#include "pthread_impl.h"
-int pthread_mutex_trylock(pthread_mutex_t *m)
+int __pthread_mutex_trylock_owner(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 old, own;
+ int type = m->_m_type & 15;
+ pthread_t self = __pthread_self();
+ int tid = self->tid;
+
+ 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 (own == 0x7fffffff) return ENOTRECOVERABLE;
+
+ if (m->_m_type & 128) {
+ if (!self->robust_list.off) {
+ self->robust_list.off = (char*)&m->_m_lock-(char *)&m->_m_next;
+ __syscall(SYS_set_robust_list, &self->robust_list, 3*sizeof(long));
+ }
+ if (m->_m_waiters) tid |= 0x80000000;
+ self->robust_list.pending = &m->_m_next;
+ }
+
+ if ((own && (!(own & 0x40000000) || !(type & 4)))
+ || a_cas(&m->_m_lock, old, tid) != old) {
+ self->robust_list.pending = 0;
+ return EBUSY;
+ }
+
+ volatile void *next = self->robust_list.head;
+ m->_m_next = next;
+ m->_m_prev = &self->robust_list.head;
+ if (next != &self->robust_list.head) *(volatile void *volatile *)
+ ((char *)next - sizeof(void *)) = &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;
+ }
- 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;
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);
+}
+
+weak_alias(__pthread_mutex_trylock, pthread_mutex_trylock);