- int r, w=0;
- while ((r=pthread_mutex_trylock(m)) == EBUSY) {
- if (!w) a_inc(&m->_m_waiters), w++;
- if (__timedwait(&m->_m_lock, 1, CLOCK_REALTIME, at, 0) == ETIMEDOUT) {
- if (w) a_dec(&m->_m_waiters);
- return ETIMEDOUT;
- }
+ if ((m->_m_type&15) == PTHREAD_MUTEX_NORMAL
+ && !a_cas(&m->_m_lock, 0, EBUSY))
+ return 0;
+
+ int type = m->_m_type;
+ int r, t, priv = (type & 128) ^ 128;
+
+ r = pthread_mutex_trylock(m);
+ if (r != EBUSY) return r;
+
+ int spins = 100;
+ while (spins-- && m->_m_lock && !m->_m_waiters) a_spin();
+
+ while ((r=__pthread_mutex_trylock(m)) == EBUSY) {
+ if (!(r=m->_m_lock) || ((r&0x40000000) && (type&4)))
+ continue;
+ if ((type&3) == PTHREAD_MUTEX_ERRORCHECK
+ && (r&0x7fffffff) == __pthread_self()->tid)
+ return EDEADLK;
+
+ a_inc(&m->_m_waiters);
+ t = r | 0x80000000;
+ a_cas(&m->_m_lock, r, t);
+ r = __timedwait(&m->_m_lock, t, CLOCK_REALTIME, at, priv);
+ a_dec(&m->_m_waiters);
+ if (r && r != EINTR) break;