jdk/src/share/classes/javax/management/event/EventClient.java
changeset 4156 acaa49a2768a
parent 4155 460e37d40f12
child 4159 9e3aae7675f1
--- a/jdk/src/share/classes/javax/management/event/EventClient.java	Wed Oct 21 16:28:57 2009 +0200
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,1104 +0,0 @@
-/*
- * Copyright 2007-2008 Sun Microsystems, Inc.  All Rights Reserved.
- * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
- *
- * This code is free software; you can redistribute it and/or modify it
- * under the terms of the GNU General Public License version 2 only, as
- * published by the Free Software Foundation.  Sun designates this
- * particular file as subject to the "Classpath" exception as provided
- * by Sun in the LICENSE file that accompanied this code.
- *
- * This code is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
- * version 2 for more details (a copy is included in the LICENSE file that
- * accompanied this code).
- *
- * You should have received a copy of the GNU General Public License version
- * 2 along with this work; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
- *
- * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
- * CA 95054 USA or visit www.sun.com if you need additional information or
- * have any questions.
- */
-
-package javax.management.event;
-
-import com.sun.jmx.event.DaemonThreadFactory;
-import com.sun.jmx.event.LeaseRenewer;
-import com.sun.jmx.event.ReceiverBuffer;
-import com.sun.jmx.event.RepeatedSingletonJob;
-import com.sun.jmx.mbeanserver.PerThreadGroupPool;
-import com.sun.jmx.remote.util.ClassLogger;
-
-import java.io.IOException;
-import java.lang.reflect.Method;
-import java.util.ArrayList;
-import java.util.Collection;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Map;
-import java.util.concurrent.Callable;
-import java.util.concurrent.Executor;
-
-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.AtomicLong;
-import javax.management.InstanceNotFoundException;
-import javax.management.ListenerNotFoundException;
-import javax.management.MBeanNotificationInfo;
-import javax.management.MBeanServerConnection;
-import javax.management.Notification;
-import javax.management.NotificationBroadcasterSupport;
-import javax.management.NotificationFilter;
-import javax.management.NotificationListener;
-import javax.management.ObjectName;
-import javax.management.remote.NotificationResult;
-import javax.management.remote.TargetedNotification;
-
-/**
- * <p>This class is used to manage its notification listeners on the client
- * side in the same way as on the MBean server side. This class needs to work
- * with an {@link EventClientDelegateMBean} on the server side.</p>
- *
- * <P>A user can specify an {@link EventRelay} object to specify how to receive
- * notifications forwarded by the {@link EventClientDelegateMBean}. By default,
- * the class {@link FetchingEventRelay} is used.</p>
- *
- * <p>A user can specify an {@link java.util.concurrent.Executor Executor}
- * to distribute notifications to local listeners. If no executor is
- * specified, the thread in the {@link EventRelay} which calls {@link
- * EventReceiver#receive EventReceiver.receive} will be reused to distribute
- * the notifications (in other words, to call the {@link
- * NotificationListener#handleNotification handleNotification} method of the
- * appropriate listeners). It is useful to make a separate thread do this
- * distribution in some cases. For example, if network communication is slow,
- * the forwarding thread can concentrate on communication while, locally,
- * the distributing thread distributes the received notifications. Another
- * usage is to share a thread pool between many clients, for scalability.
- * Note, though, that if the {@code Executor} can create more than one thread
- * then it is possible that listeners will see notifications in a different
- * order from the order in which they were sent.</p>
- *
- * <p>An object of this class sends notifications to listeners added with
- * {@link #addEventClientListener}.  The {@linkplain Notification#getType()
- * type} of each such notification is one of {@link #FAILED}, {@link #NONFATAL},
- * or {@link #NOTIFS_LOST}.</p>
- *
- * @since JMX 2.0
- */
-public class EventClient implements EventConsumer, NotificationManager {
-
-    /**
-     * <p>A notification string type used by an {@code EventClient} object
-     * to inform a listener added by {@link #addEventClientListener} that
-     * it failed to get notifications from a remote server, and that it is
-     * possible that no more notifications will be delivered.</p>
-     *
-     * @see #addEventClientListener
-     * @see EventReceiver#failed
-     */
-    public static final String FAILED = "jmx.event.service.failed";
-
-    /**
-     * <p>Reports that an unexpected exception has been received by the {@link
-     * EventRelay} object but that it is non-fatal. For example, a notification
-     * received is not serializable or its class is not found.</p>
-     *
-     * @see #addEventClientListener
-     * @see EventReceiver#nonFatal
-     */
-    public static final String NONFATAL = "jmx.event.service.nonfatal";
-
-    /**
-     * <p>A notification string type used by an {@code EventClient} object
-     * to inform a listener added by {@link #addEventClientListener
-     * addEventClientListener} that it has detected that notifications have
-     * been lost.  The {@link Notification#getUserData() userData} of the
-     * notification is a Long which is an upper bound on the number of lost
-     * notifications that have just been detected.</p>
-     *
-     * @see #addEventClientListener
-     */
-    public static final String NOTIFS_LOST = "jmx.event.service.notifs.lost";
-
-    /**
-     * The default lease time that EventClient instances will request, in
-     * milliseconds.  This value is {@value}.
