/*
 * @(#)RMIConnectionImpl.java	1.87 04/06/28
 * 
 * Copyright 2004 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

package javax.management.remote.rmi;

import java.io.InterruptedIOException;
import java.io.IOException;
import java.io.Serializable;
import java.rmi.MarshalledObject;
import java.rmi.server.RMIClientSocketFactory;
import java.rmi.server.RMIServerSocketFactory;
import java.rmi.server.UnicastRemoteObject;
import java.rmi.server.Unreferenced;
import java.rmi.NoSuchObjectException;
import java.security.AccessControlContext;
import java.security.AccessController;
import java.security.Principal;
import java.security.PrivilegedAction;
import java.security.PrivilegedActionException;
import java.security.PrivilegedExceptionAction;
import java.security.ProtectionDomain;
import java.util.Arrays;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Set;
import java.util.Map;
import java.rmi.UnmarshalException;

import javax.management.Attribute;
import javax.management.AttributeList;
import javax.management.AttributeNotFoundException;
import javax.management.InstanceAlreadyExistsException;
import javax.management.InstanceNotFoundException;
import javax.management.IntrospectionException;
import javax.management.InvalidAttributeValueException;
import javax.management.ListenerNotFoundException;
import javax.management.MalformedObjectNameException;
import javax.management.MBeanException;
import javax.management.MBeanInfo;
import javax.management.MBeanRegistrationException;
import javax.management.MBeanServer;
import javax.management.NotCompliantMBeanException;
import javax.management.Notification;
import javax.management.NotificationFilter;
import javax.management.NotificationListener;
import javax.management.ObjectInstance;
import javax.management.ObjectName;
import javax.management.QueryExp;
import javax.management.ReflectionException;
import javax.management.RuntimeOperationsException;
import javax.management.loading.ClassLoaderRepository;
import javax.management.remote.NotificationResult;
import javax.management.remote.SubjectDelegationPermission;
import javax.management.remote.TargetedNotification;
import javax.management.remote.JMXServerErrorException;

import javax.security.auth.Subject;

import com.sun.jmx.remote.internal.ServerNotifForwarder;
import com.sun.jmx.remote.internal.ServerCommunicatorAdmin;
import com.sun.jmx.remote.internal.Unmarshal;
import com.sun.jmx.remote.security.JMXSubjectDomainCombiner;
import com.sun.jmx.remote.security.SubjectDelegator;
import com.sun.jmx.remote.util.CacheMap;
import com.sun.jmx.remote.util.ClassLoaderWithRepository;
import com.sun.jmx.remote.util.ClassLogger;
import com.sun.jmx.remote.util.EnvHelp;
import com.sun.jmx.remote.util.OrderClassLoaders;

/**
 * <p>Implementation of the {@link RMIConnection} interface.  User
 * code will not usually reference this class.</p>
 *
 * @since 1.5
 * @since.unbundled 1.0
 */
public class RMIConnectionImpl implements RMIConnection, Unreferenced {

    /**
     * Constructs a new {@link RMIConnection}. This connection can be
     * used with either the JRMP or IIOP transport. This object does
     * not export itself: it is the responsibility of the caller to
     * export it appropriately (see {@link
     * RMIJRMPServerImpl#makeClient(String,Subject)} and {@link
     * RMIIIOPServerImpl#makeClient(String,Subject)}.
     *
     * @param rmiServer The RMIServerImpl object for which this
     * connection is created.  The behavior is unspecified if this
     * parameter is null.
     * @param connectionId The ID for this connection.  The behavior
     * is unspecified if this parameter is null.
     * @param defaultClassLoader The default ClassLoader to be used
     * when deserializing marshalled objects.  Can be null, to signify
     * the bootstrap class loader.
     * @param subject the authenticated subject to be used for
     * authorization.  Can be null, to signify that no subject has
     * been authenticated.
     * @param env the environment containing attributes for the new
     * <code>RMIServerImpl</code>.  Can be null, equivalent to an
     * empty map.
     */
    public RMIConnectionImpl(RMIServerImpl rmiServer,
                             String connectionId,
                             ClassLoader defaultClassLoader,
                             Subject subject,
			     Map<String,?> env) {
	if (rmiServer == null || connectionId == null)
	    throw new NullPointerException("Illegal null argument");
	if (env == null)
	    env = Collections.EMPTY_MAP;
        this.rmiServer = rmiServer;
        this.connectionId = connectionId;
        this.defaultClassLoader = defaultClassLoader;

        this.subjectDelegator = new SubjectDelegator();
        this.subject = subject;
        if (subject == null) {
            this.acc = null;
        } else {
            this.acc = JMXSubjectDomainCombiner.getContext(subject);
        }
        this.mbeanServer = rmiServer.getMBeanServer();

        final ClassLoader dcl = defaultClassLoader;
        this.classLoaderWithRepository = (ClassLoaderWithRepository)
            AccessController.doPrivileged(new PrivilegedAction() {
                    public Object run() {
                        return new ClassLoaderWithRepository(
                                              getClassLoaderRepository(),
                                              dcl);
                    }
                });

	serverCommunicatorAdmin = new 
	  RMIServerCommunicatorAdmin(EnvHelp.getServerConnectionTimeout(env));

	this.env = env;
    }
    
    private synchronized ServerNotifForwarder getServerNotifFwd() {
	// Lazily created when first use. Mainly when 
	// addNotificationListener is first called.
	if(serverNotifForwarder == null)
	    serverNotifForwarder = 
		new ServerNotifForwarder(mbeanServer, 
					 env,
					 rmiServer.getNotifBuffer());
	
	return serverNotifForwarder;
    }

    public String getConnectionId() throws IOException {
	// We should call reqIncomming() here... shouldn't we?
	return connectionId;
    }

    public synchronized void close() throws IOException {
        final boolean debug = logger.debugOn();
        final String  idstr = (debug?"["+this.toString()+"]":null);

        if (terminated) {
            if (debug) logger.debug("close",idstr + " already terminated.");
            return;
        }

        if (debug) logger.debug("close",idstr + " closing.");

        terminated = true;

	if (serverCommunicatorAdmin != null) {
	    serverCommunicatorAdmin.terminate();
	}

	if (serverNotifForwarder != null) {
	    serverNotifForwarder.terminate();
	}

        rmiServer.clientClosed(this);

        if (debug) logger.debug("close",idstr + " closed.");
    }

    public void unreferenced() {
        logger.debug("unreferenced", "called");
        try {
            close();
            logger.debug("unreferenced", "done");
        } catch (IOException e) {
            logger.fine("unreferenced", e);
        }
    }

