1 /*

     2  * Copyright (C) 2010 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  * 1. Redistributions of source code must retain the above copyright

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

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

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

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

    12  *

    13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''

    14  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,

    15  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

    16  * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS

    17  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR

    18  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF

    19  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS

    20  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN

    21  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)

    22  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF

    23  * THE POSSIBILITY OF SUCH DAMAGE.

    24  */

    25 

    26 #include "WorkQueue.h"

    27 

    28 #include <process.h>

    29 #include <wtf/Threading.h>

    30 

    31 void WorkQueue::registerHandle(HANDLE handle, PassOwnPtr<WorkItem> item)

    32 {

    33     // Add the item.

    34     {

    35         MutexLocker locker(m_handlesLock);

    36         m_handles.set(handle, item.leakPtr());

    37     }

    38 

    39     // Set the work event.

    40     ::SetEvent(m_performWorkEvent);

    41 }

    42 

    43 void* WorkQueue::workQueueThreadBody(void *context)

    44 {

    45     static_cast<WorkQueue*>(context)->workQueueThreadBody();

    46     return 0;

    47 }

    48 

    49 void WorkQueue::workQueueThreadBody()

    50 {

    51     while (true) {

    52         Vector<HANDLE> handles;

    53         {

    54             // Copy the handles to our handles vector.

    55             MutexLocker locker(m_handlesLock);

    56             copyKeysToVector(m_handles, handles);

    57         }

    58 

    59         // Add the "perform work" event handle.

    60         handles.append(m_performWorkEvent);

    61 

    62         // Now we wait.

    63         DWORD result = ::WaitForMultipleObjects(handles.size(), handles.data(), FALSE, INFINITE);

    64 

    65         if (result == handles.size() - 1)

    66             performWork();

    67         else {

    68             // FIXME: If we ever decide to support unregistering handles we would need to copy the hash map.

    69             WorkItem* workItem;

    70             HANDLE handle = handles[result];

    71 

    72             {

    73                 MutexLocker locker(m_handlesLock);

    74                 workItem = m_handles.get(handle);

    75             }

    76 

    77             // Execute the work item.

    78             workItem->execute();

    79         }

    80 

    81         // Check if this queue is invalid.

    82         {

    83             MutexLocker locker(m_isValidMutex);

    84             if (!m_isValid)

    85                 break;

    86         }

    87     }

    88 }

    89 

    90 void WorkQueue::platformInitialize(const char* name)

    91 {

    92     // Create our event.

    93     m_performWorkEvent = ::CreateEvent(0, false, false, 0);

    94 

    95     m_workQueueThread = createThread(&WorkQueue::workQueueThreadBody, this, name);

    96 }

    97 

    98 void WorkQueue::platformInvalidate()

    99 {

   100     ::CloseHandle(m_performWorkEvent);

   101 

   102     // FIXME: Stop the thread and do other cleanup.

   103 }

   104 

   105 void WorkQueue::scheduleWork(PassOwnPtr<WorkItem> item)

   106 {

   107     MutexLocker locker(m_workItemQueueLock);

   108     m_workItemQueue.append(item.leakPtr());

   109 

   110     // Set the work event.

   111     ::SetEvent(m_performWorkEvent);

   112 }

   113 

   114 void WorkQueue::performWork()

   115 {

   116     Vector<WorkItem*> workItemQueue;

   117     {

   118         MutexLocker locker(m_workItemQueueLock);

   119         m_workItemQueue.swap(workItemQueue);

   120     }

   121 

   122     for (size_t i = 0; i < workItemQueue.size(); ++i) {

   123         OwnPtr<WorkItem> item(workItemQueue[i]);

   124 

   125         MutexLocker locker(m_isValidMutex);

   126         if (m_isValid)

   127             item->execute();

   128     }

   129 }