#include "pthread_impl.h"
-int pthread_mutex_trylock(pthread_mutex_t *m)
+int __pthread_mutex_trylock_owner(pthread_mutex_t *m)
{
- int tid;
-
- if (m->_m_type == PTHREAD_MUTEX_NORMAL)
- return (m->_m_lock || a_swap(&m->_m_lock, 1)) ? EBUSY : 0;
+ int old, own;
+ int type = m->_m_type & 15;
+ pthread_t self = __pthread_self();
+ int tid = self->tid;
- tid = pthread_self()->tid;
+ if (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 == PTHREAD_MUTEX_RECURSIVE) {
+ old = m->_m_lock;
+ own = old & 0x7fffffff;
+ if (own == tid && (type&3) == PTHREAD_MUTEX_RECURSIVE) {
if ((unsigned)m->_m_count >= INT_MAX) return EAGAIN;
m->_m_count++;
return 0;
}
- if (m->_m_lock || a_cas(&m->_m_lock, 0, tid)) return EBUSY;
- m->_m_count = 1;
+ if ((own && !(own & 0x40000000)) || a_cas(&m->_m_lock, old, tid)!=old)
+ return EBUSY;
+
+ if (type < 4) return 0;
+
+ if (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_count = 0;
+ m->_m_type += 8;
+ return EOWNERDEAD;
+ }
+
return 0;
}
+
+int pthread_mutex_trylock(pthread_mutex_t *m)
+{
+ if ((m->_m_type&15) == PTHREAD_MUTEX_NORMAL)
+ return a_cas(&m->_m_lock, 0, EBUSY) & EBUSY;
+ return __pthread_mutex_trylock_owner(m);
+}