/*
 * Copyright (c) 2003, Daniel M. Eischen <deischen@freebsd.org>
 * 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. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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 <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "namespace.h"
#include <errno.h>
#include <pthread.h>
#include <stdlib.h>
#include "un-namespace.h"
#include "thr_private.h"

#define	PTHREAD_BARRIER_SERIAL_THREAD	-1
 
struct pthread_barrierattr {
	int	pshared;
};

typedef struct pthread_barrierattr *pthread_barrierattr_t;

struct pthread_barrier {
	pthread_mutex_t	b_mutex;
	pthread_cond_t	b_cv;
	int		b_shared;
	unsigned	b_count;
	int		b_waiting;
};

typedef struct pthread_barrier *pthread_barrier_t;

/*
 * Prototypes
 */
int   pthread_barrierattr_destroy(pthread_barrierattr_t *);
int   pthread_barrierattr_init(pthread_barrierattr_t *);
int   pthread_barrierattr_getpshared(
          const pthread_barrierattr_t *restrict, int *);
int   pthread_barrierattr_setpshared(pthread_barrierattr_t *, int);

int   pthread_barrier_destroy(pthread_barrier_t *);
int   pthread_barrier_init(pthread_barrier_t *,
          const pthread_barrierattr_t *, unsigned);
int   pthread_barrier_wait(pthread_barrier_t *);

__weak_reference(_pthread_barrierattr_destroy, pthread_barrierattr_destroy);
__weak_reference(_pthread_barrierattr_init, pthread_barrierattr_init);
__weak_reference(_pthread_barrierattr_getpshared,
    pthread_barrierattr_getpshared);
__weak_reference(_pthread_barrierattr_setpshared,
    pthread_barrier_attrsetpshared);
__weak_reference(_pthread_barrier_init, pthread_barrier_init);
__weak_reference(_pthread_barrier_destroy, pthread_barrier_destroy);
__weak_reference(_pthread_barrier_wait, pthread_barrier_wait);



int
_pthread_barrierattr_init(pthread_barrierattr_t *battr)
{
	struct pthread_barrierattr *attr;
	int ret;

	if (battr == NULL)
		ret = EINVAL;
	else if ((attr = malloc(sizeof(struct pthread_barrierattr))) == NULL) {
		*battr = NULL;
		ret = EINVAL;
	} else {
		attr->pshared = 0;
		*battr = attr;
		ret = 0;
	}
	return (ret);
}

int
_pthread_barrierattr_destroy(pthread_barrierattr_t *battr)
{
	int ret;

	if ((battr == NULL) || (*battr == NULL))
		ret = EINVAL;
	else {
		free(*battr);
		*battr = NULL;
		ret = 0;
	}
	return (ret);
}

int
_pthread_barrierattr_getpshared(pthread_barrierattr_t *battr)
{
	if ((battr == NULL) || (*battr == NULL))
		return (EINVAL);
	else
		return ((*battr)->pshared);
}

int
_pthread_barrierattr_setpshared(pthread_barrierattr_t *battr, int shared)
{
	if ((battr == NULL) || (*battr == NULL))
		return (EINVAL);
	else {
		(*battr)->pshared = shared;
		return (0);
	}
}

int
_pthread_barrier_init(pthread_barrier_t *barrier, pthread_barrierattr_t *attr,
    unsigned count)
{
	struct pthread_barrier *bar;
	int ret;

	if (count == 0) {
		ret = EINVAL;
		*barrier = NULL;
	} else if ((bar = (pthread_barrier_t)
	    malloc(sizeof(struct pthread_barrier))) == NULL) {
		ret = ENOMEM;
		*barrier = NULL;
	} else if ((ret = _pthread_mutex_init(&bar->b_mutex, NULL)) != 0) {
		free(bar);
		*barrier = NULL;
	} else if ((ret = (_pthread_cond_init(&bar->b_cv, NULL)) != 0)) {
		_pthread_mutex_destroy(&bar->b_mutex);
		free(bar);
		*barrier = NULL;
	} else {
		bar->b_count = count;
		if ((attr != NULL) && (*attr != NULL))
			bar->b_shared = (*attr)->pshared;
		else
			bar->b_shared = 0;
		bar->b_waiting = 0;
		*barrier = bar;
		ret = 0;
	}
	/* Return the completion status: */
	return (ret);
}

int
_pthread_barrier_destroy(pthread_barrier_t *barrier)
{
	struct pthread_barrier *bar;
	int ret = 0;

	if (barrier == NULL || *barrier == NULL)
		ret = EINVAL;
	else {
		bar = NULL;
		/* Lock the barrier structure: */
		_pthread_mutex_lock(&(*barrier)->b_mutex);
		if ((*barrier)->b_waiting > 0)
			ret = EBUSY;
		else {
			bar = *barrier;
			*barrier = NULL;
			ret = 0;
		}
		_pthread_mutex_unlock(&(*barrier)->b_mutex);
		if (bar != NULL) {
			_pthread_mutex_destroy(&(*barrier)->b_mutex);
			_pthread_cond_destroy(&(*barrier)->b_cv);
			free(bar);
		}
	}
	return (ret);
}

int
_pthread_barrier_wait(pthread_barrier_t *barrier)
{
	int ret;

	if ((barrier == NULL) || (*barrier == NULL))
		ret = EINVAL;
	else if ((ret = _pthread_mutex_lock(&(*barrier)->b_mutex)) == 0) {
		(*barrier)->b_waiting++;
		if ((*barrier)->b_waiting >= (*barrier)->b_count) {
			(*barrier)->b_waiting = 0;
			ret = _pthread_cond_broadcast(&(*barrier)->b_cv);
			if (ret = 0)
				ret = PTHREAD_BARRIER_SERIAL_THREAD;
		}
		else
			ret = _pthread_cond_wait(&(*barrier)->b_cv,
			    &(*barrier)->b_mutex);
		(void)_pthread_mutex_unlock(&(*barrier)->b_mutex);
	}
	return (ret);
}