    //-------------------------------------------------------------------------
    // MBeanServerConnection Wrapper
    //-------------------------------------------------------------------------

    public ObjectInstance createMBean(String className,
                                      ObjectName name,
                                      Subject delegationSubject)
        throws
        ReflectionException,
        InstanceAlreadyExistsException,
        MBeanRegistrationException,
        MBeanException,
        NotCompliantMBeanException,
        IOException {
        try {
            final Object params[] =
                new Object[] { className, name };

            if (logger.debugOn()) 
		logger.debug("createMBean(String,ObjectName)",
			     "connectionId=" + connectionId +", className=" + 
			     className+", name=" + name);

            return (ObjectInstance)
                doPrivilegedOperation(
                  CREATE_MBEAN,
                  params,
                  delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof ReflectionException)
                throw (ReflectionException) e;
            if (e instanceof InstanceAlreadyExistsException)
                throw (InstanceAlreadyExistsException) e;
            if (e instanceof MBeanRegistrationException)
                throw (MBeanRegistrationException) e;
            if (e instanceof MBeanException)
                throw (MBeanException) e;
            if (e instanceof NotCompliantMBeanException)
                throw (NotCompliantMBeanException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public ObjectInstance createMBean(String className,
                                      ObjectName name,
                                      ObjectName loaderName,
                                      Subject delegationSubject)
        throws
        ReflectionException,
        InstanceAlreadyExistsException,
        MBeanRegistrationException,
        MBeanException,
        NotCompliantMBeanException,
        InstanceNotFoundException,
        IOException {
        try {
            final Object params[] =
                new Object[] { className, name, loaderName };

            if (logger.debugOn())
		logger.debug("createMBean(String,ObjectName,ObjectName)",
		      "connectionId=" + connectionId
		      +", className=" + className
		      +", name=" + name
		      +", loaderName=" + loaderName);

            return (ObjectInstance)
                doPrivilegedOperation(
                  CREATE_MBEAN_LOADER,
                  params,
                  delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof ReflectionException)
                throw (ReflectionException) e;
            if (e instanceof InstanceAlreadyExistsException)
                throw (InstanceAlreadyExistsException) e;
            if (e instanceof MBeanRegistrationException)
                throw (MBeanRegistrationException) e;
            if (e instanceof MBeanException)
                throw (MBeanException) e;
            if (e instanceof NotCompliantMBeanException)
                throw (NotCompliantMBeanException) e;
            if (e instanceof InstanceNotFoundException)
                throw (InstanceNotFoundException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public ObjectInstance createMBean(String className,
                                      ObjectName name,
                                      MarshalledObject params,
                                      String signature[],
                                      Subject delegationSubject)
        throws
        ReflectionException,
        InstanceAlreadyExistsException,
        MBeanRegistrationException,
        MBeanException,
        NotCompliantMBeanException,
        IOException {

        final Object[] values;
        final boolean debug = logger.debugOn();

	if (debug) logger.debug(
		  "createMBean(String,ObjectName,Object[],String[])",
                  "connectionId=" + connectionId 
                  +", unwrapping parameters using classLoaderWithRepository.");

	values = nullIsEmpty((Object[]) unwrap(params,
						   classLoaderWithRepository));

        try {
            final Object params2[] =
                new Object[] { className, name, values,
			       nullIsEmpty(signature) };

            if (debug) 
               logger.debug("createMBean(String,ObjectName,Object[],String[])",
                             "connectionId=" + connectionId
                             +", className=" + className
                             +", name=" + name
                             +", params=" + objects(values)
                             +", signature=" + strings(signature));

            return (ObjectInstance)
                doPrivilegedOperation(
                  CREATE_MBEAN_PARAMS,
                  params2,
                  delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof ReflectionException)
                throw (ReflectionException) e;
            if (e instanceof InstanceAlreadyExistsException)
                throw (InstanceAlreadyExistsException) e;
            if (e instanceof MBeanRegistrationException)
                throw (MBeanRegistrationException) e;
            if (e instanceof MBeanException)
                throw (MBeanException) e;
            if (e instanceof NotCompliantMBeanException)
                throw (NotCompliantMBeanException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public ObjectInstance createMBean(String className,
                                      ObjectName name,
                                      ObjectName loaderName,
                                      MarshalledObject params,
                                      String signature[],
                                      Subject delegationSubject)
        throws
        ReflectionException,
        InstanceAlreadyExistsException,
        MBeanRegistrationException,
        MBeanException,
        NotCompliantMBeanException,
        InstanceNotFoundException,
        IOException {

        final Object[] values;
        final boolean debug = logger.debugOn();

	if (debug) logger.debug(
		 "createMBean(String,ObjectName,ObjectName,Object[],String[])",
                 "connectionId=" + connectionId 
                 +", unwrapping params with MBean extended ClassLoader.");

	values = nullIsEmpty((Object[]) unwrap(params,
						   getClassLoader(loaderName),
						   defaultClassLoader));

        try {
            final Object params2[] =
               new Object[] { className, name, loaderName, values,
			      nullIsEmpty(signature) };

           if (debug) logger.debug(
		 "createMBean(String,ObjectName,ObjectName,Object[],String[])",
                 "connectionId=" + connectionId
                 +", className=" + className
                 +", name=" + name
                 +", loaderName=" + loaderName
                 +", params=" + objects(values)
                 +", signature=" + strings(signature));

