genericpeergroup.java

JXTA&#8482 is a set of open, generalized peer-to-peer (P2P) protocols that allow any networked devi

/*
 * Copyright (c) 2001-2007 Sun Microsystems, Inc.  All rights reserved.
 *  
 *  The Sun Project JXTA(TM) Software License
 *  
 *  Redistribution and use in source and binary forms, with or without 
 *  modification, are permitted provided that the following conditions are met:
 *  
 *  1. Redistributions of source code must retain the above copyright notice,
 *     this list of conditions and the following disclaimer.
 *  
 *  2. Redistributions in binary form must reproduce the above copyright notice, 
 *     this list of conditions and the following disclaimer in the documentation 
 *     and/or other materials provided with the distribution.
 *  
 *  3. The end-user documentation included with the redistribution, if any, must 
 *     include the following acknowledgment: "This product includes software 
 *     developed by Sun Microsystems, Inc. for JXTA(TM) technology." 
 *     Alternately, this acknowledgment may appear in the software itself, if 
 *     and wherever such third-party acknowledgments normally appear.
 *  
 *  4. The names "Sun", "Sun Microsystems, Inc.", "JXTA" and "Project JXTA" must 
 *     not be used to endorse or promote products derived from this software 
 *     without prior written permission. For written permission, please contact 
 *     Project JXTA at http://www.jxta.org.
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 *  5. Products derived from this software may not be called "JXTA", nor may 
 *     "JXTA" appear in their name, without prior written permission of Sun.
 *  
 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
 *  INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 
 *  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SUN 
 *  MICROSYSTEMS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 
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 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 
 *  EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *  
 *  JXTA is a registered trademark of Sun Microsystems, Inc. in the United 
 *  States and other countries.
 *  
 *  Please see the license information page at :
 *  <http://www.jxta.org/project/www/license.html> for instructions on use of 
 *  the license in source files.
 *  
 *  ====================================================================
 *  
 *  This software consists of voluntary contributions made by many individuals 
 *  on behalf of Project JXTA. For more information on Project JXTA, please see 
 *  http://www.jxta.org.
 *  
 *  This license is based on the BSD license adopted by the Apache Foundation. 
 */
package net.jxta.impl.peergroup;

import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Executor;
import java.util.concurrent.ThreadPoolExecutor;
import net.jxta.access.AccessService;
import net.jxta.discovery.DiscoveryService;
import net.jxta.document.Advertisement;
import net.jxta.document.AdvertisementFactory;
import net.jxta.document.Element;
import net.jxta.document.XMLElement;
import net.jxta.endpoint.EndpointService;
import net.jxta.exception.PeerGroupException;
import net.jxta.exception.ProtocolNotSupportedException;
import net.jxta.exception.ServiceNotFoundException;
import net.jxta.id.ID;
import net.jxta.id.IDFactory;
import net.jxta.impl.loader.RefJxtaLoader;
import net.jxta.impl.protocol.PSEConfigAdv;
import net.jxta.impl.protocol.PlatformConfig;
import net.jxta.impl.util.TimeUtils;
import net.jxta.logging.Logging;
import net.jxta.membership.MembershipService;
import net.jxta.peer.PeerID;
import net.jxta.peer.PeerInfoService;
import net.jxta.peergroup.PeerGroup;
import net.jxta.peergroup.PeerGroupID;
import net.jxta.pipe.PipeService;
import net.jxta.platform.JxtaLoader;
import net.jxta.platform.Module;
import net.jxta.platform.ModuleClassID;
import net.jxta.platform.ModuleSpecID;
import net.jxta.protocol.ConfigParams;
import net.jxta.protocol.ModuleImplAdvertisement;
import net.jxta.protocol.PeerAdvertisement;
import net.jxta.protocol.PeerGroupAdvertisement;
import net.jxta.rendezvous.RendezVousService;
import net.jxta.resolver.ResolverService;
import net.jxta.service.Service;

import java.io.IOException;
import java.lang.reflect.Method;
import java.lang.reflect.UndeclaredThrowableException;
import java.net.URI;
import java.net.URL;
import java.security.cert.Certificate;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.HashMap;
import java.util.Hashtable;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.RejectedExecutionException;
import java.util.concurrent.RejectedExecutionHandler;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.ThreadFactory;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 * Provides common services for most peer group implementations.
 */
public abstract class GenericPeerGroup implements PeerGroup {
    
    /**
     * Logger
     */
    private final static transient Logger LOG = Logger.getLogger(GenericPeerGroup.class.getName());
    
    /**
     *  Holder for configuration parameters for groups in the process of being created.
     */
    private final static Map<ID, ConfigParams> group_configs = Collections.synchronizedMap(new HashMap<ID, ConfigParams>());
    
    /**
     * The loader - use the getter and setter for modifying the ClassLoader for
     * a security manager.
     * <p/>
     * This should eventually be group scoped rather than implementation
     * scoped. We are currently allowing classes to loaded into contexts which
     * they should not be known.
     */
    private final static JxtaLoader loader = new RefJxtaLoader(new URL[0], new CompatibilityEquater() {
        public boolean compatible(Element test) {
            return StdPeerGroup.isCompatible(test);
        }
    });
    
