=(U* other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-
-    CrossThreadPersistent& operator=(std::nullptr_t)
-    {
-        Parent::operator=(nullptr);
-        return *this;
-    }
-
-    CrossThreadPersistent& operator=(const CrossThreadPersistent& other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-
-    template<typename U>
-    CrossThreadPersistent& operator=(const CrossThreadPersistent<U>& other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-
-    template<typename U>
-    CrossThreadPersistent& operator=(const Member<U>& other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-};
-
-// Combines the behavior of CrossThreadPersistent and WeakPersistent.
-template<typename T>
-class CrossThreadWeakPersistent : public PersistentBase<T, WeakPersistentConfiguration, CrossThreadPersistentConfiguration> {
-    typedef PersistentBase<T, WeakPersistentConfiguration, CrossThreadPersistentConfiguration> Parent;
-public:
-    CrossThreadWeakPersistent() : Parent() { }
-    CrossThreadWeakPersistent(std::nullptr_t) : Parent(nullptr) { }
-    CrossThreadWeakPersistent(T* raw) : Parent(raw) { }
-    CrossThreadWeakPersistent(T& raw) : Parent(raw) { }
-    CrossThreadWeakPersistent(const CrossThreadWeakPersistent& other) : Parent(other) { }
-    template<typename U>
-    CrossThreadWeakPersistent(const CrossThreadWeakPersistent<U>& other) : Parent(other) { }
-    template<typename U>
-    CrossThreadWeakPersistent(const Member<U>& other) : Parent(other) { }
-
-    template<typename U>
-    CrossThreadWeakPersistent& operator=(U* other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-
-    CrossThreadWeakPersistent& operator=(std::nullptr_t)
-    {
-        Parent::operator=(nullptr);
-        return *this;
-    }
-
-    CrossThreadWeakPersistent& operator=(const CrossThreadWeakPersistent& other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-
-    template<typename U>
-    CrossThreadWeakPersistent& operator=(const CrossThreadWeakPersistent<U>& other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-
-    template<typename U>
-    CrossThreadWeakPersistent& operator=(const Member<U>& other)
-    {
-        Parent::operator=(other);
-        return *this;
-    }
-};
-
-template<typename Collection>
-class PersistentHeapCollectionBase : public Collection {
-    // We overload the various new and delete operators with using the WTF PartitionAllocator to ensure persistent
-    // heap collections are always allocated off-heap. This allows persistent collections to be used in
-    // DEFINE_STATIC_LOCAL et. al.
-    WTF_USE_ALLOCATOR(PersistentHeapCollectionBase, WTF::PartitionAllocator);
-    IS_PERSISTENT_REFERENCE_TYPE();
-public:
-    PersistentHeapCollectionBase()
-    {
-        initialize();
-    }
-
-    PersistentHeapCollectionBase(const PersistentHeapCollectionBase& other) : Collection(other)
-    {
-        initialize();
-    }
-
-    template<typename OtherCollection>
-    PersistentHeapCollectionBase(const OtherCollection& other) : Collection(other)
-    {
-        initialize();
-    }
-
-    ~PersistentHeapCollectionBase()
-    {
-        uninitialize();
-    }
-
-    template<typename VisitorDispatcher>
-    void trace(VisitorDispatcher visitor)
-    {
-        static_assert(sizeof(Collection), "Collection must be fully defined");
-        visitor->trace(*static_cast<Collection*>(this));
-    }
-
-    // See PersistentBase::registerAsStaticReference() comment.
-    PersistentHeapCollectionBase* registerAsStaticReference()
-    {
-        if (m_persistentNode) {
-            ASSERT(ThreadState::current());
-            ThreadState::current()->registerStaticPersistentNode(m_persistentNode, &PersistentHeapCollectionBase<Collection>::clearPersistentNode);
-            LEAK_SANITIZER_IGNORE_OBJECT(this);
-        }
-        return this;
-    }
-
-private:
-
-    // Used when the registered PersistentNode of this object is
-    // released during ThreadState shutdown, clearing the association.
-    static void clearPersistentNode(void *self)
-    {
-        PersistentHeapCollectionBase<Collection>* collection = (reinterpret_cast<PersistentHeapCollectionBase<Collection>*>(self));
-        collection->uninitialize();
-        collection->clear();
-    }
-
-    NO_LAZY_SWEEP_SANITIZE_ADDRESS
-    void initialize()
-    {
-        // FIXME: Derive affinity based on the collection.
