icyci: avoid timer deadlock in transitionState

If stateTransTimer has already been stopped (without reset) then drain will deadlock. Avoid this by using a select + default case, as done in golang/go#27169 . Signed-off-by: David Disseldorp <[email protected]>
ddiss · Nov 14, 2019 · 7bf1c21 · 7bf1c21
1 parent 88a5792
commit 7bf1c21
Showing 1 changed file with 5 additions and 1 deletion.
diff --git a/icyci.go b/icyci.go
@@ -419,7 +419,11 @@ func transitionState(newState State, curState *State,
 	*curState = newState
 
 	if !stateTransTimer.Stop() {
-		<-stateTransTimer.C
+		// select + default to avoid deadlock when already stopped
+		select {
+		case <-stateTransTimer.C:
+		default:
+		}
 	}
 	if states[newState].timeout == time.Duration(0) {
 		log.Printf("state %d doesn't timeout", newState)