_cv_timedwait
int _cv_timedwait(struct cv *, struct lock *, int timo, int wakesig);
_cv_timedwait((cv), (lock), 0, 0)
_cv_timedwait((cv), (lock), 0, 1)
_cv_timedwait((cv), (lock), (timeo), 0)
_cv_timedwait((cv), (lock), (timeo), 1)