/*

 * Copyright (C) 2007 Apple 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.

 */

#include "DumpRenderTree.h"

#include "WorkQueue.h"

#include "WorkQueueItem.h"

#include <JavaScriptCore/Assertions.h>

static const unsigned queueLength = 1024;

static WorkQueueItem* theQueue[queueLength];

static unsigned startOfQueue;

static unsigned endOfQueue;

WorkQueue* WorkQueue::shared()

{

    static WorkQueue* sharedInstance = new WorkQueue;

    return sharedInstance;

}

WorkQueue::WorkQueue()

    : m_frozen(false)

{

}

void WorkQueue::queue(WorkQueueItem* item)

{

    ASSERT(endOfQueue < queueLength);

    ASSERT(endOfQueue >= startOfQueue);

    if (m_frozen)

        return;

    theQueue[endOfQueue++] = item;

}

WorkQueueItem* WorkQueue::dequeue()

{

    ASSERT(endOfQueue >= startOfQueue);

    if (startOfQueue == endOfQueue)

        return 0;

    return theQueue[startOfQueue++];

}

unsigned WorkQueue::count()

{

    return endOfQueue - startOfQueue;

}

void WorkQueue::clear()

{

    for (unsigned i = startOfQueue; i < endOfQueue; ++i) {

        delete theQueue[i];

        theQueue[i] = 0;

    }

    startOfQueue = 0;

    endOfQueue = 0;

}