FELIX-4265 Provides a recorder for startup events

* Exports the o.a.f.i.extender.queue.debug package
* Register a QueueEventProxy service when JVM started with 'org.apache.felix.ipojo.extender.BootstrapQueueDebug=true' system property


git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@1528508 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/ipojo/runtime/core/pom.xml b/ipojo/runtime/core/pom.xml
index 0b2276e..654c0b5 100644
--- a/ipojo/runtime/core/pom.xml
+++ b/ipojo/runtime/core/pom.xml
@@ -161,6 +161,7 @@
                             version="${ipojo.package.version}";-split-package:=merge-first,
                             org.apache.felix.ipojo.extender.builder; version="${ipojo.package.version}",
                             org.apache.felix.ipojo.extender.queue; version="${ipojo.package.version}",
+                            org.apache.felix.ipojo.extender.queue.debug; version="${ipojo.package.version}",
                             org.apache.felix.ipojo.parser; version="${ipojo.package.version}",
                             org.apache.felix.ipojo.util; version="${ipojo.package.version}",
                             org.apache.felix.ipojo.handlers.dependency; version="${ipojo.package.version}",
diff --git a/ipojo/runtime/core/src/main/java/org/apache/felix/ipojo/extender/internal/Extender.java b/ipojo/runtime/core/src/main/java/org/apache/felix/ipojo/extender/internal/Extender.java
index df03d2e..ddac180 100644
--- a/ipojo/runtime/core/src/main/java/org/apache/felix/ipojo/extender/internal/Extender.java
+++ b/ipojo/runtime/core/src/main/java/org/apache/felix/ipojo/extender/internal/Extender.java
@@ -30,10 +30,12 @@
 import org.apache.felix.ipojo.extender.internal.queue.NamingThreadFactory;
 import org.apache.felix.ipojo.extender.internal.queue.PrefixedThreadFactory;
 import org.apache.felix.ipojo.extender.internal.queue.SynchronousQueueService;
+import org.apache.felix.ipojo.extender.internal.queue.debug.ReplayQueueEventProxy;
 import org.apache.felix.ipojo.extender.internal.queue.pref.HeaderPreferenceSelection;
 import org.apache.felix.ipojo.extender.internal.queue.pref.Preference;
 import org.apache.felix.ipojo.extender.internal.queue.pref.PreferenceQueueService;
 import org.apache.felix.ipojo.extender.internal.queue.pref.enforce.EnforcedQueueService;
+import org.apache.felix.ipojo.extender.queue.debug.QueueEventProxy;
 import org.apache.felix.ipojo.util.Logger;
 import org.osgi.framework.*;
 import org.osgi.util.tracker.BundleTracker;
@@ -43,6 +45,7 @@
  * iPOJO main activator.
  */
 public class Extender implements BundleActivator {
+    public static final String BOOTSTRAP_QUEUE_DEBUG_PROPERTY = "org.apache.felix.ipojo.extender.BootstrapQueueDebug";
     /**
      * Enables the iPOJO internal dispatcher.
      * This internal dispatcher helps the OSGi framework to support large
@@ -130,6 +133,13 @@
         // Initialize ConfigurationTracker
         ConfigurationTracker.initialize();
 
+        // Initialize the queue event proxy if wanted
+        ReplayQueueEventProxy proxy = null;
+        if (Boolean.getBoolean(BOOTSTRAP_QUEUE_DEBUG_PROPERTY)) {
+            proxy = new ReplayQueueEventProxy();
+            context.registerService(QueueEventProxy.class, proxy, null);
+        }
+
         BundleProcessor extensionBundleProcessor = new ExtensionBundleProcessor(m_logger);
         BundleProcessor componentsProcessor = new ComponentsBundleProcessor(m_logger);
         BundleProcessor configurationProcessor = new ConfigurationProcessor(m_logger);
@@ -139,6 +149,11 @@
                     new SynchronousQueueService(context),
                     Preference.SYNC,
                     m_logger);
+
+            // If required, add the event proxy
+            if (proxy != null) {
+                m_queueService.addQueueListener(proxy);
+            }
         } else {
             // Build a thread factory that will groups extender's thread together
             ThreadFactory threadFactory = new GroupThreadFactory(new ThreadGroup("iPOJO Extender"));
@@ -156,6 +171,13 @@
             extensionBundleProcessor = new QueuingActivationProcessor(extensionBundleProcessor, m_queueService);
             componentsProcessor = new QueuingActivationProcessor(componentsProcessor, m_queueService);
             configurationProcessor = new QueuingActivationProcessor(configurationProcessor, m_queueService);
+
+            // If required, add the event proxy to both real services
+            if (proxy != null) {
+                sync.addQueueListener(proxy);
+                async.addQueueListener(proxy);
+            }
+
         }
         m_queueService.start();
 
diff --git a/ipojo/runtime/core/src/main/java/org/apache/felix/ipojo/extender/internal/queue/debug/ReplayQueueEventProxy.java b/ipojo/runtime/core/src/main/java/org/apache/felix/ipojo/extender/internal/queue/debug/ReplayQueueEventProxy.java
new file mode 100644
index 0000000..0e040bb
--- /dev/null
+++ b/ipojo/runtime/core/src/main/java/org/apache/felix/ipojo/extender/internal/queue/debug/ReplayQueueEventProxy.java
@@ -0,0 +1,157 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.felix.ipojo.extender.internal.queue.debug;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+import org.apache.felix.ipojo.extender.queue.JobInfo;
+import org.apache.felix.ipojo.extender.queue.QueueListener;
+import org.apache.felix.ipojo.extender.queue.debug.QueueEventProxy;
+
+/**
+ * User: guillaume
+ * Date: 02/10/13
+ * Time: 10:51
+ */
+public class ReplayQueueEventProxy implements QueueEventProxy, QueueListener {
+    /**
+     * Store QueueListeners.
