Add log ID.

To ManagedChannelImpl, TransportSet and all client transport
implementations, so they can be correlated in the logs. Also added more
life-cycle logging in general.

core/src/main/java/io/grpc/inprocess/InProcessTransport.java

@@ -40,6 +40,7 @@ import io.grpc.MethodDescriptor;
 import io.grpc.Status;
 import io.grpc.internal.ClientStream;
 import io.grpc.internal.ClientStreamListener;
+import io.grpc.internal.GrpcUtil;
 import io.grpc.internal.ManagedClientTransport;
 import io.grpc.internal.NoopClientStream;
 import io.grpc.internal.ServerStream;
@@ -166,7 +167,12 @@ class InProcessTransport implements ServerTransport, ManagedClientTransport {
 
   @Override
   public String toString() {
-    return super.toString() + "(" + name + ")";
+    return getLogId() + "(" + name + ")";
+  }
+
+  @Override
+  public String getLogId() {
+    return GrpcUtil.getLogId(this);
   }
 
   private synchronized void notifyShutdown(Status s) {

core/src/main/java/io/grpc/internal/DelayedClientTransport.java

@@ -230,6 +230,11 @@ class DelayedClientTransport implements ManagedClientTransport {
     }
   }
 
+  @Override
+  public String getLogId() {
+    return GrpcUtil.getLogId(this);
+  }
+
   private class PendingStream extends DelayedStream {
     private final MethodDescriptor<?, ?> method;
     private final Metadata headers;

core/src/main/java/io/grpc/internal/GrpcUtil.java

@@ -479,5 +479,12 @@ public final class GrpcUtil {
     }
   }
 
+  /**
+   * The canonical implementation of {@link WithLogId#getLogId}.
+   */
+  public static String getLogId(WithLogId subject) {
+    return subject.getClass().getSimpleName() + "@" + Integer.toHexString(subject.hashCode());
+  }
+
   private GrpcUtil() {}
 }

core/src/main/java/io/grpc/internal/ManagedChannelImpl.java

@@ -68,6 +68,8 @@ import java.util.concurrent.Executor;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 import java.util.regex.Pattern;
 
 import javax.annotation.Nullable;
@@ -76,7 +78,9 @@ import javax.annotation.concurrent.ThreadSafe;
 
 /** A communication channel for making outgoing RPCs. */
 @ThreadSafe
-public final class ManagedChannelImpl extends ManagedChannel {
+public final class ManagedChannelImpl extends ManagedChannel implements WithLogId {
+  private static final Logger log = Logger.getLogger(ManagedChannelImpl.class.getName());
+
   // Matching this pattern means the target string is a URI target or at least intended to be one.
   // A URI target must be an absolute hierarchical URI.
   // From RFC 2396: scheme = alpha *( alpha | digit | "+" | "-" | "." )
@@ -173,6 +177,9 @@ public final class ManagedChannelImpl extends ManagedChannel {
         loadBalancer.handleNameResolutionError(error);
       }
     });
+    if (log.isLoggable(Level.INFO)) {
+      log.log(Level.INFO, "[{0}] Created with target {1}", new Object[] {getLogId(), target});
+    }
   }
 
   @VisibleForTesting
@@ -252,6 +259,9 @@ public final class ManagedChannelImpl extends ManagedChannel {
     for (DelayedClientTransport transport : delayedTransportsCopy) {
       transport.shutdown();
     }
+    if (log.isLoggable(Level.FINE)) {
+      log.log(Level.FINE, "[{0}] Shutting down", getLogId());
+    }
     return this;
   }
 
@@ -344,6 +354,9 @@ public final class ManagedChannelImpl extends ManagedChannel {
       return;
     }
     if (shutdown && transports.isEmpty() && delayedTransports.isEmpty()) {
+      if (log.isLoggable(Level.INFO)) {
+        log.log(Level.INFO, "[{0}] Terminated", getLogId());
+      }
       terminated = true;
       lock.notifyAll();
       if (usingSharedExecutor) {
@@ -380,6 +393,10 @@ public final class ManagedChannelImpl extends ManagedChannel {
                   }
                 }
               });
+          if (log.isLoggable(Level.FINE)) {
+            log.log(Level.FINE, "[{0}] {1} created for {2}",
+                new Object[] {getLogId(), ts.getLogId(), addressGroup});
+          }
           transports.put(addressGroup, ts);
         }
       }
@@ -403,6 +420,11 @@ public final class ManagedChannelImpl extends ManagedChannel {
     }
   };
 
+  @Override
+  public String getLogId() {
+    return GrpcUtil.getLogId(this);
+  }
+
   private class InterimTransportImpl implements InterimTransport<ClientTransport> {
     private final DelayedClientTransport delayedTransport;
     private boolean closed;

core/src/main/java/io/grpc/internal/ManagedClientTransport.java

@@ -47,7 +47,7 @@ import javax.annotation.concurrent.ThreadSafe;
  * {@link Listener#transportTerminated}.
  */
 @ThreadSafe
-public interface ManagedClientTransport extends ClientTransport {
+public interface ManagedClientTransport extends ClientTransport, WithLogId {
 