            return (ObjectInstance)
                doPrivilegedOperation(
                  CREATE_MBEAN_LOADER_PARAMS,
                  params2,
                  delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof ReflectionException)
                throw (ReflectionException) e;
            if (e instanceof InstanceAlreadyExistsException)
                throw (InstanceAlreadyExistsException) e;
            if (e instanceof MBeanRegistrationException)
                throw (MBeanRegistrationException) e;
            if (e instanceof MBeanException)
                throw (MBeanException) e;
            if (e instanceof NotCompliantMBeanException)
                throw (NotCompliantMBeanException) e;
            if (e instanceof InstanceNotFoundException)
                throw (InstanceNotFoundException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public void unregisterMBean(ObjectName name, Subject delegationSubject)
        throws
        InstanceNotFoundException,
        MBeanRegistrationException,
        IOException {
        try {
            final Object params[] = new Object[] { name };

            if (logger.debugOn()) logger.debug("unregisterMBean",
                 "connectionId=" + connectionId
                 +", name="+name);

            doPrivilegedOperation(
              UNREGISTER_MBEAN,
              params,
              delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof InstanceNotFoundException)
                throw (InstanceNotFoundException) e;
            if (e instanceof MBeanRegistrationException)
                throw (MBeanRegistrationException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public ObjectInstance getObjectInstance(ObjectName name,
                                            Subject delegationSubject)
        throws
        InstanceNotFoundException,
        IOException {

	checkNonNull("ObjectName", name);

        try {
            final Object params[] = new Object[] { name };

            if (logger.debugOn()) logger.debug("getObjectInstance",
                 "connectionId=" + connectionId
                 +", name="+name);

            return (ObjectInstance)
                doPrivilegedOperation(
                  GET_OBJECT_INSTANCE,
                  params,
                  delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof InstanceNotFoundException)
                throw (InstanceNotFoundException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public Set<ObjectInstance>
	queryMBeans(ObjectName name,
		    MarshalledObject query,
		    Subject delegationSubject)
        throws IOException {
        final QueryExp queryValue;
        final boolean debug=logger.debugOn();

	if (debug) logger.debug("queryMBeans",
                 "connectionId=" + connectionId
                 +" unwrapping query with defaultClassLoader.");

	queryValue = (QueryExp) unwrap(query, defaultClassLoader);

        try {
            final Object params[] = new Object[] { name, queryValue };

            if (debug) logger.debug("queryMBeans",
                 "connectionId=" + connectionId
                 +", name="+name +", query="+query);

            return (Set)
                doPrivilegedOperation(
                  QUERY_MBEANS,
                  params,
                  delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public Set<ObjectName>
	queryNames(ObjectName name,
		   MarshalledObject query,
		   Subject delegationSubject)
        throws IOException {
        final QueryExp queryValue;
        final boolean debug=logger.debugOn();

	if (debug) logger.debug("queryNames",
                 "connectionId=" + connectionId
                 +" unwrapping query with defaultClassLoader.");

	queryValue = (QueryExp) unwrap(query, defaultClassLoader);

        try {
            final Object params[] = new Object[] { name, queryValue };

            if (debug) logger.debug("queryNames",
                 "connectionId=" + connectionId
                 +", name="+name +", query="+query);

            return (Set)
                doPrivilegedOperation(
                  QUERY_NAMES,
                  params,
                  delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public boolean isRegistered(ObjectName name,
                                Subject delegationSubject) throws IOException {
        try {
            final Object params[] = new Object[] { name };
            return ((Boolean)
                doPrivilegedOperation(
                  IS_REGISTERED,
                  params,
                  delegationSubject)).booleanValue();
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public Integer getMBeanCount(Subject delegationSubject)
        throws IOException {
        try {
            final Object params[] = new Object[] { };

            if (logger.debugOn()) logger.debug("getMBeanCount",
                 "connectionId=" + connectionId);

            return (Integer)
                doPrivilegedOperation(
                  GET_MBEAN_COUNT,
                  params,
                  delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public Object getAttribute(ObjectName name,
                               String attribute,
                               Subject delegationSubject)
        throws
        MBeanException,
        AttributeNotFoundException,
        InstanceNotFoundException,
        ReflectionException,
        IOException {
        try {
            final Object params[] = new Object[] { name, attribute };
            if (logger.debugOn()) logger.debug("getAttribute",
                                   "connectionId=" + connectionId
                                   +", name=" + name 
                                   +", attribute="+ attribute);

            return (Object)
                doPrivilegedOperation(
                  GET_ATTRIBUTE,
                  params,
                  delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof MBeanException)
                throw (MBeanException) e;
            if (e instanceof AttributeNotFoundException)
                throw (AttributeNotFoundException) e;
            if (e instanceof InstanceNotFoundException)
                throw (InstanceNotFoundException) e;
            if (e instanceof ReflectionException)
                throw (ReflectionException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public AttributeList getAttributes(ObjectName name,
                                       String[] attributes,
                                       Subject delegationSubject)
        throws
        InstanceNotFoundException,
        ReflectionException,
        IOException {
        try {
            final Object params[] = new Object[] { name, attributes };

            if (logger.debugOn()) logger.debug("getAttributes",
                                   "connectionId=" + connectionId
                                   +", name=" + name 
                                   +", attributes="+ strings(attributes));

            return (AttributeList)
                doPrivilegedOperation(
                  GET_ATTRIBUTES,
                  params,
                  delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof InstanceNotFoundException)
                throw (InstanceNotFoundException) e;
            if (e instanceof ReflectionException)
                throw (ReflectionException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public void setAttribute(ObjectName name,
                             MarshalledObject attribute,
                             Subject delegationSubject)
        throws
        InstanceNotFoundException,
        AttributeNotFoundException,
        InvalidAttributeValueException,
        MBeanException,
        ReflectionException,
        IOException {
        final Attribute attr;
        final boolean debug=logger.debugOn();

	if (debug) logger.debug("setAttribute",
                 "connectionId=" + connectionId
                 +" unwrapping attribute with MBean extended ClassLoader.");

	attr = (Attribute) unwrap(attribute,
                                      getClassLoaderFor(name),
                                      defaultClassLoader);

        try {
            final Object params[] = new Object[] { name, attr };

            if (debug) logger.debug("setAttribute",
                             "connectionId=" + connectionId
                             +", name="+name
                             +", attribute="+attr);

