netty,okhttp,testing: always set TRANSPORT_ATTR_REMOTE_ADDR (#4217)

Always set the remote address, no reason why this should be a TLS-only
feature. This is needed for channelz, and is especially useful in unit
tests where we are using plaintext.

This PR adds the attr for plaintext.

netty/src/main/java/io/grpc/netty/ProtocolNegotiators.java

@@ -329,7 +329,7 @@ public final class ProtocolNegotiators {
       HttpClientCodec httpClientCodec = new HttpClientCodec();
       final HttpClientUpgradeHandler upgrader =
           new HttpClientUpgradeHandler(httpClientCodec, upgradeCodec, 1000);
-      return new BufferingHttp2UpgradeHandler(upgrader);
+      return new BufferingHttp2UpgradeHandler(upgrader, handler);
     }
   }
 
@@ -662,8 +662,11 @@ public final class ProtocolNegotiators {
   private static class BufferUntilChannelActiveHandler extends AbstractBufferingHandler
       implements ProtocolNegotiator.Handler {
 
-    BufferUntilChannelActiveHandler(ChannelHandler... handlers) {
+    private final GrpcHttp2ConnectionHandler handler;
-      super(handlers);
+
+    BufferUntilChannelActiveHandler(GrpcHttp2ConnectionHandler handler) {
+      super(handler);
+      this.handler = handler;
     }
 
     @Override
@@ -679,6 +682,11 @@ public final class ProtocolNegotiators {
     @Override
     public void channelActive(ChannelHandlerContext ctx) throws Exception {
       writeBufferedAndRemove(ctx);
+      handler.handleProtocolNegotiationCompleted(
+          Attributes
+              .newBuilder()
+              .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, ctx.channel().remoteAddress())
+              .build());
       super.channelActive(ctx);
     }
   }
@@ -689,8 +697,11 @@ public final class ProtocolNegotiators {
   private static class BufferingHttp2UpgradeHandler extends AbstractBufferingHandler
       implements ProtocolNegotiator.Handler {
 
-    BufferingHttp2UpgradeHandler(ChannelHandler... handlers) {
+    private final GrpcHttp2ConnectionHandler grpcHandler;
-      super(handlers);
+
+    BufferingHttp2UpgradeHandler(ChannelHandler handler, GrpcHttp2ConnectionHandler grpcHandler) {
+      super(handler);
+      this.grpcHandler = grpcHandler;
     }
 
     @Override
@@ -712,6 +723,11 @@ public final class ProtocolNegotiators {
     public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
       if (evt == HttpClientUpgradeHandler.UpgradeEvent.UPGRADE_SUCCESSFUL) {
         writeBufferedAndRemove(ctx);
+        grpcHandler.handleProtocolNegotiationCompleted(
+            Attributes
+                .newBuilder()
+                .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, ctx.channel().remoteAddress())
+                .build());
       } else if (evt == HttpClientUpgradeHandler.UpgradeEvent.UPGRADE_REJECTED) {
         fail(ctx, unavailableException("HTTP/2 upgrade rejected"));
       }

okhttp/src/main/java/io/grpc/okhttp/OkHttpClientStream.java

@@ -58,6 +58,7 @@ class OkHttpClientStream extends AbstractClientStream {
   private volatile int id = ABSENT_ID;
   private final TransportState state;
   private final Sink sink = new Sink();
+  private final Attributes attributes;
 
   private boolean useGet = false;
 
@@ -83,6 +84,10 @@ class OkHttpClientStream extends AbstractClientStream {
     this.method = method;
     this.authority = authority;
     this.userAgent = userAgent;
+    // OkHttpClientStream is only created after the transport has finished connecting,
+    // so it is safe to read the transport attributes.
+    // We make a copy here for convenience, even though we can ask the transport.
+    this.attributes = transport.getAttributes();
     this.state = new TransportState(maxMessageSize, statsTraceCtx, lock, frameWriter, outboundFlow,
         transport);
   }
@@ -123,7 +128,7 @@ class OkHttpClientStream extends AbstractClientStream {
 
