forked from DaveeFTW/pthread-embedded
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pthread_mutexattr_setpshared.c
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pthread_mutexattr_setpshared.c
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/*
* pthread_mutexattr_setpshared.c
*
* Description:
* This translation unit implements mutual exclusion (mutex) primitives.
*
* --------------------------------------------------------------------------
*
* Pthreads-embedded (PTE) - POSIX Threads Library for embedded systems
* Copyright(C) 2008 Jason Schmidlapp
*
* Contact Email: jschmidlapp@users.sourceforge.net
*
*
* Based upon Pthreads-win32 - POSIX Threads Library for Win32
* Copyright(C) 1998 John E. Bossom
* Copyright(C) 1999,2005 Pthreads-win32 contributors
*
* Contact Email: rpj@callisto.canberra.edu.au
*
* The original list of contributors to the Pthreads-win32 project
* is contained in the file CONTRIBUTORS.ptw32 included with the
* source code distribution. The list can also be seen at the
* following World Wide Web location:
* http://sources.redhat.com/pthreads-win32/contributors.html
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library in the file COPYING.LIB;
* if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
*/
#include "pthread.h"
#include "implement.h"
int
pthread_mutexattr_setpshared (pthread_mutexattr_t * attr, int pshared)
/*
* ------------------------------------------------------
* DOCPUBLIC
* Mutexes created with 'attr' can be shared between
* processes if pthread_mutex_t variable is allocated
* in memory shared by these processes.
*
* PARAMETERS
* attr
* pointer to an instance of pthread_mutexattr_t
*
* pshared
* must be one of:
*
* PTHREAD_PROCESS_SHARED
* May be shared if in shared memory
*
* PTHREAD_PROCESS_PRIVATE
* Cannot be shared.
*
* DESCRIPTION
* Mutexes creatd with 'attr' can be shared between
* processes if pthread_mutex_t variable is allocated
* in memory shared by these processes.
*
* NOTES:
* 1) pshared mutexes MUST be allocated in shared
* memory.
*
* 2) The following macro is defined if shared mutexes
* 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_mutexattr_setpshared */