1#include "pthread_impl.h"
2
3int pthread_rwlock_unlock(pthread_rwlock_t *rw)
4{
5	int val, cnt, waiters, new, priv = rw->_rw_shared^128;
6
7	do {
8		val = rw->_rw_lock;
9		cnt = val & 0x7fffffff;
10		waiters = rw->_rw_waiters;
11		new = (cnt == 0x7fffffff || cnt == 1) ? 0 : val-1;
12	} while (a_cas(&rw->_rw_lock, val, new) != val);
13
14	if (!new && (waiters || val<0))
15		__wake(&rw->_rw_lock, cnt, priv);
16
17	return 0;
18}
19