/*
 * This file is a part of Winix
 * and is distributed under the 2-Clause BSD licence.
 * Author: Tomasz Sowa <t.sowa@ttmath.org>
 */

/* 
 * Copyright (c) 2010-2014, Tomasz Sowa
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 * 1. Redistributions of source code must retain the above copyright notice,
 * this list of conditions and the following disclaimer.
 * 
 * 2. 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.
 * 
 * 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 HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 */

#include <errno.h>
#include "synchro.h"



namespace Winix
{



Synchro::Synchro()
{
	was_stop_signal = false;

#ifdef __FreeBSD__
	/*
	 * on FreeBSD a pthread's pthread_mutex_lock() is checking for deadlocks by default
	 */
	mutex = PTHREAD_MUTEX_INITIALIZER;
#else
	pthread_mutexattr_t attr;

	pthread_mutexattr_init(&attr);
	pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK);
	pthread_mutex_init(&mutex, &attr);
	pthread_mutexattr_destroy(&attr);
#endif
}



bool Synchro::Lock()
{
	int res = pthread_mutex_lock(&mutex);

	if( res == 0 )
	{
		ref[pthread_self()] = 1;
		return true;
	}
	else
	if( res == EDEADLK )
	{
		// Lock() method in this thread was called before
		ref[pthread_self()] += 1;
		return true;
	}

return false;
}



void Synchro::Unlock()
{
	int & r = ref[pthread_self()];

	if( r > 1 )
	{
		r -= 1;
	}
	else
	if( r == 1 )
	{
		pthread_mutex_unlock(&mutex);
	}
}




} // namespace Winix