            doPrivilegedOperation(
              SET_ATTRIBUTE,
              params,
              delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof InstanceNotFoundException)
                throw (InstanceNotFoundException) e;
            if (e instanceof AttributeNotFoundException)
                throw (AttributeNotFoundException) e;
            if (e instanceof InvalidAttributeValueException)
                throw (InvalidAttributeValueException) e;
            if (e instanceof MBeanException)
                throw (MBeanException) e;
            if (e instanceof ReflectionException)
                throw (ReflectionException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public AttributeList setAttributes(ObjectName name,
                                       MarshalledObject attributes,
                                       Subject delegationSubject)
        throws
        InstanceNotFoundException,
        ReflectionException,
        IOException {
        final AttributeList attrlist;
        final boolean debug=logger.debugOn();

	if (debug) logger.debug("setAttributes",
                 "connectionId=" + connectionId
                 +" unwrapping attributes with MBean extended ClassLoader.");

	attrlist =
	    (AttributeList) unwrap(attributes,
                                       getClassLoaderFor(name),
                                       defaultClassLoader);

        try {
            final Object params[] = new Object[] { name, attrlist };

            if (debug) logger.debug("setAttributes",
                             "connectionId=" + connectionId
                             +", name="+name
                             +", attributes="+attrlist);

            return (AttributeList)
                doPrivilegedOperation(
                  SET_ATTRIBUTES,
                  params,
                  delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof InstanceNotFoundException)
                throw (InstanceNotFoundException) e;
            if (e instanceof ReflectionException)
                throw (ReflectionException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public Object invoke(ObjectName name,
                         String operationName,
                         MarshalledObject params,
                         String signature[],
                         Subject delegationSubject)
        throws
        InstanceNotFoundException,
        MBeanException,
        ReflectionException,
        IOException {

	checkNonNull("ObjectName", name);
	checkNonNull("Operation name", operationName);

        final Object[] values;
        final boolean debug=logger.debugOn();

	if (debug) logger.debug("invoke",
                 "connectionId=" + connectionId
                 +" unwrapping params with MBean extended ClassLoader.");

	values = nullIsEmpty((Object[]) unwrap(params,
						   getClassLoaderFor(name), 
						   defaultClassLoader));

        try {
            final Object params2[] =
                new Object[] { name, operationName, values,
			       nullIsEmpty(signature) };

            if (debug) logger.debug("invoke",
                             "connectionId=" + connectionId
                             +", name="+name
                             +", operationName="+operationName
                             +", params="+objects(values)
                             +", signature="+strings(signature));

            return (Object)
                doPrivilegedOperation(
                  INVOKE,
                  params2,
                  delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof InstanceNotFoundException)
                throw (InstanceNotFoundException) e;
            if (e instanceof MBeanException)
                throw (MBeanException) e;
            if (e instanceof ReflectionException)
                throw (ReflectionException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public String getDefaultDomain(Subject delegationSubject)
        throws IOException {
        try {
            final Object params[] = new Object[] { };

            if (logger.debugOn())  logger.debug("getDefaultDomain",
                                    "connectionId=" + connectionId);

            return (String)
                doPrivilegedOperation(
                  GET_DEFAULT_DOMAIN,
                  params,
                  delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public String[] getDomains(Subject delegationSubject) throws IOException {
        try {
            final Object params[] = new Object[] { };

            if (logger.debugOn())  logger.debug("getDomains",
                                    "connectionId=" + connectionId);

            return (String[])
                doPrivilegedOperation(
                  GET_DOMAINS,
                  params,
                  delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public MBeanInfo getMBeanInfo(ObjectName name, Subject delegationSubject)
        throws
        InstanceNotFoundException,
        IntrospectionException,
        ReflectionException,
        IOException {

	checkNonNull("ObjectName", name);

        try {
            final Object params[] = new Object[] { name };

            if (logger.debugOn())  logger.debug("getMBeanInfo",
                                    "connectionId=" + connectionId
                                    +", name="+name);

            return (MBeanInfo)
                doPrivilegedOperation(
                  GET_MBEAN_INFO,
                  params,
                  delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof InstanceNotFoundException)
                throw (InstanceNotFoundException) e;
            if (e instanceof IntrospectionException)
                throw (IntrospectionException) e;
            if (e instanceof ReflectionException)
                throw (ReflectionException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public boolean isInstanceOf(ObjectName name,
                                String className,
                                Subject delegationSubject)
        throws InstanceNotFoundException, IOException {

	checkNonNull("ObjectName", name);

        try {
            final Object params[] = new Object[] { name, className };

            if (logger.debugOn())  logger.debug("isInstanceOf",
                                    "connectionId=" + connectionId
                                    +", name="+name
                                    +", className="+className);

            return ((Boolean)
                doPrivilegedOperation(
                  IS_INSTANCE_OF,
                  params,
                  delegationSubject)).booleanValue();
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof InstanceNotFoundException)
                throw (InstanceNotFoundException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }
    
    public Integer[] addNotificationListeners(ObjectName[] names,
                                              MarshalledObject[] filters,
                                              Subject[] delegationSubjects)
	    throws InstanceNotFoundException, IOException {

	if (names == null || filters == null) {
	    throw new IllegalArgumentException("Got null arguments.");
	}

	Subject[] sbjs = (delegationSubjects != null) ? delegationSubjects : 
	new Subject[names.length];
	if (names.length != filters.length || filters.length != sbjs.length) {
	    final String msg = 
		"The value lengths of 3 parameters are not same.";
	    throw new IllegalArgumentException(msg);
	}

	for (int i=0; i<names.length; i++) {
	    if (names[i] == null) {
		throw new IllegalArgumentException("Null Object name.");
	    }
	}

	int i=0;
	ClassLoader targetCl;
	NotificationFilter[] filterValues = 
	new NotificationFilter[names.length];
	Object params[];
	Integer[] ids = new Integer[names.length];
	final boolean debug=logger.debugOn();
 
	try {
	    for (; i<names.length; i++) {
		targetCl = getClassLoaderFor(names[i]);

		if (debug) logger.debug("addNotificationListener"+
					"(ObjectName,NotificationFilter)",
					"connectionId=" + connectionId +
		      " unwrapping filter with target extended ClassLoader.");