-     *
-     * @see EventClientDelegateMBean#lease
-     */
-    public static final long DEFAULT_REQUESTED_LEASE_TIME = 300000;
-
-    /**
-     * <p>Constructs a default {@code EventClient} object.</p>
-     *
-     * <p>This object creates a {@link FetchingEventRelay} object to
-     * receive notifications forwarded by the {@link EventClientDelegateMBean}.
-     * The {@link EventClientDelegateMBean} that it works with is the
-     * one registered with the {@linkplain EventClientDelegate#OBJECT_NAME
-     * default ObjectName}.  The thread from the {@link FetchingEventRelay}
-     * object that fetches the notifications is also used to distribute them.
-     *
-     * @param conn An {@link MBeanServerConnection} object used to communicate
-     * with an {@link EventClientDelegateMBean} MBean.
-     *
-     * @throws IllegalArgumentException If {@code conn} is null.
-     * @throws IOException If an I/O error occurs when communicating with the
-     * {@code EventClientDelegateMBean}.
-     */
-    public EventClient(MBeanServerConnection conn) throws IOException {
-        this(EventClientDelegate.getProxy(conn));
-    }
-
-    /**
-     * Constructs an {@code EventClient} object with a specified
-     * {@link EventClientDelegateMBean}.
-     *
-     * <p>This object creates a {@link FetchingEventRelay} object to receive
-     * notifications forwarded by the {@link EventClientDelegateMBean}.  The
-     * thread from the {@link FetchingEventRelay} object that fetches the
-     * notifications is also used to distribute them.
-     *
-     * @param delegate An {@link EventClientDelegateMBean} object to work with.
-     *
-     * @throws IllegalArgumentException If {@code delegate} is null.
-     * @throws IOException If an I/O error occurs when communicating with the
-     * the {@link EventClientDelegateMBean}.
-     */
-    public EventClient(EventClientDelegateMBean delegate)
-    throws IOException {
-        this(delegate, null, null, null, DEFAULT_REQUESTED_LEASE_TIME);
-    }
-
-    /**
-     * Constructs an {@code EventClient} object with the specified
-     * {@link EventClientDelegateMBean}, {@link EventRelay}
-     * object, and distributing thread.
-     *
-     * @param delegate An {@link EventClientDelegateMBean} object to work with.
-     * Usually, this will be a proxy constructed using
-     * {@link EventClientDelegate#getProxy}.
-     * @param eventRelay An object used to receive notifications
-     * forwarded by the {@link EventClientDelegateMBean}. If {@code null}, a
-     * {@link FetchingEventRelay} object will be used.
-     * @param distributingExecutor Used to distribute notifications to local
-     * listeners. Only one job at a time will be submitted to this Executor.
-     * If {@code distributingExecutor} is {@code null}, the thread that calls
-     * {@link EventReceiver#receive EventReceiver.receive} from the {@link
-     * EventRelay} object is used.
-     * @param leaseScheduler An object that will be used to schedule the
-     * periodic {@linkplain EventClientDelegateMBean#lease lease updates}.
-     * If {@code null}, a default scheduler will be used.
-     * @param requestedLeaseTime The lease time used to keep this client alive
-     * in the {@link EventClientDelegateMBean}.  A value of zero is equivalent
-     * to the {@linkplain #DEFAULT_REQUESTED_LEASE_TIME default value}.
-     *
-     * @throws IllegalArgumentException If {@code delegate} is null.
-     * @throws IOException If an I/O error occurs when communicating with the
-     * {@link EventClientDelegateMBean}.
-     */
-    public EventClient(EventClientDelegateMBean delegate,
-            EventRelay eventRelay,
-            Executor distributingExecutor,
-            ScheduledExecutorService leaseScheduler,
-            long requestedLeaseTime)
-            throws IOException {
-        if (delegate == null) {
-            throw new IllegalArgumentException("Null EventClientDelegateMBean");
-        }
-
-        if (requestedLeaseTime == 0)
-            requestedLeaseTime = DEFAULT_REQUESTED_LEASE_TIME;
-        else if (requestedLeaseTime < 0) {
-            throw new IllegalArgumentException(
-                    "Negative lease time: " + requestedLeaseTime);
-        }
-
-        eventClientDelegate = delegate;
-
-        if (eventRelay != null) {
-            this.eventRelay = eventRelay;
-        } else {
-            try {
-                this.eventRelay = new FetchingEventRelay(delegate);
-            } catch (IOException ioe) {
-                throw ioe;
-            } catch (Exception e) {
-                // impossible?
