/*

* File: ucos_mutex.c    

* Author:  MinPengli <MinPengli@gmail.com>

* Brief: mutex implement

*

* Copyright (c) 2009 - 2010  MinPengli <minpengli@gmail.com>

*

* Licensed under the Academic Free License version 2.1

*

* This program is free software; you can redistribute it and/or modify

* it under the terms of the GNU General Public License as published by

* the Free Software Foundation; either version 2 of the License, or

* (at your option) any later version.

*

* This program is distributed in the hope that it will be useful,

* but WITHOUT ANY WARRANTY; without even the implied warranty of

* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

* GNU General Public License for more details.

*

* You should have received a copy of the GNU General Public License

* along with this program; if not, write to the Free Software

* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA

*/



/*

*  History:

* ================================================================

* 2010-03-19 MinPengli <MinPengli@gmail.com> created

*

*/



#include <includes.h>

#include <ucos_mutex.h>



struct _mutex_t

{

	OS_EVENT *mtx;

};



mutex_t *mutex_init (void)

{

	mutex_t *mutex = NULL;

	OS_EVENT *local_mutex = NULL;



	mutex = malloc(sizeof(mutex_t));

	if(mutex == NULL)

	{

		return NULL;

	}



	do{

		local_mutex = OSSemCreate(1);

	}while(!local_mutex);



	mutex->mtx = local_mutex;

	

    return mutex;

}



int mutex_destroy (mutex_t *mutex)

{

    INT8U err = 0;



	if(mutex == NULL)

		return -1;



	OSSemDel(mutex->mtx, OS_DEL_ALWAYS, &err);

	free(mutex);



    return 0;

}



int mutex_lock (mutex_t *mutex)

{

    INT8U err = 0;



	if(mutex == NULL)

		return -1;



	OSSemPend(mutex->mtx, 0, &err);

	    

    return 0;

}



int mutex_trylock (mutex_t *mutex)

{

    INT8U err = 0;



	if(mutex == NULL)

	{

		return -1;

	}

    

	OSSemPend(mutex->mtx, 500, &err);

	if(err == OS_TIMEOUT);

	{

	    return -1;

	}

	    

    return 0;

}



int mutex_unlock (mutex_t *mutex)

{

	if(mutex == NULL)

	{

		return -1;

	}



	if(OS_NO_ERR==OSSemPost(mutex->mtx))

	{

        return 0;

	}

    else

    {

        return -1;

	}

}