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/*
* Mutex Timed Lock
*/
/*
* COPYRIGHT (c) 1989-2008.
* 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 <errno.h>
#include <pthread.h>
#include <rtems/system.h>
#include <rtems/score/coremutex.h>
#include <rtems/score/watchdog.h>
#if defined(RTEMS_MULTIPROCESSING)
#include <rtems/score/mpci.h>
#endif
#include <rtems/posix/mutex.h>
#include <rtems/posix/priority.h>
#include <rtems/posix/time.h>
/*
* 11.3.3 Locking and Unlocking a Mutex, P1003.1c/Draft 10, p. 93
*
* NOTE: P1003.4b/D8 adds pthread_mutex_timedlock(), p. 29
*/
int pthread_mutex_timedlock(
pthread_mutex_t *mutex,
const struct timespec *abstime
)
{
Watchdog_Interval ticks;
bool do_wait = true;
POSIX_Absolute_timeout_conversion_results_t status;
int lock_status;
/*
* POSIX requires that blocking calls with timeouts that take
* an absolute timeout must ignore issues with the absolute
* time provided if the operation would otherwise succeed.
* So we check the abstime provided, and hold on to whether it
* is valid or not. If it isn't correct and in the future,
* then we do a polling operation and convert the UNSATISFIED
* status into the appropriate error.
*
* If the status is POSIX_ABSOLUTE_TIMEOUT_INVALID,
* POSIX_ABSOLUTE_TIMEOUT_IS_IN_PAST, or POSIX_ABSOLUTE_TIMEOUT_IS_NOW,
* then we should not wait.
*/
status = _POSIX_Absolute_timeout_to_ticks( abstime, &ticks );
if ( status != POSIX_ABSOLUTE_TIMEOUT_IS_IN_FUTURE )
do_wait = false;
lock_status = _POSIX_Mutex_Lock_support( mutex, do_wait, ticks );
/*
* This service only gives us the option to block. We used a polling
* attempt to lock if the abstime was not in the future. If we did
* not obtain the mutex, then not look at the status immediately,
* make sure the right reason is returned.
*/
if ( !do_wait && (lock_status == EBUSY) ) {
if ( status == POSIX_ABSOLUTE_TIMEOUT_INVALID )
return EINVAL;
if ( status == POSIX_ABSOLUTE_TIMEOUT_IS_IN_PAST ||
status == POSIX_ABSOLUTE_TIMEOUT_IS_NOW )
return ETIMEDOUT;
}
return lock_status;
}
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