-                final IOException ioee = new IOException(e.toString());
-                ioee.initCause(e);
-                throw ioee;
-            }
-        }
-
-        if (distributingExecutor == null)
-            distributingExecutor = callerExecutor;
-        this.distributingExecutor = distributingExecutor;
-        this.dispatchingJob = new DispatchingJob();
-
-        clientId = this.eventRelay.getClientId();
-
-        this.requestedLeaseTime = requestedLeaseTime;
-        if (leaseScheduler == null)
-            leaseScheduler = defaultLeaseScheduler();
-        leaseRenewer = new LeaseRenewer(leaseScheduler, renewLease);
-
-        if (logger.traceOn()) {
-            logger.trace("init", "New EventClient: "+clientId);
-        }
-    }
-
-    private static ScheduledExecutorService defaultLeaseScheduler() {
-        // The default lease scheduler uses a ScheduledThreadPoolExecutor
-        // with a maximum of 20 threads.  This means that if you have many
-        // EventClient instances and some of them get blocked (because of an
-        // unresponsive network, for example), then even the instances that
-        // are connected to responsive servers may have their leases expire.
-        // XXX check if the above is true and possibly fix.
-        PerThreadGroupPool.Create<ScheduledThreadPoolExecutor> create =
-                new PerThreadGroupPool.Create<ScheduledThreadPoolExecutor>() {
-            public ScheduledThreadPoolExecutor createThreadPool(ThreadGroup group) {
-                ThreadFactory daemonThreadFactory = new DaemonThreadFactory(
-                        "JMX EventClient lease renewer %d");
-                ScheduledThreadPoolExecutor executor =
-                        new ScheduledThreadPoolExecutor(20, daemonThreadFactory);
-                executor.setKeepAliveTime(1, TimeUnit.SECONDS);
-                executor.allowCoreThreadTimeOut(true);
-                if (setRemoveOnCancelPolicy != null) {
-                    try {
-                        setRemoveOnCancelPolicy.invoke(executor, true);
-                    } catch (Exception e) {
-                        logger.trace("setRemoveOnCancelPolicy", e);
-                    }
-                }
-                // By default, a ScheduledThreadPoolExecutor will keep jobs
-                // in its queue even after they have been cancelled.  They
-                // will only be removed when their scheduled time arrives.
-                // Since the job references the LeaseRenewer which references
-                // this EventClient, this can lead to a moderately large number
-                // of objects remaining referenced until the renewal time
-                // arrives.  Hence the above call, which removes the job from
-                // the queue as soon as it is cancelled.  Since the call is
-                // new with JDK 7, we invoke it via reflection to make it
-                // easier to use this code on JDK 6.
-                return executor;
-            }
-        };
-        return leaseRenewerThreadPool.getThreadPoolExecutor(create);
-    }
-
-    private static final Method setRemoveOnCancelPolicy;
-    static {
-        Method m;
-        try {
-            m = ScheduledThreadPoolExecutor.class.getMethod(
-                    "setRemoveOnCancelPolicy", boolean.class);
-        } catch (Exception e) {
-            m = null;
-        }
-        setRemoveOnCancelPolicy = m;
-    }
-
-    /**
-     * <p>Closes this EventClient, removes all listeners and stops receiving
-     * notifications.</p>
-     *
-     * <p>This method calls {@link
-     * EventClientDelegateMBean#removeClient(String)} and {@link
-     * EventRelay#stop}.  Both operations occur even if one of them
-     * throws an {@code IOException}.
-     *
-     * @throws IOException if an I/O error occurs when communicating with
-     * {@link EventClientDelegateMBean}, or if {@link EventRelay#stop}
-     * throws an {@code IOException}.
-     */
-    public void close() throws IOException {
-        if (logger.traceOn()) {
-            logger.trace("close", clientId);
-        }
-
-        synchronized(listenerInfoMap) {
-            if (closed) {
-                return;
-            }
-
-            closed = true;
-            listenerInfoMap.clear();
-        }
-
-        if (leaseRenewer != null)
-            leaseRenewer.close();
-
-        IOException ioe = null;
-        try {
-            eventRelay.stop();
-        } catch (IOException e) {
-            ioe = e;
-            logger.debug("close", "EventRelay.stop", e);
-        }
-
-        try {
-            eventClientDelegate.removeClient(clientId);
-        } catch (Exception e) {
-            if (e instanceof IOException)
-                ioe = (IOException) e;
-            else
-                ioe = new IOException(e);
-            logger.debug("close",
-                    "Got exception when removing "+clientId, e);
-        }
-
-        if (ioe != null)
-            throw ioe;
-    }
-
-    /**
-     * <p>Determine if this {@code EventClient} is closed.</p>
-     *
-     * @return True if the {@code EventClient} is closed.