+     */
+    private final List<QueueListener> m_listeners = new ArrayList<QueueListener>();
+
+    /**
+     * Store QueueEvent to be replayed.
+     */
+    private List<QueueEvent> m_events = new CopyOnWriteArrayList<QueueEvent>();
+
+    public void addQueueListener(final QueueListener listener) {
+        m_listeners.add(listener);
+        // replay all the existing events to the new listener
+        replay(listener);
+    }
+
+    public void removeQueueListener(final QueueListener listener) {
+        m_listeners.remove(listener);
+    }
+
+    public void enlisted(final JobInfo info) {
+        EnlistedQueueEvent event = new EnlistedQueueEvent(info);
+        m_events.add(event);
+        forward(event);
+    }
+
+    public void started(final JobInfo info) {
+        StartedQueueEvent event = new StartedQueueEvent(info);
+        m_events.add(event);
+        forward(event);
+    }
+
+    public void executed(final JobInfo info, final Object result) {
+        ExecutedQueueEvent event = new ExecutedQueueEvent(info, result);
+        m_events.add(event);
+        forward(event);
+    }
+
+    public void failed(final JobInfo info, final Throwable throwable) {
+        FailedQueueEvent event = new FailedQueueEvent(info, throwable);
+        m_events.add(event);
+        forward(event);
+    }
+
+    /**
+     * Replay all stored events to the given QueueListener.
+     */
+    private void replay(final QueueListener listener) {
+        for (QueueEvent event : m_events) {
+            event.replay(listener);
+        }
+    }
+
+    /**
+     * Forward the given QueueEvent to all the registered listeners.
+     */
+    private void forward(final QueueEvent event) {
+        for (QueueListener listener : m_listeners) {
+            event.replay(listener);
+        }
+    }
+
+    /**
+     * Encapsulate event forwarding logic.
+     */
+    private interface QueueEvent {
+        void replay(QueueListener listener);
+    }
+
+    private class EnlistedQueueEvent implements QueueEvent {
+        private final JobInfo m_info;
+
+        public EnlistedQueueEvent(final JobInfo info) {
+            m_info = info;
+        }
+
+        public void replay(final QueueListener listener) {
+            listener.enlisted(m_info);
+        }
+    }
+
+    private class StartedQueueEvent implements QueueEvent {
+        private final JobInfo m_info;
+
+        public StartedQueueEvent(final JobInfo info) {
+            m_info = info;
+        }
+
+        public void replay(final QueueListener listener) {
+            listener.started(m_info);
+        }
+    }
+
+    private class ExecutedQueueEvent implements QueueEvent {
+        private final JobInfo m_info;
+        private final Object m_result;
+
+        public ExecutedQueueEvent(final JobInfo info, final Object result) {
+            m_info = info;
+            m_result = result;
+        }
+
+        public void replay(final QueueListener listener) {
+            listener.executed(m_info, m_result);
+        }
+    }
+
+    private class FailedQueueEvent implements QueueEvent {
+        private final JobInfo m_info;
+        private final Throwable m_throwable;
+
+        public FailedQueueEvent(final JobInfo info, final Throwable throwable) {
+            m_info = info;
+            m_throwable = throwable;
+        }
+
+        public void replay(final QueueListener listener) {
+            listener.failed(m_info, m_throwable);
+        }
+    }
+
+}
diff --git a/ipojo/runtime/core/src/main/java/org/apache/felix/ipojo/extender/queue/debug/QueueEventProxy.java b/ipojo/runtime/core/src/main/java/org/apache/felix/ipojo/extender/queue/debug/QueueEventProxy.java
new file mode 100644
index 0000000..16dce7d
--- /dev/null
+++ b/ipojo/runtime/core/src/main/java/org/apache/felix/ipojo/extender/queue/debug/QueueEventProxy.java
@@ -0,0 +1,42 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.felix.ipojo.extender.queue.debug;
+
+import org.apache.felix.ipojo.extender.queue.QueueListener;
+
+/**
+ * This service record events from a {@link org.apache.felix.ipojo.extender.queue.QueueService}.
