Michael Bayne
ea501d7083
that it be shut down manually. git-svn-id: svn+ssh://src.earth.threerings.net/narya/trunk@4794 542714f4-19e9-0310-aa3c-eee0fc999fb1
1106 lines
39 KiB
Java
1106 lines
39 KiB
Java
//
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// $Id$
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//
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// Narya library - tools for developing networked games
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// Copyright (C) 2002-2007 Three Rings Design, Inc., All Rights Reserved
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// http://www.threerings.net/code/narya/
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//
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// This library is free software; you can redistribute it and/or modify it
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// under the terms of the GNU Lesser General Public License as published
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// by the Free Software Foundation; either version 2.1 of the License, or
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// (at your option) any later version.
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//
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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// Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public
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// License along with this library; if not, write to the Free Software
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// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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package com.threerings.presents.peer.server;
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import java.util.ArrayList;
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import java.util.HashMap;
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import java.util.Iterator;
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import java.util.List;
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import java.util.logging.Level;
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import com.samskivert.io.PersistenceException;
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import com.samskivert.jdbc.depot.PersistenceContext;
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import com.samskivert.util.ArrayIntSet;
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import com.samskivert.util.ChainedResultListener;
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import com.samskivert.util.Interval;
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import com.samskivert.util.Invoker;
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import com.samskivert.util.ObjectUtil;
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import com.samskivert.util.ObserverList;
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import com.samskivert.util.ResultListener;
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import com.samskivert.util.ResultListenerList;
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import com.samskivert.util.Tuple;
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import com.threerings.io.Streamable;
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import com.threerings.util.Name;
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import com.threerings.presents.client.Client;
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import com.threerings.presents.data.ClientObject;
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import com.threerings.presents.dobj.DObject;
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import com.threerings.presents.dobj.EntryAddedEvent;
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import com.threerings.presents.dobj.EntryRemovedEvent;
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import com.threerings.presents.dobj.EntryUpdatedEvent;
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import com.threerings.presents.dobj.ObjectAccessException;
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import com.threerings.presents.dobj.SetListener;
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import com.threerings.presents.dobj.Subscriber;
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import com.threerings.presents.server.ClientManager;
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import com.threerings.presents.server.InvocationException;
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import com.threerings.presents.server.PresentsClient;
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import com.threerings.presents.server.PresentsServer;
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import com.threerings.presents.peer.data.ClientInfo;
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import com.threerings.presents.peer.data.NodeObject;
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import com.threerings.presents.peer.data.PeerMarshaller;
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import com.threerings.presents.peer.net.PeerCreds;
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import com.threerings.presents.peer.server.persist.NodeRecord;
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import com.threerings.presents.peer.server.persist.NodeRepository;
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import static com.threerings.presents.Log.log;
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/**
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* Manages connections to the other nodes in a Presents server cluster. Each server maintains a
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* client connection to the other servers and subscribes to the {@link NodeObject} of all peer
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* servers and uses those objects to communicate cross-node information.
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*/
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public class PeerManager
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implements PeerProvider, ClientManager.ClientObserver, PresentsServer.Shutdowner
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{
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/**
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* Used by entities that wish to know when cached data has become stale due to a change on
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* one of our peer servers.
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*/
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public static interface StaleCacheObserver
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{
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/**
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* Called when some possibly cached data has changed on one of our peer servers.
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*/
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public void changedCacheData (Streamable data);
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}
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/**
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* Used by entities that wish to know when this peer has been forced into immediately releasing
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* a lock.
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*/
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public static interface DroppedLockObserver
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{
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/**
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* Called when this node has been forced to drop a lock.
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*/
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public void droppedLock (NodeObject.Lock lock);
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}
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/** Used by {@link #lookupNodeDatum}. */
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public static interface Lookup<T>
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{
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public T lookup (NodeObject nodeobj);
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}
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/** Used by {@link #applyToNodes}. */
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public static interface Operation
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{
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public void apply (NodeObject nodeobj);
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}
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/**
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* Wraps an operation that needs a shared resource lock to be acquired before it can be
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* performed, and released after it completes. Used by {@link #performWithLock}.
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*/
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public static interface LockedOperation
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{
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/**
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* Called when the resource lock was acquired successfully. The lock will be released
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* immediately after this function call finishes.
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*/
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public void run ();
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/**
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* Called when the resource lock was not acquired successfully, with the name of the peer
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* who is holding the lock (or null in case of a generic failure).
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*/
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public void fail (String peerName);
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}
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/**
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* Creates a peer manager which will create a {@link NodeRepository} which will be used to
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* publish our existence and discover the other nodes.
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*/
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public PeerManager (PersistenceContext ctx, Invoker invoker)
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{
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_invoker = invoker;
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_noderepo = new NodeRepository(ctx);
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PresentsServer.registerShutdowner(this);
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}
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/**
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* Returns the distributed object that represents this node to its peers.
