- int r;
- while ((r=pthread_mutex_trylock(m)) == EBUSY)
- __wait(&m->_m_lock, &m->_m_waiters, 1, 0);
- return r;
+ if ((m->_m_type&15) == PTHREAD_MUTEX_NORMAL
+ && !a_cas(&m->_m_lock, 0, EBUSY))
+ return 0;
+
+ return __pthread_mutex_timedlock(m, 0);