		filterValues[i] = (NotificationFilter)unwrap(filters[i], 
					      targetCl, defaultClassLoader);

		if (debug) logger.debug("addNotificationListener"+
					"(ObjectName,NotificationFilter)",
					"connectionId=" + connectionId
					+", name=" + names[i]
					+", filter=" + filterValues[i]);

		ids[i] = (Integer)
		    doPrivilegedOperation(ADD_NOTIFICATION_LISTENERS,
					  new Object[] { names[i], 
							 filterValues[i] },
					  sbjs[i]);
	    }

	    return ids;
	} catch (Exception e) {
	    // remove all registered listeners
	    for (int j=0; j<i; j++) {
		try {
		    getServerNotifFwd().removeNotificationListener(names[j], 
								   ids[j]);
		} catch (Exception eee) {
		    // strange
		}
	    }
		
	    if (e instanceof PrivilegedActionException) {
		e = extractException(e);
	    }

	    if (e instanceof ClassCastException) {
		throw (ClassCastException) e;
	    } else if (e instanceof IOException) {
		throw (IOException)e;
	    } else if (e instanceof InstanceNotFoundException) {
		throw (InstanceNotFoundException) e;
	    } else if (e instanceof RuntimeException) {
		throw (RuntimeException) e;
	    } else {
		throw newIOException("Got unexpected server exception: "+e,e);
	    }
	}
    }

    public void addNotificationListener(ObjectName name,
                                        ObjectName listener,
                                        MarshalledObject filter,
                                        MarshalledObject handback,
                                        Subject delegationSubject)
        throws InstanceNotFoundException, IOException {

	checkNonNull("Target MBean name", name);
	checkNonNull("Listener MBean name", listener);

        final NotificationFilter filterValue;
        final Object handbackValue;
        final boolean debug=logger.debugOn();

	final ClassLoader targetCl = getClassLoaderFor(name);

	if (debug) logger.debug("addNotificationListener"+
                 "(ObjectName,ObjectName,NotificationFilter,Object)",
                 "connectionId=" + connectionId
                 +" unwrapping filter with target extended ClassLoader.");

	filterValue = (NotificationFilter)
                unwrap(filter, targetCl, defaultClassLoader);

	if (debug) logger.debug("addNotificationListener"+
                 "(ObjectName,ObjectName,NotificationFilter,Object)",
                 "connectionId=" + connectionId
                 +" unwrapping handback with target extended ClassLoader.");

	handbackValue = unwrap(handback, targetCl, defaultClassLoader);

        try {
            final Object params[] =
                new Object[] { name, listener, filterValue, handbackValue };

            if (debug) logger.debug("addNotificationListener"+
                 "(ObjectName,ObjectName,NotificationFilter,Object)",
                             "connectionId=" + connectionId
                             +", name=" + name
                             +", listenerName=" + listener
                             +", filter=" + filterValue
                             +", handback=" + handbackValue);

            doPrivilegedOperation(
              ADD_NOTIFICATION_LISTENER_OBJECTNAME,
              params,
              delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof InstanceNotFoundException)
                throw (InstanceNotFoundException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public void removeNotificationListeners(ObjectName name,
					    Integer[] listenerIDs,
					    Subject delegationSubject)
        throws
        InstanceNotFoundException,
        ListenerNotFoundException,
        IOException {

	if (name == null || listenerIDs == null)
	    throw new IllegalArgumentException("Illegal null parameter");

	for (int i = 0; i < listenerIDs.length; i++) {
	    if (listenerIDs[i] == null)
		throw new IllegalArgumentException("Null listener ID");
	}

        try {
            final Object params[] = new Object[] { name, listenerIDs };

            if (logger.debugOn()) logger.debug("removeNotificationListener"+
                                   "(ObjectName,Integer[])",
                                   "connectionId=" + connectionId
                                   +", name=" + name
                                   +", listenerIDs=" + objects(listenerIDs));

            doPrivilegedOperation(
              REMOVE_NOTIFICATION_LISTENER,
              params,
              delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof InstanceNotFoundException)
                throw (InstanceNotFoundException) e;
            if (e instanceof ListenerNotFoundException)
                throw (ListenerNotFoundException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public void removeNotificationListener(ObjectName name, 
                                           ObjectName listener,
                                           Subject delegationSubject)
        throws
        InstanceNotFoundException,
        ListenerNotFoundException,
        IOException {

	checkNonNull("Target MBean name", name);
	checkNonNull("Listener MBean name", listener);

        try {
            final Object params[] = new Object[] { name, listener };

            if (logger.debugOn()) logger.debug("removeNotificationListener"+
                                   "(ObjectName,ObjectName)",
                                   "connectionId=" + connectionId
                                   +", name=" + name
                                   +", listenerName=" + listener);

            doPrivilegedOperation(
              REMOVE_NOTIFICATION_LISTENER_OBJECTNAME,
              params,
              delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof InstanceNotFoundException)
                throw (InstanceNotFoundException) e;
            if (e instanceof ListenerNotFoundException)
                throw (ListenerNotFoundException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public void removeNotificationListener(ObjectName name,
                                           ObjectName listener,
                                           MarshalledObject filter,
                                           MarshalledObject handback,
                                           Subject delegationSubject)
        throws
        InstanceNotFoundException,
        ListenerNotFoundException,
        IOException {

	checkNonNull("Target MBean name", name);
	checkNonNull("Listener MBean name", listener);

        final NotificationFilter filterValue;
        final Object handbackValue;
        final boolean debug=logger.debugOn();

	final ClassLoader targetCl = getClassLoaderFor(name);

	if (debug) logger.debug("removeNotificationListener"+
                 "(ObjectName,ObjectName,NotificationFilter,Object)",
                 "connectionId=" + connectionId
                 +" unwrapping filter with target extended ClassLoader.");

	filterValue = (NotificationFilter)
                unwrap(filter, targetCl, defaultClassLoader);

	if (debug) logger.debug("removeNotificationListener"+
                 "(ObjectName,ObjectName,NotificationFilter,Object)",
                 "connectionId=" + connectionId
                 +" unwrapping handback with target extended ClassLoader.");

