int
lwp_unpark(lwpid_t target, const void *hint)
{
sleepq_t *sq;
wchan_t wchan;
kmutex_t *mp;
proc_t *p;
lwp_t *t;
/*
* Easy case: search for the LWP on the sleep queue. If
* it's parked, remove it from the queue and set running.
*/
p = curproc;
wchan = lwp_park_wchan(p, hint);
sq = sleeptab_lookup(&lwp_park_tab, wchan, &mp);
TAILQ_FOREACH(t, sq, l_sleepchain)
if (t->l_proc == p && t->l_lid == target)
break;
if (__predict_true(t != NULL)) {
sleepq_remove(sq, t);
mutex_spin_exit(mp);
return 0;
}
/*
* The LWP hasn't parked yet. Take the hit and mark the
* operation as pending.
*/
mutex_spin_exit(mp);
mutex_enter(p->p_lock);
if ((t = lwp_find(p, target)) == NULL) {
mutex_exit(p->p_lock);
return ESRCH;
}
/*
* It may not have parked yet, we may have raced, or it
* is parked on a different user sync object.
*/
lwp_lock(t);
if (t->l_syncobj == &lwp_park_sobj) {
/* Releases the LWP lock. */
lwp_unsleep(t, true);
} else {
/*
* Set the operation pending. The next call to _lwp_park
* will return early.
*/
t->l_flag |= LW_UNPARKED;
lwp_unlock(t);
}
mutex_exit(p->p_lock);
return 0;
}
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;
}
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;
}
int
sys__lwp_unpark_all(struct lwp *l, const struct sys__lwp_unpark_all_args *uap,
register_t *retval)
{
/* {
syscallarg(const lwpid_t *) targets;
syscallarg(size_t) ntargets;
syscallarg(const void *) hint;
} */
struct proc *p;
struct lwp *t;
sleepq_t *sq;
wchan_t wchan;
lwpid_t targets[32], *tp, *tpp, *tmax, target;
int error;
kmutex_t *mp;
u_int ntargets;
size_t sz;
p = l->l_proc;
ntargets = SCARG(uap, ntargets);
if (SCARG(uap, targets) == NULL) {
/*
* Let the caller know how much we are willing to do, and
* let it unpark the LWPs in blocks.
*/
*retval = LWP_UNPARK_MAX;
return 0;
}
if (ntargets > LWP_UNPARK_MAX || ntargets == 0)
return EINVAL;
/*
* Copy in the target array. If it's a small number of LWPs, then
* place the numbers on the stack.
*/
sz = sizeof(target) * ntargets;
if (sz <= sizeof(targets))
tp = targets;
else {
tp = kmem_alloc(sz, KM_SLEEP);
if (tp == NULL)
return ENOMEM;
}
error = copyin(SCARG(uap, targets), tp, sz);
if (error != 0) {
if (tp != targets) {
kmem_free(tp, sz);
}
return error;
}
wchan = lwp_park_wchan(p, SCARG(uap, hint));
sq = sleeptab_lookup(&lwp_park_tab, wchan, &mp);
for (tmax = tp + ntargets, tpp = tp; tpp < tmax; tpp++) {
target = *tpp;
/*
* Easy case: search for the LWP on the sleep queue. If
* it's parked, remove it from the queue and set running.
*/
TAILQ_FOREACH(t, sq, l_sleepchain)
if (t->l_proc == p && t->l_lid == target)
break;
if (t != NULL) {
sleepq_remove(sq, t);
continue;
}
/*
* The LWP hasn't parked yet. Take the hit and
* mark the operation as pending.
*/
mutex_spin_exit(mp);
mutex_enter(p->p_lock);
if ((t = lwp_find(p, target)) == NULL) {
mutex_exit(p->p_lock);
mutex_spin_enter(mp);
continue;
}
lwp_lock(t);
/*
* It may not have parked yet, we may have raced, or
* it is parked on a different user sync object.
*/
if (t->l_syncobj == &lwp_park_sobj) {
/* Releases the LWP lock. */
lwp_unsleep(t, true);
} else {
/*
* Set the operation pending. The next call to
* _lwp_park will return early.
*/
t->l_flag |= LW_UNPARKED;
lwp_unlock(t);
}
mutex_exit(p->p_lock);
mutex_spin_enter(mp);
}
mutex_spin_exit(mp);
if (tp != targets)
kmem_free(tp, sz);
return 0;
}