/*
 * pthread_rwlock_init.c
 *
 * Description:
 * This translation unit implements read/write lock primitives.
 *
 * --------------------------------------------------------------------------
 *
 *      Pthreads-win32 - POSIX Threads Library for Win32
 *      Copyright(C) 1998 John E. Bossom
 *      Copyright(C) 1999,2003 Pthreads-win32 contributors
 * 
 *      Contact Email: rpj@callisto.canberra.edu.au
 * 
 *      The current list of contributors is contained
 *      in the file CONTRIBUTORS included with the source
 *      code distribution. The list can also be seen at the
 *      following World Wide Web location:
 *      http://sources.redhat.com/pthreads-win32/contributors.html
 * 
 *      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 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 in the file COPYING.LIB;
 *      if not, write to the Free Software Foundation, Inc.,
 *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
 */

#include <errno.h>
#include <limits.h>

#include "pthread.h"
#include "implement.h"

int
pthread_rwlock_init(pthread_rwlock_t *rwlock, const pthread_rwlockattr_t *attr)
{
    int result;
    pthread_rwlock_t rwl = 0;

    if (rwlock == NULL)
      {
	return EINVAL;
      }

    if (attr != NULL && *attr != NULL)
      {
	result = EINVAL; /* Not supported */
	goto DONE;
      }

    rwl = (pthread_rwlock_t) calloc(1, sizeof(*rwl));

    if (rwl == NULL)
      {
	result = ENOMEM;
	goto DONE;
      }

    rwl->nSharedAccessCount = 0;
    rwl->nExclusiveAccessCount = 0;
    rwl->nCompletedSharedAccessCount = 0;

    result = pthread_mutex_init(&rwl->mtxExclusiveAccess, NULL);
    if (result != 0)
      {
	goto FAIL0;
      }

    result = pthread_mutex_init(&rwl->mtxSharedAccessCompleted, NULL);
    if (result != 0)
      {
	goto FAIL1;
      }

    result = pthread_cond_init(&rwl->cndSharedAccessCompleted, NULL);
    if (result != 0)
      {
	goto FAIL2;
      }

    rwl->nMagic = PTW32_RWLOCK_MAGIC;

    result = 0;
    goto DONE;

FAIL2:
    (void) pthread_mutex_destroy(&(rwl->mtxSharedAccessCompleted));

FAIL1:
    (void) pthread_mutex_destroy(&(rwl->mtxExclusiveAccess));

FAIL0:
    (void) free(rwl);
    rwl = NULL;

DONE:
    *rwlock = rwl;

    return result;
}