    /*
     * Shortcuts to well known services.
     */
    private EndpointService endpoint;
    private ResolverService resolver;
    private DiscoveryService discovery;
    private PipeService pipe;
    private MembershipService membership;
    private RendezVousService rendezvous;
    private PeerInfoService peerinfo;
    private AccessService access;
    
    /**
     * This peer's advertisement in this group.
     */
    private final PeerAdvertisement peerAdvertisement;
    
    /**
     * This group's advertisement.
     */
    private PeerGroupAdvertisement peerGroupAdvertisement = null;
    
    /**
     * This group's implAdvertisement.
     */
    protected ModuleImplAdvertisement implAdvertisement = null;
    
    /**
     * This peer's config advertisement.
     */
    protected ConfigParams configAdvertisement = null;
    
    /**
     * This service implements a group but, being a Service, it runs inside of
     * some group. That's its home group.
     * <p/>
     * Exception: The platform peer group does not have a parent group. It
     * has to be entirely self sufficient.
     */
    protected PeerGroup parentGroup = null;
    
    /**
     * The location of our store
     */
    protected URI jxtaHome = null;
    
    /**
     * The services that do the real work of the Peer Group.
     */
    private final Map<ModuleClassID, Service> services = new HashMap<ModuleClassID, Service>();
    
    /**
     * {@code true} when we have decided to stop this group.
     */
    private volatile boolean stopping = false;
    
    /**
     * {@code true} when the PG adv has been published.
     */
    private boolean published = false; // assume it hasn't
    
    /**
     * Counts the number of times an interface to this group has been given out.
     * This is decremented every time an interface object is GCed or
     * its owner calls unref().
     *
     * <p/>When it reaches zero, if it is time to tear-down the group instance;
     * nomatter what the GC thinks. There are threads that need to be stopped
     * before the group instance object ever becomes un-reachable.
     */
    private int masterRefCount = 0;
    
    /**
     * Is {@code true} when at least one interface object has been generated AFTER
     * initComplete has become true. If true, the group stops when its ref
     * count reaches zero.
     */
    private boolean stopWhenUnreferenced = false;
    
    /**
     * Is set to {@code true} when {@code init()} is completed enough that it
     * makes sense to perform ref-counting.
     */
    protected volatile boolean initComplete = false;
    
    /**
     * The thread group in which threads created by this group or services of
     * this group should live. The thread group is used primarily for debugging
     * and classification purposes--we don't try to use any of the fancy (and
     * mostly useless) ThreadGroup features.
     */
    private ThreadGroup threadGroup = null;
        
    /**
     * The minimum number of Threads our Executor will reserve. Once started
     * these Threads will remain.
     *
     * todo convert these hardcoded settings into group config params.
     */
    private final int COREPOOLSIZE = 5;

    
    /**
     * The number of seconds that Threads above {@code COREPOOLSIZE} will
     * remain idle before terminating.
     *
     * todo convert these hardcoded settings into group config params.
     */
    private final long KEEPALIVETIME = 15;

    
    /**
     * The intended upper bound on the number of threads we will allow our 
     * Executor to create. We will allow the pool to grow to twice this size if
     * we run out of threads.
     *
     * todo convert these hardcoded settings into group config params.
     */
    private final int MAXPOOLSIZE = 100;

    
    /**
     * Queue for tasks waiting to be run by our {@code Executor}.
     */
    private BlockingQueue<Runnable> taskQueue;

    
    /**
     * The PeerGroup ThreadPool
     */
    private ThreadPoolExecutor threadPool;
    
    /**
     * The PeerGroup ScheduledExecutor
     */
    private ScheduledThreadPoolExecutor scheduledExecutor;    

    
    /**
     * {@inheritDoc}
     * <p/>
     * We do not want to count on the invoker to properly unreference the group
     * object that we return; this call is often used in a loop and it is silly
     * to increment and decrement ref-counts for references that are sure to 
     * live shorter than the referee.
     * <p/>
     * On the other hand it is dangerous for us to share our reference object to
     * the parent group. That's where weak interface objects come in handy. We
     * can safely make one and give it away.
     */
    public PeerGroup getParentGroup() {
        if (parentGroup == null) {
            return null;
        }
        return parentGroup.getWeakInterface();
    }
    
    /**
     * {@inheritDoc}
     */
    public URI getStoreHome() {
        return jxtaHome;
    }
    
    /**
     * Sets the root location for the store to be used by this peergroup.
     * <p/>
     * This should be set early in the peer group's life and then never
     * changed.
     *
     * @param newHome The new store location.
     */
    protected void setStoreHome(URI newHome) {
        jxtaHome = newHome;
    }

    /**
     * {@inheritDoc}
     */
    public static JxtaLoader getJxtaLoader() {
        return loader;
    }
    
    public GenericPeerGroup() {
        // Start building our peer adv.
        peerAdvertisement = (PeerAdvertisement)
                AdvertisementFactory.newAdvertisement(PeerAdvertisement.getAdvertisementType());
    }
    
    /**
     * {@inheritDoc}
     */
    @Override
    public boolean equals(Object target) {