wtf/ThreadIdentifierDataPthreads.cpp

   1 /*
   2  * Copyright (C) 2009 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 USE(PTHREADS)
  34
  35 #include "ThreadIdentifierDataPthreads.h"
  36
  37 #include "Threading.h"
  38
  39 namespace WTF {
  40
  41 pthread_key_t ThreadIdentifierData::m_key;
  42
  43 void clearPthreadHandleForIdentifier(ThreadIdentifier);
  44
  45 ThreadIdentifierData::~ThreadIdentifierData()
  46 {
  47     clearPthreadHandleForIdentifier(m_identifier);
  48 }
  49
  50 ThreadIdentifier ThreadIdentifierData::identifier()
  51 {
  52     initializeKeyOnce();
  53     ThreadIdentifierData* threadIdentifierData = static_cast<ThreadIdentifierData*>(pthread_getspecific(m_key));
  54
  55     return threadIdentifierData ? threadIdentifierData->m_identifier : 0;
  56 }
  57
  58 void ThreadIdentifierData::initialize(ThreadIdentifier id)
  59 {
  60     ASSERT(!identifier());
  61
  62     initializeKeyOnce();
  63     pthread_setspecific(m_key, new ThreadIdentifierData(id));
  64 }
  65
  66 void ThreadIdentifierData::destruct(void* data)
  67 {
  68     ThreadIdentifierData* threadIdentifierData = static_cast<ThreadIdentifierData*>(data);
  69     ASSERT(threadIdentifierData);
  70
  71     if (threadIdentifierData->m_isDestroyedOnce) {
  72         delete threadIdentifierData;
  73         return;
  74     }
  75
  76     threadIdentifierData->m_isDestroyedOnce = true;
  77     // Re-setting the value for key causes another destruct() call after all other thread-specific destructors were called.
  78     pthread_setspecific(m_key, threadIdentifierData);
  79 }
  80
  81 void ThreadIdentifierData::initializeKeyOnceHelper()
  82 {
  83     if (pthread_key_create(&m_key, destruct))
  84         CRASH();
  85 }
  86
  87 void ThreadIdentifierData::initializeKeyOnce()
  88 {
  89     static pthread_once_t onceControl = PTHREAD_ONCE_INIT;
  90     if (pthread_once(&onceControl, initializeKeyOnceHelper))
  91         CRASH();
  92 }
  93
  94 } // namespace WTF
  95
  96 #endif // USE(PTHREADS)
  97