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*/
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public NodeObject getNodeObject ()
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{
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return _nodeobj;
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}
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/**
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* Initializes this peer manager and initiates the process of connecting to its peer
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* nodes. This will also reconfigure the ConnectionManager and ClientManager with peer related
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* bits, so this should not be called until <em>after</em> the main server has set up its
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* client factory and authenticator.
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*
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* @param nodeName this node's unique name.
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* @param sharedSecret a shared secret used to allow the peers to authenticate with one
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* another.
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* @param hostName the DNS name of the server running this node.
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* @param publicHostName if non-null, a separate public DNS hostname by which the node is to be
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* known to normal clients (we may want inter-peer communication to take place over a different
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* network than the communication between real clients and the various peer servers).
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* @param port the port on which other nodes should connect to us.
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* @param conprov used to obtain our JDBC connections.
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* @param invoker we will perform all database operations on the supplied invoker thread.
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*/
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public void init (String nodeName, String sharedSecret, String hostName,
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String publicHostName, int port)
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{
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_nodeName = nodeName;
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_sharedSecret = sharedSecret;
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// wire ourselves into the server
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PresentsServer.conmgr.setAuthenticator(
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new PeerAuthenticator(this, PresentsServer.conmgr.getAuthenticator()));
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PresentsServer.clmgr.setClientFactory(
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new PeerClientFactory(this, PresentsServer.clmgr.getClientFactory()));
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// create our node object
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_nodeobj = PresentsServer.omgr.registerObject(createNodeObject());
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_nodeobj.setNodeName(nodeName);
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// register ourselves with the node table
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final NodeRecord record = new NodeRecord(
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_nodeName, hostName, (publicHostName == null) ? hostName : publicHostName, port);
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_invoker.postUnit(new Invoker.Unit("registerNode") {
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public boolean invoke () {
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try {
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_noderepo.updateNode(record);
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} catch (PersistenceException pe) {
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log.warning("Failed to register node record [rec=" + record +
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", error=" + pe + "].");
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}
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return false;
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}
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});
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// set the invocation service
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_nodeobj.setPeerService(
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(PeerMarshaller)PresentsServer.invmgr.registerDispatcher(new PeerDispatcher(this)));
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// register ourselves as a client observer
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PresentsServer.clmgr.addClientObserver(this);
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// and start our peer refresh interval (this need not use a runqueue as all it will do is
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// post an invoker unit)
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new Interval() {
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public void expired () {
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refreshPeers();
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}
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}.schedule(5000L, 60*1000L);
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// give derived classes an easy way to get in on the init action
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didInit();
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}
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/**
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* Locates the client with the specified name. Returns null if the client is not logged onto
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* any peer.
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*/
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public ClientInfo locateClient (final Name key)
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{
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return lookupNodeDatum(new Lookup<ClientInfo>() {
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public ClientInfo lookup (NodeObject nodeobj) {
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return nodeobj.clients.get(key);
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}
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});
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}
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/**
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* Locates a datum from among the set of peer {@link NodeObject}s. Objects are searched in
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* arbitrary order and the first non-null value returned by the supplied lookup operation is
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* returned to the caller. Null if all lookup operations returned null.
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*/
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public <T> T lookupNodeDatum (Lookup<T> op)
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{
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T value = op.lookup(_nodeobj);
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if (value != null) {
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return value;
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}
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for (PeerNode peer : _peers.values()) {
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if (peer.nodeobj == null) {
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continue;
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}
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value = op.lookup(peer.nodeobj);
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if (value != null) {
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return value;
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}
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}
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return value;
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}
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/**
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* Applies the supplied operation to all {@link NodeObject}s. The operation should not modify
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* the objects unless you really know what you're doing. more likely it will summarize
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* information contained therein.
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*/
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public void applyToNodes (Operation op)
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{
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op.apply(_nodeobj);
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for (PeerNode peer : _peers.values()) {
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if (peer.nodeobj != null) {
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op.apply(peer.nodeobj);
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}
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}
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}
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/**
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* Returns true if the supplied peer credentials match our shared secret.
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*/
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public boolean isAuthenticPeer (PeerCreds creds)
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{
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return PeerCreds.createPassword(creds.getNodeName(), _sharedSecret).equals(
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creds.getPassword());
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}
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/**
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* Initiates a proxy on an object that is managed by the specified peer. The object will be
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* proxied into this server's distributed object space and its local oid reported back to the
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* supplied result listener.
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*
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* <p> Note that proxy requests <em>do not</em> stack like subscription requests. Only one
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* entity must issue a request to proxy an object and that entity must be responsible for
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* releasing the proxy when it knows that there are no longer any local subscribers to the
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* object.
