subsystem/subsystem-core/src/main/java/org/apache/aries/subsystem/core/internal/Activator.java - aries - Git at Google

 /*
  * Licensed 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.aries.subsystem.core.internal;

 import java.util.Collection;
 import java.util.Collections;
 import java.util.Dictionary;
 import java.util.HashSet;
 import java.util.Hashtable;

 import org.apache.aries.subsystem.ContentHandler;
 import org.apache.aries.subsystem.core.content.ConfigAdminContentHandler;
 import org.apache.aries.util.filesystem.IDirectoryFinder;
 import org.eclipse.equinox.region.RegionDigraph;
 import org.osgi.framework.BundleActivator;
 import org.osgi.framework.BundleContext;
 import org.osgi.framework.Filter;
 import org.osgi.framework.FrameworkUtil;
 import org.osgi.framework.InvalidSyntaxException;
 import org.osgi.framework.ServiceReference;
 import org.osgi.framework.ServiceRegistration;
 import org.osgi.framework.hooks.bundle.EventHook;
 import org.osgi.framework.hooks.resolver.ResolverHookFactory;
 import org.osgi.service.coordinator.Coordinator;
 import org.osgi.service.resolver.Resolver;
 import org.osgi.util.tracker.ServiceTracker;
 import org.osgi.util.tracker.ServiceTrackerCustomizer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;

 /**
  * The bundle activator for the this bundle. When the bundle is starting, this
  * activator will create and register the SubsystemAdmin service.
  */
 public class Activator implements BundleActivator, ServiceTrackerCustomizer<Object, Object> {
     private static final Logger logger = LoggerFactory.getLogger(Activator.class);
     public static final String MODELLED_RESOURCE_MANAGER = "org.apache.aries.application.modelling.ModelledResourceManager";

     public static final String LOG_ENTRY = "Method entry: {}, args {}";
     public static final String LOG_EXIT = "Method exit: {}, returning {}";

     private static Activator instance;

 	public static synchronized Activator getInstance() {
 		logger.debug(LOG_ENTRY, "getInstance");
 		checkInstance();
 		logger.debug(LOG_EXIT, "getInstance", instance);
 		return instance;
 	}

 	private static synchronized void checkInstance() {
 		logger.debug(LOG_ENTRY, "checkInstance");
 		if (instance == null)
 			throw new IllegalStateException("The activator has not been initialized or has been shutdown");
 		logger.debug(LOG_EXIT, "checkInstance");
 	}

 	// @GuardedBy("this")
 	private BundleEventHook bundleEventHook;
 	private volatile BundleContext bundleContext;
     private volatile ConfigAdminContentHandler configAdminHandler;
 	private volatile Coordinator coordinator;
     private volatile Object modelledResourceManager;
     private volatile ServiceModeller serviceModeller;
 	private volatile SubsystemServiceRegistrar registrar;
 	private volatile RegionDigraph regionDigraph;
 	private volatile Resolver resolver;
 	private ServiceTracker<?,?> serviceTracker;

 	private volatile Subsystems subsystems;

 	private final Collection<ServiceRegistration<?>> registrations = new HashSet<ServiceRegistration<?>>();
 	private final Collection<IDirectoryFinder> finders = Collections.synchronizedSet(new HashSet<IDirectoryFinder>());

 	public BundleContext getBundleContext() {
 		return bundleContext;
 	}

 	public Coordinator getCoordinator() {
 		return coordinator;
 	}

     public ServiceModeller getServiceModeller() {
         return serviceModeller;
     }

     public RegionDigraph getRegionDigraph() {
 		return regionDigraph;
 	}

 	public Collection<IDirectoryFinder> getIDirectoryFinders() {
 		return Collections.unmodifiableCollection(finders);
 	}

 	public Resolver getResolver() {
 		return resolver;
 	}

 	public Subsystems getSubsystems() {
 		return subsystems;
 	}

 	public SubsystemServiceRegistrar getSubsystemServiceRegistrar() {
 		logger.debug(LOG_ENTRY, "getSubsystemServiceRegistrar");
 		SubsystemServiceRegistrar result = registrar;
 		logger.debug(LOG_EXIT, "getSubsystemServiceRegistrar", result);
 		return result;
 	}

 	public org.apache.aries.subsystem.core.repository.Repository getSystemRepository() {
 		return new SystemRepository(getSubsystems().getRootSubsystem());
 	}

