Add a bundle tracker to externalize the tracking code from the extension manager.
git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@654647 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/ipojo/extender.pattern.handler/src/main/java/org/apache/felix/ipojo/handler/extender/BundleTracker.java b/ipojo/extender.pattern.handler/src/main/java/org/apache/felix/ipojo/handler/extender/BundleTracker.java
new file mode 100644
index 0000000..a693023
--- /dev/null
+++ b/ipojo/extender.pattern.handler/src/main/java/org/apache/felix/ipojo/handler/extender/BundleTracker.java
@@ -0,0 +1,154 @@
+/*
+ * 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.handler.extender;
+
+import java.util.HashSet;
+import java.util.Set;
+import org.osgi.framework.Bundle;
+import org.osgi.framework.BundleContext;
+import org.osgi.framework.BundleEvent;
+import org.osgi.framework.SynchronousBundleListener;
+
+/**
+ * This is a very simple bundle tracker utility class that tracks active
+ * bundles. The tracker must be given a bundle context upon creation,
+ * which it uses to listen for bundle events. The bundle tracker must be
+ * opened to track objects and closed when it is no longer needed. This
+ * class is abstract, which means in order to use it you must create a
+ * subclass of it. Subclasses must implement the <tt>addedBundle()</tt>
+ * and <tt>removedBundle()</tt> methods, which can be used to perform some
+ * custom action upon the activation or deactivation of bundles. Since this
+ * tracker is quite simple, its concurrency control approach is also
+ * simplistic. This means that subclasses should take great care to ensure
+ * that their <tt>addedBundle()</tt> and <tt>removedBundle()</tt> methods
+ * are very simple and do not do anything to change the state of any bundles.
+ * @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a>
+ **/
+public abstract class BundleTracker {
+ /**
+ * Set of tracked bundles.
+ */
+ final Set m_bundleSet = new HashSet();
+
+ /**
+ * Bundle context.
+ */
+ final BundleContext m_context;
+
+ /**
+ * Synchronous bundle listener.
+ */
+ final SynchronousBundleListener m_listener;
+
+ /**
+ * Flag indicating if the tracking is open.
+ */
+ boolean m_open;
+
+ /**
+ * Constructs a bundle tracker object that will use the specified
+ * bundle context.
+ * @param context The bundle context to use to track bundles.
+ **/
+ public BundleTracker(BundleContext context) {
+ m_context = context;
+ m_listener = new SynchronousBundleListener() {
+ public void bundleChanged(BundleEvent evt) {
+ synchronized (BundleTracker.this) {
+ if (!m_open) { return; }
+
+ if (evt.getType() == BundleEvent.STARTED) {
+ if (!m_bundleSet.contains(evt.getBundle())) {
+ m_bundleSet.add(evt.getBundle());
+ addedBundle(evt.getBundle());
+ }
+ } else if (evt.getType() == BundleEvent.STOPPED) {
+ if (m_bundleSet.contains(evt.getBundle())) {
+ m_bundleSet.remove(evt.getBundle());
+ removedBundle(evt.getBundle());
+ }
+ }
+ }
+ }
+ };
+ }
+
+ /**
+ * Returns the current set of active bundles.
+ * @return The current set of active bundles.
+ **/
+ public synchronized Bundle[] getBundles() {
+ return (Bundle[]) m_bundleSet.toArray(new Bundle[m_bundleSet.size()]);
+ }
+
+ /**
+ * Call this method to start the tracking of active bundles.
+ **/
+ public synchronized void open() {
+ if (!m_open) {
+ m_open = true;
+
+ m_context.addBundleListener(m_listener);
+
+ Bundle[] bundles = m_context.getBundles();
+ for (int i = 0; i < bundles.length; i++) {
+ if (bundles[i].getState() == Bundle.ACTIVE) {
+ m_bundleSet.add(bundles[i]);
+ addedBundle(bundles[i]);
+ }
+ }
+ }
+ }
+
+ /**
+ * Call this method to stop the tracking of active bundles.
