/*
* Cancellation behaivor:
* Thread may be canceled at start, if thread is canceled, it means it
* did not get a wakeup from pthread_cond_signal(), otherwise, it is
* not canceled.
* Thread cancellation never cause wakeup from pthread_cond_signal()
* to be lost.
*/
static int
cond_wait_kernel(struct pthread_cond *cvp, struct pthread_mutex *mp,
const struct timespec *abstime, int cancel)
{
struct pthread *curthread = _get_curthread();
int recurse;
int error, error2 = 0;
error = _mutex_cv_detach(mp, &recurse);
if (error != 0)
return (error);
if (cancel) {
_thr_cancel_enter2(curthread, 0);
error = _thr_ucond_wait((struct ucond *)&cvp->__has_kern_waiters,
(struct umutex *)&mp->m_lock, abstime,
CVWAIT_ABSTIME|CVWAIT_CLOCKID);
_thr_cancel_leave(curthread, 0);
} else {
error = _thr_ucond_wait((struct ucond *)&cvp->__has_kern_waiters,
(struct umutex *)&mp->m_lock, abstime,
CVWAIT_ABSTIME|CVWAIT_CLOCKID);
}
/*
* Note that PP mutex and ROBUST mutex may return
* interesting error codes.
*/
if (error == 0) {
error2 = _mutex_cv_lock(mp, recurse);
} else if (error == EINTR || error == ETIMEDOUT) {
error2 = _mutex_cv_lock(mp, recurse);
if (error2 == 0 && cancel)
_thr_testcancel(curthread);
if (error == EINTR)
error = 0;
} else {
/* We know that it didn't unlock the mutex. */
error2 = _mutex_cv_attach(mp, recurse);
if (error2 == 0 && cancel)
_thr_testcancel(curthread);
}
return (error2 != 0 ? error2 : error);
}
static int
cond_wait_user(struct pthread_cond *cvp, struct pthread_mutex *mp,
const struct timespec *abstime, int cancel)
{
struct pthread *curthread = _get_curthread();
struct sleepqueue *sq;
int recurse;
int error;
if (curthread->wchan != NULL)
PANIC("thread was already on queue.");
if (cancel)
_thr_testcancel(curthread);
_sleepq_lock(cvp);
/*
* set __has_user_waiters before unlocking mutex, this allows
* us to check it without locking in pthread_cond_signal().
*/
cvp->__has_user_waiters = 1;
curthread->will_sleep = 1;
(void)_mutex_cv_unlock(mp, &recurse);
curthread->mutex_obj = mp;
_sleepq_add(cvp, curthread);
for(;;) {
_thr_clear_wake(curthread);
_sleepq_unlock(cvp);
if (cancel) {
_thr_cancel_enter2(curthread, 0);
error = _thr_sleep(curthread, cvp->__clock_id, abstime);
_thr_cancel_leave(curthread, 0);
} else {
error = _thr_sleep(curthread, cvp->__clock_id, abstime);
}
_sleepq_lock(cvp);
if (curthread->wchan == NULL) {
error = 0;
break;
} else if (cancel && SHOULD_CANCEL(curthread)) {
sq = _sleepq_lookup(cvp);
cvp->__has_user_waiters =
_sleepq_remove(sq, curthread);
_sleepq_unlock(cvp);
curthread->mutex_obj = NULL;
_mutex_cv_lock(mp, recurse);
if (!THR_IN_CRITICAL(curthread))
_pthread_exit(PTHREAD_CANCELED);
else /* this should not happen */
return (0);
} else if (error == ETIMEDOUT) {
sq = _sleepq_lookup(cvp);
cvp->__has_user_waiters =
_sleepq_remove(sq, curthread);
break;
}
}
_sleepq_unlock(cvp);
curthread->mutex_obj = NULL;
_mutex_cv_lock(mp, recurse);
return (error);
}
/*
* Cancellation behavior:
* if the thread is canceled, joinee is not recycled.
*/
static int
join_common(pthread_t pthread, void **thread_return,
const struct timespec *abstime)
{
struct pthread *curthread = _get_curthread();
struct timespec ts, ts2, *tsp;
void *tmp;
long tid;
int ret = 0;
if (pthread == NULL)
return (EINVAL);
if (pthread == curthread)
return (EDEADLK);
if ((ret = _thr_find_thread(curthread, pthread, 1)) != 0)
return (ESRCH);
if ((pthread->flags & THR_FLAGS_DETACHED) != 0) {
ret = EINVAL;
} else if (pthread->joiner != NULL) {
/* Multiple joiners are not supported. */
ret = ENOTSUP;
}
if (ret) {
THR_THREAD_UNLOCK(curthread, pthread);
return (ret);
}
/* Set the running thread to be the joiner: */
pthread->joiner = curthread;
THR_THREAD_UNLOCK(curthread, pthread);
THR_CLEANUP_PUSH(curthread, backout_join, pthread);
_thr_cancel_enter(curthread);
tid = pthread->tid;
while (pthread->tid != TID_TERMINATED) {
_thr_testcancel(curthread);
if (abstime != NULL) {
clock_gettime(CLOCK_REALTIME, &ts);
TIMESPEC_SUB(&ts2, abstime, &ts);
if (ts2.tv_sec < 0) {
ret = ETIMEDOUT;
break;
}
tsp = &ts2;
} else
tsp = NULL;
ret = _thr_umtx_wait(&pthread->tid, tid, tsp);
if (ret == ETIMEDOUT)
break;
}
_thr_cancel_leave(curthread, 0);
THR_CLEANUP_POP(curthread, 0);
if (ret == ETIMEDOUT) {
THR_THREAD_LOCK(curthread, pthread);
pthread->joiner = NULL;
THR_THREAD_UNLOCK(curthread, pthread);
} else {
ret = 0;
tmp = pthread->ret;
THR_THREAD_LOCK(curthread, pthread);
pthread->flags |= THR_FLAGS_DETACHED;
pthread->joiner = NULL;
_thr_try_gc(curthread, pthread); /* thread lock released */
if (thread_return != NULL)
*thread_return = tmp;
}
return (ret);
}