-     */
-    public boolean closed() {
-        return closed;
-    }
-
-    /**
-     * <p>Return the {@link EventRelay} associated with this
-     * {@code EventClient}.</p>
-     *
-     * @return The {@link EventRelay} object used.
-     */
-    public EventRelay getEventRelay() {
-        return eventRelay;
-    }
-
-    /**
-     * <p>Return the lease time that this {@code EventClient} requests
-     * on every lease renewal.</p>
-     *
-     * @return The requested lease time.
-     *
-     * @see EventClientDelegateMBean#lease
-     */
-    public long getRequestedLeaseTime() {
-        return requestedLeaseTime;
-    }
-
-    /**
-     * @see javax.management.MBeanServerConnection#addNotificationListener(
-     * ObjectName, NotificationListener, NotificationFilter, Object).
-     */
-    public void addNotificationListener(ObjectName name,
-            NotificationListener listener,
-            NotificationFilter filter,
-            Object handback)
-            throws InstanceNotFoundException, IOException {
-        if (logger.traceOn()) {
-            logger.trace("addNotificationListener", "");
-        }
-
-        checkState();
-
-        Integer listenerId;
-        try {
-            listenerId =
-                    eventClientDelegate.addListener(clientId, name, filter);
-        } catch (EventClientNotFoundException ecnfe) {
-            final IOException ioe = new IOException(ecnfe.getMessage());
-            ioe.initCause(ecnfe);
-            throw ioe;
-        }
-
-        synchronized(listenerInfoMap) {
-            listenerInfoMap.put(listenerId,  new ListenerInfo(
-                    name,
-                    listener,
-                    filter,
-                    handback,
-                    false));
-        }
-
-        startListening();
-    }
-
-    /**
-     * @see javax.management.MBeanServerConnection#removeNotificationListener(
-     * ObjectName, NotificationListener).
-     */
-    public void removeNotificationListener(ObjectName name,
-            NotificationListener listener)
-            throws InstanceNotFoundException,
-            ListenerNotFoundException,
-            IOException {
-        if (logger.traceOn()) {
-            logger.trace("removeNotificationListener", "");
-        }
-        checkState();
-
-        for (Integer id : getListenerInfo(name, listener, false)) {
-            removeListener(id);
-        }
-    }
-
-    /**
-     * @see javax.management.MBeanServerConnection#removeNotificationListener(
-     * ObjectName, NotificationListener, NotificationFilter, Object).
-     */
-    public void removeNotificationListener(ObjectName name,
-            NotificationListener listener,
-            NotificationFilter filter,
-            Object handback)
-            throws InstanceNotFoundException,
-            ListenerNotFoundException,
-            IOException {
-        if (logger.traceOn()) {
-            logger.trace("removeNotificationListener", "with all arguments.");
-        }
-        checkState();
-        final Integer listenerId =
-                getListenerInfo(name, listener, filter, handback, false);
-
-        removeListener(listenerId);
-    }
-
-    /**
-     * @see javax.management.event.EventConsumer#unsubscribe(
-     * ObjectName, NotificationListener).
-     */
-    public void unsubscribe(ObjectName name,
-            NotificationListener listener)
-            throws ListenerNotFoundException, IOException {
-        if (logger.traceOn()) {
-            logger.trace("unsubscribe", "");
-        }
-        checkState();
-        final Integer listenerId =
-                getMatchedListenerInfo(name, listener, true);
-
-        synchronized(listenerInfoMap) {
-            if (listenerInfoMap.remove(listenerId) == null) {
-                throw new ListenerNotFoundException();
-            }
-        }
-
-        stopListening();
-
-        try {
-            eventClientDelegate.removeListenerOrSubscriber(clientId, listenerId);
-        } catch (InstanceNotFoundException e) {
-            logger.trace("unsubscribe", "removeSubscriber", e);
-        } catch (EventClientNotFoundException cnfe) {
-            logger.trace("unsubscribe", "removeSubscriber", cnfe);
-        }
-    }
-
-    /**
-     * @see javax.management.event.EventConsumer#subscribe(
-     * ObjectName, NotificationListener, NotificationFilter, Object).
