diff options
| -rw-r--r-- | os/rt/src/chvt.c | 27 |
1 files changed, 20 insertions, 7 deletions
diff --git a/os/rt/src/chvt.c b/os/rt/src/chvt.c index 965c79121..51db54cc3 100644 --- a/os/rt/src/chvt.c +++ b/os/rt/src/chvt.c @@ -131,23 +131,36 @@ void chVTDoSetI(virtual_timer_t *vtp, systime_t delay, return;
}
- /* Special case where the timer will be placed as first element in a
- non-empty list, the alarm needs to be recalculated.*/
- delta = now + delay - ch.vtlist.lasttime;
- if (delta < ch.vtlist.next->delta) {
-
- /* New alarm deadline.*/
+ /* Pointer to the first element in the delta list, which is non-empty.*/
+ p = ch.vtlist.next;
+
+ /* Delay as delta from 'lasttime'. Note, it can overflow and the value
+ becomes lower than 'now'.*/
+ delta = now - ch.vtlist.lasttime + delay;
+
+ if (delta < now - ch.vtlist.lasttime) {
+ /* Scenario where a very large delay excedeed the numeric range, it
+ requires a special handling. We need to skip the first element and
+ adjust the delta to wrap back in the previous numeric range.*/
+ delta -= p->delta;
+ p = p->next;
+ }
+ else if (delta < p->delta) {
+ /* A small delay that will become the first element in the delta list
+ and next deadline.*/
port_timer_set_alarm(ch.vtlist.lasttime + delta);
}
}
#else /* CH_CFG_ST_TIMEDELTA == 0 */
/* Delta is initially equal to the specified delay.*/
delta = delay;
+
+ /* Pointer to the first element in the delta list.*/
+ p = ch.vtlist.next;
#endif /* CH_CFG_ST_TIMEDELTA == 0 */
/* The delta list is scanned in order to find the correct position for
this timer. */
- p = ch.vtlist.next;
while (p->delta < delta) {
delta -= p->delta;
p = p->next;
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