1 /*

     2  * Copyright (C) 2010 Google 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 are

     6  * met:

     7  *

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

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

    10  *     * Redistributions in binary form must reproduce the above

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

    12  * in the documentation and/or other materials provided with the

    13  * distribution.

    14  *     * Neither the name of Google Inc. nor the names of its

    15  * contributors may be used to endorse or promote products derived from

    16  * this software without specific prior written permission.

    17  *

    18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

    19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

    20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR

    21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT

    22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

    23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT

    24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

    25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

    26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

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

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

    29  */

    30 

    31 #include "config.h"

    32 

    33 #if ENABLE(FILE_WRITER) || ENABLE(FILE_READER)

    34 

    35 #include "FileThread.h"

    36 

    37 #include "AutodrainedPool.h"

    38 #include "Logging.h"

    39 

    40 namespace WebCore {

    41 

    42 FileThread::FileThread()

    43     : m_threadID(0)

    44 {

    45     m_selfRef = this;

    46 }

    47 

    48 FileThread::~FileThread()

    49 {

    50     ASSERT(m_queue.killed());

    51 }

    52 

    53 bool FileThread::start()

    54 {

    55     MutexLocker lock(m_threadCreationMutex);

    56     if (m_threadID)

    57         return true;

    58     m_threadID = createThread(FileThread::fileThreadStart, this, "WebCore: File");

    59     return m_threadID;

    60 }

    61 

    62 void FileThread::stop()

    63 {

    64     return m_queue.kill();

    65 }

    66 

    67 void FileThread::postTask(PassOwnPtr<Task> task)

    68 {

    69     m_queue.append(task);

    70 }

    71 

    72 class SameFilePredicate {

    73 public:

    74     SameFilePredicate(const FileStream* stream) : m_stream(stream) { }

    75     bool operator()(FileThread::Task* task) const { return task->stream() == m_stream; }

    76 private:

    77     const FileStream* m_stream;

    78 };

    79 

    80 void FileThread::unscheduleTasks(const FileStream* stream)

    81 {

    82     SameFilePredicate predicate(stream);

    83     m_queue.removeIf(predicate);

    84 }

    85 

    86 void* FileThread::fileThreadStart(void* arg)

    87 {

    88     FileThread* fileThread = static_cast<FileThread*>(arg);

    89     return fileThread->runLoop();

    90 }

    91 

    92 void* FileThread::runLoop()

    93 {

    94     {

    95         // Wait for FileThread::start() to complete to have m_threadID

    96         // established before starting the main loop.

    97         MutexLocker lock(m_threadCreationMutex);

    98         LOG(FileAPI, "Started FileThread %p", this);

    99     }

   100 

   101     AutodrainedPool pool;

   102     while (OwnPtr<Task> task = m_queue.waitForMessage()) {

   103         task->performTask();

   104         pool.cycle();

   105     }

   106 

   107     LOG(FileAPI, "About to detach thread %i and clear the ref to FileThread %p, which currently has %i ref(s)", m_threadID, this, refCount());

   108 

   109     detachThread(m_threadID);

   110 

   111     // Clear the self refptr, possibly resulting in deletion

   112     m_selfRef = 0;

   113 

   114     return 0;

   115 }

   116 

   117 } // namespace WebCore

   118 

   119 #endif // ENABLE(FILE_WRITER) || ENABLE(FILE_READER)