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*/
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public <T extends DObject> void proxyRemoteObject (
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String nodeName, int remoteOid, final ResultListener<Integer> listener)
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{
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final Client peer = getPeerClient(nodeName);
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if (peer == null) {
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String errmsg = "Have no connection to peer [node=" + nodeName + "].";
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listener.requestFailed(new ObjectAccessException(errmsg));
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return;
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}
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final Tuple<String,Integer> key = new Tuple<String,Integer>(nodeName, remoteOid);
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if (_proxies.containsKey(key)) {
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String errmsg = "Cannot proxy already proxied object [key=" + key + "].";
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listener.requestFailed(new ObjectAccessException(errmsg));
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return;
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}
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// issue a request to subscribe to the remote object
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peer.getDObjectManager().subscribeToObject(remoteOid, new Subscriber<T>() {
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public void objectAvailable (T object) {
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// make a note of this proxy mapping
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_proxies.put(key, new Tuple<Subscriber<?>,DObject>(this, object));
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// map the object into our local oid space
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PresentsServer.omgr.registerProxyObject(object, peer.getDObjectManager());
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// then tell the caller about the (now remapped) oid
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listener.requestCompleted(object.getOid());
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}
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public void requestFailed (int oid, ObjectAccessException cause) {
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listener.requestFailed(cause);
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}
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});
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}
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/**
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* Unsubscribes from and clears a proxied object. The caller must be sure that there are no
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* remaining subscribers to the object on this local server.
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*/
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public void unproxyRemoteObject (String nodeName, int remoteOid)
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{
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Tuple<String,Integer> key = new Tuple<String,Integer>(nodeName, remoteOid);
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Tuple<Subscriber<?>,DObject> bits = _proxies.remove(key);
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if (bits == null) {
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log.warning("Requested to clear unknown proxy [key=" + key + "].");
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return;
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}
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// clear out the local object manager's proxy mapping
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PresentsServer.omgr.clearProxyObject(remoteOid, bits.right);
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final Client peer = getPeerClient(nodeName);
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if (peer == null) {
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log.warning("Unable to unsubscribe from proxy, missing peer [key=" + key + "].");
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return;
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}
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// restore the object's omgr reference to our ClientDObjectMgr and its oid back to the
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// remote oid so that it can properly finish the unsubscription process
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bits.right.setOid(remoteOid);
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bits.right.setManager(peer.getDObjectManager());
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// finally unsubscribe from the object on our peer
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peer.getDObjectManager().unsubscribeFromObject(remoteOid, bits.left);
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}
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/**
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* Returns the client object representing the connection to the named peer, or
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* <code>null</code> if we are not currently connected to it.
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*/
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public Client getPeerClient (String nodeName)
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{
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PeerNode peer = _peers.get(nodeName);
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return (peer == null) ? null : peer.getClient();
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}
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/**
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* Returns the public hostname to use when connecting to the specified peer or null if the peer
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* is not currently connected to this server.
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*/
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public String getPeerPublicHostName (String nodeName)
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{
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PeerNode peer = _peers.get(nodeName);
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return (peer == null) ? null : peer.getPublicHostName();
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}
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/**
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* Returns the port on which to connect to the specified peer or -1 if the peer is not
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* currently connected to this server.
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*/
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public int getPeerPort (String nodeName)
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{
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PeerNode peer = _peers.get(nodeName);
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return (peer == null) ? -1 : peer.getPort();
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}
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/**
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* Acquires a lock on a resource shared amongst this node's peers. If the lock is successfully
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* acquired, the supplied listener will receive this node's name. If another node acquires the
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* lock first, then the listener will receive the name of that node.
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*/
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public void acquireLock (final NodeObject.Lock lock, final ResultListener<String> listener)
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{
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// wait until any pending resolution is complete
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queryLock(lock, new ChainedResultListener<String>(listener) {
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public void requestCompleted (String result) {
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if (result == null) {
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if (_suboids.isEmpty()) {
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_nodeobj.addToLocks(lock);
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listener.requestCompleted(_nodeName);
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} else {
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_locks.put(lock, new LockHandler(lock, true, listener));
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}
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} else {
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listener.requestCompleted(result);
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}
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}
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});
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}
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/**
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* Releases a lock. This can be cancelled using {@link #reacquireLock}, in which case the
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* passed listener will receive this node's name as opposed to <code>null</code>, which
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* signifies that the lock has been successfully released.
