int sem_timedwait(
sem_t *sem,
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_Semaphore_Wait_support( sem, do_wait, ticks );
/*
* This service only gives us the option to block. We used a polling
* attempt to obtain if the abstime was not in the future. If we did
* not obtain the semaphore, then not look at the status immediately,
* make sure the right reason is returned.
*/
if ( !do_wait && (lock_status == EBUSY) ) {
switch (lock_status) {
case POSIX_ABSOLUTE_TIMEOUT_INVALID:
rtems_set_errno_and_return_minus_one( EINVAL );
case POSIX_ABSOLUTE_TIMEOUT_IS_IN_PAST:
case POSIX_ABSOLUTE_TIMEOUT_IS_NOW:
rtems_set_errno_and_return_minus_one( ETIMEDOUT );
case POSIX_ABSOLUTE_TIMEOUT_IS_IN_FUTURE:
break;
}
}
return lock_status;
}
int sem_trywait(
sem_t *sem
)
{
return _POSIX_Semaphore_Wait_support(sem, false, THREAD_QUEUE_WAIT_FOREVER);
}
int sem_wait(
sem_t *sem
)
{
return _POSIX_Semaphore_Wait_support( sem, true, WATCHDOG_NO_TIMEOUT );
}
