TUN-4456: Replaced instances of Tick() with Ticker() in h2mux paths

time.Tick() does not get garbage collected because the channel
underneath never gets deleted and the underlying Ticker can never be
recovered by the garbage collector. We replace this with NewTicker() to
avoid this.

connection/h2mux.go

@@ -167,7 +167,8 @@ func (h *h2muxConnection) serveMuxer(ctx context.Context) error {
 }
 
 func (h *h2muxConnection) controlLoop(ctx context.Context, connectedFuse ConnectedFuse, isNamedTunnel bool) {
-	updateMetricsTickC := time.Tick(h.muxerConfig.MetricsUpdateFreq)
+	updateMetricsTicker := time.NewTicker(h.muxerConfig.MetricsUpdateFreq)
+	defer updateMetricsTicker.Stop()
 	var shutdownCompleted <-chan struct{}
 	for {
 		select {
@@ -191,7 +192,7 @@ func (h *h2muxConnection) controlLoop(ctx context.Context, connectedFuse Connect
 			// don't wait for shutdown to finish when context is closed, this is the hard termination path
 			return
 
-		case <-updateMetricsTickC:
+		case <-updateMetricsTicker.C:
 			h.observer.metrics.updateMuxerMetrics(h.connIndexStr, h.muxer.Metrics())
 		}
 	}

h2mux/muxreader.go

@@ -69,12 +69,13 @@ func (r *MuxReader) run(log *zerolog.Logger) error {
 
 	// routine to periodically update bytesRead
 	go func() {
-		tickC := time.Tick(updateFreq)
+		ticker := time.NewTicker(updateFreq)
+		defer ticker.Stop()
 		for {
 			select {
 			case <-r.abortChan:
 				return
-			case <-tickC:
+			case <-ticker.C:
 				r.metricsUpdater.updateInBoundBytes(r.bytesRead.Count())
 			}
 		}

h2mux/muxwriter.go

@@ -78,12 +78,13 @@ func (w *MuxWriter) run(log *zerolog.Logger) error {
 
 	// routine to periodically communicate bytesWrote
 	go func() {
-		tickC := time.Tick(updateFreq)
+		ticker := time.NewTicker(updateFreq)
+		defer ticker.Stop()
 		for {
 			select {
 			case <-w.abortChan:
 				return
-			case <-tickC:
+			case <-ticker.C:
 				w.metricsUpdater.updateOutBoundBytes(w.bytesWrote.Count())
 			}
 		}