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*/
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public void releaseLock (final NodeObject.Lock lock, final ResultListener<String> listener)
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{
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// wait until any pending resolution is complete
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queryLock(lock, new ChainedResultListener<String>(listener) {
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public void requestCompleted (String result) {
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if (_nodeName.equals(result)) {
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if (_suboids.isEmpty()) {
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_nodeobj.removeFromLocks(lock);
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listener.requestCompleted(null);
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} else {
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_locks.put(lock, new LockHandler(lock, false, listener));
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}
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} else {
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if (result != null) {
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log.warning("Tried to release lock held by another peer [lock=" + lock +
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", owner=" + result + "].");
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}
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listener.requestCompleted(result);
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}
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}
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});
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}
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/**
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* Reacquires a lock after a call to {@link #releaseLock} but before the result listener
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* supplied to that method has been notified with the result of the action. The result
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* listener will receive the name of this node to indicate that the lock is still held. If a
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* node requests to release a lock, then receives a lock-related request from another peer, it
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* can use this method to cancel the release reliably, since the lock-related request will have
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* been sent before the peer's ratification of the release.
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*/
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public void reacquireLock (NodeObject.Lock lock)
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{
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// make sure we're releasing it
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LockHandler handler = _locks.get(lock);
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if (handler == null || !handler.getNodeName().equals(_nodeName) || handler.isAcquiring()) {
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log.warning("Tried to reacquire lock not being released [lock=" + lock +
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", handler=" + handler + "].");
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return;
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}
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// perform an update to let other nodes know that we're reacquiring
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_nodeobj.updateLocks(lock);
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// cancel the handler and report to any listeners
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_locks.remove(lock);
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handler.cancel();
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handler.listeners.requestCompleted(_nodeName);
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}
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/**
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* Determines the owner of the specified lock, waiting for any resolution to complete before
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* notifying the supplied listener.
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*/
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public void queryLock (NodeObject.Lock lock, ResultListener<String> listener)
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{
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// if it's being resolved, add the listener to the list
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LockHandler handler = _locks.get(lock);
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if (handler != null) {
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handler.listeners.add(listener);
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return;
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}
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// otherwise, return its present value
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listener.requestCompleted(queryLock(lock));
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}
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/**
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* Finds the owner of the specified lock (if any) among this node and its peers. This answer
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* is not definitive, as the lock may be in the process of resolving.
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*/
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public String queryLock (NodeObject.Lock lock)
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{
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// look for it in our own lock set
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if (_nodeobj.locks.contains(lock)) {
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return _nodeName;
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}
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// then in our peers
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for (PeerNode peer : _peers.values()) {
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if (peer.nodeobj != null && peer.nodeobj.locks.contains(lock)) {
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return peer.getNodeName();
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}
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}
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return null;
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}
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/**
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* Tries to acquire the resource lock and, if successful, performs the operation and releases
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* the lock; if unsuccessful, calls the operation's failure handler. Please note: the lock will
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* be released immediately after the operation.
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*/
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public void performWithLock (final NodeObject.Lock lock, final LockedOperation operation)
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{
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acquireLock(lock, new ResultListener<String>() {
|
|
public void requestCompleted (String nodeName) {
|
|
if (getNodeObject().nodeName.equals(nodeName)) {
|
|
// lock acquired successfully - perform the operation, and release the lock.
|
|
operation.run();
|
|
releaseLock(lock, new ResultListener.NOOP<String>());
|
|
} else {
|
|
// some other peer beat us to it
|
|
operation.fail(nodeName);
|
|
if (nodeName == null) {
|
|
log.warning("Lock acquired by null? [lock=" + lock + "].");
|
|
}
|
|
}
|
|
}
|
|
public void requestFailed (Exception cause) {
|
|
log.log(Level.WARNING, "Lock acquisition failed [lock=" + lock + "].", cause);
|
|
operation.fail(null);
|
|
}
|
|
});
|
|
}
|
|
|
|
/**
|
|
* Adds an observer to notify when this peer has been forced to drop a lock immediately.
|
|
*/
|
|
public void addDroppedLockObserver (DroppedLockObserver observer)
|
|
{
|
|
_dropobs.add(observer);
|
|
}
|
|
|
|
/**
|
|
* Removes a dropped lock observer from the list.
|
|
*/
|
|
public void removeDroppedLockObserver (DroppedLockObserver observer)
|
|
{
|
|
_dropobs.remove(observer);
|
|
}
|
|
|
|
/**
|
|
* Called by {@link PeerClient}s when clients subscribe to the {@link NodeObject}.
|
|
*/
|
|
public void clientSubscribedToNode (int cloid)
|
|
{
|
|
_suboids.add(cloid);
|
|
}
|
|
|
|
/**
|
|
* Called by {@link PeerClient}s when clients unsubscribe from the {@link NodeObject}.
|
|
*/
|
|
public void clientUnsubscribedFromNode (int cloid)
|
|
{
|
|
_suboids.remove(cloid);
|
|
for (LockHandler handler : _locks.values().toArray(new LockHandler[_locks.size()])) {
|
|
if (handler.getNodeName().equals(_nodeName)) {
|
|
handler.clientUnsubscribed(cloid);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Registers a stale cache observer.
