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/**
* @file
*
* @brief Obtain a Read Lock on a RWLock Instance
* @ingroup POSIXAPI
*/
/*
* 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.org/license/LICENSE.
*/
#if HAVE_CONFIG_H
#include "config.h"
#endif
#include <pthread.h>
#include <errno.h>
#include <rtems/posix/rwlockimpl.h>
#include <rtems/score/thread.h>
/**
* This directive attempts to obtain a read only lock on an rwlock instance.
*
* @param[in] rwlock is the pointer to rwlock id
*
* @retval 0 if successful
* @retval error_code if unsuccessful
*/
int pthread_rwlock_rdlock(
pthread_rwlock_t *rwlock
)
{
POSIX_RWLock_Control *the_rwlock;
Objects_Locations location;
Thread_Control *executing;
if ( !rwlock )
return EINVAL;
the_rwlock = _POSIX_RWLock_Get( rwlock, &location );
switch ( location ) {
case OBJECTS_LOCAL:
executing = _Thread_Executing;
_CORE_RWLock_Obtain_for_reading(
&the_rwlock->RWLock,
executing,
*rwlock,
true, /* we are willing to wait forever */
0,
NULL
);
_Objects_Put( &the_rwlock->Object );
return _POSIX_RWLock_Translate_core_RWLock_return_code(
(CORE_RWLock_Status) executing->Wait.return_code
);
#if defined(RTEMS_MULTIPROCESSING)
case OBJECTS_REMOTE:
#endif
case OBJECTS_ERROR:
break;
}
return EINVAL;
}
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