-     */
-    public void subscribe(ObjectName name,
-            NotificationListener listener,
-            NotificationFilter filter,
-            Object handback) throws IOException {
-        if (logger.traceOn()) {
-            logger.trace("subscribe", "");
-        }
-
-        checkState();
-
-        Integer listenerId;
-        try {
-            listenerId =
-                    eventClientDelegate.addSubscriber(clientId, name, filter);
-        } catch (EventClientNotFoundException ecnfe) {
-            final IOException ioe = new IOException(ecnfe.getMessage());
-            ioe.initCause(ecnfe);
-            throw ioe;
-        }
-
-        synchronized(listenerInfoMap) {
-            listenerInfoMap.put(listenerId,  new ListenerInfo(
-                    name,
-                    listener,
-                    filter,
-                    handback,
-                    true));
-        }
-
-        startListening();
-    }
-
-    /**
-     * <p>Adds a set of listeners to the remote MBeanServer.  This method can
-     * be used to copy the listeners from one {@code EventClient} to another.</p>
-     *
-     * <p>A listener is represented by a {@link ListenerInfo} object. The listener
-     * is added by calling {@link #subscribe(ObjectName,
-     * NotificationListener, NotificationFilter, Object)} if the method
-     * {@link ListenerInfo#isSubscription() isSubscription}
-     * returns {@code true}; otherwise it is added by calling
-     * {@link #addNotificationListener(ObjectName, NotificationListener,
-     * NotificationFilter, Object)}.</p>
-     *
-     * <P>The method returns the listeners which were added successfully. The
-     * elements in the returned collection are a subset of the elements in
-     * {@code listeners}. If all listeners were added successfully, the two
-     * collections are the same. If no listener was added successfully, the
-     * returned collection is empty.</p>
-     *
-     * @param listeners the listeners to add.
-     *
-     * @return The listeners that were added successfully.
-     *
-     * @throws IOException If an I/O error occurs.
-     *
-     * @see #getListeners()
-     */
-    public Collection<ListenerInfo> addListeners(Collection<ListenerInfo> listeners)
-    throws IOException {
-        if (logger.traceOn()) {
-            logger.trace("addListeners", "");
-        }
-
-        checkState();
-
-        if (listeners == null || listeners.isEmpty())
-            return Collections.emptySet();
-
-        final List<ListenerInfo> list = new ArrayList<ListenerInfo>();
-        for (ListenerInfo l : listeners) {
-            try {
-                if (l.isSubscription()) {
-                    subscribe(l.getObjectName(),
-                            l.getListener(),
-                            l.getFilter(),
-                            l.getHandback());
-                } else {
-                    addNotificationListener(l.getObjectName(),
-                            l.getListener(),
-                            l.getFilter(),
-                            l.getHandback());
-                }
-
-                list.add(l);
-            } catch (Exception e) {
-                if (logger.traceOn()) {
-                    logger.trace("addListeners", "failed to add: "+l, e);
-                }
-            }
-        }
-
-        return list;
-    }
-
-    /**
-     * <p>Returns the collection of listeners that have been added through
-     * this {@code EventClient} and not subsequently removed.  The returned
-     * collection contains one entry for every listener added with
-     * {@link #addNotificationListener addNotificationListener} or
-     * {@link #subscribe subscribe} and not subsequently removed with
-     * {@link #removeNotificationListener removeNotificationListener} or
-     * {@link #unsubscribe unsubscribe}, respectively.</p>
-     *
-     * @return A collection of listener information. Empty if there are no
-     * current listeners or if this {@code EventClient} has been {@linkplain
-     * #close closed}.
-     *
-     * @see #addListeners
-     */
-    public Collection<ListenerInfo> getListeners() {
-        if (logger.traceOn()) {
-            logger.trace("getListeners", "");
-        }
-
-        synchronized(listenerInfoMap) {
-            return Collections.unmodifiableCollection(listenerInfoMap.values());
-        }
-    }
-
-    /**
-     * Adds a listener to receive the {@code EventClient} notifications specified in
-     * {@link #getEventClientNotificationInfo}.
-     *
-     * @param listener A listener to receive {@code EventClient} notifications.
-     * @param filter A filter to select which notifications are to be delivered
-     * to the listener, or {@code null} if all notifications are to be delivered.
-     * @param handback An object to be given to the listener along with each
-     * notification. Can be null.
-     * @throws NullPointerException If listener is null.
-     * @see #removeEventClientListener
-     */
-    public void addEventClientListener(NotificationListener listener,
-            NotificationFilter filter,
-            Object handback) {
-        if (logger.traceOn()) {
-            logger.trace("addEventClientListener", "");
-        }
-        broadcaster.addNotificationListener(listener, filter, handback);
-    }
-
-    /**
-     * Removes a listener added to receive {@code EventClient} notifications specified in
-     * {@link #getEventClientNotificationInfo}.
-     *
-     * @param listener A listener to receive {@code EventClient} notifications.
-     * @throws NullPointerException If listener is null.
-     * @throws ListenerNotFoundException If the listener is not added to
-     * this {@code EventClient}.
-     */
-    public void removeEventClientListener(NotificationListener listener)
-    throws ListenerNotFoundException {
-        if (logger.traceOn()) {
-            logger.trace("removeEventClientListener", "");
-        }
-        broadcaster.removeNotificationListener(listener);
-    }
-
-    /**
-     * <p>Get the types of notification that an {@code EventClient} can send
-     * to listeners added with {@link #addEventClientListener
-     * addEventClientListener}.</p>
-     *
-     * @return Types of notification emitted by this {@code EventClient}.