	handbackValue = unwrap(handback, targetCl, defaultClassLoader);

        try {
            final Object params[] =
                new Object[] { name, listener, filterValue, handbackValue };

            if (debug) logger.debug("removeNotificationListener"+
                 "(ObjectName,ObjectName,NotificationFilter,Object)",
                             "connectionId=" + connectionId
                             +", name=" + name
                             +", listenerName=" + listener
                             +", filter=" + filterValue
                             +", handback=" + handbackValue);

            doPrivilegedOperation(
              REMOVE_NOTIFICATION_LISTENER_OBJECTNAME_FILTER_HANDBACK,
              params,
              delegationSubject);
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof InstanceNotFoundException)
                throw (InstanceNotFoundException) e;
            if (e instanceof ListenerNotFoundException)
                throw (ListenerNotFoundException) e;
            if (e instanceof IOException)
                throw (IOException) e;
            throw newIOException("Got unexpected server exception: " + e, e);
        }
    }

    public NotificationResult fetchNotifications(long clientSequenceNumber,
                                                 int maxNotifications,
                                                 long timeout)
        throws IOException {

        if (logger.debugOn()) logger.debug("fetchNotifications",
                               "connectionId=" + connectionId
                               +", timeout=" + timeout);

	if (maxNotifications < 0 || timeout < 0)
	    throw new IllegalArgumentException("Illegal negative argument");

	final boolean serverTerminated = 
	    serverCommunicatorAdmin.reqIncoming();
	try {
	    if (serverTerminated) {
		// we must not call fetchNotifs() if the server is 
		// terminated (timeout elapsed).
		//
		return new NotificationResult(0L, 0L,
					      new TargetedNotification[0]);

	    }

	    return getServerNotifFwd().fetchNotifs(clientSequenceNumber,
						   timeout, maxNotifications);
	} finally {
	    serverCommunicatorAdmin.rspOutgoing();
	}
    }

    /**
     * <p>Returns a string representation of this object.  In general,
     * the <code>toString</code> method returns a string that
     * "textually represents" this object. The result should be a
     * concise but informative representation that is easy for a
     * person to read.</p>
     *
     * @return a String representation of this object.
     **/
    public String toString() {
        return super.toString() + ": connectionId=" + connectionId;
    }

    //------------------------------------------------------------------------
    // private classes
    //------------------------------------------------------------------------

    private class PrivilegedOperation implements PrivilegedExceptionAction {

        public PrivilegedOperation(int operation, Object[] params) {
            this.operation = operation;
            this.params = params;
        }

        public Object run() throws Exception {
            return doOperation(operation, params);
        }

        private int operation;
        private Object[] params;
    }

    //------------------------------------------------------------------------
    // private classes
    //------------------------------------------------------------------------
    private class RMIServerCommunicatorAdmin extends ServerCommunicatorAdmin {
	public RMIServerCommunicatorAdmin(long timeout) {
	    super(timeout);
	}

	protected void doStop() {
	    try {
		close();
	    } catch (IOException ie) {
		logger.warning("RMIServerCommunicatorAdmin-doStop", 
			       "Failed to close: " + ie);
		logger.debug("RMIServerCommunicatorAdmin-doStop",ie);
	    }
	} 

    }


    //------------------------------------------------------------------------
    // private methods
    //------------------------------------------------------------------------

    private ClassLoaderRepository getClassLoaderRepository() {
        return (ClassLoaderRepository)
            AccessController.doPrivileged(new PrivilegedAction() {
                    public Object run() {
                        return mbeanServer.getClassLoaderRepository();
                    }
                });
    }

    private ClassLoader getClassLoader(final ObjectName name)
        throws InstanceNotFoundException {
        try {
            return (ClassLoader)
                AccessController.doPrivileged(new PrivilegedExceptionAction() {
                        public Object run() throws InstanceNotFoundException {
                            return mbeanServer.getClassLoader(name);
                        }
                    });
        } catch (PrivilegedActionException pe) {
            throw (InstanceNotFoundException) extractException(pe);
        }
    }

    private ClassLoader getClassLoaderFor(final ObjectName name)
        throws InstanceNotFoundException {
        try {
            return (ClassLoader)
                AccessController.doPrivileged(new PrivilegedExceptionAction() {
                        public Object run() throws InstanceNotFoundException {
                            return mbeanServer.getClassLoaderFor(name);
                        }
                    });
        } catch (PrivilegedActionException pe) {
            throw (InstanceNotFoundException) extractException(pe);
        }
    }

    private Object doPrivilegedOperation(final int operation,
                                         final Object[] params,
                                         final Subject delegationSubject)
        throws PrivilegedActionException, IOException {

	serverCommunicatorAdmin.reqIncoming();
	try {

	    final AccessControlContext reqACC;
	    if (delegationSubject == null)
		reqACC = acc;
	    else {
		if (subject == null) {
		    final String msg =
			"Subject delegation cannot be enabled unless " +
			"an authenticated subject is put in place";
		    throw new SecurityException(msg);
		}
		reqACC =
		    subjectDelegator.delegatedContext(acc,
						      delegationSubject);
	    }

	    PrivilegedOperation op =
		new PrivilegedOperation(operation, params);
	    if (reqACC == null) {
		try {
		    return op.run();
		} catch (Exception e) {
		    if (e instanceof RuntimeException)
			throw (RuntimeException) e;
		    throw new PrivilegedActionException(e);
		}
	    } else {
		return AccessController.doPrivileged(op, reqACC);
	    }
	} catch (Error e) {
	    throw new JMXServerErrorException(e.toString(),e);
	} finally {
	    serverCommunicatorAdmin.rspOutgoing();
	}
    }

    private Object doOperation(int operation, Object[] params)
        throws Exception {

	switch (operation) {

	case CREATE_MBEAN:
	    return mbeanServer.createMBean((String)params[0],
					   (ObjectName)params[1]);

	case CREATE_MBEAN_LOADER:
	    return mbeanServer.createMBean((String)params[0],
					   (ObjectName)params[1],
					   (ObjectName)params[2]);