-        ThreadState* state = ThreadState::current();
-        ASSERT(state->checkThread());
-        m_persistentNode = state->getPersistentRegion()->allocatePersistentNode(this, TraceMethodDelegate<PersistentHeapCollectionBase<Collection>, &PersistentHeapCollectionBase<Collection>::trace>::trampoline);
-#if ENABLE(ASSERT)
-        m_state = state;
-#endif
-    }
-
-    void uninitialize()
-    {
-        if (!m_persistentNode)
-            return;
-        ThreadState* state = ThreadState::current();
-        ASSERT(state->checkThread());
-        // Persistent handle must be created and destructed in the same thread.
-        ASSERT(m_state == state);
-        state->freePersistentNode(m_persistentNode);
-        m_persistentNode = nullptr;
-    }
-
-    PersistentNode* m_persistentNode;
-#if ENABLE(ASSERT)
-    ThreadState* m_state;
-#endif
-};
-
-template<
-    typename KeyArg,
-    typename MappedArg,
-    typename HashArg = typename DefaultHash<KeyArg>::Hash,
-    typename KeyTraitsArg = HashTraits<KeyArg>,
-    typename MappedTraitsArg = HashTraits<MappedArg>>
-class PersistentHeapHashMap : public PersistentHeapCollectionBase<HeapHashMap<KeyArg, MappedArg, HashArg, KeyTraitsArg, MappedTraitsArg>> { };
-
-template<
-    typename ValueArg,
-    typename HashArg = typename DefaultHash<ValueArg>::Hash,
-    typename TraitsArg = HashTraits<ValueArg>>
-class PersistentHeapHashSet : public PersistentHeapCollectionBase<HeapHashSet<ValueArg, HashArg, TraitsArg>> { };
-
-template<
-    typename ValueArg,
-    typename HashArg = typename DefaultHash<ValueArg>::Hash,
-    typename TraitsArg = HashTraits<ValueArg>>
-class PersistentHeapLinkedHashSet : public PersistentHeapCollectionBase<HeapLinkedHashSet<ValueArg, HashArg, TraitsArg>> { };
-
-template<
-    typename ValueArg,
-    size_t inlineCapacity = 0,
-    typename HashArg = typename DefaultHash<ValueArg>::Hash>
-class PersistentHeapListHashSet : public PersistentHeapCollectionBase<HeapListHashSet<ValueArg, inlineCapacity, HashArg>> { };
-
-template<
-    typename ValueArg,
-    typename HashFunctions = typename DefaultHash<ValueArg>::Hash,
-    typename Traits = HashTraits<ValueArg>>
-class PersistentHeapHashCountedSet : public PersistentHeapCollectionBase<HeapHashCountedSet<ValueArg, HashFunctions, Traits>> { };
-
-template<typename T, size_t inlineCapacity = 0>
-class PersistentHeapVector : public PersistentHeapCollectionBase<HeapVector<T, inlineCapacity>> {
-public:
-    PersistentHeapVector()
-    {
-        initializeUnusedSlots();
-    }
-
-    explicit PersistentHeapVector(size_t size)
-        : PersistentHeapCollectionBase<HeapVector<T, inlineCapacity>>(size)
-    {
-        initializeUnusedSlots();
-    }
-
-    PersistentHeapVector(const PersistentHeapVector& other)
-        : PersistentHeapCollectionBase<HeapVector<T, inlineCapacity>>(other)
-    {
-        initializeUnusedSlots();
-    }
-
-    template<size_t otherCapacity>
-    PersistentHeapVector(const HeapVector<T, otherCapacity>& other)
-        : PersistentHeapCollectionBase<HeapVector<T, inlineCapacity>>(other)
-    {
-        initializeUnusedSlots();
-    }
-
-private:
-    void initializeUnusedSlots()
-    {
-        // The PersistentHeapVector is allocated off heap along with its
-        // inline buffer (if any.) Maintain the invariant that unused
-        // slots are cleared for the off-heap inline buffer also.
