Move Source/WTF/wtf to Source/wtf

Source/WTF/wtf/ThreadSafeRefCounted.h

-/*
- * Copyright (C) 2007, 2008, 2010 Apple Inc. All rights reserved.
- * Copyright (C) 2007 Justin Haygood (jhaygood@reaktix.com)
- *
- * 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. 
- * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
- *     its contributors may be used to endorse or promote products derived
- *     from this software without specific prior written permission. 
- *
- * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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.
- *
- *
- * Note: The implementations of InterlockedIncrement and InterlockedDecrement are based
- * on atomic_increment and atomic_exchange_and_add from the Boost C++ Library. The license
- * is virtually identical to the Apple license above but is included here for completeness.
- *
- * Boost Software License - Version 1.0 - August 17th, 2003
- * 
- * Permission is hereby granted, free of charge, to any person or organization
- * obtaining a copy of the software and accompanying documentation covered by
- * this license (the "Software") to use, reproduce, display, distribute,
- * execute, and transmit the Software, and to prepare derivative works of the
- * Software, and to permit third-parties to whom the Software is furnished to
- * do so, all subject to the following:
- * 
- * The copyright notices in the Software and this entire statement, including
- * the above license grant, this restriction and the following disclaimer,
- * must be included in all copies of the Software, in whole or in part, and
- * all derivative works of the Software, unless such copies or derivative
- * works are solely in the form of machine-executable object code generated by
- * a source language processor.
- * 
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
- * SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
- * FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
- * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
- * DEALINGS IN THE SOFTWARE.
- */
-
-#ifndef ThreadSafeRefCounted_h
-#define ThreadSafeRefCounted_h
-
-#include <wtf/Platform.h>
-
-#include <wtf/Atomics.h>
-#include <wtf/DynamicAnnotations.h>
-#include <wtf/ThreadingPrimitives.h>
-
-namespace WTF {
-
-class ThreadSafeRefCountedBase {
-    WTF_MAKE_NONCOPYABLE(ThreadSafeRefCountedBase);
-    WTF_MAKE_FAST_ALLOCATED;
-public:
-    ThreadSafeRefCountedBase(int initialRefCount = 1)
-        : m_refCount(initialRefCount)
-    {
-    }
-
-    void ref()
-    {
-#if USE(LOCKFREE_THREADSAFEREFCOUNTED)
-        atomicIncrement(&m_refCount);
-#else
-        MutexLocker locker(m_mutex);
-        ++m_refCount;
-#endif
-    }
-
-    bool hasOneRef()
-    {
-        return refCount() == 1;
-    }
-
-    int refCount() const
-    {
-#if !USE(LOCKFREE_THREADSAFEREFCOUNTED)
-        MutexLocker locker(m_mutex);
-#endif
-        return static_cast<int const volatile &>(m_refCount);
-    }
-
-protected:
-    // Returns whether the pointer should be freed or not.
-    bool derefBase()
-    {
-#if USE(LOCKFREE_THREADSAFEREFCOUNTED)
-        WTF_ANNOTATE_HAPPENS_BEFORE(&m_refCount);
-        if (atomicDecrement(&m_refCount) <= 0) {
-            WTF_ANNOTATE_HAPPENS_AFTER(&m_refCount);
-            return true;
-        }
-#else
-        int refCount;
-        {
-            MutexLocker locker(m_mutex);
-            --m_refCount;
-            refCount = m_refCount;
-        }
-        if (refCount <= 0)
-            return true;
-#endif
-        return false;
-    }
-
-private:
-    int m_refCount;
-#if !USE(LOCKFREE_THREADSAFEREFCOUNTED)
-    mutable Mutex m_mutex;
-#endif
-};
-
-template<class T> class ThreadSafeRefCounted : public ThreadSafeRefCountedBase {
-public:
-    void deref()
-    {
-        if (derefBase())
-            delete static_cast<T*>(this);
-    }
-
-protected:
-    ThreadSafeRefCounted()
-    {
-    }
-};
-
-} // namespace WTF
-
-using WTF::ThreadSafeRefCounted;
-
-#endif // ThreadSafeRefCounted_h