-     *
-     * @see #FAILED
-     * @see #NONFATAL
-     * @see #NOTIFS_LOST
-     */
-    public MBeanNotificationInfo[] getEventClientNotificationInfo() {
-        return myInfo.clone();
-    }
-
-    private static boolean match(ListenerInfo li,
-            ObjectName name,
-            NotificationListener listener,
-            boolean subscribed) {
-        return li.getObjectName().equals(name) &&
-                li.getListener() == listener &&
-                li.isSubscription() == subscribed;
-    }
-
-    private static boolean match(ListenerInfo li,
-            ObjectName name,
-            NotificationListener listener,
-            NotificationFilter filter,
-            Object handback,
-            boolean subscribed) {
-        return li.getObjectName().equals(name) &&
-                li.getFilter() == filter &&
-                li.getListener() == listener &&
-                li.getHandback() == handback &&
-                li.isSubscription() == subscribed;
-    }
-
-// ---------------------------------------------------
-// private classes
-// ---------------------------------------------------
-    private class DispatchingJob extends RepeatedSingletonJob {
-        public DispatchingJob() {
-            super(distributingExecutor);
-        }
-
-        public boolean isSuspended() {
-            return closed || buffer.size() == 0;
-        }
-
-        public void task() {
-            TargetedNotification[] tns ;
-            int lost = 0;
-
-            synchronized(buffer) {
-                tns = buffer.removeNotifs();
-                lost = buffer.removeLost();
-            }
-
-            if ((tns == null || tns.length == 0)
-            && lost == 0) {
-                return;
-            }
-
-            // forwarding
-            if (tns != null && tns.length > 0) {
-                if (logger.traceOn()) {
-                    logger.trace("DispatchingJob-task",
-                            "Forwarding: "+tns.length);
-                }
-                for (TargetedNotification tn : tns) {
-                    final ListenerInfo li = listenerInfoMap.get(tn.getListenerID());
-                    try {
-                        li.getListener().handleNotification(tn.getNotification(),
-                                li.getHandback());
-                    } catch (Exception e) {
-                        logger.fine(
-                                "DispatchingJob.task", "listener got exception", e);
-                    }
-                }
-            }
-
-            if (lost > 0) {
-                if (logger.traceOn()) {
-                    logger.trace("DispatchingJob-task",
-                            "lost: "+lost);
-                }
-                final Notification n = new Notification(NOTIFS_LOST,
-                        EventClient.this,
-                        myNotifCounter.getAndIncrement(),
-                        System.currentTimeMillis(),
-                        "Lost notifications.");
-                n.setUserData(new Long(lost));
-                broadcaster.sendNotification(n);
-            }
-        }
-    }
-
-
-    private class EventReceiverImpl implements EventReceiver {
-        public void receive(NotificationResult nr) {
-            if (logger.traceOn()) {
-                logger.trace("MyEventReceiver-receive", "");
-            }
-
-            synchronized(buffer) {
-                buffer.addNotifs(nr);
-
-                dispatchingJob.resume();
-            }
-        }
-
-        public void failed(Throwable t) {
-            if (logger.traceOn()) {
-                logger.trace("MyEventReceiver-failed", "", t);
-            }
-            final Notification n = new Notification(FAILED,
-                    this,
-                    myNotifCounter.getAndIncrement(),
-                    System.currentTimeMillis());
-            n.setSource(t);
-            broadcaster.sendNotification(n);
-        }
-
-        public void nonFatal(Exception e) {
-            if (logger.traceOn()) {
-                logger.trace("MyEventReceiver-nonFatal", "", e);
-            }
-
-            final Notification n = new Notification(NONFATAL,
-                    this,
-                    myNotifCounter.getAndIncrement(),
-                    System.currentTimeMillis());
-            n.setSource(e);
-            broadcaster.sendNotification(n);
-        }
-    }
-
-// ----------------------------------------------------
-// private class
-// ----------------------------------------------------
-
-
-// ----------------------------------------------------
-// private methods
-// ----------------------------------------------------
-    private Integer getListenerInfo(ObjectName name,
-            NotificationListener listener,
-            NotificationFilter filter,
-            Object handback,
-            boolean subscribed) throws ListenerNotFoundException {
-
-        synchronized(listenerInfoMap) {
-            for (Map.Entry<Integer, ListenerInfo> entry :
-                    listenerInfoMap.entrySet()) {
-                ListenerInfo li = entry.getValue();
-                if (match(li, name, listener, filter, handback, subscribed)) {
-                    return entry.getKey();
-                }
-            }
-        }
-
-        throw new ListenerNotFoundException();
-    }
-
-    private Integer getMatchedListenerInfo(ObjectName name,
-            NotificationListener listener,
-            boolean subscribed) throws ListenerNotFoundException {
-
-        synchronized(listenerInfoMap) {
-            for (Map.Entry<Integer, ListenerInfo> entry :
-                    listenerInfoMap.entrySet()) {
-                ListenerInfo li = entry.getValue();
-                if (li.getObjectName().equals(name) &&
-                        li.getListener() == listener &&
