native_client_sdk/src/libraries/third_party/pthreads-win32/pthread_rwlockattr_setpshared.c

   1 /*
   2  * pthread_rwlockattr_setpshared.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_setpshared (pthread_rwlockattr_t * attr, int pshared)
  44      /*
  45       * ------------------------------------------------------
  46       * DOCPUBLIC
  47       *      Rwlocks created with 'attr' can be shared between
  48       *      processes if pthread_rwlock_t variable is allocated
  49       *      in memory shared by these processes.
  50       *
  51       * PARAMETERS
  52       *      attr
  53       *              pointer to an instance of pthread_rwlockattr_t
  54       *
  55       *      pshared
  56       *              must be 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       * DESCRIPTION
  65       *      Rwlocks creatd with 'attr' can be shared between
  66       *      processes if pthread_rwlock_t variable is allocated
  67       *      in memory shared by these processes.
  68       *
  69       *      NOTES:
  70       *              1)      pshared rwlocks MUST be allocated in shared
  71       *                      memory.
  72       *
  73       *              2)      The following macro is defined if shared rwlocks
  74       *                      are supported:
  75       *                              _POSIX_THREAD_PROCESS_SHARED
  76       *
  77       * RESULTS
  78       *              0               successfully set attribute,
  79       *              EINVAL          'attr' or pshared is invalid,
  80       *              ENOSYS          PTHREAD_PROCESS_SHARED not supported,
  81       *
  82       * ------------------------------------------------------
  83       */
  84 {
  85   int result;
  86
  87   if ((attr != NULL && *attr != NULL) &&
  88       ((pshared == PTHREAD_PROCESS_SHARED) ||
  89        (pshared == PTHREAD_PROCESS_PRIVATE)))
  90     {
  91       if (pshared == PTHREAD_PROCESS_SHARED)
  92         {
  93
  94 #if !defined( _POSIX_THREAD_PROCESS_SHARED )
  95
  96           result = ENOSYS;
  97           pshared = PTHREAD_PROCESS_PRIVATE;
  98
  99 #else
 100
 101           result = 0;
 102
 103 #endif /* _POSIX_THREAD_PROCESS_SHARED */
 104
 105         }
 106       else
 107         {
 108           result = 0;
 109         }
 110
 111       (*attr)->pshared = pshared;
 112     }
 113   else
 114     {
 115       result = EINVAL;
 116     }
 117
 118   return (result);
 119
 120 }                               /* pthread_rwlockattr_setpshared */