-        size_t unusedSlots = this->capacity() - this->size();
-        if (unusedSlots)
-            this->clearUnusedSlots(this->end(), this->end() + unusedSlots);
-    }
-};
-
-template<typename T, size_t inlineCapacity = 0>
-class PersistentHeapDeque : public PersistentHeapCollectionBase<HeapDeque<T, inlineCapacity>> {
-public:
-    PersistentHeapDeque() { }
-
-    template<size_t otherCapacity>
-    PersistentHeapDeque(const HeapDeque<T, otherCapacity>& other)
-        : PersistentHeapCollectionBase<HeapDeque<T, inlineCapacity>>(other)
-    {
-    }
-};
-
-// Members are used in classes to contain strong pointers to other oilpan heap
-// allocated objects.
-// All Member fields of a class must be traced in the class' trace method.
-// During the mark phase of the GC all live objects are marked as live and
-// all Member fields of a live object will be traced marked as live as well.
-template<typename T>
-class Member {
-    DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
-public:
-    Member() : m_raw(nullptr)
-    {
-    }
-
-    Member(std::nullptr_t) : m_raw(nullptr)
-    {
-    }
-
-    Member(T* raw) : m_raw(raw)
-    {
-        checkPointer();
-    }
-
-    explicit Member(T& raw) : m_raw(&raw)
-    {
-        checkPointer();
-    }
-
-    Member(WTF::HashTableDeletedValueType) : m_raw(reinterpret_cast<T*>(-1))
-    {
-    }
-
-    bool isHashTableDeletedValue() const { return m_raw == reinterpret_cast<T*>(-1); }
-
-    template<typename U>
-    Member(const Persistent<U>& other) : m_raw(other)
-    {
-        checkPointer();
-    }
-
-    Member(const Member& other) : m_raw(other)
-    {
-        checkPointer();
-    }
-
-    template<typename U>
-    Member(const Member<U>& other) : m_raw(other)
-    {
-        checkPointer();
-    }
-
-    T* release()
-    {
-        T* result = m_raw;
-        m_raw = nullptr;
-        return result;
-    }
-
-    explicit operator bool() const { return m_raw; }
-
-    operator T*() const { return m_raw; }
-
-    T* operator->() const { return m_raw; }
-    T& operator*() const { return *m_raw; }
-
-    template<typename U>
-    Member& operator=(const Persistent<U>& other)
-    {
-        m_raw = other;
-        checkPointer();
-        return *this;
-    }
-
-    template<typename U>
-    Member& operator=(const Member<U>& other)
-    {
-        m_raw = other;
-        checkPointer();
-        return *this;
-    }
-
-    template<typename U>
-    Member& operator=(U* other)
-    {
-        m_raw = other;
-        checkPointer();
-        return *this;
-    }
-
-    Member& operator=(std::nullptr_t)
-    {
-        m_raw = nullptr;
-        return *this;
-    }
-
-    void swap(Member<T>& other)
-    {
-        std::swap(m_raw, other.m_raw);
-        checkPointer();
-    }
-
-    T* get() const { return m_raw; }
-
-    void clear() { m_raw = nullptr; }
-
-
-protected:
-    void checkPointer()
-    {
-#if ENABLE(ASSERT) && defined(ADDRESS_SANITIZER)
-        if (!m_raw)
-            return;
-        // HashTable can store a special value (which is not aligned to the
-        // allocation granularity) to Member<> to represent a deleted entry.
-        // Thus we treat a pointer that is not aligned to the granularity
-        // as a valid pointer.
-        if (reinterpret_cast<intptr_t>(m_raw) % allocationGranularity)
-            return;
-
-        // TODO(haraken): What we really want to check here is that the pointer
-        // is a traceable object. In other words, the pointer is either of:
-        //
-        //   (a) a pointer to the head of an on-heap object.
-        //   (b) a pointer to the head of an on-heap mixin object.
-        //
-        // We can check it by calling ThreadHeap::isHeapObjectAlive(m_raw),
-        // but we cannot call it here because it requires to include T.h.
-        // So we currently only try to implement the check for (a), but do
-        // not insist that T's definition is in scope.
-        if (IsFullyDefined<T>::value && !IsGarbageCollectedMixin<T>::value)
-            ASSERT(HeapObjectHeader::fromPayload(m_raw)->checkHeader());
-#endif
-    }
-
-    T* m_raw;
-
-    template<bool x, WTF::WeakHandlingFlag y, WTF::ShouldWeakPointersBeMarkedStrongly z, typename U, typename V> friend struct CollectionBackingTraceTrait;
-    friend class Visitor;
-
-};
-
-// WeakMember is similar to Member in that it is used to point to other oilpan
-// heap allocated objects.
