_pthread_cond_wait vs. __pthread_condwait

[Alexander Kabaev]

The _pthread_cond_wait function has this at the beginning:

        _thr_enter_cancellation_point(curthread);

        if (cond == NULL) {
                _thr_leave_cancellation_point(curthread);
and this at the end: 
        _thr_leave_cancellation_point(curthread);


__pthread_cond_wait is defined as

       _thr_enter_cancellation_point(curthread);
        ret = _pthread_cond_wait(cond, mutex);
        _thr_leave_cancellation_point(curthread);
        return (ret);

So what is the difference between the two? Should't cancellantion checks
ve removed from _pthread_cond_wait?

-- 
Alexander Kabaev