Move Source/WTF/wtf to Source/wtf

Source/WTF/wtf/MessageQueue.h

-/*
- * Copyright (C) 2008 Apple Inc. All rights reserved.
- * Copyright (C) 2009 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.
- * 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.
- */
-
-#ifndef MessageQueue_h
-#define MessageQueue_h
-
-#include <limits>
-#include <wtf/Assertions.h>
-#include <wtf/Deque.h>
-#include <wtf/Noncopyable.h>
-#include <wtf/Threading.h>
-
-namespace WTF {
-
-    enum MessageQueueWaitResult {
-        MessageQueueTerminated,       // Queue was destroyed while waiting for message.
-        MessageQueueTimeout,          // Timeout was specified and it expired.
-        MessageQueueMessageReceived   // A message was successfully received and returned.
-    };
-
-    // The queue takes ownership of messages and transfer it to the new owner
-    // when messages are fetched from the queue.
-    // Essentially, MessageQueue acts as a queue of OwnPtr<DataType>.
-    template<typename DataType>
-    class MessageQueue {
-        WTF_MAKE_NONCOPYABLE(MessageQueue);
-    public:
-        MessageQueue() : m_killed(false) { }
-        ~MessageQueue();
-
-        void append(PassOwnPtr<DataType>);
-        void appendAndKill(PassOwnPtr<DataType>);
-        bool appendAndCheckEmpty(PassOwnPtr<DataType>);
-        void prepend(PassOwnPtr<DataType>);
-
-        PassOwnPtr<DataType> waitForMessage();
-        PassOwnPtr<DataType> tryGetMessage();
-        PassOwnPtr<DataType> tryGetMessageIgnoringKilled();
-        template<typename Predicate>
-        PassOwnPtr<DataType> waitForMessageFilteredWithTimeout(MessageQueueWaitResult&, Predicate&, double absoluteTime);
-
-        template<typename Predicate>
-        void removeIf(Predicate&);
-
-        void kill();
-        bool killed() const;
-
-        // The result of isEmpty() is only valid if no other thread is manipulating the queue at the same time.
-        bool isEmpty();
-
-        static double infiniteTime() { return std::numeric_limits<double>::max(); }
-
-    private:
-        static bool alwaysTruePredicate(DataType*) { return true; }
-
-        mutable Mutex m_mutex;
-        ThreadCondition m_condition;
-        Deque<DataType*> m_queue;
-        bool m_killed;
-    };
-
-    template<typename DataType>
-    MessageQueue<DataType>::~MessageQueue()
-    {
-        deleteAllValues(m_queue);
-    }
-
-    template<typename DataType>
-    inline void MessageQueue<DataType>::append(PassOwnPtr<DataType> message)
-    {
-        MutexLocker lock(m_mutex);
-        m_queue.append(message.leakPtr());
-        m_condition.signal();
-    }
-
-    template<typename DataType>
-    inline void MessageQueue<DataType>::appendAndKill(PassOwnPtr<DataType> message)
-    {
-        MutexLocker lock(m_mutex);
-        m_queue.append(message.leakPtr());
-        m_killed = true;
-        m_condition.broadcast();
-    }
-
-    // Returns true if the queue was empty before the item was added.
-    template<typename DataType>
-    inline bool MessageQueue<DataType>::appendAndCheckEmpty(PassOwnPtr<DataType> message)
-    {
-        MutexLocker lock(m_mutex);
-        bool wasEmpty = m_queue.isEmpty();
-        m_queue.append(message.leakPtr());
-        m_condition.signal();
-        return wasEmpty;
-    }
-
-    template<typename DataType>
-    inline void MessageQueue<DataType>::prepend(PassOwnPtr<DataType> message)
-    {
-        MutexLocker lock(m_mutex);
-        m_queue.prepend(message.leakPtr());
-        m_condition.signal();
-    }
-
-    template<typename DataType>
-    inline PassOwnPtr<DataType> MessageQueue<DataType>::waitForMessage()
-    {
-        MessageQueueWaitResult exitReason; 
-        OwnPtr<DataType> result = waitForMessageFilteredWithTimeout(exitReason, MessageQueue<DataType>::alwaysTruePredicate, infiniteTime());
-        ASSERT(exitReason == MessageQueueTerminated || exitReason == MessageQueueMessageReceived);
-        return result.release();
-    }
-
-    template<typename DataType>
-    template<typename Predicate>
-    inline PassOwnPtr<DataType> MessageQueue<DataType>::waitForMessageFilteredWithTimeout(MessageQueueWaitResult& result, Predicate& predicate, double absoluteTime)
-    {
-        MutexLocker lock(m_mutex);
-        bool timedOut = false;
-
-        DequeConstIterator<DataType*> found = m_queue.end();
-        while (!m_killed && !timedOut && (found = m_queue.findIf(predicate)) == m_queue.end())
-            timedOut = !m_condition.timedWait(m_mutex, absoluteTime);
-
-        ASSERT(!timedOut || absoluteTime != infiniteTime());
-
-        if (m_killed) {
-            result = MessageQueueTerminated;
-            return nullptr;
-        }
-
-        if (timedOut) {
-            result = MessageQueueTimeout;
-            return nullptr;
-        }
-
-        ASSERT(found != m_queue.end());
-        OwnPtr<DataType> message = adoptPtr(*found);
-        m_queue.remove(found);
-        result = MessageQueueMessageReceived;
-        return message.release();
-    }
-
-    template<typename DataType>
-    inline PassOwnPtr<DataType> MessageQueue<DataType>::tryGetMessage()
-    {
-        MutexLocker lock(m_mutex);
-        if (m_killed)
-            return nullptr;
-        if (m_queue.isEmpty())
-            return nullptr;
-
-        return adoptPtr(m_queue.takeFirst());
-    }
-
-    template<typename DataType>
-    inline PassOwnPtr<DataType> MessageQueue<DataType>::tryGetMessageIgnoringKilled()
-    {
-        MutexLocker lock(m_mutex);
-        if (m_queue.isEmpty())
-            return nullptr;
-
-        return adoptPtr(m_queue.takeFirst());
-    }
-
-    template<typename DataType>
-    template<typename Predicate>
-    inline void MessageQueue<DataType>::removeIf(Predicate& predicate)
-    {
-        MutexLocker lock(m_mutex);
-        DequeConstIterator<DataType*> found = m_queue.end();
-        while ((found = m_queue.findIf(predicate)) != m_queue.end()) {
-            DataType* message = *found;
-            m_queue.remove(found);
-            delete message;
-        }
-    }
-
-    template<typename DataType>
-    inline bool MessageQueue<DataType>::isEmpty()
-    {
-        MutexLocker lock(m_mutex);
-        if (m_killed)
-            return true;
-        return m_queue.isEmpty();
-    }
-
-    template<typename DataType>
-    inline void MessageQueue<DataType>::kill()
-    {
-        MutexLocker lock(m_mutex);
-        m_killed = true;
-        m_condition.broadcast();
-    }
-
-    template<typename DataType>
-    inline bool MessageQueue<DataType>::killed() const
-    {
-        MutexLocker lock(m_mutex);
-        return m_killed;
-    }
-} // namespace WTF
-
-using WTF::MessageQueue;
-// MessageQueueWaitResult enum and all its values.
-using WTF::MessageQueueWaitResult;
-using WTF::MessageQueueTerminated;
-using WTF::MessageQueueTimeout;
-using WTF::MessageQueueMessageReceived;
-
-#endif // MessageQueue_h