-// However instead of creating a strong pointer to the object, the WeakMember creates
-// a weak pointer, which does not keep the pointee alive. Hence if all pointers to
-// to a heap allocated object are weak the object will be garbage collected. At the
-// time of GC the weak pointers will automatically be set to null.
-template<typename T>
-class WeakMember : public Member<T> {
-public:
-    WeakMember() : Member<T>() { }
-
-    WeakMember(std::nullptr_t) : Member<T>(nullptr) { }
-
-    WeakMember(T* raw) : Member<T>(raw) { }
-
-    WeakMember(WTF::HashTableDeletedValueType x) : Member<T>(x) { }
-
-    template<typename U>
-    WeakMember(const Persistent<U>& other) : Member<T>(other) { }
-
-    template<typename U>
-    WeakMember(const Member<U>& other) : Member<T>(other) { }
-
-    template<typename U>
-    WeakMember& operator=(const Persistent<U>& other)
-    {
-        this->m_raw = other;
-        this->checkPointer();
-        return *this;
-    }
-
-    template<typename U>
-    WeakMember& operator=(const Member<U>& other)
-    {
-        this->m_raw = other;
-        this->checkPointer();
-        return *this;
-    }
-
-    template<typename U>
-    WeakMember& operator=(U* other)
-    {
-        this->m_raw = other;
-        this->checkPointer();
-        return *this;
-    }
-
-    WeakMember& operator=(std::nullptr_t)
-    {
-        this->m_raw = nullptr;
-        return *this;
-    }
-
-private:
-    T** cell() const { return const_cast<T**>(&this->m_raw); }
-
-    template<typename Derived> friend class VisitorHelper;
-};
-
-// UntracedMember is a pointer to an on-heap object that is not traced for some
-// reason. Please don't use this unless you understand what you're doing.
-// Basically, all pointers to on-heap objects must be stored in either of
-// Persistent, Member or WeakMember. It is not allowed to leave raw pointers to
-// on-heap objects. However, there can be scenarios where you have to use raw
-// pointers for some reason, and in that case you can use UntracedMember. Of
-// course, it must be guaranteed that the pointing on-heap object is kept alive
-// while the raw pointer is pointing to the object.
-template<typename T>
-class UntracedMember final : public Member<T> {
-public:
-    UntracedMember() : Member<T>() { }
-
-    UntracedMember(std::nullptr_t) : Member<T>(nullptr) { }
-
-    UntracedMember(T* raw) : Member<T>(raw) { }
-
-    template<typename U>
-    UntracedMember(const Persistent<U>& other) : Member<T>(other) { }
-
-    template<typename U>
-    UntracedMember(const Member<U>& other) : Member<T>(other) { }
-
-    UntracedMember(WTF::HashTableDeletedValueType x) : Member<T>(x) { }
-
-    template<typename U>
-    UntracedMember& operator=(const Persistent<U>& other)
-    {
-        this->m_raw = other;
-        this->checkPointer();
-        return *this;
-    }
-
-    template<typename U>
-    UntracedMember& operator=(const Member<U>& other)
-    {
-        this->m_raw = other;
-        this->checkPointer();
-        return *this;
-    }
-
-    template<typename U>
-    UntracedMember& operator=(U* other)
-    {
-        this->m_raw = other;
-        this->checkPointer();
-        return *this;
-    }
-
-    UntracedMember& operator=(std::nullptr_t)
-    {
-        this->m_raw = nullptr;
-        return *this;
-    }
-};
-
-// Comparison operators between (Weak)Members, Persistents, and UntracedMembers.