	case CREATE_MBEAN_PARAMS:
	    return mbeanServer.createMBean((String)params[0],
					   (ObjectName)params[1],
					   (Object[])params[2],
					   (String[])params[3]);

	case CREATE_MBEAN_LOADER_PARAMS:
	    return mbeanServer.createMBean((String)params[0],
					   (ObjectName)params[1],
					   (ObjectName)params[2],
					   (Object[])params[3],
					   (String[])params[4]);

	case GET_ATTRIBUTE:
	    return mbeanServer.getAttribute((ObjectName)params[0],
					    (String)params[1]);

	case GET_ATTRIBUTES:
	    return mbeanServer.getAttributes((ObjectName)params[0],
					     (String[])params[1]);

	case GET_DEFAULT_DOMAIN:
	    return mbeanServer.getDefaultDomain();
		
	case GET_DOMAINS:
	    return mbeanServer.getDomains();
		
	case GET_MBEAN_COUNT:
	    return mbeanServer.getMBeanCount();

	case GET_MBEAN_INFO:
	    return mbeanServer.getMBeanInfo((ObjectName)params[0]);
		
	case GET_OBJECT_INSTANCE:
	    return mbeanServer.getObjectInstance((ObjectName)params[0]);
		
	case INVOKE:
	    return mbeanServer.invoke((ObjectName)params[0],
				      (String)params[1],
				      (Object[])params[2],
				      (String[])params[3]);

	case IS_INSTANCE_OF:
	    return mbeanServer.isInstanceOf((ObjectName)params[0],
					    (String)params[1])
		? Boolean.TRUE : Boolean.FALSE;

	case IS_REGISTERED:
	    return mbeanServer.isRegistered((ObjectName)params[0])
		? Boolean.TRUE : Boolean.FALSE;

	case QUERY_MBEANS:
	    return mbeanServer.queryMBeans((ObjectName)params[0],
					   (QueryExp)params[1]);

	case QUERY_NAMES:
	    return mbeanServer.queryNames((ObjectName)params[0],
					  (QueryExp)params[1]);

	case SET_ATTRIBUTE:
	    mbeanServer.setAttribute((ObjectName)params[0],
				     (Attribute)params[1]);
	    return null;
		
	case SET_ATTRIBUTES:
	    return mbeanServer.setAttributes((ObjectName)params[0],
                                             (AttributeList)params[1]);

	case UNREGISTER_MBEAN:
	    mbeanServer.unregisterMBean((ObjectName)params[0]);
	    return null;

	case ADD_NOTIFICATION_LISTENERS:
	    return getServerNotifFwd().addNotificationListener(
						(ObjectName)params[0],
						(NotificationFilter)params[1]);
	    
	case ADD_NOTIFICATION_LISTENER_OBJECTNAME:
	    mbeanServer.addNotificationListener((ObjectName)params[0],
                                                (ObjectName)params[1],
                                                (NotificationFilter)params[2],
                                                (Object)params[3]);
	    return null;
	    
	case REMOVE_NOTIFICATION_LISTENER:
	    getServerNotifFwd().removeNotificationListener(
                                                   (ObjectName)params[0],
                                                   (Integer[])params[1]);
	    return null;

	case REMOVE_NOTIFICATION_LISTENER_OBJECTNAME:
	    mbeanServer.removeNotificationListener((ObjectName)params[0],
                                                   (ObjectName)params[1]);
	    return null;

	case REMOVE_NOTIFICATION_LISTENER_OBJECTNAME_FILTER_HANDBACK:
	    mbeanServer.removeNotificationListener(
                                          (ObjectName)params[0],
                                          (ObjectName)params[1],
                                          (NotificationFilter)params[2],
                                          (Object)params[3]);
	    return null;

	default:
	    throw new IllegalArgumentException("Invalid operation");
	}
    }

    /*
       Parameters to certain MBeanServer operations are passed
       remotely wrapped inside a MarshalledObject, so that they can be
       unwrapped with the right class loader.  This loader is
       typically the target MBean's class loader.
       MarshalledObject.get() uses the context class loader to load
       classes as it deserializes, which is what we want.  However,
       before consulting the context class loader, it consults the
       calling class's loader, if that's not null.  So, in the
       standalone version of javax.management.remote, if the class
       you're looking for is known to RMIConnectionImpl's class loader
       (typically the system class loader) then that loader will load
       it. This contradicts the class-loading semantics defined in JSR
       160, and can lead to problems if the same class name is known
       to RMIConnectionImpl's class loader and to the class loader of
       the target MBean in an invoke, setAttribute, or createMBean
       operation. If it is deserialized by the former, it can't be
       passed to the MBean, which expects the latter.

       We therefore call MarshalledObject.get() from within a class
       that is loaded by a NoCallStackClassLoader.  This loader
       doesn't know any other classes, so cannot load any that it is
       not supposed to.

       This is not needed in J2SE 5, where javax.management.remote
       is loaded by the bootstrap class loader.

       The byteCodeString below encodes the following Java class,
       compiled with "javac -g:none" on J2SE 1.4.2.

	package com.sun.jmx.remote.internal;

	import java.io.IOException;
	import java.rmi.MarshalledObject;

	public class MOGet implements Unmarshal {
	    public Object get(MarshalledObject mo)
		    throws IOException, ClassNotFoundException {
		return mo.get();
	    }
	}
     
