post-review updates

transport/control.go

@@ -56,7 +56,6 @@ const (
 // The following defines various control items which could flow through
 // the control buffer of transport. They represent different aspects of
 // control tasks, e.g., flow control, settings, streaming resetting, etc.
-
 type windowUpdate struct {
 	streamID  uint32
 	increment uint32

transport/http2_client.go

@@ -103,10 +103,10 @@ type http2Client struct {
 
 	creds []credentials.PerRPCCredentials
 
-	// Counter to keep track of reading activity on transport.
+	// Boolean to keep track of reading activity on transport.
-	activity uint64 // Accessed atomically.
+	// 1 is true and 0 is false.
-
+	activity uint32 // Accessed atomically.
-	kp keepalive.ClientParameters
+	kp       keepalive.ClientParameters
 
 	statsHandler stats.Handler
 
@@ -278,7 +278,9 @@ func newHTTP2Client(ctx context.Context, addr TargetInfo, opts ConnectOptions) (
 		}
 	}
 	go t.controller()
-	go t.keepalive()
+	if t.kp.Time != infinity {
+		go t.keepalive()
+	}
 	t.writableChan <- 0
 	return t, nil
 }
@@ -401,7 +403,7 @@ func (t *http2Client) NewStream(ctx context.Context, callHdr *CallHdr) (_ *Strea
 	if len(t.activeStreams) == 1 {
 		select {
 		case t.awakenKeepalive <- struct{}{}:
-			t.framer.writePing(true, false, [8]byte{})
+			t.framer.writePing(false, false, [8]byte{})
 		default:
 		}
 	}
@@ -1014,7 +1016,7 @@ func (t *http2Client) reader() {
 		t.notifyError(err)
 		return
 	}
-	atomic.AddUint64(&t.activity, 1)
+	atomic.CompareAndSwapUint32(&t.activity, 0, 1)
 	sf, ok := frame.(*http2.SettingsFrame)
 	if !ok {
 		t.notifyError(err)
@@ -1025,7 +1027,7 @@ func (t *http2Client) reader() {
 	// loop to keep reading incoming messages on this transport.
 	for {
 		frame, err := t.framer.readFrame()
-		atomic.AddUint64(&t.activity, 1)
+		atomic.CompareAndSwapUint32(&t.activity, 0, 1)
 		if err != nil {
 			// Abort an active stream if the http2.Framer returns a
 			// http2.StreamError. This can happen only if the server's response
@@ -1140,15 +1142,12 @@ func (t *http2Client) controller() {
 
 // keepalive running in a separate goroutune makes sure the connection is alive by sending pings.
 func (t *http2Client) keepalive() {
-	if t.kp.Time == infinity {
-		return
-	}
 	p := &ping{data: [8]byte{}}
 	timer := time.NewTimer(t.kp.Time)
 	for {
 		select {
 		case <-timer.C:
-			if a := atomic.SwapUint64(&t.activity, 0); a > 0 {
+			if a := atomic.SwapUint32(&t.activity, 0); a == 1 {
 				timer.Reset(t.kp.Time)
 				continue
 			}
@@ -1175,11 +1174,12 @@ func (t *http2Client) keepalive() {
 			timer.Reset(t.kp.Timeout)
 			select {
 			case <-timer.C:
-				if a := atomic.SwapUint64(&t.activity, 0); a > 0 {
+				if a := atomic.SwapUint32(&t.activity, 0); a == 1 {
 					timer.Reset(t.kp.Time)
 					continue
 				}
 				t.Close()
+				return
 			case <-t.shutdownChan:
 				if !timer.Stop() {
 					<-timer.C