-template<typename T, typename U> inline bool operator==(const Member<T>& a, const Member<U>& b) { return a.get() == b.get(); }
-template<typename T, typename U> inline bool operator!=(const Member<T>& a, const Member<U>& b) { return a.get() != b.get(); }
-template<typename T, typename U> inline bool operator==(const Persistent<T>& a, const Persistent<U>& b) { return a.get() == b.get(); }
-template<typename T, typename U> inline bool operator!=(const Persistent<T>& a, const Persistent<U>& b) { return a.get() != b.get(); }
-
-template<typename T, typename U> inline bool operator==(const Member<T>& a, const Persistent<U>& b) { return a.get() == b.get(); }
-template<typename T, typename U> inline bool operator!=(const Member<T>& a, const Persistent<U>& b) { return a.get() != b.get(); }
-template<typename T, typename U> inline bool operator==(const Persistent<T>& a, const Member<U>& b) { return a.get() == b.get(); }
-template<typename T, typename U> inline bool operator!=(const Persistent<T>& a, const Member<U>& b) { return a.get() != b.get(); }
-
-template<typename T, bool = IsGarbageCollectedType<T>::value>
-class RawPtrOrMemberTrait {
-    STATIC_ONLY(RawPtrOrMemberTrait)
-public:
-    using Type = T*;
-};
-
-template<typename T>
-class RawPtrOrMemberTrait<T, true> {
-    STATIC_ONLY(RawPtrOrMemberTrait)
-public:
-    using Type = Member<T>;
-};
-
-// Abstraction for injecting calls to an object's 'dispose()' method
-// on leaving a stack scope, ensuring earlier release of resources
-// than waiting until the object is eventually GCed.
-template<typename T, void (T::*Disposer)() = (&T::dispose)>
-class ScopedDisposal {
-    STACK_ALLOCATED();
-public:
-    ScopedDisposal(T* object)
-        : m_object(object)
-    {
-    }
-
-    ~ScopedDisposal()
-    {
-        if (m_object)
-            (m_object->*Disposer)();
-    }
-
-    void clear() { m_object.clear(); }
-
-private:
-    typename RawPtrOrMemberTrait<T>::Type m_object;
-};
-
-// SelfKeepAlive<Object> is the idiom to use for objects that have to keep
-// themselves temporarily alive and cannot rely on there being some
-// external reference in that interval:
-//
-//  class Opener {
-//  public:
-//     ...
-//     void open()
-//     {
-//         // Retain a self-reference while in an open()ed state:
-//         m_keepAlive = this;
-//         ....
-//     }
-//
-//     void close()
-//     {
-//         // Clear self-reference that ensured we were kept alive while opened.
-//         m_keepAlive.clear();
-//         ....
-//     }
-//
-//  private:
-//     ...
-//     SelfKeepAlive m_keepAlive;
-//  };
-//
-// The responsibility to call clear() in a timely fashion resides with the implementation
-// of the object.
-//
-//
-template<typename Self>
-class SelfKeepAlive final {
-    DISALLOW_NEW();
-public:
-    SelfKeepAlive()
-    {
-    }
-
-    explicit SelfKeepAlive(Self* self)
-    {
-        assign(self);
-    }
-
-    SelfKeepAlive& operator=(Self* self)
-    {
-        assign(self);
-        return *this;
-    }
-
-    void clear()
-    {
-        m_keepAlive.clear();
-    }
-
-    typedef Persistent<Self> (SelfKeepAlive::*UnspecifiedBoolType);
-    operator UnspecifiedBoolType() const { return m_keepAlive ? &SelfKeepAlive::m_keepAlive : 0; }
-
-private:
-    void assign(Self* self)
-    {
-        ASSERT(!m_keepAlive || m_keepAlive.get() == self);
-        m_keepAlive = self;
-    }
-
-    GC_PLUGIN_IGNORE("420515")
-    Persistent<Self> m_keepAlive;
-};
-
-// Only a very reduced form of weak heap object references can currently be held
-// by WTF::Closure<>s. i.e., bound as a 'this' pointer only.
-//
-// TODO(sof): once wtf/Functional.h is able to work over platform/heap/ types
-// (like CrossThreadWeakPersistent<>), drop the restriction on weak persistent
-// use by function closures (and rename this ad-hoc type.)
-template<typename T>
-class WeakPersistentThisPointer {
-    STACK_ALLOCATED();
-public:
-    explicit WeakPersistentThisPointer(T* value) : m_value(value) { }
-    WeakPersistent<T> value() const { return m_value; }
-private:
-    WeakPersistent<T> m_value;
-};
-
-template<typename T>
-class CrossThreadWeakPersistentThisPointer {
-    STACK_ALLOCATED();
-public:
-    explicit CrossThreadWeakPersistentThisPointer(T* value) : m_value(value) { }
-    CrossThreadWeakPersistent<T> value() const { return m_value; }
-private:
-    CrossThreadWeakPersistent<T> m_value;
-};
-
-template <typename T>
-Persistent<T> wrapPersistent(T* value)
-{
-    return Persistent<T>(value);
-}
-
-template <typename T>
-CrossThreadPersistent<T> wrapCrossThreadPersistent(T* value)
-{
-    return CrossThreadPersistent<T>(value);
-}
-
 // LEAK_SANITIZER_DISABLED_SCOPE: all allocations made in the current scope
 // will be exempted from LSan consideration.
