001/*
002 * (C) Copyright 2006-2010 Nuxeo SAS (http://nuxeo.com/) and contributors.
003 *
004 * All rights reserved. This program and the accompanying materials
005 * are made available under the terms of the GNU Lesser General Public License
006 * (LGPL) version 2.1 which accompanies this distribution, and is available at
007 * http://www.gnu.org/licenses/lgpl.html
008 *
009 * This library is distributed in the hope that it will be useful,
010 * but WITHOUT ANY WARRANTY; without even the implied warranty of
011 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012 * Lesser General Public License for more details.
013 *
014 * Contributors:
015 *     bstefanescu
016 */
017package org.nuxeo.runtime.model.impl;
018
019import java.util.Set;
020
021import org.nuxeo.runtime.model.ComponentName;
022import org.nuxeo.runtime.model.RegistrationInfo;
023
024/**
025 * Deactivate components in the proper order to avoid exceptions at shutdown.
026 * 
027 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
028 */
029public class ShutdownTask {
030
031    final static void shutdown(ComponentManagerImpl mgr) {
032        RegistrationInfoImpl[] ris = mgr.reg.getComponentsArray();
033        for (RegistrationInfoImpl ri : ris) {
034            shutdown(mgr, ri);
035        }
036    }
037
038    private static void shutdown(ComponentManagerImpl mgr, RegistrationInfoImpl ri) {
039        ComponentName name = ri.getName();
040        if (name == null) {
041            return; // already destroyed
042        }
043        if (ri.getState() <= RegistrationInfo.RESOLVED) {
044            // not yet activated so we can destroy it right now
045            mgr.unregister(name);
046            return;
047        }
048        // an active component - get the components depending on it
049        Set<ComponentName> reqs = mgr.reg.requirements.get(name);
050        if (reqs != null && !reqs.isEmpty()) {
051            // there are some components depending on me - cannot shutdown
052            for (ComponentName req : reqs.toArray(new ComponentName[reqs.size()])) {
053                RegistrationInfoImpl parentRi = mgr.reg.components.get(req);
054                if (parentRi != null) {
055                    shutdown(mgr, parentRi);
056                }
057            }
058        }
059        // no components are depending on me - shutdown now
060        mgr.unregister(name);
061    }
062
063}