/**
* Sleep some amount of time.
*
* This service suspends the calling thread until the wakeup time specified by
* @a rqtp, or a signal is delivered to the caller. If the flag TIMER_ABSTIME is
* set in the @a flags argument, the wakeup time is specified as an absolute
* value of the clock @a clock_id. If the flag TIMER_ABSTIME is not set, the
* wakeup time is specified as a time interval.
*
* If this service is interrupted by a signal, the flag TIMER_ABSTIME is not
* set, and @a rmtp is not @a NULL, the time remaining until the specified
* wakeup time is returned at the address @a rmtp.
*
* The resolution of this service is one system clock tick.
*
* @param clock_id clock identifier, either CLOCK_REALTIME,
* CLOCK_MONOTONIC or CLOCK_MONOTONIC_RAW.
*
* @param flags one of:
* - 0 meaning that the wakeup time @a rqtp is a time interval;
* - TIMER_ABSTIME, meaning that the wakeup time is an absolute value of the
* clock @a clock_id.
*
* @param rqtp address of the wakeup time.
*
* @param rmtp address where the remaining time before wakeup will be stored if
* the service is interrupted by a signal.
*
* @return 0 on success;
* @return an error number if:
* - EPERM, the caller context is invalid;
* - ENOTSUP, the specified clock is unsupported;
* - EINVAL, the specified wakeup time is invalid;
* - EINTR, this service was interrupted by a signal.
*
* @par Valid contexts:
* - Xenomai kernel-space thread,
* - Xenomai user-space thread (switches to primary mode).
*
* @see
* <a href="http://www.opengroup.org/onlinepubs/000095399/functions/clock_nanosleep.html">
* Specification.</a>
*
*/
int clock_nanosleep(clockid_t clock_id,
int flags,
const struct timespec *rqtp, struct timespec *rmtp)
{
xnthread_t *cur;
spl_t s;
int err = 0;
if (xnpod_unblockable_p())
return EPERM;
if (clock_id != CLOCK_MONOTONIC &&
clock_id != CLOCK_MONOTONIC_RAW &&
clock_id != CLOCK_REALTIME)
return ENOTSUP;
if ((unsigned long)rqtp->tv_nsec >= ONE_BILLION)
return EINVAL;
if (flags & ~TIMER_ABSTIME)
return EINVAL;
cur = xnpod_current_thread();
xnlock_get_irqsave(&nklock, s);
thread_cancellation_point(cur);
xnpod_suspend_thread(cur, XNDELAY, ts2ticks_ceil(rqtp) + 1,
clock_flag(flags, clock_id), NULL);
thread_cancellation_point(cur);
if (xnthread_test_info(cur, XNBREAK)) {
if (flags == 0 && rmtp) {
xnticks_t now, expiry;
xnsticks_t rem;
now = clock_get_ticks(clock_id);
expiry = xntimer_get_date(&cur->rtimer);
xnlock_put_irqrestore(&nklock, s);
rem = expiry - now;
ticks2ts(rmtp, rem > 0 ? rem : 0);
} else
xnlock_put_irqrestore(&nklock, s);
return EINTR;
}
xnlock_put_irqrestore(&nklock, s);
return err;
}
static inline int sem_timedwait_internal(struct __shadow_sem *shadow,
int timed, xnticks_t to)
{
pse51_sem_t *sem = shadow->sem;
xnthread_t *cur;
int err;
if (xnpod_unblockable_p())
return EPERM;
cur = xnpod_current_thread();
if ((err = sem_trywait_internal(shadow)) != EAGAIN)
return err;
thread_cancellation_point(cur);
if (timed)
xnsynch_sleep_on(&sem->synchbase, to, XN_REALTIME);
else
xnsynch_sleep_on(&sem->synchbase, XN_INFINITE, XN_RELATIVE);
/* Handle cancellation requests. */
thread_cancellation_point(cur);
if (xnthread_test_info(cur, XNRMID))
return EINVAL;
if (xnthread_test_info(cur, XNBREAK))
return EINTR;
if (xnthread_test_info(cur, XNTIMEO))
return ETIMEDOUT;
return 0;
}
