mutex.h

/***************************************************************************
 * include/stxxl/bits/common/mutex.h
 *
 * Part of the STXXL. See http://stxxl.sourceforge.net
 *
 * Copyright (C) 2002 Roman Dementiev <[email protected]>
 * Copyright (C) 2008 Andreas Beckmann <[email protected]>
 *
 * Distributed under the Boost Software License, Version 1.0.
 * (See accompanying file LICENSE_1_0.txt or copy at
 * http://www.boost.org/LICENSE_1_0.txt)
 **************************************************************************/

#ifndef STXXL_MUTEX_HEADER
#define STXXL_MUTEX_HEADER

#include <stxxl/bits/namespace.h>

#ifdef STXXL_BOOST_THREADS

 #include <boost/thread/mutex.hpp>

#else

 #include <pthread.h>
 #include <cerrno>

 #include <stxxl/bits/noncopyable.h>
 #include <stxxl/bits/common/error_handling.h>

#endif


__STXXL_BEGIN_NAMESPACE

#ifdef STXXL_BOOST_THREADS

typedef boost::mutex mutex;

#else

class mutex : private noncopyable
{
 pthread_mutex_t _mutex;

public:
 mutex()
 {
 check_pthread_call(pthread_mutex_init(&_mutex, NULL));
 }

 ~mutex()
 {
 int res = pthread_mutex_trylock(&_mutex);

 if (res == 0 || res == EBUSY) {
 check_pthread_call(pthread_mutex_unlock(&_mutex));
 } else
 stxxl_function_error(resource_error);

 check_pthread_call(pthread_mutex_destroy(&_mutex));
 }
 void lock()
 {
 check_pthread_call(pthread_mutex_lock(&_mutex));
 }
 void unlock()
 {
 check_pthread_call(pthread_mutex_unlock(&_mutex));
 }
};

#endif

#ifdef STXXL_BOOST_THREADS

typedef boost::mutex::scoped_lock scoped_mutex_lock;

#else

class scoped_mutex_lock
{
 mutex & mtx;
 bool is_locked;

public:
 scoped_mutex_lock(mutex & mtx_) : mtx(mtx_), is_locked(false)
 {
 lock();
 }

 ~scoped_mutex_lock()
 {
 unlock();
 }

 void lock()
 {
 if (!is_locked) {
 mtx.lock();
 is_locked = true;
 }
 }

 void unlock()
 {
 if (is_locked) {
 mtx.unlock();
 is_locked = false;
 }
 }
};

#endif

__STXXL_END_NAMESPACE

#endif // !STXXL_MUTEX_HEADER