int pthread_mutex_trylock(pthread_mutex_t *m)
{
- if (m->__type == PTHREAD_MUTEX_RECURSIVE) {
- pthread_t self = pthread_self();
- if (m->__owner == self) {
- if ((unsigned)m->__lock >= INT_MAX) return EAGAIN;
- a_inc(&m->__lock);
- return 0;
- }
- if (a_fetch_add(&m->__lock, 1)) {
- if (a_fetch_add(&m->__lock, -1)==1 && m->__waiters)
- __wake(&m->__lock, 1, 0);
- return EBUSY;
- }
- m->__owner = self;
+ int tid;
+ int own;
+ pthread_t self;
+
+ if (m->_m_type == PTHREAD_MUTEX_NORMAL)
+ return -a_swap(&m->_m_lock, 1) & EBUSY;
+
+ self = pthread_self();
+ tid = self->tid | 0x80000000;
+
+ if (m->_m_type >= 4) {
+ if (!self->robust_list.off)
+ syscall(SYS_set_robust_list,
+ &self->robust_list, 3*sizeof(long));
+ self->robust_list.off = (char*)&m->_m_lock-(char *)&m->_m_next;
+ self->robust_list.pending = &m->_m_next;
+ }
+
+ if (m->_m_lock == tid && (m->_m_type&3) == PTHREAD_MUTEX_RECURSIVE) {
+ if ((unsigned)m->_m_count >= INT_MAX) return EAGAIN;
+ m->_m_count++;
return 0;
}
- if (a_xchg(&m->__lock, 1))
- if (m->__type == PTHREAD_MUTEX_ERRORCHECK
- && m->__owner == pthread_self()) return EDEADLK;
- else return EBUSY;
- if (m->__type == PTHREAD_MUTEX_ERRORCHECK)
- m->__owner = pthread_self();
+ own = m->_m_lock;
+ if ((own && !(own & 0x40000000)) || a_cas(&m->_m_lock, own, tid)!=own)
+ return EBUSY;
+
+ m->_m_count = 1;
+
+ if (m->_m_type < 4) return 0;
+
+ if (m->_m_type >= 8) {
+ m->_m_lock = 0;
+ return ENOTRECOVERABLE;
+ }
+ m->_m_next = self->robust_list.head;
+ m->_m_prev = &self->robust_list.head;
+ if (self->robust_list.head)
+ self->robust_list.head[-1] = &m->_m_next;
+ self->robust_list.head = &m->_m_next;
+ self->robust_list.pending = 0;
+ if (own) {
+ m->_m_type += 8;
+ return EOWNERDEAD;
+ }
+
return 0;
}