optimize spinlock spin

diff --git a/src/thread/pthread_spin_lock.c b/src/thread/pthread_spin_lock.c
index 59fa6ea..9e43f47 100644 (file)
--- a/src/thread/pthread_spin_lock.c
+++ b/src/thread/pthread_spin_lock.c
@@ -2,6 +2,6 @@
 
 int pthread_spin_lock(pthread_spinlock_t *s)
 {
-       while (a_xchg(s, 1));
+       while (*s || a_xchg(s, 1));
        return 0;
 }