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/*
 * pthread_rwlockattr_setpshared.c
 *
 * Description:
 * This translation unit implements read/write lock primitives.
 *
 * --------------------------------------------------------------------------
 *
 *      Pthreads4w - POSIX Threads Library for Win32
 *      Copyright(C) 1998 John E. Bossom
 *      Copyright(C) 1999-2018, Pthreads4w contributors
 *
 *      Homepage: https://sourceforge.net/projects/pthreads4w/
 *
 *      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:
 *      https://sourceforge.net/p/pthreads4w/wiki/Contributors/
 *
 * This file is part of Pthreads4w.
 *
 *    Pthreads4w is free software: you can redistribute it and/or modify
 *    it under the terms of the GNU General Public License as published by
 *    the Free Software Foundation, either version 3 of the License, or
 *    (at your option) any later version.
 *
 *    Pthreads4w 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 General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with Pthreads4w.  If not, see <http://www.gnu.org/licenses/>. *
 */

#ifdef HAVE_CONFIG_H
# include <config.h>
#endif

#include <limits.h>

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

int
pthread_rwlockattr_setpshared (pthread_rwlockattr_t * attr, int pshared)
     /*
      * ------------------------------------------------------
      * DOCPUBLIC
      *      Rwlocks created with 'attr' can be shared between
      *      processes if pthread_rwlock_t variable is allocated
      *      in memory shared by these processes.
      *
      * PARAMETERS
      *      attr
      *              pointer to an instance of pthread_rwlockattr_t
      *
      *      pshared
      *              must be one of:
      *
      *                      PTHREAD_PROCESS_SHARED
      *                              May be shared if in shared memory
      *
      *                      PTHREAD_PROCESS_PRIVATE
      *                              Cannot be shared.
      *
      * DESCRIPTION
      *      Rwlocks creatd with 'attr' can be shared between
      *      processes if pthread_rwlock_t variable is allocated
      *      in memory shared by these processes.
      *
      *      NOTES:
      *              1)      pshared rwlocks MUST be allocated in shared
      *                      memory.
      *
      *              2)      The following macro is defined if shared rwlocks
      *                      are supported:
      *                              _POSIX_THREAD_PROCESS_SHARED
      *
      * RESULTS
      *              0               successfully set attribute,
      *              EINVAL          'attr' or pshared is invalid,
      *              ENOSYS          PTHREAD_PROCESS_SHARED not supported,
      *
      * ------------------------------------------------------
      */
{
  int result;

  if ((attr != NULL && *attr != NULL) &&
      ((pshared == PTHREAD_PROCESS_SHARED) ||
       (pshared == PTHREAD_PROCESS_PRIVATE)))
    {
      if (pshared == PTHREAD_PROCESS_SHARED)
	{

#if !defined( _POSIX_THREAD_PROCESS_SHARED )

	  result = ENOSYS;
	  pshared = PTHREAD_PROCESS_PRIVATE;

#else

	  result = 0;

#endif /* _POSIX_THREAD_PROCESS_SHARED */

	}
      else
	{
	  result = 0;
	}

      (*attr)->pshared = pshared;
    }
  else
    {
      result = EINVAL;
    }

  return (result);

}				/* pthread_rwlockattr_setpshared */