 	@Override
 	public synchronized void start(BundleContext context) throws Exception {
 		logger.debug(LOG_ENTRY, "start", context);
 		bundleContext = context;
 		serviceTracker = new ServiceTracker<Object, Object>(bundleContext, generateServiceFilter(), this);
 		serviceTracker.open();
 		logger.debug(LOG_EXIT, "start");
 	}

 	@Override
 	public synchronized void stop(BundleContext context) {
 		logger.debug(LOG_ENTRY, "stop", context);
 		serviceTracker.close();
 		serviceTracker = null;
 		bundleContext = null;
 		logger.debug(LOG_EXIT, "stop");
 	}

 	private void activate() {
 		if (isActive() || !hasRequiredServices())
 			return;
 		synchronized (Activator.class) {
 			instance = Activator.this;
 		}
 		subsystems = new Subsystems();
 		registerBundleEventHook();
 		registrations.add(bundleContext.registerService(ResolverHookFactory.class, new SubsystemResolverHookFactory(subsystems), null));
         Dictionary<String, Object> handlerProps = new Hashtable<String, Object>();
         handlerProps.put(ContentHandler.CONTENT_TYPE_PROPERTY, ConfigAdminContentHandler.CONTENT_TYPES);
         configAdminHandler = new ConfigAdminContentHandler(bundleContext);
         registrations.add(bundleContext.registerService(ContentHandler.class, configAdminHandler, handlerProps));
 		registrar = new SubsystemServiceRegistrar(bundleContext);
 		BasicSubsystem root = subsystems.getRootSubsystem();
 		bundleEventHook.activate();
 		root.start();
 		registerWovenClassListener();
 	}

 	private void deactivate() {
 		if (!isActive())
 			return;
 		bundleEventHook.deactivate();
 		new StopAction(subsystems.getRootSubsystem(), subsystems.getRootSubsystem(), true).run();
 		for (ServiceRegistration<?> registration : registrations) {
 			try {
 				registration.unregister();
 			}
 			catch (IllegalStateException e) {
 				logger.debug("Service had already been unregistered", e);
 			}
 		}
         configAdminHandler.shutDown();
 		bundleEventHook.processPendingEvents();
 		synchronized (Activator.class) {
 			instance = null;
 		}
 	}

 	private <T> T findAlternateServiceFor(Class<T> service) {
 		Object[] services = serviceTracker.getServices();
 		if (services == null)
 			return null;
 		for (Object alternate : services)
 			if (service.isInstance(alternate))
 					return service.cast(alternate);
 		return null;
 	}

 	private Filter generateServiceFilter() throws InvalidSyntaxException {
 		return FrameworkUtil.createFilter(generateServiceFilterString());
 	}

 	private String generateServiceFilterString() {
 		return new StringBuilder("(|(")
 				.append(org.osgi.framework.Constants.OBJECTCLASS).append('=')
 				.append(Coordinator.class.getName()).append(")(")
 				.append(org.osgi.framework.Constants.OBJECTCLASS).append('=')
 				.append(RegionDigraph.class.getName()).append(")(")
 				.append(org.osgi.framework.Constants.OBJECTCLASS).append('=')
 				.append(Resolver.class.getName()).append(")(")
 				.append(org.osgi.framework.Constants.OBJECTCLASS).append('=')
 				.append("org.osgi.service.repository.Repository").append(")(")
 				.append(org.osgi.framework.Constants.OBJECTCLASS).append('=')
 				.append(MODELLED_RESOURCE_MANAGER).append(")(")
 				.append(org.osgi.framework.Constants.OBJECTCLASS).append('=')
 				.append(IDirectoryFinder.class.getName()).append("))").toString();
 	}