+ **/
+ public synchronized void close() {
+ if (m_open) {
+ m_open = false;
+
+ m_context.removeBundleListener(m_listener);
+
+ Bundle[] bundles = (Bundle[]) m_bundleSet.toArray(new Bundle[m_bundleSet.size()]);
+ for (int i = 0; i < bundles.length; i++) {
+ if (m_bundleSet.remove(bundles[i])) {
+ removedBundle(bundles[i]);
+ }
+ }
+ }
+ }
+
+ /**
+ * Subclasses must implement this method; it can be used to perform
+ * actions upon the activation of a bundle. Subclasses should keep
+ * this method implementation as simple as possible and should not
+ * cause the change in any bundle state to avoid concurrency issues.
+ * @param bundle The bundle being added to the active set.
+ **/
+ protected abstract void addedBundle(Bundle bundle);
+
+ /**
+ * Subclasses must implement this method; it can be used to perform
+ * actions upon the deactivation of a bundle. Subclasses should keep
+ * this method implementation as simple as possible and should not
+ * cause the change in any bundle state to avoid concurrency issues.
+ * @param bundle The bundle being removed from the active set.
+ **/
+ protected abstract void removedBundle(Bundle bundle);
+}
diff --git a/ipojo/extender.pattern.handler/src/main/java/org/apache/felix/ipojo/handler/extender/ExtenderManager.java b/ipojo/extender.pattern.handler/src/main/java/org/apache/felix/ipojo/handler/extender/ExtenderManager.java
index aa8341a..69fdea3 100644
--- a/ipojo/extender.pattern.handler/src/main/java/org/apache/felix/ipojo/handler/extender/ExtenderManager.java
+++ b/ipojo/extender.pattern.handler/src/main/java/org/apache/felix/ipojo/handler/extender/ExtenderManager.java
@@ -19,22 +19,19 @@
package org.apache.felix.ipojo.handler.extender;
import java.lang.reflect.InvocationTargetException;
-import java.util.ArrayList;
import java.util.Dictionary;
-import java.util.List;
+import java.util.HashSet;
+import java.util.Set;
import org.apache.felix.ipojo.PrimitiveHandler;
import org.apache.felix.ipojo.util.Callback;
import org.osgi.framework.Bundle;
-import org.osgi.framework.BundleContext;
-import org.osgi.framework.BundleEvent;
-import org.osgi.framework.SynchronousBundleListener;
/**
* Track and manage extensions.
* @author <a href="mailto:dev@felix.apache.org">Felix Project Team</a>
*/
-public class ExtenderManager implements SynchronousBundleListener {
+public class ExtenderManager extends BundleTracker {
/**
* Looked extension.
@@ -57,14 +54,9 @@
private PrimitiveHandler m_handler;
/**
- * Bundle context.
+ * Set of managed bundles.
*/
- private BundleContext m_context;
-
- /**
- * List of managed bundles.
- */
- private List m_bundles = new ArrayList();
+ private Set m_bundles = new HashSet();
/**
* Constructor.
@@ -74,40 +66,27 @@
* @param unbind : onDeparture method.
*/
public ExtenderManager(ExtenderModelHandler handler, String extension, String bind, String unbind) {
+ super(handler.getInstanceManager().getContext());
m_handler = handler;
m_onArrival = new Callback(bind, new Class[] {Bundle.class, String.class}, false, m_handler.getInstanceManager());
m_onDeparture = new Callback(unbind, new Class[] {Bundle.class}, false, m_handler.getInstanceManager());
m_extension = extension;
- m_context = handler.getInstanceManager().getContext();
}
-
+
+
/**
- * Start method.
- * Look for already presents bundle and register a (synchronous) bundle listener.
+ * A bundle arrives.
+ * Checks if the bundle match with the looked extension, if so call the arrival callback.