|
|
*/
|
|
public void addStaleCacheObserver (String cache, StaleCacheObserver observer)
|
|
{
|
|
ObserverList<StaleCacheObserver> list = _cacheobs.get(cache);
|
|
if (list == null) {
|
|
list = new ObserverList<StaleCacheObserver>(ObserverList.FAST_UNSAFE_NOTIFY);
|
|
_cacheobs.put(cache, list);
|
|
}
|
|
list.add(observer);
|
|
}
|
|
|
|
/**
|
|
* Removes a stale cache observer registration.
|
|
*/
|
|
public void removeStaleCacheObserver (String cache, StaleCacheObserver observer)
|
|
{
|
|
ObserverList<StaleCacheObserver> list = _cacheobs.get(cache);
|
|
if (list == null) {
|
|
return;
|
|
}
|
|
list.remove(observer);
|
|
if (list.isEmpty()) {
|
|
_cacheobs.remove(cache);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Called when cached data has changed on the local server and needs to inform our peers.
|
|
*/
|
|
public void broadcastStaleCacheData (String cache, Streamable data)
|
|
{
|
|
_nodeobj.setCacheData(new NodeObject.CacheData(cache, data));
|
|
}
|
|
|
|
// from interface PresentsServer.Shutdowner
|
|
public void shutdown ()
|
|
{
|
|
// clear out our invocation service
|
|
if (_nodeobj != null) {
|
|
PresentsServer.invmgr.clearDispatcher(_nodeobj.peerService);
|
|
}
|
|
|
|
// clear out our client observer registration
|
|
PresentsServer.clmgr.removeClientObserver(this);
|
|
|
|
// clear our record from the node table
|
|
_invoker.postUnit(new Invoker.Unit("deleteNode") {
|
|
public boolean invoke () {
|
|
try {
|
|
_noderepo.deleteNode(_nodeName);
|
|
} catch (PersistenceException pe) {
|
|
log.warning("Failed to delete node record [nodeName=" + _nodeName +
|
|
", error=" + pe + "].");
|
|
}
|
|
return false;
|
|
}
|
|
});
|
|
|
|
// shut down the peers
|
|
for (PeerNode peer : _peers.values()) {
|
|
peer.shutdown();
|
|
}
|
|
}
|
|
|
|
// from interface PeerProvider
|
|
public void ratifyLockAction (ClientObject caller, NodeObject.Lock lock, boolean acquire)
|
|
{
|
|
LockHandler handler = _locks.get(lock);
|
|
if (handler != null && handler.getNodeName().equals(_nodeName)) {
|
|
handler.ratify(caller, acquire);
|
|
} else {
|
|
// this is not an error condition, as we may have cancelled the handler or
|
|
// allowed another to take priority
|
|
}
|
|
}
|
|
|
|
// from interface ClientManager.ClientObserver
|
|
public void clientSessionDidStart (PresentsClient client)
|
|
{
|
|
// if this is another peer, don't publish their info
|
|
if (client instanceof PeerClient) {
|
|
return;
|
|
}
|
|
|
|
// create and publish a ClientInfo record for this client
|
|
ClientInfo clinfo = createClientInfo();
|
|
initClientInfo(client, clinfo);
|
|
|
|
// sanity check
|
|
if (_nodeobj.clients.contains(clinfo)) {
|
|
log.warning("Received clientSessionDidStart() for already registered client!? " +
|
|
"[old=" + _nodeobj.clients.get(clinfo.getKey()) + ", new=" + clinfo + "].");
|
|
// go ahead and update the record
|
|
_nodeobj.updateClients(clinfo);
|
|
} else {
|
|
_nodeobj.addToClients(clinfo);
|
|
}
|
|
}
|
|
|
|
// from interface ClientManager.ClientObserver
|
|
public void clientSessionDidEnd (PresentsClient client)
|
|
{
|
|
// if this is another peer, don't worry about it
|
|
if (client instanceof PeerClient) {
|
|
return;
|
|
}
|
|
|
|
// we scan through the list instead of relying on ClientInfo.getKey() because we want
|
|
// derived classes to be able to override that for lookups that happen way more frequently
|
|
// than logging off
|
|
Name username = client.getCredentials().getUsername();
|
|
for (ClientInfo clinfo : _nodeobj.clients) {
|
|
if (clinfo.username.equals(username)) {
|
|
clearClientInfo(client, clinfo);
|
|
return;
|
|
}
|
|
}
|
|
log.warning("Session ended for unregistered client [who=" + username + "].");
|
|
}
|
|
|
|
/**
|
|
* Called after we have finished our initialization.
|
|
*/
|
|
protected void didInit ()
|
|
{
|
|
}
|
|
|
|
/**
|
|
* Reloads the list of peer nodes from our table and refreshes each with a call to {@link
|
|
* #refreshPeer}.
