src/third_party/WebKit/Source/WTF/wtf/ThreadIdentifierDataPthreads.cpp

/*
 * Copyright (C) 2009, 2011 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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 */

#include "config.h"

#if USE(PTHREADS)

#include "ThreadIdentifierDataPthreads.h"

#include "Threading.h"

#if OS(ANDROID) || OS(HURD) || defined(__ANDROID__)
// PTHREAD_KEYS_MAX is not defined in bionic nor in Hurd, so explicitly define it here.
#define PTHREAD_KEYS_MAX 1024
#else
#include <limits.h>
#endif

namespace WTF {

#if defined(__LB_SHELL__)
std::map<ThreadIdentifier, ThreadIdentifierData*> ThreadIdentifierData::local_handle;
Mutex ThreadIdentifierData::lock_local_handle;
#endif

#if defined(PTW32_VERSION)
// pthreads-win32 uses a pointer for pthread_key_t, meaning you can't go
// assigning any old number you want to it without casting. NULL is a more
// reasonable uninitialized value.
pthread_key_t ThreadIdentifierData::m_key = NULL;
#else
pthread_key_t ThreadIdentifierData::m_key = PTHREAD_KEYS_MAX;
#endif

void threadDidExit(ThreadIdentifier);

ThreadIdentifierData::~ThreadIdentifierData()
{
    threadDidExit(m_identifier);
}

void ThreadIdentifierData::initializeOnce()
{
    if (pthread_key_create(&m_key, destruct))
        CRASH();
}

ThreadIdentifier ThreadIdentifierData::identifier()
{
#if defined(PTW32_VERSION)
    ASSERT(m_key != NULL);
#else
    ASSERT(m_key != PTHREAD_KEYS_MAX);
#endif
    ThreadIdentifierData* threadIdentifierData = static_cast<ThreadIdentifierData*>(pthread_getspecific(m_key));

    return threadIdentifierData ? threadIdentifierData->m_identifier : 0;
}

void ThreadIdentifierData::initialize(ThreadIdentifier id)
{
    ASSERT(!identifier());
#if defined(__LB_SHELL__)
    ThreadIdentifierData *created = new ThreadIdentifierData(id);
    pthread_setspecific(m_key, created);
    {
      MutexLocker m(lock_local_handle);
      ASSERT(local_handle.find(id) == local_handle.end());
      local_handle.insert(std::make_pair(id, created));
    }
#else
    pthread_setspecific(m_key, new ThreadIdentifierData(id));
#endif
}

void ThreadIdentifierData::destruct(void* data)
{
    ThreadIdentifierData* threadIdentifierData = static_cast<ThreadIdentifierData*>(data);
    ASSERT(threadIdentifierData);

    if (threadIdentifierData->m_isDestroyedOnce) {
        delete threadIdentifierData;
        return;
    }

    threadIdentifierData->m_isDestroyedOnce = true;
    // Re-setting the value for key causes another destruct() call after all other thread-specific destructors were called.
    pthread_setspecific(m_key, threadIdentifierData);
}

} // namespace WTF

#endif // USE(PTHREADS)