Move Source/WTF/wtf to Source/wtf

Source/WTF/wtf/WeakPtr.h

-/*
- * Copyright (C) 2013 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:
- * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- *    notice, this list of conditions and the following disclaimer in the
- *    documentation and/or other materials provided with the distribution.
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
- * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
- * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
- * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
- * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
- * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
- * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (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 WTF_WeakPtr_h
-#define WTF_WeakPtr_h
-
-#include <wtf/Noncopyable.h>
-#include <wtf/PassRefPtr.h>
-#include <wtf/RefPtr.h>
-#include <wtf/ThreadSafeRefCounted.h>
-#include <wtf/Threading.h>
-
-namespace WTF {
-
-template<typename T>
-class WeakReference : public ThreadSafeRefCounted<WeakReference<T> > {
-    WTF_MAKE_NONCOPYABLE(WeakReference<T>);
-    WTF_MAKE_FAST_ALLOCATED;
-public:
-    static PassRefPtr<WeakReference<T> > create(T* ptr) { return adoptRef(new WeakReference(ptr)); }
-    static PassRefPtr<WeakReference<T> > createUnbound() { return adoptRef(new WeakReference()); }
-
-    T* get() const
-    {
-        ASSERT(m_boundThread == currentThread());
-        return m_ptr;
-    }
-
-    void clear()
-    {
-        ASSERT(m_boundThread == currentThread());
-        m_ptr = 0;
-    }
-
-    void bindTo(T* ptr)
-    {
-        ASSERT(!m_ptr);
-#ifndef NDEBUG
-        m_boundThread = currentThread();
-#endif
-        m_ptr = ptr;
-    }
-
-private:
-    WeakReference() : m_ptr(0) { }
-
-    explicit WeakReference(T* ptr)
-        : m_ptr(ptr)
-#ifndef NDEBUG
-        , m_boundThread(currentThread())
-#endif
-    {
-    }
-
-    T* m_ptr;
-#ifndef NDEBUG
-    ThreadIdentifier m_boundThread;
-#endif
-};
-
-template<typename T>
-class WeakPtr {
-    WTF_MAKE_FAST_ALLOCATED;
-public:
-    WeakPtr() { }
-    WeakPtr(PassRefPtr<WeakReference<T> > ref) : m_ref(ref) { }
-
-    T* get() const { return m_ref->get(); }
-
-private:
-    RefPtr<WeakReference<T> > m_ref;
-};
-
-template<typename T>
-class WeakPtrFactory {
-    WTF_MAKE_NONCOPYABLE(WeakPtrFactory<T>);
-    WTF_MAKE_FAST_ALLOCATED;
-public:
-    explicit WeakPtrFactory(T* ptr) : m_ref(WeakReference<T>::create(ptr)) { }
-
-    WeakPtrFactory(PassRefPtr<WeakReference<T> > ref, T* ptr)
-        : m_ref(ref)
-    {
-        m_ref->bindTo(ptr);
-    }
-
-    ~WeakPtrFactory() { m_ref->clear(); }
-
-    // We should consider having createWeakPtr populate m_ref the first time createWeakPtr is called.
-    WeakPtr<T> createWeakPtr() { return WeakPtr<T>(m_ref); }
-
-    void revokeAll()
-    {
-        T* ptr = m_ref->get();
-        m_ref->clear();
-        // We create a new WeakReference so that future calls to createWeakPtr() create nonzero WeakPtrs.
-        m_ref = WeakReference<T>::create(ptr);
-    }
-
-private:
-    RefPtr<WeakReference<T> > m_ref;
-};
-
-} // namespace WTF
-
-using WTF::WeakPtr;
-using WTF::WeakPtrFactory;
-using WTF::WeakReference;
-
-#endif