|
|
*/
|
|
protected void refreshPeers ()
|
|
{
|
|
// load up information on our nodes
|
|
_invoker.postUnit(new Invoker.Unit("refreshPeers") {
|
|
public boolean invoke () {
|
|
try {
|
|
// let the world know that we're alive
|
|
_noderepo.heartbeatNode(_nodeName);
|
|
// then load up all the peer records
|
|
_nodes = _noderepo.loadNodes();
|
|
return true;
|
|
} catch (PersistenceException pe) {
|
|
log.warning("Failed to load node records: " + pe + ".");
|
|
// we'll just try again next time
|
|
return false;
|
|
}
|
|
}
|
|
public void handleResult () {
|
|
for (NodeRecord record : _nodes) {
|
|
if (record.nodeName.equals(_nodeName)) {
|
|
continue;
|
|
}
|
|
try {
|
|
refreshPeer(record);
|
|
} catch (Exception e) {
|
|
log.log(Level.WARNING, "Failure refreshing peer " + record + ".", e);
|
|
}
|
|
}
|
|
}
|
|
protected List<NodeRecord> _nodes;
|
|
});
|
|
}
|
|
|
|
/**
|
|
* Ensures that we have a connection to the specified node if it has checked in since we last
|
|
* failed to connect.
|
|
*/
|
|
protected void refreshPeer (NodeRecord record)
|
|
{
|
|
PeerNode peer = _peers.get(record.nodeName);
|
|
if (peer == null) {
|
|
_peers.put(record.nodeName, peer = createPeerNode(record));
|
|
}
|
|
peer.refresh(record);
|
|
}
|
|
|
|
/**
|
|
* Creates the appropriate derived class of {@link NodeObject} which will be registered with
|
|
* the distributed object system.
|
|
*/
|
|
protected NodeObject createNodeObject ()
|
|
{
|
|
return new NodeObject();
|
|
}
|
|
|
|
/**
|
|
* Creates a {@link ClientInfo} record which will subsequently be initialized by a call to
|
|
* {@link #initClientInfo}.
|
|
*/
|
|
protected ClientInfo createClientInfo ()
|
|
{
|
|
return new ClientInfo();
|
|
}
|
|
|
|
/**
|
|
* Returns the lock handler for the specified lock.
|
|
*/
|
|
protected LockHandler getLockHandler (NodeObject.Lock lock)
|
|
{
|
|
return _locks.get(lock);
|
|
}
|
|
|
|
protected LockHandler createLockHandler (PeerNode peer, NodeObject.Lock lock, boolean acquire)
|
|
{
|
|
LockHandler handler = new LockHandler(peer, lock, acquire);
|
|
_locks.put(lock, handler);
|
|
return handler;
|
|
}
|
|
|
|
/**
|
|
* Called when possibly cached data has changed on one of our peer servers.
|
|
*/
|
|
protected void changedCacheData (String cache, final Streamable data)
|
|
{
|
|
// see if we have any observers
|
|
ObserverList<StaleCacheObserver> list = _cacheobs.get(cache);
|
|
if (list == null) {
|
|
return;
|
|
}
|
|
// if so, notify them
|
|
list.apply(new ObserverList.ObserverOp<StaleCacheObserver>() {
|
|
public boolean apply (StaleCacheObserver observer) {
|
|
observer.changedCacheData(data);
|
|
return true;
|
|
}
|
|
});
|
|
}
|
|
|
|
/**
|
|
* Called when we have been forced to drop a lock.
|
|
*/
|
|
protected void droppedLock (final NodeObject.Lock lock)
|
|
{
|
|
_nodeobj.removeFromLocks(lock);
|
|
_dropobs.apply(new ObserverList.ObserverOp<DroppedLockObserver>() {
|
|
public boolean apply (DroppedLockObserver observer) {
|
|
observer.droppedLock(lock);
|
|
return true;
|
|
}
|
|
});
|
|
}
|
|
|
|
/**
|
|
* Initializes the supplied client info for the supplied client.
|
|
*/
|
|
protected void initClientInfo (PresentsClient client, ClientInfo info)
|
|
{
|
|
info.username = client.getCredentials().getUsername();
|
|
}
|
|
|
|
/**
|
|
* Called when a client ends their session to clear their information from our node object.
|
|
*/
|
|
protected void clearClientInfo (PresentsClient client, ClientInfo info)
|
|
{
|
|
_nodeobj.removeFromClients(info.getKey());
|
|
}
|
|
|
|
/**
|
|
* Creates a {@link PeerNode} to manage our connection to the specified peer.
|
|
*/
|
|
protected PeerNode createPeerNode (NodeRecord record)
|
|
{
|
|
return new PeerNode(this, record);
|
|
}
|
|
|
|
/**
|
|
* Creates credentials that a {@link PeerNode} can use to authenticate with another node.