+ * When a listener is added, all recorded events are replayed into the listener.
+ */
+public interface QueueEventProxy {
+    /**
+     * Add a {@link org.apache.felix.ipojo.extender.queue.QueueListener} that will be notified on events
+     * relative to the observed {@link org.apache.felix.ipojo.extender.queue.QueueService}.
+     * @param listener added listener
+     */
+    void addQueueListener(QueueListener listener);
+
+    /**
+     * Remove a {@link QueueListener} from the observed {@link org.apache.felix.ipojo.extender.queue.QueueService}.
+     * @param listener removed listener
+     */
+    void removeQueueListener(QueueListener listener);
+
+}
diff --git a/ipojo/runtime/core/src/test/java/org/apache/felix/ipojo/extender/internal/queue/debug/ReplayQueueEventProxyTestCase.java b/ipojo/runtime/core/src/test/java/org/apache/felix/ipojo/extender/internal/queue/debug/ReplayQueueEventProxyTestCase.java
new file mode 100644
index 0000000..3253ef9
--- /dev/null
+++ b/ipojo/runtime/core/src/test/java/org/apache/felix/ipojo/extender/internal/queue/debug/ReplayQueueEventProxyTestCase.java
@@ -0,0 +1,122 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.felix.ipojo.extender.internal.queue.debug;
+
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.verifyNoMoreInteractions;
+
+import org.apache.felix.ipojo.extender.queue.JobInfo;
+import org.apache.felix.ipojo.extender.queue.QueueListener;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+
+import junit.framework.TestCase;
+
+/**
+ * User: guillaume
+ * Date: 02/10/13
+ * Time: 12:01
+ */
+public class ReplayQueueEventProxyTestCase extends TestCase {
+
+    @Mock
+    private JobInfo m_info1;
+
+    @Mock
+    private JobInfo m_info2;
+
+    @Mock
+    private QueueListener m_listener;
+
+    @Override
+    public void setUp() throws Exception {
+        MockitoAnnotations.initMocks(this);
+    }
+
+    public void testEventsAreReplayedOnListenerAddition() throws Exception {
+        ReplayQueueEventProxy proxy = new ReplayQueueEventProxy();
+
+        proxy.enlisted(m_info1);
+        proxy.started(m_info1);
+        proxy.enlisted(m_info2);
+        proxy.executed(m_info1, "hello");
+        proxy.started(m_info2);
+        Exception throwable = new Exception();
+        proxy.failed(m_info2, throwable);
+
+        proxy.addQueueListener(m_listener);
+
+        verify(m_listener).enlisted(m_info1);
+        verify(m_listener).started(m_info1);
+        verify(m_listener).executed(m_info1, "hello");
+        verify(m_listener).enlisted(m_info2);
+        verify(m_listener).started(m_info2);
+        verify(m_listener).failed(m_info2, throwable);
+
+    }
+
+    public void testNoEventsAreSendAfterListenerRemoval() throws Exception {
+        ReplayQueueEventProxy proxy = new ReplayQueueEventProxy();
+
+        proxy.enlisted(m_info1);
+        proxy.started(m_info1);
+
+        proxy.addQueueListener(m_listener);
+
+        proxy.enlisted(m_info2);
+
+        proxy.removeQueueListener(m_listener);
+
+        proxy.executed(m_info1, "hello");
+        proxy.started(m_info2);
+        Exception throwable = new Exception();
+        proxy.failed(m_info2, throwable);
+
+        // Ensure no methods are called after removal
+        verify(m_listener).enlisted(m_info1);
+        verify(m_listener).started(m_info1);
+        verify(m_listener).enlisted(m_info2);
+        verifyNoMoreInteractions(m_listener);
+
+    }
+
+    public void testEventsAreForwarded() throws Exception {
+        ReplayQueueEventProxy proxy = new ReplayQueueEventProxy();
+
+        proxy.enlisted(m_info1);
+        proxy.started(m_info1);
+
+        proxy.addQueueListener(m_listener);
+
+        proxy.enlisted(m_info2);
+        proxy.executed(m_info1, "hello");
+        proxy.started(m_info2);
+        Exception throwable = new Exception();
+        proxy.failed(m_info2, throwable);
+
+        verify(m_listener).enlisted(m_info1);
+        verify(m_listener).started(m_info1);
+        verify(m_listener).executed(m_info1, "hello");
+        verify(m_listener).enlisted(m_info2);
+        verify(m_listener).started(m_info2);
+        verify(m_listener).failed(m_info2, throwable);
+
+    }
+}