int pthread_mutex_trylock(pthread_mutex_t *m)
{
- if (m->_m_type == PTHREAD_MUTEX_RECURSIVE) {
- pthread_t self = pthread_self();
- if (m->_m_owner == self->tid) {
- if ((unsigned)m->_m_lock >= INT_MAX) return EAGAIN;
- a_inc(&m->_m_lock);
- return 0;
- }
- if (a_fetch_add(&m->_m_lock, 1)) {
- if (a_fetch_add(&m->_m_lock, -1)==1 && m->_m_waiters)
- __wake(&m->_m_lock, 1, 0);
- return EBUSY;
- }
- m->_m_owner = self->tid;
+ int tid;
+
+ if (m->_m_type == PTHREAD_MUTEX_NORMAL)
+ return -a_xchg(&m->_m_lock, 1) & EBUSY;
+
+ tid = pthread_self()->tid;
+
+ if (m->_m_owner == tid) {
+ if (m->_m_type != PTHREAD_MUTEX_RECURSIVE)
+ return EDEADLK;
+ if ((unsigned)m->_m_count >= INT_MAX) return EAGAIN;
+ m->_m_count++;
return 0;
}
- if (a_xchg(&m->_m_lock, 1))
- if (m->_m_type == PTHREAD_MUTEX_ERRORCHECK
- && m->_m_owner == pthread_self()->tid) return EDEADLK;
- else return EBUSY;
- if (m->_m_type == PTHREAD_MUTEX_ERRORCHECK)
- m->_m_owner = pthread_self()->tid;
+ if (a_xchg(&m->_m_lock, 1)) return EBUSY;
+ m->_m_owner = tid;
+ m->_m_count = 1;
return 0;
}