int pthread_mutex_trylock(pthread_mutex_t *m)
{
int tid;
+ int own;
+ pthread_t self;
if (m->_m_type == PTHREAD_MUTEX_NORMAL)
- return (m->_m_lock || a_swap(&m->_m_lock, 1)) ? EBUSY : 0;
+ return a_swap(&m->_m_lock, EBUSY);
- tid = pthread_self()->tid;
+ self = pthread_self();
+ tid = self->tid | 0x80000000;
- if (m->_m_owner == tid && m->_m_type == PTHREAD_MUTEX_RECURSIVE) {
+ 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 (m->_m_owner || a_xchg(&m->_m_lock, 1)) return EBUSY;
- m->_m_owner = tid;
+ 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;
}