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Diffstat (limited to 'src/thread/pthread_cond_timedwait.c')
-rw-r--r--src/thread/pthread_cond_timedwait.c21
1 files changed, 19 insertions, 2 deletions
diff --git a/src/thread/pthread_cond_timedwait.c b/src/thread/pthread_cond_timedwait.c
index c71edc95..9616dd85 100644
--- a/src/thread/pthread_cond_timedwait.c
+++ b/src/thread/pthread_cond_timedwait.c
@@ -5,10 +5,25 @@ struct cm {
pthread_mutex_t *m;
};
+static void unwait(pthread_cond_t *c, pthread_mutex_t *m)
+{
+ int w;
+
+ /* Cannot leave waiting status if there are any live broadcasters
+ * which might be inspecting/using the mutex. */
+ while ((w=c->_c_bcast)) __wait(&c->_c_bcast, &c->_c_leavers, w, 0);
+
+ /* If the waiter count is zero, it must be the case that the
+ * caller's count has been moved to the mutex due to bcast. */
+ do w = c->_c_waiters;
+ while (w && a_cas(&c->_c_waiters, w, w-1)!=w);
+ if (!w) a_dec(&m->_m_waiters);
+}
+
static void cleanup(void *p)
{
struct cm *cm = p;
- a_dec(&cm->c->_c_waiters);
+ unwait(cm->c, cm->m);
pthread_mutex_lock(cm->m);
}
@@ -22,6 +37,8 @@ int pthread_cond_timedwait(pthread_cond_t *c, pthread_mutex_t *m, const struct t
pthread_testcancel();
+ if (c->_c_mutex != (void *)-1) c->_c_mutex = m;
+
a_inc(&c->_c_waiters);
c->_c_block = tid = pthread_self()->tid;
@@ -31,7 +48,7 @@ int pthread_cond_timedwait(pthread_cond_t *c, pthread_mutex_t *m, const struct t
while (c->_c_block == tid && (!e || e==EINTR));
if (e == EINTR) e = 0;
- a_dec(&c->_c_waiters);
+ unwait(c, m);
if ((r=pthread_mutex_lock(m))) return r;