orte/liborte/rtl/pthread_rwlockattr_getpshared.c

   1 /*
   2  * pthread_rwlockattr_getpshared.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) 1999,2002 Pthreads-win32 contributors
  12  *
  13  *      Contact Email: rpj@ise.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 <errno.h>
  38 //#include <limits.h>
  39
  40 //#include "pthread.h"
  41 //#include "implement.h"
  42
  43 #include "orte.h"
  44
  45 int
  46 pthread_rwlockattr_getpshared (const pthread_rwlockattr_t * attr,
  47                                int *pshared)
  48      /*
  49       * ------------------------------------------------------
  50       * DOCPUBLIC
  51       *      Determine whether rwlocks created with 'attr' can be
  52       *      shared between processes.
  53       *
  54       * PARAMETERS
  55       *      attr
  56       *              pointer to an instance of pthread_rwlockattr_t
  57       *
  58       *      pshared
  59       *              will be set to one of:
  60       *
  61       *                      PTHREAD_PROCESS_SHARED
  62       *                              May be shared if in shared memory
  63       *
  64       *                      PTHREAD_PROCESS_PRIVATE
  65       *                              Cannot be shared.
  66       *
  67       *
  68       * DESCRIPTION
  69       *      Rwlocks creatd with 'attr' can be shared between
  70       *      processes if pthread_rwlock_t variable is allocated
  71       *      in memory shared by these processes.
  72       *      NOTES:
  73       *              1)      pshared rwlocks MUST be allocated in shared
  74       *                      memory.
  75       *              2)      The following macro is defined if shared rwlocks
  76       *                      are supported:
  77       *                              _POSIX_THREAD_PROCESS_SHARED
  78       *
  79       * RESULTS
  80       *              0               successfully retrieved attribute,
  81       *              EINVAL          'attr' is invalid,
  82       *
  83       * ------------------------------------------------------
  84       */
  85 {
  86   int result;
  87
  88   if ((attr != NULL && *attr != NULL) &&
  89       (pshared != NULL))
  90     {
  91       *pshared = (*attr)->pshared;
  92       result = 0;
  93     }
  94   else
  95     {
  96       result = EINVAL;
  97     }
  98
  99   return (result);
 100
 101 }                               /* pthread_rwlockattr_getpshared */