    001    // Copyright 2006, 2007, 2011 The Apache Software Foundation
    002    //
    003    // Licensed under the Apache License, Version 2.0 (the "License");
    004    // you may not use this file except in compliance with the License.
    005    // You may obtain a copy of the License at
    006    //
    007    //     http://www.apache.org/licenses/LICENSE-2.0
    008    //
    009    // Unless required by applicable law or agreed to in writing, software
    010    // distributed under the License is distributed on an "AS IS" BASIS,
    011    // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    012    // See the License for the specific language governing permissions and
    013    // limitations under the License.
    014
    015    package org.apache.tapestry5.ioc.internal.services;
    016
    017    import org.apache.tapestry5.func.F;
    018    import org.apache.tapestry5.func.Worker;
    019    import org.apache.tapestry5.ioc.internal.util.OneShotLock;
    020    import org.apache.tapestry5.ioc.services.RegistryShutdownHub;
    021    import org.apache.tapestry5.ioc.services.RegistryShutdownListener;
    022    import org.slf4j.Logger;
    023
    024    import java.util.List;
    025
    026    import static org.apache.tapestry5.ioc.internal.util.CollectionFactory.newThreadSafeList;
    027
    028    public class RegistryShutdownHubImpl implements RegistryShutdownHub
    029    {
    030        private final OneShotLock lock = new OneShotLock();
    031
    032        private final Logger logger;
    033
    034        private final List<Runnable> listeners = newThreadSafeList();
    035
    036        private final List<Runnable> preListeners = newThreadSafeList();
    037
    038        public RegistryShutdownHubImpl(Logger logger)
    039        {
    040            this.logger = logger;
    041        }
    042
    043        public void addRegistryShutdownListener(final RegistryShutdownListener listener)
    044        {
    045            assert listener != null;
    046
    047            addRegistryShutdownListener(new Runnable()
    048            {
    049                public void run()
    050                {
    051                    listener.registryDidShutdown();
    052                }
    053            });
    054        }
    055
    056        public void addRegistryShutdownListener(Runnable listener)
    057        {
    058            assert listener != null;
    059
    060            lock.check();
    061
    062            listeners.add(listener);
    063        }
    064
    065        public void addRegistryWillShutdownListener(Runnable listener)
    066        {
    067            assert listener != null;
    068
    069            lock.check();
    070
    071            preListeners.add(listener);
    072        }
    073
    074        /**
    075         * Fires the {@link RegistryShutdownListener#registryDidShutdown()} method on each listener. At the end, all the
    076         * listeners are discarded.
    077         */
    078        public void fireRegistryDidShutdown()
    079        {
    080            lock.lock();
    081
    082            F.flow(preListeners).concat(listeners).each(new Worker<Runnable>()
    083            {
    084                public void work(Runnable element)
    085                {
    086                    try
    087                    {
    088                        element.run();
    089                    } catch (RuntimeException ex)
    090                    {
    091                        logger.error(ServiceMessages.shutdownListenerError(element, ex), ex);
    092                    }
    093                }
    094            });
    095
    096            preListeners.clear();
    097            listeners.clear();
    098        }
    099
    100    }