1 /*

     2  * Copyright (C) 2007 Apple Inc.  All rights reserved.

     3  *

     4  * Redistribution and use in source and binary forms, with or without

     5  * modification, are permitted provided that the following conditions

     6  * are met:

     7  *

     8  * 1.  Redistributions of source code must retain the above copyright

     9  *     notice, this list of conditions and the following disclaimer. 

    10  * 2.  Redistributions in binary form must reproduce the above copyright

    11  *     notice, this list of conditions and the following disclaimer in the

    12  *     documentation and/or other materials provided with the distribution. 

    13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of

    14  *     its contributors may be used to endorse or promote products derived

    15  *     from this software without specific prior written permission. 

    16  *

    17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY

    18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

    19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

    20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY

    21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

    22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

    23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

    24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

    25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

    26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

    27  */

    28 

    29 #include "DumpRenderTree.h"

    30 #include "WorkQueue.h"

    31 

    32 #include "WorkQueueItem.h"

    33 

    34 #include <JavaScriptCore/Assertions.h>

    35 

    36 static const unsigned queueLength = 1024;

    37 

    38 static WorkQueueItem* theQueue[queueLength];

    39 static unsigned startOfQueue;

    40 static unsigned endOfQueue;

    41 

    42 WorkQueue* WorkQueue::shared()

    43 {

    44     static WorkQueue* sharedInstance = new WorkQueue;

    45     return sharedInstance;

    46 }

    47 

    48 WorkQueue::WorkQueue()

    49     : m_frozen(false)

    50 {

    51 }

    52 

    53 void WorkQueue::queue(WorkQueueItem* item)

    54 {

    55     ASSERT(endOfQueue < queueLength);

    56     ASSERT(endOfQueue >= startOfQueue);

    57 

    58     if (m_frozen)

    59         return;

    60 

    61     theQueue[endOfQueue++] = item;

    62 }

    63 

    64 WorkQueueItem* WorkQueue::dequeue()

    65 {

    66     ASSERT(endOfQueue >= startOfQueue);

    67 

    68     if (startOfQueue == endOfQueue)

    69         return 0;

    70 

    71     return theQueue[startOfQueue++];

    72 }

    73 

    74 unsigned WorkQueue::count()

    75 {

    76     return endOfQueue - startOfQueue;

    77 }

    78 

    79 void WorkQueue::clear()

    80 {

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

    82         delete theQueue[i];

    83         theQueue[i] = 0;

    84     }

    85 

    86     startOfQueue = 0;

    87     endOfQueue = 0;

    88 }