+ * @param bundle : arriving bundle.
+ * @see org.apache.felix.ipojo.handler.extender.BundleTracker#addedBundle(org.osgi.framework.Bundle)
*/
- public void start() {
- synchronized (this) {
- // listen to any changes in bundles.
- m_context.addBundleListener(this);
- // compute already started bundles.
- for (int i = 0; i < m_context.getBundles().length; i++) {
- if (m_context.getBundles()[i].getState() == Bundle.ACTIVE) {
- onArrival(m_context.getBundles()[i]);
- }
- }
- }
- }
-
- /**
- * Manage a bundle arrival:
- * Check the extension and manage it if present.
- * @param bundle : bundle.
- */
- private void onArrival(Bundle bundle) {
+ protected void addedBundle(Bundle bundle) {
Dictionary headers = bundle.getHeaders();
String header = (String) headers.get(m_extension);
if (header != null) {
- m_bundles.add(bundle);
+ synchronized (this) {
+ m_bundleSet.add(bundle);
+ }
try {
m_onArrival.call(new Object[] {bundle, header});
} catch (NoSuchMethodException e) {
@@ -124,40 +103,18 @@
}
/**
- * Stop method.
- * Remove the bundle listener.
+ * A bundle is stopping.
+ * Check if the bundle was managed, if so call the remove departure callback.
+ * @param bundle : leaving bundle.
+ * @see org.apache.felix.ipojo.handler.extender.BundleTracker#removedBundle(org.osgi.framework.Bundle)
*/
- public void stop() {
- m_context.removeBundleListener(this);
- m_bundles.clear();
- }
-
- /**
- * Bundle listener.
- * @param event : event.
- * @see org.osgi.framework.BundleListener#bundleChanged(org.osgi.framework.BundleEvent)
- */
- public void bundleChanged(BundleEvent event) {
- switch (event.getType()) {
- case BundleEvent.STARTED:
- onArrival(event.getBundle());
- break;
- case BundleEvent.STOPPING:
- onDeparture(event.getBundle());
- break;
- default:
- break;
+ protected void removedBundle(Bundle bundle) {
+ boolean contained;
+ synchronized (this) {
+ contained = m_bundles.remove(bundle); // Stack confinement
}
- }
-
- /**
- * Manage a bundle departure.
- * If the bundle was managed, invoke the OnDeparture callback, and remove the bundle from the list.
- * @param bundle : bundle.
- */
- private void onDeparture(Bundle bundle) {
- if (m_bundles.contains(bundle)) {
+ if (contained) {
try {
m_onDeparture.call(new Object[] {bundle});
} catch (NoSuchMethodException e) {
diff --git a/ipojo/extender.pattern.handler/src/main/java/org/apache/felix/ipojo/handler/extender/ExtenderModelHandler.java b/ipojo/extender.pattern.handler/src/main/java/org/apache/felix/ipojo/handler/extender/ExtenderModelHandler.java
index 8fc50b9..0f51828 100644
--- a/ipojo/extender.pattern.handler/src/main/java/org/apache/felix/ipojo/handler/extender/ExtenderModelHandler.java
+++ b/ipojo/extender.pattern.handler/src/main/java/org/apache/felix/ipojo/handler/extender/ExtenderModelHandler.java
@@ -41,6 +41,7 @@
/**
* Extension manager list.
+ * Immutable once set.
*/
private List m_managers = new ArrayList(1);
@@ -77,7 +78,7 @@
*/
public void start() {
for (int i = 0; i < m_managers.size(); i++) {
- ((ExtenderManager) m_managers.get(i)).start();
+ ((ExtenderManager) m_managers.get(i)).open();
}
}
@@ -87,7 +88,7 @@
*/
public void stop() {
for (int i = 0; i < m_managers.size(); i++) {
- ((ExtenderManager) m_managers.get(i)).stop();
+ ((ExtenderManager) m_managers.get(i)).close();
}
}