 	private boolean hasRequiredServices() {
 		return coordinator != null &&
 				regionDigraph != null &&
 				resolver != null;
 	}

 	private boolean isActive() {
 		synchronized (Activator.class) {
 			return instance != null && getSubsystems() != null;
 		}
 	}

 	private void registerBundleEventHook() {
 		Dictionary<String, Object> properties = new Hashtable<String, Object>(1);
 		properties.put(org.osgi.framework.Constants.SERVICE_RANKING, Integer.MAX_VALUE);
 		bundleEventHook = new BundleEventHook();
 		registrations.add(bundleContext.registerService(EventHook.class, bundleEventHook, properties));
 	}

 	private void registerWovenClassListener() {
 		registrations.add(
 				bundleContext.registerService(
 						org.osgi.framework.hooks.weaving.WovenClassListener.class,
 						new WovenClassListener(bundleContext, subsystems),
 						null));
 	}

 	/* Begin ServiceTrackerCustomizer methods */

 	@Override
 	public synchronized Object addingService(ServiceReference<Object> reference) {
 		Object service = bundleContext.getService(reference);
 		// Use all of each type of the following services.
 		if (service instanceof IDirectoryFinder)
 			finders.add((IDirectoryFinder) service);
 		// Use only one of each type of the following services.
 		else if (service instanceof Coordinator && coordinator == null)
 			coordinator = (Coordinator) service;
 		else if (service instanceof RegionDigraph && regionDigraph == null)
 			regionDigraph = (RegionDigraph) service;
 		else if (service instanceof Resolver && resolver == null)
 			resolver = (Resolver) service;
 		else {
 			try {
 				Class clazz = getClass().getClassLoader().loadClass(MODELLED_RESOURCE_MANAGER);
 				if (clazz.isInstance(service) && serviceModeller == null) {
 					modelledResourceManager = service;
 					serviceModeller = new ApplicationServiceModeller(service);
 				} else {
 					service = null;
 				}
 			} catch (ClassNotFoundException e) {
 				service = null;
 			} catch (NoClassDefFoundError e) {
 				service = null;
 			}
 		}
 		// Activation is harmless if already active or all required services
 		// have not yet been found.
 		activate();
 		// Filter guarantees we want to track all services received.
 		return service;
 	}

 	@Override
 	public void modifiedService(ServiceReference<Object> reference, Object service) {
 		// Nothing
 	}

 	@Override
 	public synchronized void removedService(ServiceReference<Object> reference, Object service) {
 		if (service instanceof Coordinator) {
 			if (service.equals(coordinator)) {
 				Coordinator coordinator = findAlternateServiceFor(Coordinator.class);
 				if (coordinator == null)
 					deactivate();
 				this.coordinator = coordinator;
 			}
 		}
 		else if (service instanceof RegionDigraph) {
 			if (service.equals(regionDigraph)) {
 				RegionDigraph regionDigraph = findAlternateServiceFor(RegionDigraph.class);
 				if (regionDigraph == null)
 					deactivate();
 				this.regionDigraph = regionDigraph;
 			}
 		}
 		else if (service instanceof Resolver) {
 			if (service.equals(resolver)) {
 				Resolver resolver = findAlternateServiceFor(Resolver.class);
 				if (resolver == null)
 					deactivate();
 				this.resolver = resolver;
 			}
 		}
 		else if (service instanceof IDirectoryFinder)
 			finders.remove(service);
         else {
             if (service.equals(modelledResourceManager)) {
                 try {
                     Class clazz = getClass().getClassLoader().loadClass(MODELLED_RESOURCE_MANAGER);
                     Object manager = findAlternateServiceFor(clazz);
                     if (manager == null) {
                         modelledResourceManager = null;
                         serviceModeller = null;
                     } else {
                         modelledResourceManager = service;
                         serviceModeller = new ApplicationServiceModeller(service);
                     }
                 } catch (ClassNotFoundException e) {
                     // ignore
                 } catch (NoClassDefFoundError e) {
                     // ignore
                 }
             }
         }
 	}

