void alarmSchedule(Alarm_t *alarm, uint32_t milliseconds)
{
// we want to avoid inserting local variables in the global alarm list
// (but this warning, not an error, because the user function may never return)
WARN_ON(isStackAddress(alarm));
// PRINTF("alarmSchedule %p, ms=%lu\n", alarm, milliseconds);
alarm->jiffies = (uint32_t)getJiffies() + milliseconds;
// locking is required, because both kernel and user threads can be using this function
Handle_t h;
ATOMIC_START(h);
// unschedule the alarm, if it was already scheduled
SLIST_REMOVE_SAFE(&alarmListHead, alarm, Alarm_s, chain);
// insert it in appropriate position
Alarm_t **prev = &SLIST_FIRST(&alarmListHead);
Alarm_t *a = *prev;
while (a && timeAfter32(alarm->jiffies, a->jiffies)) {
prev = &SLIST_NEXT(a, chain);
a = *prev;
}
SLIST_INSERT(prev, alarm, chain);
#if USE_THREADS
// always reschedule alarm processing in case some alarm was added
// that might need to be processed before end of current kernel sleep time
processFlags.bits.alarmsProcess = true;
// and make sure the kernel thread is awake and ready to deal with it
threadWakeup(KERNEL_THREAD_INDEX, THREAD_READY);
#endif
ATOMIC_END(h);
}
int
vtSleep(VtRendez *q)
{
Thread *s, *t, *tt;
VtLock *p;
p = q->lk;
lock(&p->lk);
s = *vtRock;
/*
* venti currently contains code that assume locks can be passed between threads :-(
* assert(p->writer != s);
*/
assert(p->writer != nil);
assert(p->readers == 0);
t = p->qfirst;
if(t == nil) {
p->writer = nil;
} else if(t->state == QueuingW) {
p->qfirst = t->next;
p->writer = t;
threadWakeup(t);
} else {
p->writer = nil;
while(t != nil && t->state == QueuingR) {
tt = t;
t = t->next;
p->readers++;
threadWakeup(tt);
}
}
if(q->wfirst == nil)
q->wfirst = s;
else
q->wlast->next = s;
q->wlast = s;
s->next = nil;
unlock(&p->lk);
threadSleep(s);
assert(p->writer == s);
return 1;
}
void
vtUnlock(VtLock *p)
{
Thread *t, *tt;
lock(&p->lk);
/*
* venti currently has code that assumes lock can be passed between threads :-)
* assert(p->writer == *vtRock);
*/
assert(p->writer != nil);
assert(p->readers == 0);
t = p->qfirst;
if(t == nil) {
p->writer = nil;
unlock(&p->lk);
return;
}
if(t->state == QueuingW) {
p->qfirst = t->next;
p->writer = t;
unlock(&p->lk);
threadWakeup(t);
return;
}
p->writer = nil;
while(t != nil && t->state == QueuingR) {
tt = t;
t = t->next;
p->readers++;
threadWakeup(tt);
}
p->qfirst = t;
unlock(&p->lk);
}
void
vtRUnlock(VtLock *p)
{
Thread *t;
lock(&p->lk);
assert(p->writer == nil && p->readers > 0);
p->readers--;
t = p->qfirst;
if(p->readers > 0 || t == nil) {
unlock(&p->lk);
return;
}
assert(t->state == QueuingW);
p->qfirst = t->next;
p->writer = t;
unlock(&p->lk);
threadWakeup(t);
}