 //
 // TODO(sof): move this to wtf/LeakAnnotations.h (LeakSanitizer.h?) once
 // wtf/ can freely call upon Oilpan functionality.
 #if defined(LEAK_SANITIZER)
 class LeakSanitizerDisableScope {
     STACK_ALLOCATED();
     WTF_MAKE_NONCOPYABLE(LeakSanitizerDisableScope);
 public:
@@ skipping 11 matching lines @@
             ThreadState::current()->leaveStaticReferenceRegistrationDisabledScope();
     }
 };
 #define LEAK_SANITIZER_DISABLED_SCOPE LeakSanitizerDisableScope lsanDisabledScope
 #else
 #define LEAK_SANITIZER_DISABLED_SCOPE
 #endif
 
 } // namespace blink
 
-namespace WTF {
-
-template <typename T>
-struct MemberHash : PtrHash<T> {
-    STATIC_ONLY(MemberHash);
-    template <typename U>
-    static unsigned hash(const U& key) { return PtrHash<T>::hash(key); }
-    template <typename U, typename V>
-    static bool equal(const U& a, const V& b) { return a == b; }
-};
-
-template <typename T>
-struct WeakMemberHash : MemberHash<T> {
-    STATIC_ONLY(WeakMemberHash);
-};
-
-template <typename T>
-struct UntracedMemberHash : MemberHash<T> {
-    STATIC_ONLY(UntracedMemberHash);
-};
-
-// PtrHash is the default hash for hash tables with members.
-template <typename T>
-struct DefaultHash<blink::Member<T>> {
-    STATIC_ONLY(DefaultHash);
-    using Hash = MemberHash<T>;
-};
-
-template <typename T>
-struct DefaultHash<blink::WeakMember<T>> {
-    STATIC_ONLY(DefaultHash);
-    using Hash = WeakMemberHash<T>;
-};
-
-template <typename T>
-struct DefaultHash<blink::UntracedMember<T>> {
-    STATIC_ONLY(DefaultHash);
-    using Hash = UntracedMemberHash<T>;
-};
-
-template<typename T>
-struct NeedsTracing<blink::Member<T>> {
-    STATIC_ONLY(NeedsTracing);
-    static const bool value = true;
-};
-
-template<typename T>
-struct IsWeak<blink::WeakMember<T>> {
-    STATIC_ONLY(IsWeak);
-    static const bool value = true;
-};
-
-template<typename T>
-struct ParamStorageTraits<blink::WeakPersistentThisPointer<T>> {
-    STATIC_ONLY(ParamStorageTraits);
-    static_assert(sizeof(T), "T must be fully defined");
-    using StorageType = blink::WeakPersistent<T>;
-
-    static StorageType wrap(const blink::WeakPersistentThisPointer<T>& value) { return value.value(); }
-
-    // WTF::FunctionWrapper<> handles WeakPtr<>, so recast this weak persistent
-    // into it.
-    //
-    // TODO(sof): remove this hack once wtf/Functional.h can also work with a type like
-    // WeakPersistent<>.
-    static WeakPtr<T> unwrap(const StorageType& value) { return WeakPtr<T>(WeakReference<T>::create(value.get())); }
-};
-
-template<typename T>
-struct ParamStorageTraits<blink::CrossThreadWeakPersistentThisPointer<T>> {
-    STATIC_ONLY(ParamStorageTraits);
-    static_assert(sizeof(T), "T must be fully defined");
-    using StorageType = blink::CrossThreadWeakPersistent<T>;
-
-    static StorageType wrap(const blink::CrossThreadWeakPersistentThisPointer<T>& value) { return value.value(); }
-
-    // WTF::FunctionWrapper<> handles WeakPtr<>, so recast this weak persistent
-    // into it.
-    //
-    // TODO(sof): remove this hack once wtf/Functional.h can also work with a type like
-    // CrossThreadWeakPersistent<>.
-    static WeakPtr<T> unwrap(const StorageType& value) { return WeakPtr<T>(WeakReference<T>::create(value.get())); }
-};
-
-} // namespace WTF
-
 #endif