Home | History | Annotate | Download | only in pthreads-win32 
      1 /*
      2  * pthread_rwlock_init.c
      3  *
      4  * Description:
      5  * This translation unit implements read/write lock primitives.
      6  *
      7  * --------------------------------------------------------------------------
      8  *
      9  *      Pthreads-win32 - POSIX Threads Library for Win32
     10  *      Copyright(C) 1998 John E. Bossom
     11  *      Copyright(C) 1999,2005 Pthreads-win32 contributors
     12  *
     13  *      Contact Email: rpj (at) callisto.canberra.edu.au
     14  *
     15  *      The current list of contributors is contained
     16  *      in the file CONTRIBUTORS included with the source
     17  *      code distribution. The list can also be seen at the
     18  *      following World Wide Web location:
     19  *      http://sources.redhat.com/pthreads-win32/contributors.html
     20  *
     21  *      This library is free software; you can redistribute it and/or
     22  *      modify it under the terms of the GNU Lesser General Public
     23  *      License as published by the Free Software Foundation; either
     24  *      version 2 of the License, or (at your option) any later version.
     25  *
     26  *      This library is distributed in the hope that it will be useful,
     27  *      but WITHOUT ANY WARRANTY; without even the implied warranty of
     28  *      MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     29  *      Lesser General Public License for more details.
     30  *
     31  *      You should have received a copy of the GNU Lesser General Public
     32  *      License along with this library in the file COPYING.LIB;
     33  *      if not, write to the Free Software Foundation, Inc.,
     34  *      59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
     35  */
     36 
     37 #include <limits.h>
     38 
     39 #include "pthread.h"
     40 #include "implement.h"
     41 
     42 int
     43 pthread_rwlock_init (pthread_rwlock_t * rwlock,
     44 		     const pthread_rwlockattr_t * attr)
     45 {
     46   int result;
     47   pthread_rwlock_t rwl = 0;
     48 
     49   if (rwlock == NULL)
     50     {
     51       return EINVAL;
     52     }
     53 
     54   if (attr != NULL && *attr != NULL)
     55     {
     56       result = EINVAL;		/* Not supported */
     57       goto DONE;
     58     }
     59 
     60   rwl = (pthread_rwlock_t) calloc (1, sizeof (*rwl));
     61 
     62   if (rwl == NULL)
     63     {
     64       result = ENOMEM;
     65       goto DONE;
     66     }
     67 
     68   rwl->nSharedAccessCount = 0;
     69   rwl->nExclusiveAccessCount = 0;
     70   rwl->nCompletedSharedAccessCount = 0;
     71 
     72   result = pthread_mutex_init (&rwl->mtxExclusiveAccess, NULL);
     73   if (result != 0)
     74     {
     75       goto FAIL0;
     76     }
     77 
     78   result = pthread_mutex_init (&rwl->mtxSharedAccessCompleted, NULL);
     79   if (result != 0)
     80     {
     81       goto FAIL1;
     82     }
     83 
     84   result = pthread_cond_init (&rwl->cndSharedAccessCompleted, NULL);
     85   if (result != 0)
     86     {
     87       goto FAIL2;
     88     }
     89 
     90   rwl->nMagic = PTW32_RWLOCK_MAGIC;
     91 
     92   result = 0;
     93   goto DONE;
     94 
     95 FAIL2:
     96   (void) pthread_mutex_destroy (&(rwl->mtxSharedAccessCompleted));
     97 
     98 FAIL1:
     99   (void) pthread_mutex_destroy (&(rwl->mtxExclusiveAccess));
    100 
    101 FAIL0:
    102   (void) free (rwl);
    103   rwl = NULL;
    104 
    105 DONE:
    106   *rwlock = rwl;
    107 
    108   return result;
    109 }
    110