condition variable signal/bcast need not wake unless there are waiters

diff --git a/src/thread/pthread_cond_broadcast.c b/src/thread/pthread_cond_broadcast.c
index 1d378c0b271b0420044a5dc842eba04f6c3887e0..30f7f6df6984bf403694e78d73ebd5a563ba4976 100644 (file)
--- a/src/thread/pthread_cond_broadcast.c
+++ b/src/thread/pthread_cond_broadcast.c
@@ -2,7 +2,7 @@
 
 int pthread_cond_broadcast(pthread_cond_t *c)
 {
-       c->_c_block = 0;
-       __wake(&c->_c_block, -1, 0);
+       if (a_swap(&c->_c_block, 0))
+               __wake(&c->_c_block, -1, 0);
        return 0;
 }

diff --git a/src/thread/pthread_cond_signal.c b/src/thread/pthread_cond_signal.c
index 574f5c79bab9a6e04a3078a1748a2a45f2901d39..a0211287be7dd748b2d9f2cd76352692493e8d26 100644 (file)
--- a/src/thread/pthread_cond_signal.c
+++ b/src/thread/pthread_cond_signal.c
@@ -2,7 +2,7 @@
 
 int pthread_cond_signal(pthread_cond_t *c)
 {
-       c->_c_block = 0;
-       __wake(&c->_c_block, 1, 0);
+       if (a_swap(&c->_c_block, 0));
+               __wake(&c->_c_block, 1, 0);
        return 0;
 }