wtf/ParallelJobsGeneric.cpp

   1 /*
   2  * Copyright (C) 2011 University of Szeged
   3  * Copyright (C) 2011 Gabor Loki <loki@webkit.org>
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  * 2. Redistributions in binary form must reproduce the above copyright
  12  *    notice, this list of conditions and the following disclaimer in the
  13  *    documentation and/or other materials provided with the distribution.
  14  *
  15  * THIS SOFTWARE IS PROVIDED BY UNIVERSITY OF SZEGED ``AS IS'' AND ANY
  16  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  18  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL UNIVERSITY OF SZEGED OR
  19  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  20  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  21  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  22  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  23  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  25  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  26  */
  27
  28 #include "config.h"
  29
  30 #if ENABLE(PARALLEL_JOBS) && ENABLE(THREADING_GENERIC)
  31
  32 #include "ParallelJobs.h"
  33
  34 namespace WTF {
  35
  36 Vector< RefPtr<ParallelEnvironment::ThreadPrivate> >* ParallelEnvironment::s_threadPool = 0;
  37
  38 bool ParallelEnvironment::ThreadPrivate::tryLockFor(ParallelEnvironment* parent)
  39 {
  40     bool locked = m_mutex.tryLock();
  41
  42     if (!locked)
  43         return false;
  44
  45     if (m_parent) {
  46         m_mutex.unlock();
  47         return false;
  48     }
  49
  50     if (!m_threadID)
  51         m_threadID = createThread(&ParallelEnvironment::ThreadPrivate::workerThread, this, "Parallel worker");
  52
  53     if (m_threadID)
  54         m_parent = parent;
  55
  56     m_mutex.unlock();
  57     return m_threadID;
  58 }
  59
  60 void ParallelEnvironment::ThreadPrivate::execute(ThreadFunction threadFunction, void* parameters)
  61 {
  62     MutexLocker lock(m_mutex);
  63
  64     m_threadFunction = threadFunction;
  65     m_parameters = parameters;
  66     m_running = true;
  67     m_threadCondition.signal();
  68 }
  69
  70 void ParallelEnvironment::ThreadPrivate::waitForFinish()
  71 {
  72     MutexLocker lock(m_mutex);
  73
  74     while (m_running)
  75         m_threadCondition.wait(m_mutex);
  76 }
  77
  78 void* ParallelEnvironment::ThreadPrivate::workerThread(void* threadData)
  79 {
  80     ThreadPrivate* sharedThread = reinterpret_cast<ThreadPrivate*>(threadData);
  81     MutexLocker lock(sharedThread->m_mutex);
  82
  83     while (sharedThread->m_threadID) {
  84         if (sharedThread->m_running) {
  85             (*sharedThread->m_threadFunction)(sharedThread->m_parameters);
  86             sharedThread->m_running = false;
  87             sharedThread->m_parent = 0;
  88             sharedThread->m_threadCondition.signal();
  89         }
  90
  91         sharedThread->m_threadCondition.wait(sharedThread->m_mutex);
  92     }
  93     return 0;
  94 }
  95
  96 } // namespace WTF
  97
  98 #endif // ENABLE(PARALLEL_JOBS) && ENABLE(THREADING_GENERIC)