   @Override
   public Attributes getAttributes() {
-    return Attributes.EMPTY;
+    return attributes;
   }
 
   class Sink implements AbstractClientStream.Sink {

okhttp/src/main/java/io/grpc/okhttp/OkHttpClientTransport.java

@@ -31,6 +31,7 @@ import com.squareup.okhttp.Request;
 import com.squareup.okhttp.internal.http.StatusLine;
 import io.grpc.Attributes;
 import io.grpc.CallOptions;
+import io.grpc.Grpc;
 import io.grpc.Metadata;
 import io.grpc.MethodDescriptor;
 import io.grpc.MethodDescriptor.MethodType;
@@ -149,6 +150,8 @@ class OkHttpClientTransport implements ConnectionClientTransport {
   private final int maxMessageSize;
   private int connectionUnacknowledgedBytesRead;
   private ClientFrameHandler clientFrameHandler;
+  // Caution: Not synchronized, new value can only be safely read after the connection is complete.
+  private Attributes attributes = Attributes.EMPTY;
   /**
    * Indicates the transport is in go-away state: no new streams will be processed, but existing
    * streams may continue.
@@ -467,6 +470,12 @@ class OkHttpClientTransport implements ConnectionClientTransport {
           sock.setTcpNoDelay(true);
           source = Okio.buffer(Okio.source(sock));
           sink = Okio.buffer(Okio.sink(sock));
+          // TODO(zhangkun83): fill channel security attributes
+          // The return value of OkHttpTlsUpgrader.upgrade is an SSLSocket that has this info
+          attributes = Attributes
+              .newBuilder()
+              .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, sock.getRemoteSocketAddress())
+              .build();
         } catch (StatusException e) {
           startGoAway(0, ErrorCode.INTERNAL_ERROR, e.getStatus());
           return;
@@ -482,6 +491,7 @@ class OkHttpClientTransport implements ConnectionClientTransport {
         synchronized (lock) {
           socket = sock;
           maxConcurrentStreams = Integer.MAX_VALUE;
+
           startPendingStreams();
         }
 
@@ -675,8 +685,7 @@ class OkHttpClientTransport implements ConnectionClientTransport {
 
   @Override
   public Attributes getAttributes() {
-    // TODO(zhangkun83): fill channel security attributes
+    return attributes;
-    return Attributes.EMPTY;
   }
 