|
|
*/
|
|
protected PeerCreds createCreds ()
|
|
{
|
|
return new PeerCreds(_nodeName, _sharedSecret);
|
|
}
|
|
|
|
/**
|
|
* Called when a peer connects to this server.
|
|
*/
|
|
protected void peerDidLogon (PeerNode peer)
|
|
{
|
|
// check for lock conflicts
|
|
for (NodeObject.Lock lock : peer.nodeobj.locks) {
|
|
PeerManager.LockHandler handler = _locks.get(lock);
|
|
if (handler != null) {
|
|
log.warning("Client hijacked lock in process of resolution [handler=" + handler +
|
|
", node=" + peer.getNodeName() + "].");
|
|
handler.clientHijackedLock(peer.getNodeName());
|
|
|
|
} else if (_nodeobj.locks.contains(lock)) {
|
|
log.warning("Client hijacked lock owned by this node [lock=" + lock +
|
|
", node=" + peer.getNodeName() + "].");
|
|
droppedLock(lock);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Called when a peer disconnects from this server.
|
|
*/
|
|
protected void peerDidLogoff (PeerNode peer)
|
|
{
|
|
// clear any locks held by that peer
|
|
for (LockHandler handler : _locks.values().toArray(new LockHandler[_locks.size()])) {
|
|
if (handler.getNodeName().equals(peer.getNodeName())) {
|
|
handler.clientDidLogoff();
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Handles a lock in a state of resolution.
|
|
*/
|
|
protected class LockHandler
|
|
implements SetListener
|
|
{
|
|
/** Listeners waiting for resolution. */
|
|
public ResultListenerList<String> listeners = new ResultListenerList<String>();
|
|
|
|
/**
|
|
* Creates a handler to acquire or release a lock for this node.
|
|
*/
|
|
public LockHandler (NodeObject.Lock lock, boolean acquire, ResultListener<String> listener)
|
|
{
|
|
_lock = lock;
|
|
_acquire = acquire;
|
|
listeners.add(listener);
|
|
|
|
// signal our desire to acquire or release the lock
|
|
if (acquire) {
|
|
_nodeobj.setAcquiringLock(lock);
|
|
} else {
|
|
_nodeobj.setReleasingLock(lock);
|
|
}
|
|
|
|
// take a snapshot of the set of subscriber client oids; we will act when all of them
|
|
// ratify
|
|
_remoids = (ArrayIntSet)_suboids.clone();
|
|
|
|
// schedule a timeout to act if something goes wrong
|
|
(_timeout = new Interval(PresentsServer.omgr) {
|
|
public void expired () {
|
|
log.warning("Lock handler timed out, acting anyway [lock=" + _lock +
|
|
", acquire=" + _acquire + "].");
|
|
activate();
|
|
}
|
|
}).schedule(LOCK_TIMEOUT);
|
|
}
|
|
|
|
/**
|
|
* Creates a handle that tracks another node's acquisition or release of a lock.
|
|
*/
|
|
public LockHandler (PeerNode peer, NodeObject.Lock lock, boolean acquire)
|
|
{
|
|
_peer = peer;
|
|
_lock = lock;
|
|
_acquire = acquire;
|
|
|
|
// ratify the action
|
|
peer.nodeobj.peerService.ratifyLockAction(peer.getClient(), lock, acquire);
|
|
|
|
// listen for the act to take place
|
|
peer.nodeobj.addListener(this);
|
|
}
|
|
|
|
/**
|
|
* Returns the name of the node waiting to perform the action.
|
|
*/
|
|
public String getNodeName ()
|
|
{
|
|
return (_peer == null) ? _nodeName : _peer.getNodeName();
|
|
}
|
|
|
|
/**
|
|
* Checks whether we are acquiring as opposed to releasing a lock.
|
|
*/
|
|
public boolean isAcquiring ()
|
|
{
|
|
return _acquire;
|
|
}
|
|
|
|
/**
|
|
* Signals that one of the remote nodes has ratified the pending action.
|
|
*/
|
|
public void ratify (ClientObject caller, boolean acquire)
|
|
{
|
|
if (acquire != _acquire) {
|
|
return;
|
|
}
|
|
if (!_remoids.remove(caller.getOid())) {
|
|
log.warning("Received unexpected ratification [handler=" + this +
|
|
", who=" + caller.who() + "].");
|
|
}
|
|
maybeActivate();
|
|
}
|
|
|
|
/**
|
|
* Called when a client has unsubscribed from this node (which is waiting for
|
|
* ratification).
|
|
*/
|
|
public void clientUnsubscribed (int cloid)
|
|
{
|
|
// unsubscription is implicit ratification
|
|
if (_remoids.remove(cloid)) {
|
|
maybeActivate();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Called when the connection to the controlling node has been broken.
