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/*
* POSIX RWLock Manager -- Obtain a Read Lock on a RWLock Instance
*
* COPYRIGHT (c) 1989-2007.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.com/license/LICENSE.
*
* $Id$
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <pthread.h>
#include <errno.h>
#include <rtems/system.h>
#include <rtems/posix/rwlock.h>
/*
* pthread_rwlock_rdlock
*
* This directive attempts to obtain a read only lock on an rwlock instance.
*
* Input parameters:
* rwlock - pointer to rwlock id
*
* Output parameters:
* 0 - if successful
* error code - if unsuccessful
*/
int pthread_rwlock_rdlock(
pthread_rwlock_t *rwlock
)
{
POSIX_RWLock_Control *the_rwlock;
Objects_Locations location;
if ( !rwlock )
return EINVAL;
the_rwlock = _POSIX_RWLock_Get( rwlock, &location );
switch ( location ) {
#if defined(RTEMS_MULTIPROCESSING)
case OBJECTS_REMOTE:
#endif
case OBJECTS_ERROR:
return EINVAL;
case OBJECTS_LOCAL:
_CORE_RWLock_Obtain_for_reading(
&the_rwlock->RWLock,
*rwlock,
TRUE, // we are willing to wait forever
0,
NULL
);
_Thread_Enable_dispatch();
return _POSIX_RWLock_Translate_core_RWLock_return_code(
(CORE_RWLock_Status) _Thread_Executing->Wait.return_code
);
}
return POSIX_BOTTOM_REACHED();
}
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