1 #include "pthread_impl.h"
2
__pthread_mutex_unlock(pthread_mutex_t * m)3 int __pthread_mutex_unlock(pthread_mutex_t *m)
4 {
5 pthread_t self;
6 int waiters = m->_m_waiters;
7 int cont;
8 int type = m->_m_type & 15;
9 int priv = (m->_m_type & 128) ^ 128;
10 int new = 0;
11 int old;
12
13 if (type != PTHREAD_MUTEX_NORMAL) {
14 self = __pthread_self();
15 old = m->_m_lock;
16 int own = old & 0x3fffffff;
17 if (own != self->tid)
18 return EPERM;
19 if ((type&3) == PTHREAD_MUTEX_RECURSIVE && m->_m_count)
20 return m->_m_count--, 0;
21 if ((type&4) && (old&0x40000000))
22 new = 0x7fffffff;
23 if (!priv) {
24 self->robust_list.pending = &m->_m_next;
25 __vm_lock();
26 }
27 volatile void *prev = m->_m_prev;
28 volatile void *next = m->_m_next;
29 *(volatile void *volatile *)prev = next;
30 if (next != &self->robust_list.head) *(volatile void *volatile *)
31 ((char *)next - sizeof(void *)) = prev;
32 }
33 if (type&8) {
34 if (old<0 || a_cas(&m->_m_lock, old, new)!=old) {
35 if (new) a_store(&m->_m_waiters, -1);
36 __syscall(SYS_futex, &m->_m_lock, FUTEX_UNLOCK_PI|priv);
37 }
38 cont = 0;
39 waiters = 0;
40 } else {
41 cont = a_swap(&m->_m_lock, new);
42 }
43 if (type != PTHREAD_MUTEX_NORMAL && !priv) {
44 self->robust_list.pending = 0;
45 __vm_unlock();
46 }
47 if (waiters || cont<0)
48 __wake(&m->_m_lock, 1, priv);
49 return 0;
50 }
51
52 weak_alias(__pthread_mutex_unlock, pthread_mutex_unlock);
53