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/**
* @file
*
* @brief Get the Value of a Semaphore
* @ingroup POSIX_SEMAPHORE
*/
/*
* COPYRIGHT (c) 1989-2014.
* 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 <stdarg.h>
#include <errno.h>
#include <fcntl.h>
#include <pthread.h>
#include <semaphore.h>
#include <limits.h>
#include <rtems/system.h>
#include <rtems/posix/semaphoreimpl.h>
#include <rtems/seterr.h>
int sem_getvalue(
sem_t *__restrict sem,
int *__restrict sval
)
{
POSIX_Semaphore_Control *the_semaphore;
Objects_Locations location;
ISR_lock_Context lock_context;
the_semaphore = _POSIX_Semaphore_Get_interrupt_disable(
sem,
&location,
&lock_context
);
switch ( location ) {
case OBJECTS_LOCAL:
/*
* Assume a relaxed atomic load of the value on SMP configurations.
* Thus, there is no need to acquire a lock.
*/
*sval = _CORE_semaphore_Get_count( &the_semaphore->Semaphore );
_ISR_lock_ISR_enable( &lock_context );
return 0;
#if defined(RTEMS_MULTIPROCESSING)
case OBJECTS_REMOTE:
#endif
case OBJECTS_ERROR:
break;
}
rtems_set_errno_and_return_minus_one( EINVAL );
}
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