001/*
002 * (C) Copyright 2006-2010 Nuxeo SA (http://nuxeo.com/) and others.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *     http://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 *
016 * Contributors:
017 *     bstefanescu
018 */
019package org.nuxeo.runtime.model.impl;
020
021import java.util.Set;
022
023import org.nuxeo.runtime.model.ComponentName;
024import org.nuxeo.runtime.model.RegistrationInfo;
025
026/**
027 * Deactivate components in the proper order to avoid exceptions at shutdown.
028 * 
029 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
030 */
031public class ShutdownTask {
032
033    final static void shutdown(ComponentManagerImpl mgr) {
034        RegistrationInfoImpl[] ris = mgr.reg.getComponentsArray();
035        for (RegistrationInfoImpl ri : ris) {
036            shutdown(mgr, ri);
037        }
038    }
039
040    private static void shutdown(ComponentManagerImpl mgr, RegistrationInfoImpl ri) {
041        ComponentName name = ri.getName();
042        if (name == null) {
043            return; // already destroyed
044        }
045        if (ri.getState() <= RegistrationInfo.RESOLVED) {
046            // not yet activated so we can destroy it right now
047            mgr.unregister(name);
048            return;
049        }
050        // an active component - get the components depending on it
051        Set<ComponentName> reqs = mgr.reg.requirements.get(name);
052        if (reqs != null && !reqs.isEmpty()) {
053            // there are some components depending on me - cannot shutdown
054            for (ComponentName req : reqs.toArray(new ComponentName[reqs.size()])) {
055                RegistrationInfoImpl parentRi = mgr.reg.components.get(req);
056                if (parentRi != null) {
057                    shutdown(mgr, parentRi);
058                }
059            }
060        }
061        // no components are depending on me - shutdown now
062        mgr.unregister(name);
063    }
064
065}