   /**
    * Starts transport. This method may only be called once.

core/src/main/java/io/grpc/internal/TransportSet.java

@@ -59,9 +59,8 @@ import javax.annotation.concurrent.ThreadSafe;
  * Transports for a single {@link SocketAddress}.
  */
 @ThreadSafe
-final class TransportSet {
+final class TransportSet implements WithLogId {
   private static final Logger log = Logger.getLogger(TransportSet.class.getName());
-
   private static final ClientTransport SHUTDOWN_TRANSPORT =
       new FailingClientTransport(Status.UNAVAILABLE.withDescription("TransportSet is shutdown"));
 
@@ -217,8 +216,10 @@ final class TransportSet {
             backoffWatch.reset().start();
           }
           newActiveTransport = transportFactory.newClientTransport(address, authority);
-          log.log(Level.FINE, "Created transport {0} for {1}",
-              new Object[] {newActiveTransport, address});
+          if (log.isLoggable(Level.FINE)) {
+            log.log(Level.FINE, "[{0}] Created {1} for {2}",
+                new Object[] {getLogId(), newActiveTransport.getLogId(), address});
+          }
           transports.add(newActiveTransport);
           newActiveTransport.start(
               new TransportListener(newActiveTransport, address));
@@ -258,6 +259,10 @@ final class TransportSet {
       }
     }
     firstAttempt = false;
+    if (log.isLoggable(Level.FINE)) {
+      log.log(Level.FINE, "[{0}] Scheduling connection after {1} ms for {2}",
+          new Object[]{getLogId(), delayMillis, address});
+    }
     if (delayMillis <= 0) {
       reconnectTask = null;
       // No back-off this time.
@@ -315,6 +320,11 @@ final class TransportSet {
     }
   }
 
+  @Override
+  public String getLogId() {
+    return GrpcUtil.getLogId(this);
+  }
+
   /** Shared base for both delayed and real transports. */
   private class BaseTransportListener implements ManagedClientTransport.Listener {
     protected final ManagedClientTransport transport;
@@ -335,6 +345,9 @@ final class TransportSet {
       synchronized (lock) {
         transports.remove(transport);
         if (shutdown && transports.isEmpty()) {
+          if (log.isLoggable(Level.FINE)) {
+            log.log(Level.FINE, "[{0}] Terminated", getLogId());
+          }
           runCallback = true;
           cancelReconnectTask();
         }
@@ -360,7 +373,10 @@ final class TransportSet {
 
     @Override
     public void transportReady() {
-      log.log(Level.FINE, "Transport {0} for {1} is ready", new Object[] {transport, address});
+      if (log.isLoggable(Level.FINE)) {
+        log.log(Level.FINE, "[{0}] {1} for {2} is ready",
+            new Object[] {getLogId(), transport.getLogId(), address});
+      }
       super.transportReady();
       synchronized (lock) {
         if (isAttachedToActiveTransport()) {
@@ -372,8 +388,10 @@ final class TransportSet {
 
     @Override
     public void transportShutdown(Status s) {
-      log.log(Level.FINE, "Transport {0} for {1} is being shutdown",
-          new Object[] {transport, address});
+      if (log.isLoggable(Level.FINE)) {
+        log.log(Level.FINE, "[{0}] {1} for {2} is being shutdown with status {3}",
+            new Object[] {getLogId(), transport.getLogId(), address, s});
+      }
       super.transportShutdown(s);
       synchronized (lock) {
         if (isAttachedToActiveTransport()) {
@@ -385,8 +403,10 @@ final class TransportSet {
 
     @Override
     public void transportTerminated() {
-      log.log(Level.FINE, "Transport {0} for {1} is terminated",
-          new Object[] {transport, address});
+      if (log.isLoggable(Level.FINE)) {
+        log.log(Level.FINE, "[{0}] {1} for {2} is terminated",
+            new Object[] {getLogId(), transport.getLogId(), address});
+      }
       super.transportTerminated();
       Preconditions.checkState(!isAttachedToActiveTransport(),
           "Listener is still attached to activeTransport. "

core/src/main/java/io/grpc/internal/WithLogId.java

@@ -0,0 +1,47 @@
+/*
+ * Copyright 2016, Google Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *    * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *    * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *
+ *    * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package io.grpc.internal;
+
+/**
+ * An object that has an ID that is unique within the JVM, primarily for debug logging.
+ */
+public interface WithLogId {
+  /**
+   * Returns an ID that is primarily used in debug logs. It usually contains the class name and a
+   * numeric ID that is unique among the instances. {@link GprcUtil#getLogId} is a canonical
+   * implementation.
+   *
+   * <p>The subclasses of this interface usually want to include the log ID in their {@link
+   * #toString} results.
+   */
+  String getLogId();
+}