-                        li.isSubscription() == subscribed) {
-                    return entry.getKey();
-                }
-            }
-        }
-
-        throw new ListenerNotFoundException();
-    }
-
-    private Collection<Integer> getListenerInfo(ObjectName name,
-            NotificationListener listener,
-            boolean subscribed) throws ListenerNotFoundException {
-
-        final ArrayList<Integer> ids = new ArrayList<Integer>();
-        synchronized(listenerInfoMap) {
-            for (Map.Entry<Integer, ListenerInfo> entry :
-                    listenerInfoMap.entrySet()) {
-                ListenerInfo li = entry.getValue();
-                if (match(li, name, listener, subscribed)) {
-                    ids.add(entry.getKey());
-                }
-            }
-        }
-
-        if (ids.isEmpty()) {
-            throw new ListenerNotFoundException();
-        }
-
-        return ids;
-    }
-
-    private void checkState() throws IOException {
-        synchronized(listenerInfoMap) {
-            if (closed) {
-                throw new IOException("Ended!");
-            }
-        }
-    }
-
-    private void startListening() throws IOException {
-        synchronized(listenerInfoMap) {
-            if (!startedListening && listenerInfoMap.size() > 0) {
-                eventRelay.setEventReceiver(myReceiver);
-            }
-
-            startedListening = true;
-
-            if (logger.traceOn()) {
-                logger.trace("startListening", "listening");
-            }
-        }
-    }
-
-    private void stopListening() throws IOException {
-        synchronized(listenerInfoMap) {
-            if (listenerInfoMap.size() == 0 && startedListening) {
-                eventRelay.setEventReceiver(null);
-
-                startedListening = false;
-
-                if (logger.traceOn()) {
-                    logger.trace("stopListening", "non listening");
-                }
-            }
-        }
-    }
-
-    private void removeListener(Integer id)
-    throws InstanceNotFoundException,
-            ListenerNotFoundException,
-            IOException {
-        synchronized(listenerInfoMap) {
-            if (listenerInfoMap.remove(id) == null) {
-                throw new ListenerNotFoundException();
-            }
-
-            stopListening();
-        }
-
-        try {
-            eventClientDelegate.removeListenerOrSubscriber(clientId, id);
-        } catch (EventClientNotFoundException cnfe) {
-            logger.trace("removeListener", "ecd.removeListener", cnfe);
-        }
-    }
-
-
-// ----------------------------------------------------
-// private variables
-// ----------------------------------------------------
-    private static final ClassLogger logger =
-            new ClassLogger("javax.management.event", "EventClient");
-
-    private final Executor distributingExecutor;
-    private final EventClientDelegateMBean eventClientDelegate;
-    private final EventRelay eventRelay;
-    private volatile String clientId = null;
-    private final long requestedLeaseTime;
-
-    private final ReceiverBuffer buffer = new ReceiverBuffer();
-
-    private final EventReceiverImpl myReceiver =
-            new EventReceiverImpl();
-    private final DispatchingJob dispatchingJob;
-
-    private final HashMap<Integer, ListenerInfo> listenerInfoMap =
-            new HashMap<Integer, ListenerInfo>();
-
-    private volatile boolean closed = false;
-
-    private volatile boolean startedListening = false;
-
-    // Could change synchronization here. But at worst a race will mean
-    // sequence numbers are not contiguous, which may not matter much.
-    private final AtomicLong myNotifCounter = new AtomicLong();
-
-    private final static MBeanNotificationInfo[] myInfo =
-            new MBeanNotificationInfo[] {
-        new MBeanNotificationInfo(
-                new String[] {FAILED, NONFATAL, NOTIFS_LOST},
-                Notification.class.getName(),
-                "Notifications that can be sent to a listener added with " +
-                "EventClient.addEventClientListener")};
-
-    private final NotificationBroadcasterSupport broadcaster =
-            new NotificationBroadcasterSupport();
-
-    private final static Executor callerExecutor = new Executor() {
-        // DirectExecutor using caller thread
-        public void execute(Runnable r) {
-            r.run();
-        }
-    };
-
-    private static void checkInit(final MBeanServerConnection conn,
-            final ObjectName delegateName)
-            throws IOException {
-        if (conn == null) {
-            throw new IllegalArgumentException("No connection specified");
-        }
-        if (delegateName != null &&
-                (!conn.isRegistered(delegateName))) {
-            throw new IllegalArgumentException(
-                    delegateName +
-                    ": not found");
-        }
-        if (delegateName == null &&
-                (!conn.isRegistered(
-                EventClientDelegate.OBJECT_NAME))) {
-            throw new IllegalArgumentException(
-                    EventClientDelegate.OBJECT_NAME +
-                    ": not found");
-        }
-    }
-
-// ----------------------------------------------------
-// private event lease issues
-// ----------------------------------------------------
-    private Callable<Long> renewLease = new Callable<Long>() {
-        public Long call() throws IOException, EventClientNotFoundException {
-            return eventClientDelegate.lease(clientId, requestedLeaseTime);
-        }
-    };
-
-    private final LeaseRenewer leaseRenewer;
-
-// ------------------------------------------------------------------------
-    /**
-     * Constructs an {@code MBeanServerConnection} that uses an {@code EventClient} object,
-     * if the underlying connection has an {@link EventClientDelegateMBean}.
