/*

    SDL - Simple DirectMedia Layer

    Copyright (C) 1997-2006 Sam Lantinga

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Lesser General Public

    License as published by the Free Software Foundation; either

    version 2.1 of the License, or (at your option) any later version.

    This library 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

    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public

    License along with this library; if not, write to the Free Software

    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga

    slouken@libsdl.org

*/

#include "SDL_config.h"

#include <sys/time.h>

#include <unistd.h>

#include <errno.h>

#include <pthread.h>

#include "SDL_thread.h"

#include "SDL_sysmutex_c.h"

struct SDL_cond

{

	pthread_cond_t cond;

};

/* Create a condition variable */

SDL_cond * SDL_CreateCond(void)

{

	SDL_cond *cond;

	cond = (SDL_cond *) SDL_malloc(sizeof(SDL_cond));

	if ( cond ) {

		if ( pthread_cond_init(&cond->cond, NULL) < 0 ) {

			SDL_SetError("pthread_cond_init() failed");

			SDL_free(cond);

			cond = NULL;

		}

	}

	return(cond);

}

/* Destroy a condition variable */

void SDL_DestroyCond(SDL_cond *cond)

{

	if ( cond ) {

		pthread_cond_destroy(&cond->cond);

		SDL_free(cond);

	}

}

/* Restart one of the threads that are waiting on the condition variable */

int SDL_CondSignal(SDL_cond *cond)

{

	int retval;

	if ( ! cond ) {

		SDL_SetError("Passed a NULL condition variable");

		return -1;

	}

	retval = 0;

	if ( pthread_cond_signal(&cond->cond) != 0 ) {

		SDL_SetError("pthread_cond_signal() failed");

		retval = -1;

	}

	return retval;

}

/* Restart all threads that are waiting on the condition variable */

int SDL_CondBroadcast(SDL_cond *cond)

{

	int retval;

	if ( ! cond ) {

		SDL_SetError("Passed a NULL condition variable");

		return -1;

	}

	retval = 0;

	if ( pthread_cond_broadcast(&cond->cond) != 0 ) {

		SDL_SetError("pthread_cond_broadcast() failed");

		retval = -1;

	}

	return retval;

}

int SDL_CondWaitTimeout(SDL_cond *cond, SDL_mutex *mutex, Uint32 ms)

{

	int retval;

	struct timeval delta;

	struct timespec abstime;

	if ( ! cond ) {

		SDL_SetError("Passed a NULL condition variable");

		return -1;

	}

	gettimeofday(&delta, NULL);

	abstime.tv_sec = delta.tv_sec + (ms/1000);

	abstime.tv_nsec = (delta.tv_usec + (ms%1000) * 1000) * 1000;

        if ( abstime.tv_nsec > 1000000000 ) {

          abstime.tv_sec += 1;

          abstime.tv_nsec -= 1000000000;

        }

  tryagain:

	retval = pthread_cond_timedwait(&cond->cond, &mutex->id, &abstime);

	switch (retval) {

	    case EINTR:

		goto tryagain;

		break;

	    case ETIMEDOUT:

		retval = SDL_MUTEX_TIMEDOUT;

		break;

	    case 0:

		break;

	    default:

		SDL_SetError("pthread_cond_timedwait() failed");

		retval = -1;

		break;

	}

	return retval;

}

/* Wait on the condition variable, unlocking the provided mutex.

   The mutex must be locked before entering this function!

 */

int SDL_CondWait(SDL_cond *cond, SDL_mutex *mutex)

{

	int retval;

	if ( ! cond ) {

		SDL_SetError("Passed a NULL condition variable");

		return -1;

	}

	retval = 0;

	if ( pthread_cond_wait(&cond->cond, &mutex->id) != 0 ) {

		SDL_SetError("pthread_cond_wait() failed");

		retval = -1;

	}

	return retval;

}