 	/* End ServiceTrackerCustomizer methods */
 }
	/*
	* Licensed 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.aries.subsystem.core.internal;

	import java.util.Collection;
	import java.util.Collections;
	import java.util.Dictionary;
	import java.util.HashSet;
	import java.util.Hashtable;

	import org.apache.aries.subsystem.ContentHandler;
	import org.apache.aries.subsystem.core.content.ConfigAdminContentHandler;
	import org.apache.aries.util.filesystem.IDirectoryFinder;
	import org.eclipse.equinox.region.RegionDigraph;
	import org.osgi.framework.BundleActivator;
	import org.osgi.framework.BundleContext;
	import org.osgi.framework.Filter;
	import org.osgi.framework.FrameworkUtil;
	import org.osgi.framework.InvalidSyntaxException;
	import org.osgi.framework.ServiceReference;
	import org.osgi.framework.ServiceRegistration;
	import org.osgi.framework.hooks.bundle.EventHook;
	import org.osgi.framework.hooks.resolver.ResolverHookFactory;
	import org.osgi.service.coordinator.Coordinator;
	import org.osgi.service.resolver.Resolver;
	import org.osgi.util.tracker.ServiceTracker;
	import org.osgi.util.tracker.ServiceTrackerCustomizer;
	import org.slf4j.Logger;
	import org.slf4j.LoggerFactory;

	/**
	* The bundle activator for the this bundle. When the bundle is starting, this
	* activator will create and register the SubsystemAdmin service.
	*/
	public class Activator implements BundleActivator, ServiceTrackerCustomizer<Object, Object> {
	private static final Logger logger = LoggerFactory.getLogger(Activator.class);
	public static final String MODELLED_RESOURCE_MANAGER = "org.apache.aries.application.modelling.ModelledResourceManager";

	public static final String LOG_ENTRY = "Method entry: {}, args {}";
	public static final String LOG_EXIT = "Method exit: {}, returning {}";

	private static Activator instance;

	public static synchronized Activator getInstance() {
	logger.debug(LOG_ENTRY, "getInstance");
	checkInstance();
	logger.debug(LOG_EXIT, "getInstance", instance);
	return instance;
	}

	private static synchronized void checkInstance() {
	logger.debug(LOG_ENTRY, "checkInstance");
	if (instance == null)
	throw new IllegalStateException("The activator has not been initialized or has been shutdown");
	logger.debug(LOG_EXIT, "checkInstance");
	}

	// @GuardedBy("this")
	private BundleEventHook bundleEventHook;
	private volatile BundleContext bundleContext;
	private volatile ConfigAdminContentHandler configAdminHandler;
	private volatile Coordinator coordinator;
	private volatile Object modelledResourceManager;
	private volatile ServiceModeller serviceModeller;
	private volatile SubsystemServiceRegistrar registrar;
	private volatile RegionDigraph regionDigraph;
	private volatile Resolver resolver;
	private ServiceTracker<?,?> serviceTracker;

	private volatile Subsystems subsystems;

	private final Collection<ServiceRegistration<?>> registrations = new HashSet<ServiceRegistration<?>>();
	private final Collection<IDirectoryFinder> finders = Collections.synchronizedSet(new HashSet<IDirectoryFinder>());

	public BundleContext getBundleContext() {
	return bundleContext;
	}

	public Coordinator getCoordinator() {
	return coordinator;
	}

	public ServiceModeller getServiceModeller() {
	return serviceModeller;
	}

	public RegionDigraph getRegionDigraph() {
	return regionDigraph;
	}

	public Collection<IDirectoryFinder> getIDirectoryFinders() {
	return Collections.unmodifiableCollection(finders);
	}

	public Resolver getResolver() {
	return resolver;
	}

	public Subsystems getSubsystems() {
	return subsystems;
	}

	public SubsystemServiceRegistrar getSubsystemServiceRegistrar() {
	logger.debug(LOG_ENTRY, "getSubsystemServiceRegistrar");
	SubsystemServiceRegistrar result = registrar;
	logger.debug(LOG_EXIT, "getSubsystemServiceRegistrar", result);
	return result;
	}

	public org.apache.aries.subsystem.core.repository.Repository getSystemRepository() {
	return new SystemRepository(getSubsystems().getRootSubsystem());
	}

