int px4_sem_timedwait(px4_sem_t *sem, const struct timespec *ts)
{
work_s _hpwork = {};
// Get the current time.
struct timespec ts_now;
px4_clock_gettime(CLOCK_MONOTONIC, &ts_now);
// We get an absolute time but want to calculate a timeout in us.
hrt_abstime timeout_us = ts_to_abstime((struct timespec *)ts) - ts_to_abstime(&ts_now);
// Create a timer to unblock.
hrt_work_queue(&_hpwork, (worker_t)&timer_cb, (void *)sem, timeout_us);
sem_wait(sem);
hrt_work_cancel(&_hpwork);
return 0;
}
/**
* Reschedule the next timer interrupt.
*
* This routine must be called with interrupts disabled.
*/
static void
hrt_call_reschedule()
{
hrt_abstime now = hrt_absolute_time();
hrt_abstime delay = HRT_INTERVAL_MAX;
struct hrt_call *next = (struct hrt_call *)sq_peek(&callout_queue);
hrt_abstime deadline = now + HRT_INTERVAL_MAX;
//PX4_INFO("hrt_call_reschedule");
/*
* Determine what the next deadline will be.
*
* Note that we ensure that this will be within the counter
* period, so that when we truncate all but the low 16 bits
* the next time the compare matches it will be the deadline
* we want.
*
* It is important for accurate timekeeping that the compare
* interrupt fires sufficiently often that the base_time update in
* hrt_absolute_time runs at least once per timer period.
*/
if (next != NULL) {
//lldbg("entry in queue\n");
if (next->deadline <= (now + HRT_INTERVAL_MIN)) {
//lldbg("pre-expired\n");
/* set a minimal deadline so that we call ASAP */
delay = HRT_INTERVAL_MIN;
} else if (next->deadline < deadline) {
//lldbg("due soon\n");
delay = next->deadline - now;
}
}
// There is no timer ISR, so simulate one by putting an event on the
// high priority work queue
// Remove the existing expiry and update with the new expiry
hrt_work_cancel(&_hrt_work);
hrt_work_queue(&_hrt_work, (worker_t)&hrt_tim_isr, NULL, delay);
}