-     * <P> The {@code EventClient} object creates a default
-     * {@link FetchingEventRelay} object to
-     * receive notifications forwarded by the {@link EventClientDelegateMBean}.
-     * The {@link EventClientDelegateMBean} it works with is the
-     * default one registered with the ObjectName
-     * {@link EventClientDelegate#OBJECT_NAME
-     * OBJECT_NAME}.
-     * The thread from the {@link FetchingEventRelay} object that fetches the
-     * notifications is also used to distribute them.
-     *
-     * @param conn An {@link MBeanServerConnection} object used to communicate
-     * with an {@link EventClientDelegateMBean}.
-     * @throws IllegalArgumentException If the value of {@code conn} is null,
-     *         or the default {@link EventClientDelegateMBean} is not registered.
-     * @throws IOException If an I/O error occurs.
-     */
-    public static MBeanServerConnection getEventClientConnection(
-            final MBeanServerConnection conn)
-            throws IOException {
-        return getEventClientConnection(conn, null);
-    }
-
-    /**
-     * Constructs an MBeanServerConnection that uses an {@code EventClient}
-     * object with a user-specific {@link EventRelay}
-     * object.
-     * <P>
-     * The {@link EventClientDelegateMBean} which it works with is the
-     * default one registered with the ObjectName
-     * {@link EventClientDelegate#OBJECT_NAME
-     * OBJECT_NAME}
-     * The thread that calls {@link EventReceiver#receive
-     * EventReceiver.receive} from the {@link EventRelay} object is used
-     * to distribute notifications to their listeners.
-     *
-     * @param conn An {@link MBeanServerConnection} object used to communicate
-     * with an {@link EventClientDelegateMBean}.
-     * @param eventRelay A user-specific object used to receive notifications
-     * forwarded by the {@link EventClientDelegateMBean}. If null, the default
-     * {@link FetchingEventRelay} object is used.
-     * @throws IllegalArgumentException If the value of {@code conn} is null,
-     *         or the default {@link EventClientDelegateMBean} is not registered.
-     * @throws IOException If an I/O error occurs.
-     */
-    public static MBeanServerConnection getEventClientConnection(
-            final MBeanServerConnection conn,
-            final EventRelay eventRelay)
-            throws IOException {
-
-        if (newEventConn == null) {
-            throw new IllegalArgumentException(
-                    "Class not found: EventClientConnection");
-        }
-
-        checkInit(conn,null);
-        final Callable<EventClient> factory = new Callable<EventClient>() {
-            final public EventClient call() throws Exception {
-                EventClientDelegateMBean ecd = EventClientDelegate.getProxy(conn);
-                return new EventClient(ecd, eventRelay, null, null,
-                        DEFAULT_REQUESTED_LEASE_TIME);
-            }
-        };
-
-        try {
-            return (MBeanServerConnection)newEventConn.invoke(null,
-                    conn, factory);
-        } catch (Exception e) {
-            throw new IllegalArgumentException(e);
-        }
-    }
-
-    private static Method newEventConn = null;
-    static {
-        try {
-            Class<?> c = Class.forName(
-                    "com.sun.jmx.remote.util.EventClientConnection",
-                    false, Thread.currentThread().getContextClassLoader());
-            newEventConn = c.getMethod("getEventConnectionFor",
-                    MBeanServerConnection.class, Callable.class);
-        } catch (Exception e) {
-            // OK: we're running in a subset of our classes
-        }
-    }
-
-    /**
-     * <p>Get the client id of this {@code EventClient} in the
-     * {@link EventClientDelegateMBean}.
-     *
-     * @return the client id.
-     *
-     * @see EventClientDelegateMBean#addClient(String, Object[], String[])
-     * EventClientDelegateMBean.addClient
-     */
-    public String getClientId() {
-        return clientId;
-    }
-
-    private static final PerThreadGroupPool<ScheduledThreadPoolExecutor>
-            leaseRenewerThreadPool = PerThreadGroupPool.make();
-}