	@Override
	public synchronized void start(BundleContext context) throws Exception {
	logger.debug(LOG_ENTRY, "start", context);
	bundleContext = context;
	serviceTracker = new ServiceTracker<Object, Object>(bundleContext, generateServiceFilter(), this);
	serviceTracker.open();
	logger.debug(LOG_EXIT, "start");
	}

	@Override
	public synchronized void stop(BundleContext context) {
	logger.debug(LOG_ENTRY, "stop", context);
	serviceTracker.close();
	serviceTracker = null;
	bundleContext = null;
	logger.debug(LOG_EXIT, "stop");
	}

	private void activate() {
	if (isActive() \|\| !hasRequiredServices())
	return;
	synchronized (Activator.class) {
	instance = Activator.this;
	}
	subsystems = new Subsystems();
	registerBundleEventHook();
	registrations.add(bundleContext.registerService(ResolverHookFactory.class, new SubsystemResolverHookFactory(subsystems), null));
	Dictionary<String, Object> handlerProps = new Hashtable<String, Object>();
	handlerProps.put(ContentHandler.CONTENT_TYPE_PROPERTY, ConfigAdminContentHandler.CONTENT_TYPES);
	configAdminHandler = new ConfigAdminContentHandler(bundleContext);
	registrations.add(bundleContext.registerService(ContentHandler.class, configAdminHandler, handlerProps));
	registrar = new SubsystemServiceRegistrar(bundleContext);
	BasicSubsystem root = subsystems.getRootSubsystem();
	bundleEventHook.activate();
	root.start();
	registerWovenClassListener();
	}

	private void deactivate() {
	if (!isActive())
	return;
	bundleEventHook.deactivate();
	new StopAction(subsystems.getRootSubsystem(), subsystems.getRootSubsystem(), true).run();
	for (ServiceRegistration<?> registration : registrations) {
	try {
	registration.unregister();
	}
	catch (IllegalStateException e) {
	logger.debug("Service had already been unregistered", e);
	}
	}
	configAdminHandler.shutDown();
	bundleEventHook.processPendingEvents();
	synchronized (Activator.class) {
	instance = null;
	}
	}

	private <T> T findAlternateServiceFor(Class<T> service) {
	Object[] services = serviceTracker.getServices();
	if (services == null)
	return null;
	for (Object alternate : services)
	if (service.isInstance(alternate))
	return service.cast(alternate);
	return null;
	}

	private Filter generateServiceFilter() throws InvalidSyntaxException {
	return FrameworkUtil.createFilter(generateServiceFilterString());
	}

	private String generateServiceFilterString() {
	return new StringBuilder("(\|(")
	.append(org.osgi.framework.Constants.OBJECTCLASS).append('=')
	.append(Coordinator.class.getName()).append(")(")
	.append(org.osgi.framework.Constants.OBJECTCLASS).append('=')
	.append(RegionDigraph.class.getName()).append(")(")
	.append(org.osgi.framework.Constants.OBJECTCLASS).append('=')
	.append(Resolver.class.getName()).append(")(")
	.append(org.osgi.framework.Constants.OBJECTCLASS).append('=')
	.append("org.osgi.service.repository.Repository").append(")(")
	.append(org.osgi.framework.Constants.OBJECTCLASS).append('=')
	.append(MODELLED_RESOURCE_MANAGER).append(")(")
	.append(org.osgi.framework.Constants.OBJECTCLASS).append('=')
	.append(IDirectoryFinder.class.getName()).append("))").toString();
	}

