void vtimer_callback(void *ptr)
{
DEBUG("vtimer_callback ptr=%p\n", ptr);
(void) ptr;
in_callback = true;
hwtimer_id = -1;
/* get the vtimer that fired */
vtimer_t *timer = node_get_timer(priority_queue_remove_head(&shortterm_priority_queue_root));
if (timer) {
#if ENABLE_DEBUG
vtimer_print(timer);
#endif
DEBUG("vtimer_callback(): Shooting %" PRIu32 ".\n", timer->absolute.microseconds);
/* shoot timer */
timer->action(timer);
}
else {
DEBUG("vtimer_callback(): spurious call.\n");
}
in_callback = false;
update_shortterm();
}
static int update_shortterm(void)
{
if (shortterm_priority_queue_root.first == NULL) {
/* there is no vtimer to schedule, queue is empty */
DEBUG("update_shortterm: shortterm_priority_queue_root.next == NULL - dont know what to do here\n");
return 0;
}
if (hwtimer_id != -1) {
/* there is a running hwtimer for us */
if (hwtimer_next_absolute != shortterm_priority_queue_root.first->priority) {
/* the next timer in the vtimer queue is not the next hwtimer */
/* we have to remove the running hwtimer (and schedule a new one) */
hwtimer_remove(hwtimer_id);
}
else {
/* the next vtimer is the next hwtimer, nothing to do */
return 0;
}
}
/* short term part of the next vtimer */
hwtimer_next_absolute = shortterm_priority_queue_root.first->priority;
uint32_t next = hwtimer_next_absolute;
/* current short term time */
uint32_t now = HWTIMER_TICKS_TO_US(hwtimer_now());
/* make sure the longterm_tick_timer does not get truncated */
if (node_get_timer(shortterm_priority_queue_root.first)->action != vtimer_callback_tick) {
/* the next vtimer to schedule is the long term tick */
/* it has a shortterm offset of longterm_tick_start */
next += longterm_tick_start;
}
if((next - HWTIMER_TICKS_TO_US(VTIMER_THRESHOLD) - now) > MICROSECONDS_PER_TICK ) {
DEBUG("truncating next (next - HWTIMER_TICKS_TO_US(VTIMER_THRESHOLD) - now): %lu\n", (next - HWTIMER_TICKS_TO_US(VTIMER_THRESHOLD) - now));
next = now + HWTIMER_TICKS_TO_US(VTIMER_BACKOFF);
}
DEBUG("update_shortterm: Set hwtimer to %" PRIu32 " (now=%lu)\n", next, HWTIMER_TICKS_TO_US(hwtimer_now()));
hwtimer_id = hwtimer_set_absolute(HWTIMER_TICKS(next), vtimer_callback, NULL);
return 0;
}
void vtimer_callback_tick(vtimer_t *timer)
{
(void) timer;
DEBUG("vtimer_callback_tick().\n");
longterm_tick_start += MICROSECONDS_PER_TICK;
longterm_tick_timer.absolute.seconds += SECONDS_PER_TICK;
longterm_tick_timer.absolute.microseconds = MICROSECONDS_PER_TICK; // Should never change, just for clarity.
set_shortterm(&longterm_tick_timer);
while (longterm_priority_queue_root.first) {
vtimer_t *timer = node_get_timer(longterm_priority_queue_root.first);
if (timer->absolute.seconds == longterm_tick_timer.absolute.seconds) {
priority_queue_remove_head(&longterm_priority_queue_root);
set_shortterm(timer);
}
else {
break;
}
}
}
