cv_tick: bug fix.

5ac7038c · Silas Boyd-Wickizer · 69db41a0 · 5ac7038c
--- a/condvar.c
+++ b/condvar.c
@@ -28,6 +28,7 @@ void
 cv_tick(void)
 {
  struct proc *p, *tmp;
+  struct condvar *cv;
  int again;
  u64 now;
@@ -45,10 +46,11 @@ cv_tick(void)
        if (tryacquire(&p->lock)) {
          if (tryacquire(&p->oncv->lock)) {
            LIST_REMOVE(p, cv_sleep);
+            cv = p->oncv;
            p->cv_wakeup = 0;
            wakeup(p);
            release(&p->lock);
-            release(&p->oncv->lock);
+            release(&cv->lock);
            continue;
          } else {
            release(&p->lock);