1#include "pthread_impl.h"
 2
 3int __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
52weak_alias(__pthread_mutex_unlock, pthread_mutex_unlock);