/*
* Copyright (C) 2009 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.
* * Neither the name of Google Inc. nor the names of its
* 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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* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef ThreadIdentifierDataPthreads_h
#define ThreadIdentifierDataPthreads_h
#include "wtf/Noncopyable.h"
#include "wtf/Threading.h"
#include <pthread.h>
namespace WTF {
// Holds ThreadIdentifier in the thread-specific storage and employs pthreads-specific 2-pass destruction to reliably remove
// ThreadIdentifier from threadMap. It assumes regular ThreadSpecific types don't use multiple-pass destruction.
class ThreadIdentifierData {
WTF_MAKE_NONCOPYABLE(ThreadIdentifierData);
public:
~ThreadIdentifierData();
// One time initialization for this class as a whole.
// This method must be called before initialize() and it is not thread-safe.
static void initializeOnce();
// Creates and puts an instance of ThreadIdentifierData into thread-specific storage.
static void initialize(ThreadIdentifier identifier);
// Returns 0 if thread-specific storage was not initialized.
static ThreadIdentifier identifier();
private:
ThreadIdentifierData(ThreadIdentifier identifier)
: m_identifier(identifier)
, m_isDestroyedOnce(false)
{
}
// This thread-specific destructor is called 2 times when thread terminates:
// - first, when all the other thread-specific destructors are called, it simply remembers it was 'destroyed once'
// and re-sets itself into the thread-specific slot to make Pthreads to call it again later.
// - second, after all thread-specific destructors were invoked, it gets called again - this time, we remove the
// ThreadIdentifier from the threadMap, completing the cleanup.
static void destruct(void* data);
ThreadIdentifier m_identifier;
bool m_isDestroyedOnce;
static pthread_key_t m_key;
};
} // namespace WTF
#endif // ThreadIdentifierDataPthreads_h