   /**

testing/src/main/java/io/grpc/internal/testing/AbstractTransportTest.java

@@ -68,8 +68,6 @@ import io.grpc.internal.ServerTransportListener;
 import java.io.ByteArrayInputStream;
 import java.io.IOException;
 import java.io.InputStream;
-import java.net.InetAddress;
-import java.net.InetSocketAddress;
 import java.net.SocketAddress;
 import java.util.Arrays;
 import java.util.List;
@@ -231,7 +229,7 @@ public abstract class AbstractTransportTest {
   public void frameAfterRstStreamShouldNotBreakClientChannel() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     serverTransport = serverTransportListener.transport;
@@ -298,7 +296,7 @@ public abstract class AbstractTransportTest {
     server.start(serverListener);
     client = newClientTransport(server);
     InOrder inOrder = inOrder(mockClientTransportListener);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     Status shutdownReason = Status.UNAVAILABLE.withDescription("shutdown called");
     client.shutdown(shutdownReason);
     verify(mockClientTransportListener, timeout(TIMEOUT_MS)).transportTerminated();
@@ -312,7 +310,7 @@ public abstract class AbstractTransportTest {
     server.start(serverListener);
     client = newClientTransport(server);
     InOrder inOrder = inOrder(mockClientTransportListener);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     verify(mockClientTransportListener, timeout(TIMEOUT_MS)).transportReady();
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
@@ -340,7 +338,7 @@ public abstract class AbstractTransportTest {
   public void openStreamPreventsTermination() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     serverTransport = serverTransportListener.transport;
@@ -392,7 +390,7 @@ public abstract class AbstractTransportTest {
   public void shutdownNowKillsClientStream() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     serverTransport = serverTransportListener.transport;
@@ -429,7 +427,7 @@ public abstract class AbstractTransportTest {
   public void shutdownNowKillsServerStream() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     serverTransport = serverTransportListener.transport;
@@ -470,7 +468,7 @@ public abstract class AbstractTransportTest {
   public void ping() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     ClientTransport.PingCallback mockPingCallback = mock(ClientTransport.PingCallback.class);
     try {
       client.ping(mockPingCallback, MoreExecutors.directExecutor());
@@ -486,7 +484,7 @@ public abstract class AbstractTransportTest {
   public void ping_duringShutdown() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     // Stream prevents termination
     ClientStream stream = client.newStream(methodDescriptor, new Metadata(), callOptions);
     ClientStreamListenerBase clientStreamListener = new ClientStreamListenerBase();
@@ -508,7 +506,7 @@ public abstract class AbstractTransportTest {
   public void ping_afterTermination() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     verify(mockClientTransportListener, timeout(TIMEOUT_MS)).transportReady();
     Status shutdownReason = Status.UNAVAILABLE.withDescription("shutdown called");
     client.shutdown(shutdownReason);
@@ -530,7 +528,7 @@ public abstract class AbstractTransportTest {
     InOrder inOrder = inOrder(clientStreamTracerFactory);
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     // Stream prevents termination
     ClientStream stream = client.newStream(methodDescriptor, new Metadata(), callOptions);
     inOrder.verify(clientStreamTracerFactory).newClientStreamTracer(
@@ -570,7 +568,7 @@ public abstract class AbstractTransportTest {
     // dealing with afterTermination is harder than duringShutdown.
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     verify(mockClientTransportListener, timeout(TIMEOUT_MS)).transportReady();
     Status shutdownReason = Status.UNAVAILABLE.withDescription("shutdown called");
     client.shutdown(shutdownReason);
@@ -594,7 +592,7 @@ public abstract class AbstractTransportTest {
   public void transportInUse_normalClose() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     ClientStream stream1 = client.newStream(methodDescriptor, new Metadata(), callOptions);
     ClientStreamListenerBase clientStreamListener1 = new ClientStreamListenerBase();
     stream1.start(clientStreamListener1);
@@ -624,7 +622,7 @@ public abstract class AbstractTransportTest {
   public void transportInUse_clientCancel() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     ClientStream stream1 = client.newStream(methodDescriptor, new Metadata(), callOptions);
     ClientStreamListenerBase clientStreamListener1 = new ClientStreamListenerBase();
     stream1.start(clientStreamListener1);
@@ -649,7 +647,7 @@ public abstract class AbstractTransportTest {
     InOrder serverInOrder = inOrder(serverStreamTracerFactory);
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     serverTransport = serverTransportListener.transport;
@@ -804,7 +802,7 @@ public abstract class AbstractTransportTest {
   public void authorityPropagation() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
             = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
 
@@ -823,7 +821,7 @@ public abstract class AbstractTransportTest {
   public void zeroMessageStream() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     serverTransport = serverTransportListener.transport;
@@ -859,7 +857,7 @@ public abstract class AbstractTransportTest {
   public void earlyServerClose_withServerHeaders() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     serverTransport = serverTransportListener.transport;
@@ -894,7 +892,7 @@ public abstract class AbstractTransportTest {
   public void earlyServerClose_noServerHeaders() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     serverTransport = serverTransportListener.transport;
@@ -938,7 +936,7 @@ public abstract class AbstractTransportTest {
   public void earlyServerClose_serverFailure() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     serverTransport = serverTransportListener.transport;
@@ -1016,7 +1014,7 @@ public abstract class AbstractTransportTest {
   public void clientCancel() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     serverTransport = serverTransportListener.transport;
@@ -1047,7 +1045,7 @@ public abstract class AbstractTransportTest {
   public void clientCancelFromWithinMessageRead() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     serverTransport = serverTransportListener.transport;
@@ -1134,7 +1132,7 @@ public abstract class AbstractTransportTest {
   public void serverCancel() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     serverTransport = serverTransportListener.transport;
@@ -1182,7 +1180,7 @@ public abstract class AbstractTransportTest {
 
