int
__thr_umutex_lock_spin(struct umutex *mtx, uint32_t id)
{
uint32_t owner;
if (!_thr_is_smp)
return __thr_umutex_lock(mtx, id);
if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) {
for (;;) {
int count = SPINLOOPS;
while (count--) {
owner = mtx->m_owner;
if ((owner & ~UMUTEX_CONTESTED) == 0) {
if (atomic_cmpset_acq_32(
&mtx->m_owner,
owner, id|owner)) {
return (0);
}
}
CPU_SPINWAIT;
}
/* wait in kernel */
_umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, 0);
}
}
return _umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, 0);
}
int
__thr_umutex_lock(struct umutex *mtx, uint32_t id)
{
uint32_t owner;
if ((mtx->m_flags & (UMUTEX_PRIO_PROTECT | UMUTEX_PRIO_INHERIT)) == 0) {
for (;;) {
/* wait in kernel */
_umtx_op_err(mtx, UMTX_OP_MUTEX_WAIT, 0, 0, 0);
owner = mtx->m_owner;
if ((owner & ~UMUTEX_CONTESTED) == 0 &&
atomic_cmpset_acq_32(&mtx->m_owner, owner, id|owner))
return (0);
}
}
return _umtx_op_err(mtx, UMTX_OP_MUTEX_LOCK, 0, 0, 0);
}
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;
int defered;
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;
defered = 0;
(void)_mutex_cv_unlock(mp, &recurse, &defered);
curthread->mutex_obj = mp;
_sleepq_add(cvp, curthread);
for(;;) {
_thr_clear_wake(curthread);
_sleepq_unlock(cvp);
if (defered) {
defered = 0;
if ((mp->m_lock.m_owner & UMUTEX_CONTESTED) == 0)
(void)_umtx_op_err(&mp->m_lock, UMTX_OP_MUTEX_WAKE2,
mp->m_lock.m_flags, 0, 0);
}
if (curthread->nwaiter_defer > 0) {
_thr_wake_all(curthread->defer_waiters,
curthread->nwaiter_defer);
curthread->nwaiter_defer = 0;
}
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);
}