core/src/test/java/io/grpc/internal/ManagedChannelImplTest.java

@@ -41,6 +41,7 @@ import static org.mockito.Matchers.anyBoolean;
 import static org.mockito.Matchers.eq;
 import static org.mockito.Matchers.isA;
 import static org.mockito.Matchers.same;
+import static org.mockito.Mockito.atLeast;
 import static org.mockito.Mockito.atMost;
 import static org.mockito.Mockito.doAnswer;
 import static org.mockito.Mockito.mock;
@@ -248,6 +249,7 @@ public class ManagedChannelImplTest {
 
     verify(mockTransportFactory).release();
     verifyNoMoreInteractions(mockTransportFactory);
+    verify(mockTransport, atLeast(0)).getLogId();
     verifyNoMoreInteractions(mockTransport);
     verifyNoMoreInteractions(mockStream);
   }

core/src/test/java/io/grpc/internal/TransportSetTest.java

@@ -108,7 +108,7 @@ public class TransportSetTest {
 
   @Test public void singleAddressBackoff() {
     SocketAddress addr = mock(SocketAddress.class);
-    createTransortSet(addr);
+    createTransportSet(addr);
 
     // Invocation counters
     int transportsCreated = 0;
@@ -162,7 +162,7 @@ public class TransportSetTest {
   @Test public void twoAddressesBackoff() {
     SocketAddress addr1 = mock(SocketAddress.class);
     SocketAddress addr2 = mock(SocketAddress.class);
-    createTransortSet(addr1, addr2);
+    createTransportSet(addr1, addr2);
 
     // Invocation counters
     int transportsAddr1 = 0;
@@ -232,7 +232,7 @@ public class TransportSetTest {
   @Test
   public void connectIsLazy() {
     SocketAddress addr = mock(SocketAddress.class);
-    createTransortSet(addr);
+    createTransportSet(addr);
 
     // Invocation counters
     int transportsCreated = 0;
@@ -268,7 +268,7 @@ public class TransportSetTest {
   @Test
   public void shutdownBeforeTransportCreatedWithPendingStream() throws Exception {
     SocketAddress addr = mock(SocketAddress.class);
-    createTransortSet(addr);
+    createTransportSet(addr);
 
     // First transport is created immediately
     ClientTransport pick = transportSet.obtainActiveTransport();
@@ -316,7 +316,7 @@ public class TransportSetTest {
   @Test
   public void shutdownBeforeTransportCreatedWithoutPendingStream() throws Exception {
     SocketAddress addr = mock(SocketAddress.class);
-    createTransortSet(addr);
+    createTransportSet(addr);
 
     // First transport is created immediately
     ClientTransport pick = transportSet.obtainActiveTransport();
@@ -350,7 +350,7 @@ public class TransportSetTest {
   @Test
   public void obtainTransportAfterShutdown() throws Exception {
     SocketAddress addr = mock(SocketAddress.class);
-    createTransortSet(addr);
+    createTransportSet(addr);
 
     transportSet.shutdown();
     ClientTransport pick = transportSet.obtainActiveTransport();
@@ -358,7 +358,14 @@ public class TransportSetTest {
     verify(mockTransportFactory, times(0)).newClientTransport(addr, authority);
   }
 
-  private void createTransortSet(SocketAddress ... addrs) {
+  @Test
+  public void logId() {
+    createTransportSet(mock(SocketAddress.class));
+    assertEquals("TransportSet@" + Integer.toHexString(transportSet.hashCode()),
+        transportSet.getLogId());
+  }
+
+  private void createTransportSet(SocketAddress ... addrs) {
     addressGroup = new EquivalentAddressGroup(Arrays.asList(addrs));
     transportSet = new TransportSet(addressGroup, authority, mockLoadBalancer,
         mockBackoffPolicyProvider, mockTransportFactory, fakeClock.scheduledExecutorService,

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

@@ -40,6 +40,7 @@ import io.grpc.Metadata;
 import io.grpc.MethodDescriptor;
 import io.grpc.Status;
 import io.grpc.internal.ClientStream;
+import io.grpc.internal.GrpcUtil;
 import io.grpc.internal.Http2Ping;
 import io.grpc.internal.ManagedClientTransport;
 import io.netty.bootstrap.Bootstrap;
@@ -191,7 +192,12 @@ class NettyClientTransport implements ManagedClientTransport {
 
   @Override
   public String toString() {
-    return super.toString() + "(" + address + ")";
+    return getLogId() + "(" + address + ")";
+  }
+
+  @Override
+  public String getLogId() {
+    return GrpcUtil.getLogId(this);
   }
 
   /**

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

@@ -400,7 +400,12 @@ class OkHttpClientTransport implements ManagedClientTransport {
 
   @Override
   public String toString() {
-    return super.toString() + "(" + address + ")";
+    return getLogId() + "(" + address + ")";
+  }
+
+  @Override
+  public String getLogId() {
+    return GrpcUtil.getLogId(this);
   }
 
   /**