Do not allow validator to be restarted

ops/validator.go

@@ -19,23 +19,30 @@ type Validator struct {
 	Logger   tacitus.Logger
 	Products []string
 
-	ticker *time.Ticker
-	done   chan bool
+	done   chan struct{}
+	dirty  bool
 }
 
 func (v *Validator) Stop() {
-	if v.ticker == nil || v.done == nil {
-		v.ticker.Stop()
-		v.done <- true
+	if v.done != nil {
+		select {
+		case v.done <- struct{}{}:
+		default:
+		}
+
 	}
 }
 
 func (v *Validator) Start(frequency time.Duration) {
-	v.ticker = time.NewTicker(frequency)
-	v.done = make(chan bool)
+	if v.dirty == true {
+		return
+	}
+
+	v.dirty = true
+	v.done = make(chan struct{})
 
 	go func() {
-		v.emitProducts()
+		ticker := time.NewTicker(frequency)
 
 		var done bool
 
@@ -43,12 +50,12 @@ func (v *Validator) Start(frequency time.Duration) {
 			select {
 			case <-v.done:
 				done = true
-			case <-v.ticker.C:
+				ticker.Stop()
+			case <-ticker.C:
 				v.emitProducts()
 			}
 		}
 
-		v.ticker = nil
 		v.done = nil
 	}()
 }