add lock

typed.go

@@ -36,6 +36,7 @@ var (
 	stacks        starmap.StarStack
 	stackStarted  bool = false
 	stackStopChan chan int
+	stackMu       sync.Mutex
 	stdScreen     io.Writer = colorable.NewColorableStdout()
 )
 
@@ -145,11 +146,14 @@ func generateId() string {
 }
 
 func StartStacks() {
+	stackMu.Lock()
 	if stackStarted {
+		stackMu.Unlock()
 		return
 	}
 	go func() {
 		stackStarted = true
+		stackMu.Unlock()
 		defer func() {
 			stackStarted = false
 		}()