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener =
         serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     serverTransport = serverTransportListener.transport;
@@ -1343,7 +1341,7 @@ public abstract class AbstractTransportTest {
   public void interactionsAfterServerStreamCloseAreNoops() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     serverTransport = serverTransportListener.transport;
@@ -1375,7 +1373,7 @@ public abstract class AbstractTransportTest {
   public void interactionsAfterClientStreamCancelAreNoops() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     serverTransport = serverTransportListener.transport;
@@ -1411,7 +1409,7 @@ public abstract class AbstractTransportTest {
   public void transportTracer_streamStarted() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     MockServerTransportListener serverTransportListener
         = serverListener.takeListenerOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     if (!haveTransportTracer()) {
@@ -1496,7 +1494,7 @@ public abstract class AbstractTransportTest {
   public void transportTracer_server_streamEnded_ok() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     ClientStream clientStream = client.newStream(methodDescriptor, new Metadata(), callOptions);
     ClientStreamListenerBase clientStreamListener = new ClientStreamListenerBase();
     clientStream.start(clientStreamListener);
@@ -1535,7 +1533,7 @@ public abstract class AbstractTransportTest {
   public void transportTracer_server_streamEnded_nonOk() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     ClientStream clientStream = client.newStream(methodDescriptor, new Metadata(), callOptions);
     ClientStreamListenerBase clientStreamListener = new ClientStreamListenerBase();
     clientStream.start(clientStreamListener);
@@ -1575,7 +1573,7 @@ public abstract class AbstractTransportTest {
   public void transportTracer_client_streamEnded_nonOk() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     ClientStream clientStream = client.newStream(methodDescriptor, new Metadata(), callOptions);
     ClientStreamListenerBase clientStreamListener = new ClientStreamListenerBase();
     clientStream.start(clientStreamListener);
@@ -1610,7 +1608,7 @@ public abstract class AbstractTransportTest {
   public void transportTracer_server_receive_msg() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     ClientStream clientStream = client.newStream(methodDescriptor, new Metadata(), callOptions);
     ClientStreamListenerBase clientStreamListener = new ClientStreamListenerBase();
     clientStream.start(clientStreamListener);
@@ -1655,7 +1653,7 @@ public abstract class AbstractTransportTest {
   public void transportTracer_server_send_msg() throws Exception {
     server.start(serverListener);
     client = newClientTransport(server);
-    runIfNotNull(client.start(mockClientTransportListener));
+    startTransport(client, mockClientTransportListener);
     ClientStream clientStream = client.newStream(methodDescriptor, new Metadata(), callOptions);
     ClientStreamListenerBase clientStreamListener = new ClientStreamListenerBase();
     clientStream.start(clientStreamListener);
@@ -1700,7 +1698,7 @@ public abstract class AbstractTransportTest {
   public void socketStats_addresses() throws Exception {
     server.start(serverListener);
     ManagedClientTransport client = newClientTransport(server);
-    runIfNotNull(client.start(mock(ManagedClientTransport.Listener.class)));
+    startTransport(client, mockClientTransportListener);
     ClientStream clientStream = client.newStream(methodDescriptor, new Metadata(), callOptions);
     ClientStreamListenerBase clientStreamListener = new ClientStreamListenerBase();
     clientStream.start(clientStreamListener);
@@ -1711,9 +1709,7 @@ public abstract class AbstractTransportTest {
         = serverTransportListener.takeStreamOrFail(TIMEOUT_MS, TimeUnit.MILLISECONDS);
     ServerStream serverStream = serverStreamCreation.stream;
 
-    // clients do not have TRANSPORT_ATTR_REMOTE_ADDR so use a hack for serverAddress
+    SocketAddress serverAddress = clientStream.getAttributes().get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR);
-    SocketAddress serverAddress
-        = new InetSocketAddress(InetAddress.getByName("127.0.0.1"), server.getPort());
     SocketAddress clientAddress = serverStream.getAttributes().get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR);
 
     SocketStats clientSocketStats = client.getStats().get();
@@ -1733,7 +1729,8 @@ public abstract class AbstractTransportTest {
    */
   private void doPingPong(MockServerListener serverListener) throws Exception {
     ManagedClientTransport client = newClientTransport(server);
-    runIfNotNull(client.start(mock(ManagedClientTransport.Listener.class)));
+    ManagedClientTransport.Listener listener = mock(ManagedClientTransport.Listener.class);
+    startTransport(client, listener);
     ClientStream clientStream = client.newStream(methodDescriptor, new Metadata(), callOptions);
     ClientStreamListenerBase clientStreamListener = new ClientStreamListenerBase();
     clientStream.start(clientStreamListener);
@@ -1798,6 +1795,13 @@ public abstract class AbstractTransportTest {
     }
   }
 
+  private static void startTransport(
+      ManagedClientTransport clientTransport,
+      ManagedClientTransport.Listener listener) {
+    runIfNotNull(clientTransport.start(listener));
+    verify(listener, timeout(100)).transportReady();
+  }
+
   private static class MockServerListener implements ServerListener {
     public final BlockingQueue<MockServerTransportListener> listeners
         = new LinkedBlockingQueue<MockServerTransportListener>();