Minor code cleanup

processor.go

@@ -159,17 +159,18 @@ func (p *processor) start(wg *sync.WaitGroup) {
 func (p *processor) exec() {
 	qnames := p.queues()
 	msg, err := p.broker.Dequeue(qnames...)
-	if err == rdb.ErrNoProcessableTask { // TODO: Need to decouple this error from rdb to support other brokers
+	switch {
+	case err == rdb.ErrNoProcessableTask:
 		// queues are empty, this is a normal behavior.
-		if len(p.queueConfig) > 1 {
+		if len(qnames) > 1 {
 			// sleep to avoid slamming redis and let scheduler move tasks into queues.
 			// Note: With multiple queues, we are not using blocking pop operation and
 			// polling queues instead. This adds significant load to redis.
 			time.Sleep(time.Second)
 		}
+		p.logger.Debug("All queues are empty")
 		return
-	}
-	if err != nil {
+	case err != nil:
 		if p.errLogLimiter.Allow() {
 			p.logger.Errorf("Dequeue error: %v", err)
 		}
@@ -186,7 +187,7 @@ func (p *processor) exec() {
 		go func() {
 			defer func() {
 				p.ss.DeleteWorkerStats(msg)
-				<-p.sema /* release token */
+				<-p.sema // release token
 			}()
 
 			ctx, cancel := createContext(msg)