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path: root/src/thread/pthread_mutex_unlock.c
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Diffstat (limited to 'src/thread/pthread_mutex_unlock.c')
-rw-r--r--src/thread/pthread_mutex_unlock.c14
1 files changed, 12 insertions, 2 deletions
diff --git a/src/thread/pthread_mutex_unlock.c b/src/thread/pthread_mutex_unlock.c
index ea9f54dd..b66423e6 100644
--- a/src/thread/pthread_mutex_unlock.c
+++ b/src/thread/pthread_mutex_unlock.c
@@ -8,10 +8,11 @@ int __pthread_mutex_unlock(pthread_mutex_t *m)
int type = m->_m_type & 15;
int priv = (m->_m_type & 128) ^ 128;
int new = 0;
+ int old;
if (type != PTHREAD_MUTEX_NORMAL) {
self = __pthread_self();
- int old = m->_m_lock;
+ old = m->_m_lock;
int own = old & 0x3fffffff;
if (own != self->tid)
return EPERM;
@@ -29,7 +30,16 @@ int __pthread_mutex_unlock(pthread_mutex_t *m)
if (next != &self->robust_list.head) *(volatile void *volatile *)
((char *)next - sizeof(void *)) = prev;
}
- cont = a_swap(&m->_m_lock, new);
+ if (type&8) {
+ if (old<0 || a_cas(&m->_m_lock, old, new)!=old) {
+ if (new) a_store(&m->_m_waiters, -1);
+ __syscall(SYS_futex, &m->_m_lock, FUTEX_UNLOCK_PI|priv);
+ }
+ cont = 0;
+ waiters = 0;
+ } else {
+ cont = a_swap(&m->_m_lock, new);
+ }
if (type != PTHREAD_MUTEX_NORMAL && !priv) {
self->robust_list.pending = 0;
__vm_unlock();