/**
* set next_timer to the next lowest enabled timer index
*/
void schedule_timer(void)
{
/* try to find *an active* timer */
next_timer = -1;
for (int i = 0; i < HWTIMER_MAXTIMERS; i++) {
if (native_hwtimer_isset[i] == 1) {
next_timer = i;
break;
}
}
if (next_timer == -1) {
DEBUG("schedule_timer(): no valid timer found - nothing to schedule\n");
struct itimerval null_timer;
null_timer.it_interval.tv_sec = 0;
null_timer.it_interval.tv_usec = 0;
null_timer.it_value.tv_sec = 0;
null_timer.it_value.tv_usec = 0;
if (real_setitimer(ITIMER_REAL, &null_timer, NULL) == -1) {
err(EXIT_FAILURE, "schedule_timer: setitimer");
}
return;
}
/* find the next pending timer (next_timer now points to *a* valid pending timer) */
for (int i = 0; i < HWTIMER_MAXTIMERS; i++) {
if (
(native_hwtimer_isset[i] == 1) &&
(tv2ticks(&(native_hwtimer[i].it_value)) < tv2ticks(&(native_hwtimer[next_timer].it_value)))
) {
/* timer in slot i is active and the timeout is more recent than next_timer */
next_timer = i;
}
}
/* next pending timer is in slot next_timer */
struct timeval now;
hwtimer_arch_now(); // update timer
ticks2tv(native_hwtimer_now, &now);
struct itimerval result;
memset(&result, 0, sizeof(result));
int retval = timeval_subtract(&result.it_value, &native_hwtimer[next_timer].it_value, &now);
if (retval || (tv2ticks(&result.it_value) < HWTIMERMINOFFSET)) {
DEBUG("\033[31mschedule_timer(): timer is already due (%i), mitigating.\033[0m\n", next_timer);
result.it_value.tv_sec = 0;
result.it_value.tv_usec = 1;
}
_native_syscall_enter();
if (real_setitimer(ITIMER_REAL, &result, NULL) == -1) {
err(EXIT_FAILURE, "schedule_timer: setitimer");
}
else {
DEBUG("schedule_timer(): set next timer (%i).\n", next_timer);
}
_native_syscall_leave();
}
static void do_timer_set(unsigned int offset)
{
DEBUG("%s\n", __func__);
if (offset && offset < NATIVE_TIMER_MIN_RES) {
offset = NATIVE_TIMER_MIN_RES;
}
memset(&itv, 0, sizeof(itv));
itv.it_value.tv_sec = (offset / 1000000);
itv.it_value.tv_usec = offset % 1000000;
DEBUG("timer_set(): setting %u.%06u\n", (unsigned)itv.it_value.tv_sec, (unsigned)itv.it_value.tv_usec);
_native_syscall_enter();
if (real_setitimer(ITIMER_REAL, &itv, NULL) == -1) {
err(EXIT_FAILURE, "timer_arm: setitimer");
}
_native_syscall_leave();
}
