fix comments

balancer/roundrobin/roundrobin_test.go

@@ -37,6 +37,8 @@ import (
 	"google.golang.org/grpc/test/leakcheck"
 )
 
+var rr = balancer.Get("roundrobin")
+
 type testServer struct {
 	testpb.TestServiceServer
 }
@@ -100,10 +102,6 @@ func TestOneBackend(t *testing.T) {
 	}
 	defer test.cleanup()
 
-	rr := balancer.Get("roundrobin")
-	if rr == nil {
-		t.Fatalf("got nil when trying to get roundrobin balancer builder")
-	}
 	cc, err := grpc.Dial(r.Scheme()+":///test.server", grpc.WithInsecure(), grpc.WithBalancerBuilder(rr))
 	if err != nil {
 		t.Fatalf("failed to dial: %v", err)
@@ -136,10 +134,6 @@ func TestBackendsRoundRobin(t *testing.T) {
 	}
 	defer test.cleanup()
 
-	rr := balancer.Get("roundrobin")
-	if rr == nil {
-		t.Fatalf("got nil when trying to get roundrobin balancer builder")
-	}
 	cc, err := grpc.Dial(r.Scheme()+":///test.server", grpc.WithInsecure(), grpc.WithBalancerBuilder(rr))
 	if err != nil {
 		t.Fatalf("failed to dial: %v", err)
@@ -199,10 +193,6 @@ func TestAddressesRemoved(t *testing.T) {
 	}
 	defer test.cleanup()
 
-	rr := balancer.Get("roundrobin")
-	if rr == nil {
-		t.Fatalf("got nil when trying to get roundrobin balancer builder")
-	}
 	cc, err := grpc.Dial(r.Scheme()+":///test.server", grpc.WithInsecure(), grpc.WithBalancerBuilder(rr))
 	if err != nil {
 		t.Fatalf("failed to dial: %v", err)
@@ -245,10 +235,6 @@ func TestCloseWithPendingRPC(t *testing.T) {
 	}
 	defer test.cleanup()
 
-	rr := balancer.Get("roundrobin")
-	if rr == nil {
-		t.Fatalf("got nil when trying to get roundrobin balancer builder")
-	}
 	cc, err := grpc.Dial(r.Scheme()+":///test.server", grpc.WithInsecure(), grpc.WithBalancerBuilder(rr))
 	if err != nil {
 		t.Fatalf("failed to dial: %v", err)
@@ -283,10 +269,6 @@ func TestNewAddressWhileBlocking(t *testing.T) {
 	}
 	defer test.cleanup()
 
-	rr := balancer.Get("roundrobin")
-	if rr == nil {
-		t.Fatalf("got nil when trying to get roundrobin balancer builder")
-	}
 	cc, err := grpc.Dial(r.Scheme()+":///test.server", grpc.WithInsecure(), grpc.WithBalancerBuilder(rr))
 	if err != nil {
 		t.Fatalf("failed to dial: %v", err)
@@ -336,10 +318,6 @@ func TestOneServerDown(t *testing.T) {
 	}
 	defer test.cleanup()
 
-	rr := balancer.Get("roundrobin")
-	if rr == nil {
-		t.Fatalf("got nil when trying to get roundrobin balancer builder")
-	}
 	cc, err := grpc.Dial(r.Scheme()+":///test.server", grpc.WithInsecure(), grpc.WithBalancerBuilder(rr))
 	if err != nil {
 		t.Fatalf("failed to dial: %v", err)
@@ -433,10 +411,6 @@ func TestAllServersDown(t *testing.T) {
 	}
 	defer test.cleanup()
 
-	rr := balancer.Get("roundrobin")
-	if rr == nil {
-		t.Fatalf("got nil when trying to get roundrobin balancer builder")
-	}
 	cc, err := grpc.Dial(r.Scheme()+":///test.server", grpc.WithInsecure(), grpc.WithBalancerBuilder(rr))
 	if err != nil {
 		t.Fatalf("failed to dial: %v", err)

balancer_switching_test.go

@@ -37,14 +37,25 @@ func checkPickFirst(cc *ClientConn, servers []*server) error {
 		reply string
 		err   error
 	)
-	// The second RPC should succeed with the first server.
+	connected := false
 	for i := 0; i < 1000; i++ {
 		if err = Invoke(context.Background(), "/foo/bar", &req, &reply, cc); err != nil && ErrorDesc(err) == servers[0].port {
-			return nil
+			connected = true
+			break
 		}
 		time.Sleep(time.Millisecond)
 	}
-	return fmt.Errorf("EmptyCall() = _, %v, want _, %v", err, servers[0].port)
+	if !connected {
+		return fmt.Errorf("EmptyCall() = _, %v, want _, %v", err, servers[0].port)
+	}
+	// The following RPCs should all succeed with the first server.
+	for i := 0; i < 3; i++ {
+		err = Invoke(context.Background(), "/foo/bar", &req, &reply, cc)
+		if ErrorDesc(err) != servers[0].port {
+			return fmt.Errorf("Index %d: want peer %v, got peer %v", i, servers[0].port, err)
+		}
+	}
+	return nil
 }
 
 func checkRoundRobin(cc *ClientConn, servers []*server) error {

clientconn.go

@@ -623,15 +623,14 @@ func (cc *ClientConn) handleResolvedAddrs(addrs []resolver.Address, err error) {
 // switchBalancer starts the switching from current balancer to the balancer with name.
 func (cc *ClientConn) switchBalancer(name string) {
 	cc.mu.Lock()
+	defer cc.mu.Unlock()
 	if cc.conns == nil {
-		cc.mu.Unlock()
 		return
 	}
-	defer cc.mu.Unlock()
 	grpclog.Infof("ClientConn switching balancer to %q", name)
 
 	if cc.customBalancer {
-		grpclog.Infoln("failed to switch balancer because custom balancer was set")
+		grpclog.Infoln("ignoring service config balancer configuration: WithBalancer DialOption used instead")
 		return
 	}
 
@@ -659,10 +658,10 @@ func (cc *ClientConn) handleSubConnStateChange(sc balancer.SubConn, s connectivi
 		cc.mu.Unlock()
 		return
 	}
-	defer cc.mu.Unlock()
 	// TODO(bar switching) send updates to all balancer wrappers when balancer
 	// gracefully switching is supported.
 	cc.balancerWrapper.handleSubConnStateChange(sc, s)
+	cc.mu.Unlock()
 }
 
 // newAddrConn creates an addrConn for addrs and adds it to cc.conns.