int
lwp_park(struct timespec *ts, const void *hint)
{
struct timespec tsx;
sleepq_t *sq;
kmutex_t *mp;
wchan_t wchan;
int timo, error;
lwp_t *l;
/* Fix up the given timeout value. */
if (ts != NULL) {
getnanotime(&tsx);
timespecsub(ts, &tsx, &tsx);
if (tsx.tv_sec < 0 || (tsx.tv_sec == 0 && tsx.tv_nsec <= 0))
return ETIMEDOUT;
if ((error = itimespecfix(&tsx)) != 0)
return error;
timo = tstohz(&tsx);
KASSERT(timo != 0);
} else
timo = 0;
/* Find and lock the sleep queue. */
l = curlwp;
wchan = lwp_park_wchan(l->l_proc, hint);
sq = sleeptab_lookup(&lwp_park_tab, wchan, &mp);
/*
* Before going the full route and blocking, check to see if an
* unpark op is pending.
*/
lwp_lock(l);
if ((l->l_flag & (LW_CANCELLED | LW_UNPARKED)) != 0) {
l->l_flag &= ~(LW_CANCELLED | LW_UNPARKED);
lwp_unlock(l);
mutex_spin_exit(mp);
return EALREADY;
}
lwp_unlock_to(l, mp);
l->l_biglocks = 0;
sleepq_enqueue(sq, wchan, "parked", &lwp_park_sobj);
error = sleepq_block(timo, true);
switch (error) {
case EWOULDBLOCK:
error = ETIMEDOUT;
break;
case ERESTART:
error = EINTR;
break;
default:
/* nothing */
break;
}
return error;
}
/*
* callout_halt:
*
* Cancel a pending callout. If in-flight, block until it completes.
* May not be called from a hard interrupt handler. If the callout
* can take locks, the caller of callout_halt() must not hold any of
* those locks, otherwise the two could deadlock. If 'interlock' is
* non-NULL and we must wait for the callout to complete, it will be
* released and re-acquired before returning.
*/
bool
callout_halt(callout_t *cs, void *interlock)
{
callout_impl_t *c = (callout_impl_t *)cs;
struct callout_cpu *cc;
struct lwp *l;
kmutex_t *lock, *relock;
bool expired;
KASSERT(c->c_magic == CALLOUT_MAGIC);
KASSERT(!cpu_intr_p());
lock = callout_lock(c);
relock = NULL;
expired = ((c->c_flags & CALLOUT_FIRED) != 0);
if ((c->c_flags & CALLOUT_PENDING) != 0)
CIRCQ_REMOVE(&c->c_list);
c->c_flags &= ~(CALLOUT_PENDING|CALLOUT_FIRED);
l = curlwp;
for (;;) {
cc = c->c_cpu;
if (__predict_true(cc->cc_active != c || cc->cc_lwp == l))
break;
if (interlock != NULL) {
/*
* Avoid potential scheduler lock order problems by
* dropping the interlock without the callout lock
* held.
*/
mutex_spin_exit(lock);
mutex_exit(interlock);
relock = interlock;
interlock = NULL;
} else {
/* XXX Better to do priority inheritance. */
KASSERT(l->l_wchan == NULL);
cc->cc_nwait++;
cc->cc_ev_block.ev_count++;
l->l_kpriority = true;
sleepq_enter(&cc->cc_sleepq, l, cc->cc_lock);
sleepq_enqueue(&cc->cc_sleepq, cc, "callout",
&sleep_syncobj);
sleepq_block(0, false);
}
lock = callout_lock(c);
}
mutex_spin_exit(lock);
if (__predict_false(relock != NULL))
mutex_enter(relock);
return expired;
}
int
lwp_park(clockid_t clock_id, int flags, struct timespec *ts, const void *hint)
{
sleepq_t *sq;
kmutex_t *mp;
wchan_t wchan;
int timo, error;
lwp_t *l;
if (ts != NULL) {
if ((error = ts2timo(clock_id, flags, ts, &timo, NULL)) != 0)
return error;
KASSERT(timo != 0);
} else {
timo = 0;
}
/* Find and lock the sleep queue. */
l = curlwp;
wchan = lwp_park_wchan(l->l_proc, hint);
sq = sleeptab_lookup(&lwp_park_tab, wchan, &mp);
/*
* Before going the full route and blocking, check to see if an
* unpark op is pending.
*/
lwp_lock(l);
if ((l->l_flag & (LW_CANCELLED | LW_UNPARKED)) != 0) {
l->l_flag &= ~(LW_CANCELLED | LW_UNPARKED);
lwp_unlock(l);
mutex_spin_exit(mp);
return EALREADY;
}
lwp_unlock_to(l, mp);
l->l_biglocks = 0;
sleepq_enqueue(sq, wchan, "parked", &lwp_park_sobj);
error = sleepq_block(timo, true);
switch (error) {
case EWOULDBLOCK:
error = ETIMEDOUT;
break;
case ERESTART:
error = EINTR;
break;
default:
/* nothing */
break;
}
return error;
}
