unsigned long hwtimer_arch_now(void)
{
struct timespec t;
DEBUG("hwtimer_arch_now()\n");
_native_syscall_enter();
#ifdef __MACH__
clock_serv_t cclock;
mach_timespec_t mts;
host_get_clock_service(mach_host_self(), SYSTEM_CLOCK, &cclock);
clock_get_time(cclock, &mts);
mach_port_deallocate(mach_task_self(), cclock);
t.tv_sec = mts.tv_sec;
t.tv_nsec = mts.tv_nsec;
#else
if (real_clock_gettime(CLOCK_MONOTONIC, &t) == -1) {
err(EXIT_FAILURE, "hwtimer_arch_now: clock_gettime");
}
#endif
_native_syscall_leave();
native_hwtimer_now = ts2ticks(&t) - time_null;
struct timeval tv;
ticks2tv(native_hwtimer_now, &tv);
DEBUG("hwtimer_arch_now(): it is now %lu s %lu us\n",
(unsigned long)tv.tv_sec, (unsigned long)tv.tv_usec);
DEBUG("hwtimer_arch_now(): returning %lu\n", native_hwtimer_now);
return native_hwtimer_now;
}
/**
* 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();
}
void hwtimer_arch_set_absolute(unsigned long value, short timer)
{
DEBUG("hwtimer_arch_set_absolute(%lu, %i)\n", value, timer);
ticks2tv(value, &(native_hwtimer[timer].it_value));
DEBUG("hwtimer_arch_set_absolute(): that is at %lu s %lu us\n",
(unsigned long)native_hwtimer[timer].it_value.tv_sec,
(unsigned long)native_hwtimer[timer].it_value.tv_usec);
native_hwtimer_isset[timer] = 1;
schedule_timer();
return;
}
void hwtimer_arch_set(unsigned long offset, short timer)
{
DEBUG("hwtimer_arch_set(%lu, %i)\n", offset, timer);
if (offset < HWTIMERMINOFFSET) {
offset = HWTIMERMINOFFSET;
DEBUG("hwtimer_arch_set: offset < MIN, set to: %lu\n", offset);
}
native_hwtimer_irq[timer] = 1;
native_hwtimer_isset[timer] = 1;
ticks2tv(offset, &(native_hwtimer[timer].it_value));
DEBUG("hwtimer_arch_set(): that is %lu s %lu us from now\n",
(unsigned long)native_hwtimer[timer].it_value.tv_sec,
(unsigned long)native_hwtimer[timer].it_value.tv_usec);
schedule_timer();
return;
}