	private boolean hasRequiredServices() {
	return coordinator != null &&
	regionDigraph != null &&
	resolver != null;
	}

	private boolean isActive() {
	synchronized (Activator.class) {
	return instance != null && getSubsystems() != null;
	}
	}

	private void registerBundleEventHook() {
	Dictionary<String, Object> properties = new Hashtable<String, Object>(1);
	properties.put(org.osgi.framework.Constants.SERVICE_RANKING, Integer.MAX_VALUE);
	bundleEventHook = new BundleEventHook();
	registrations.add(bundleContext.registerService(EventHook.class, bundleEventHook, properties));
	}

	private void registerWovenClassListener() {
	registrations.add(
	bundleContext.registerService(
	org.osgi.framework.hooks.weaving.WovenClassListener.class,
	new WovenClassListener(bundleContext, subsystems),
	null));
	}

	/* Begin ServiceTrackerCustomizer methods */

	@Override
	public synchronized Object addingService(ServiceReference<Object> reference) {
	Object service = bundleContext.getService(reference);
	// Use all of each type of the following services.
	if (service instanceof IDirectoryFinder)
	finders.add((IDirectoryFinder) service);
	// Use only one of each type of the following services.
	else if (service instanceof Coordinator && coordinator == null)
	coordinator = (Coordinator) service;
	else if (service instanceof RegionDigraph && regionDigraph == null)
	regionDigraph = (RegionDigraph) service;
	else if (service instanceof Resolver && resolver == null)
	resolver = (Resolver) service;
	else {
	try {
	Class clazz = getClass().getClassLoader().loadClass(MODELLED_RESOURCE_MANAGER);
	if (clazz.isInstance(service) && serviceModeller == null) {
	modelledResourceManager = service;
	serviceModeller = new ApplicationServiceModeller(service);
	} else {
	service = null;
	}
	} catch (ClassNotFoundException e) {
	service = null;
	} catch (NoClassDefFoundError e) {
	service = null;
	}
	}
	// Activation is harmless if already active or all required services
	// have not yet been found.
	activate();
	// Filter guarantees we want to track all services received.
	return service;
	}

	@Override
	public void modifiedService(ServiceReference<Object> reference, Object service) {
	// Nothing
	}

	@Override
	public synchronized void removedService(ServiceReference<Object> reference, Object service) {
	if (service instanceof Coordinator) {
	if (service.equals(coordinator)) {
	Coordinator coordinator = findAlternateServiceFor(Coordinator.class);
	if (coordinator == null)
	deactivate();
	this.coordinator = coordinator;
	}
	}
	else if (service instanceof RegionDigraph) {
	if (service.equals(regionDigraph)) {
	RegionDigraph regionDigraph = findAlternateServiceFor(RegionDigraph.class);
	if (regionDigraph == null)
	deactivate();
	this.regionDigraph = regionDigraph;
	}
	}
	else if (service instanceof Resolver) {
	if (service.equals(resolver)) {
	Resolver resolver = findAlternateServiceFor(Resolver.class);
	if (resolver == null)
	deactivate();
	this.resolver = resolver;
	}
	}
	else if (service instanceof IDirectoryFinder)
	finders.remove(service);
	else {
	if (service.equals(modelledResourceManager)) {
	try {
	Class clazz = getClass().getClassLoader().loadClass(MODELLED_RESOURCE_MANAGER);
	Object manager = findAlternateServiceFor(clazz);
	if (manager == null) {
	modelledResourceManager = null;
	serviceModeller = null;
	} else {
	modelledResourceManager = service;
	serviceModeller = new ApplicationServiceModeller(service);
	}
	} catch (ClassNotFoundException e) {
	// ignore
	} catch (NoClassDefFoundError e) {
	// ignore
	}
	}
	}
	}

	/* End ServiceTrackerCustomizer methods */
	}