|
|
*/
|
|
public void clientDidLogoff ()
|
|
{
|
|
_locks.remove(_lock);
|
|
listeners.requestCompleted(null);
|
|
}
|
|
|
|
/**
|
|
* Called when a client hijacks the lock by having it in its node object when it connects.
|
|
*/
|
|
public void clientHijackedLock (String nodeName)
|
|
{
|
|
cancel();
|
|
_locks.remove(_lock);
|
|
listeners.requestCompleted(nodeName);
|
|
}
|
|
|
|
/**
|
|
* Cancels this handler, as another one will be taking its place.
|
|
*/
|
|
public void cancel ()
|
|
{
|
|
if (_peer != null) {
|
|
_peer.nodeobj.removeListener(this);
|
|
} else {
|
|
_timeout.cancel();
|
|
}
|
|
}
|
|
|
|
// documentation inherited from interface SetListener
|
|
public void entryAdded (EntryAddedEvent event)
|
|
{
|
|
if (_acquire && event.getName().equals(NodeObject.LOCKS) &&
|
|
event.getEntry().equals(_lock)) {
|
|
wasActivated(_peer.getNodeName());
|
|
}
|
|
}
|
|
|
|
// documentation inherited from interface SetListener
|
|
public void entryRemoved (EntryRemovedEvent event)
|
|
{
|
|
if (!_acquire && event.getName().equals(NodeObject.LOCKS) &&
|
|
event.getOldEntry().equals(_lock)) {
|
|
wasActivated(null);
|
|
}
|
|
}
|
|
|
|
// documentation inherited from interface SetListener
|
|
public void entryUpdated (EntryUpdatedEvent event)
|
|
{
|
|
if (!_acquire && event.getName().equals(NodeObject.LOCKS) &&
|
|
event.getEntry().equals(_lock)) {
|
|
wasActivated(_peer.getNodeName());
|
|
}
|
|
}
|
|
|
|
@Override // documentation inherited
|
|
public String toString ()
|
|
{
|
|
return "[node=" + getNodeName() + ", lock=" + _lock + ", acquire=" + _acquire + "]";
|
|
}
|
|
|
|
/**
|
|
* Performs the action if all remote nodes have ratified.
|
|
*/
|
|
protected void maybeActivate ()
|
|
{
|
|
if (_remoids.isEmpty()) {
|
|
_timeout.cancel();
|
|
activate();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Performs the configured action.
|
|
*/
|
|
protected void activate ()
|
|
{
|
|
_locks.remove(_lock);
|
|
if (_acquire) {
|
|
_nodeobj.addToLocks(_lock);
|
|
listeners.requestCompleted(_nodeName);
|
|
} else {
|
|
_nodeobj.removeFromLocks(_lock);
|
|
listeners.requestCompleted(null);
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Called when the remote node has performed its action.
|
|
*/
|
|
protected void wasActivated (String owner)
|
|
{
|
|
_peer.nodeobj.removeListener(this);
|
|
_locks.remove(_lock);
|
|
listeners.requestCompleted(owner);
|
|
}
|
|
|
|
protected PeerNode _peer;
|
|
protected NodeObject.Lock _lock;
|
|
protected boolean _acquire;
|
|
protected ArrayIntSet _remoids;
|
|
protected Interval _timeout;
|
|
}
|
|
|
|
protected String _nodeName, _sharedSecret;
|
|
protected Invoker _invoker;
|
|
protected NodeRepository _noderepo;
|
|
protected NodeObject _nodeobj;
|
|
protected HashMap<String,PeerNode> _peers = new HashMap<String,PeerNode>();
|
|
|
|
/** The client oids of all peers subscribed to the node object. */
|
|
protected ArrayIntSet _suboids = new ArrayIntSet();
|
|
|
|
/** Contains a mapping of proxied objects to subscriber instances. */
|
|
protected HashMap<Tuple<String,Integer>,Tuple<Subscriber<?>,DObject>> _proxies =
|
|
new HashMap<Tuple<String,Integer>,Tuple<Subscriber<?>,DObject>>();
|
|
|
|
/** Our stale cache observers. */
|
|
protected HashMap<String, ObserverList<StaleCacheObserver>> _cacheobs =
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new HashMap<String, ObserverList<StaleCacheObserver>>();
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/** Listeners for dropped locks. */
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protected ObserverList<DroppedLockObserver> _dropobs =
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new ObserverList<DroppedLockObserver>(ObserverList.FAST_UNSAFE_NOTIFY);
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/** Locks in the process of resolution. */
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protected HashMap<NodeObject.Lock, LockHandler> _locks =
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new HashMap<NodeObject.Lock, LockHandler>();
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|
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/** We wait this long for peer ratification to complete before acquiring/releasing the lock. */
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protected static final long LOCK_TIMEOUT = 5000L;
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}
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