native_client_sdk/src/libraries/third_party/pthreads-win32/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) 1999,2005 Pthreads-win32 contributors
  12  *
  13  *      Contact Email: rpj@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_rwlockattr_getpshared (const pthread_rwlockattr_t * attr,
  44                                int *pshared)
  45      /*
  46       * ------------------------------------------------------
  47       * DOCPUBLIC
  48       *      Determine whether rwlocks created with 'attr' can be
  49       *      shared between processes.
  50       *
  51       * PARAMETERS
  52       *      attr
  53       *              pointer to an instance of pthread_rwlockattr_t
  54       *
  55       *      pshared
  56       *              will be set to one of:
  57       *
  58       *                      PTHREAD_PROCESS_SHARED
  59       *                              May be shared if in shared memory
  60       *
  61       *                      PTHREAD_PROCESS_PRIVATE
  62       *                              Cannot be shared.
  63       *
  64       *
  65       * DESCRIPTION
  66       *      Rwlocks creatd with 'attr' can be shared between
  67       *      processes if pthread_rwlock_t variable is allocated
  68       *      in memory shared by these processes.
  69       *      NOTES:
  70       *              1)      pshared rwlocks MUST be allocated in shared
  71       *                      memory.
  72       *              2)      The following macro is defined if shared rwlocks
  73       *                      are supported:
  74       *                              _POSIX_THREAD_PROCESS_SHARED
  75       *
  76       * RESULTS
  77       *              0               successfully retrieved attribute,
  78       *              EINVAL          'attr' is invalid,
  79       *
  80       * ------------------------------------------------------
  81       */
  82 {
  83   int result;
  84
  85   if ((attr != NULL && *attr != NULL) && (pshared != NULL))
  86     {
  87       *pshared = (*attr)->pshared;
  88       result = 0;
  89     }
  90   else
  91     {
  92       result = EINVAL;
  93     }
  94
  95   return (result);
  96
  97 }                               /* pthread_rwlockattr_getpshared */