Add topology recovery started method to RecoveryListener

src/main/java/com/rabbitmq/client/RecoveryListener.java

@@ -36,4 +36,12 @@ public interface RecoveryListener {
      * @param recoverable a {@link Recoverable} connection.
      */
     void handleRecoveryStarted(Recoverable recoverable);
+
+    /**
+     * Invoked before automatic topology recovery starts.
+     * This means that the connection and channel recovery has completed 
+     * and that exchange/queue/binding/consumer recovery is about to begin.
+     * @param recoverable a {@link Recoverable} connection.
+     */
+    default void handleTopologyRecoveryStarted(Recoverable recoverable) {}
 }

src/main/java/com/rabbitmq/client/impl/recovery/AutorecoveringConnection.java

@@ -560,7 +560,10 @@ public void removeConsumerRecoveryListener(ConsumerRecoveryListener listener) {
     }
 
     private synchronized void beginAutomaticRecovery() throws InterruptedException {
-        this.wait(this.params.getRecoveryDelayHandler().getDelay(0));
+        final long delay = this.params.getRecoveryDelayHandler().getDelay(0);
+        if (delay > 0)  {
+            this.wait(delay);
+        }
 
         this.notifyRecoveryListenersStarted();
 
@@ -576,6 +579,7 @@ private synchronized void beginAutomaticRecovery() throws InterruptedException {
 	    // don't assign new delegate connection until channel recovery is complete
 	    this.delegate = newConn;
 	    if (this.params.isTopologyRecoveryEnabled()) {
+	        notifyTopologyRecoveryListenersStarted();
 	        recoverTopology(params.getTopologyRecoveryExecutor());
 	    }
 		this.notifyRecoveryListenersComplete();
@@ -650,6 +654,12 @@ private void notifyRecoveryListenersStarted() {
         }
     }
 
+    private void notifyTopologyRecoveryListenersStarted() {
+        for (RecoveryListener f : Utility.copy(this.recoveryListeners)) {
+            f.handleTopologyRecoveryStarted(this);
+        }
+    }
+
     private void recoverTopology(final ExecutorService executor) {
         // The recovery sequence is the following:
         // 1. Recover exchanges

src/test/java/com/rabbitmq/client/test/functional/ConnectionRecovery.java

@@ -170,7 +170,7 @@ public String getPassword() {
     // see https://github.com/rabbitmq/rabbitmq-java-client/issues/135
     @Test public void thatShutdownHooksOnConnectionFireBeforeRecoveryStarts() throws IOException, InterruptedException {
         final List<String> events = new CopyOnWriteArrayList<String>();
-        final CountDownLatch latch = new CountDownLatch(2); // one when started, another when complete
+        final CountDownLatch latch = new CountDownLatch(3); // one when started, another when complete
         connection.addShutdownListener(new ShutdownListener() {
             @Override
             public void shutdownCompleted(ShutdownSignalException cause) {
@@ -202,6 +202,10 @@ public void handleRecovery(Recoverable recoverable) {
             public void handleRecoveryStarted(Recoverable recoverable) {
                 latch.countDown();
             }
+            @Override
+            public void handleTopologyRecoveryStarted(Recoverable recoverable) {
+                latch.countDown();
+            }
         });
         assertThat(connection.isOpen()).isTrue();
         closeAndWaitForRecovery();