Method TestServer_MaxHandlers

server_ext_test.go:42–105

TestServer_MaxHandlers ensures that no more than MaxConcurrentStreams server handlers are active at one time.

(t *testing.T)

// TestServer_MaxHandlers ensures that no more than MaxConcurrentStreams server
// handlers are active at one time.
func (s) TestServer_MaxHandlers(t *testing.T) {
	started := make(chan struct{})
	blockCalls := grpcsync.NewEvent()

	// This stub server does not properly respect the stream context, so it will
	// not exit when the context is canceled.
	ss := stubserver.StubServer{
		FullDuplexCallF: func(testgrpc.TestService_FullDuplexCallServer) error {
			started <- struct{}{}
			<-blockCalls.Done()
			return nil
		},
	}
	if err := ss.Start([]grpc.ServerOption{grpc.MaxConcurrentStreams(1)}); err != nil {
		t.Fatal("Error starting server:", err)
	}
	defer ss.Stop()

	ctx, cancel := context.WithTimeout(context.Background(), defaultTestTimeout)
	defer cancel()

	// Start one RPC to the server.
	ctx1, cancel1 := context.WithCancel(ctx)
	_, err := ss.Client.FullDuplexCall(ctx1)
	if err != nil {
		t.Fatal("Error staring call:", err)
	}

	// Wait for the handler to be invoked.
	select {
	case <-started:
	case <-ctx.Done():
		t.Fatalf("Timed out waiting for RPC to start on server.")
	}

	// Cancel it on the client.  The server handler will still be running.
	cancel1()

	ctx2, cancel2 := context.WithCancel(ctx)
	defer cancel2()
	s, err := ss.Client.FullDuplexCall(ctx2)
	if err != nil {
		t.Fatal("Error staring call:", err)
	}

	// After 100ms, allow the first call to unblock.  That should allow the
	// second RPC to run and finish.
	select {
	case <-started:
		blockCalls.Fire()
		t.Fatalf("RPC started unexpectedly.")
	case <-time.After(100 * time.Millisecond):
		blockCalls.Fire()
	}

	select {
	case <-started:
	case <-ctx.Done():