     */

    private static final String unmarshalClassName =
	"com.sun.jmx.remote.internal.MOGet";

    private static boolean bootstrapLoaded =
	(RMIConnectionImpl.class.getClassLoader() ==
	 Object.class.getClassLoader());

    private static final Unmarshal unmarshal;
    static {
	final String byteCodeString =
	    "\312\376\272\276\0\0\0.\0\30\12\0\4\0\16\12\0\17\0\20\7\0\21\7\0"+
	    "\22\7\0\23\1\0\6<init>\1\0\3()V\1\0\4Code\1\0\3get\1\0/(Ljava/r"+
	    "mi/MarshalledObject;)Ljava/lang/Object;\1\0\12Exceptions\7\0\24"+
	    "\7\0\25\14\0\6\0\7\7\0\26\14\0\11\0\27\1\0!com/sun/jmx/remote/i"+
	    "nternal/MOGet\1\0\20java/lang/Object\1\0%com/sun/jmx/remote/int"+
	    "ernal/Unmarshal\1\0\23java/io/IOException\1\0\40java/lang/Class"+
	    "NotFoundException\1\0\31java/rmi/MarshalledObject\1\0\24()Ljava"+
	    "/lang/Object;\0!\0\3\0\4\0\1\0\5\0\0\0\2\0\1\0\6\0\7\0\1\0\10\0"+
	    "\0\0\21\0\1\0\1\0\0\0\5*\267\0\1\261\0\0\0\0\0\1\0\11\0\12\0\2\0"+
	    "\10\0\0\0\21\0\1\0\2\0\0\0\5+\266\0\2\260\0\0\0\0\0\13\0\0\0\6\0"+
	    "\2\0\14\0\15\0\0";
	if (bootstrapLoaded)
	    unmarshal = null;
	else {
	    final byte[] byteCode =
		NoCallStackClassLoader.stringToBytes(byteCodeString);
	    final String[] otherClassNames = {
		Unmarshal.class.getName()
	    };
	    final Class thisClass = RMIConnectionImpl.class;
	    final ClassLoader thisClassLoader = thisClass.getClassLoader();
	    final PrivilegedExceptionAction action =
		new PrivilegedExceptionAction() {
		    public Object run() throws Exception {
			final ProtectionDomain thisProtectionDomain =
			    thisClass.getProtectionDomain();
			ClassLoader cl =
			    new NoCallStackClassLoader(unmarshalClassName,
						       byteCode,
						       otherClassNames,
						       thisClassLoader,
						       thisProtectionDomain);
			Class c = cl.loadClass(unmarshalClassName);
			return c.newInstance();
		    }
		};
	    try {
		unmarshal = (Unmarshal) AccessController.doPrivileged(action);
	    } catch (PrivilegedActionException e) {
		Error error = new Error("Internal error: " + e);
		EnvHelp.initCause(error, e);
		throw error;
	    }
	}
    }

    private static Object unwrap(final MarshalledObject mo,
				 final ClassLoader cl)
	    throws IOException {
        if (mo == null) {
            return null;
        }
        try {
            return AccessController.doPrivileged(
		new PrivilegedExceptionAction() {
                    public Object run()
			    throws IOException {
                        final ClassLoader old =
                            Thread.currentThread().getContextClassLoader();
                        Thread.currentThread().setContextClassLoader(cl);
                        try {
			    if (bootstrapLoaded)
				return mo.get();
			    else
				return unmarshal.get(mo);
			} catch (ClassNotFoundException cnfe) {
			    throw new UnmarshalException(cnfe.toString(), cnfe);
                        } finally {
                            Thread.currentThread().setContextClassLoader(old);
                        }
                    }
                });
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof IOException) {
                throw (IOException) e;
            }
            if (e instanceof ClassNotFoundException) {
		throw new UnmarshalException(e.toString(), e);
            }
	    logger.warning("unwrap", "Failed to unmarshall object: " + e);
	    logger.debug("unwrap", e);
        }
        return null;
    }

    private static Object unwrap(final MarshalledObject mo,
				 final ClassLoader cl1,
				 final ClassLoader cl2)
        throws IOException {
        if (mo == null) {
            return null;
        }
        try {
            return AccessController.doPrivileged(
                   new PrivilegedExceptionAction() {
                       public Object run()
                           throws IOException {
                           return unwrap(mo, new OrderClassLoaders(cl1, cl2));
                       }
                   });
        } catch (PrivilegedActionException pe) {
            Exception e = extractException(pe);
            if (e instanceof IOException) {
                throw (IOException) e;
            }
            if (e instanceof ClassNotFoundException) {
                throw new UnmarshalException(e.toString(), e);
            }
	    logger.warning("unwrap", "Failed to unmarshall object: " + e);
	    logger.debug("unwrap", e);
        }
        return null;
    }

    /**
     * Construct a new IOException with a nested exception.
     * The nested exception is set only if JDK >= 1.4
     */
    private static IOException newIOException(String message, 
                                              Throwable cause) {
        final IOException x = new IOException(message);
        return (IOException) EnvHelp.initCause(x,cause);
    }

    /**
     * Iterate until we extract the real exception
     * from a stack of PrivilegedActionExceptions.
     */
    private static Exception extractException(Exception e) {
        while (e instanceof PrivilegedActionException) {
            e = ((PrivilegedActionException)e).getException(); 
        }
        return e;
    }

    private static final Object[] NO_OBJECTS = new Object[0];
    private static final String[] NO_STRINGS = new String[0];

    /*
     * The JMX spec doesn't explicitly say that a null Object[] or
     * String[] in e.g. MBeanServer.invoke is equivalent to an empty
     * array, but the RI behaves that way.  In the interests of
     * maximal interoperability, we make it so even when we're
     * connected to some other JMX implementation that might not do
     * that.  This should be clarified in the next version of JMX.
     */
    private static Object[] nullIsEmpty(Object[] array) {
	return (array == null) ? NO_OBJECTS : array;
    }

    private static String[] nullIsEmpty(String[] array) {
	return (array == null) ? NO_STRINGS : array;
    }

    /*
     * Similarly, the JMX spec says for some but not all methods in
     * MBeanServer that take an ObjectName target, that if it's null
     * you get this exception.  We specify it for all of them, and
     * make it so for the ones where it's not specified in JMX even if
     * the JMX implementation doesn't do so.
     */
    private static void checkNonNull(String what, Object x) {
	if (x == null) {
	    RuntimeException wrapped =
		new IllegalArgumentException(what + " must not be null");
	    throw new RuntimeOperationsException(wrapped);
	}
    }

    //------------------------------------------------------------------------
    // private variables
    //------------------------------------------------------------------------

    private final Subject subject;

    private final SubjectDelegator subjectDelegator;

    private final AccessControlContext acc;

    private final RMIServerImpl rmiServer;

    private final MBeanServer mbeanServer;

    private final ClassLoader defaultClassLoader;

    private final ClassLoaderWithRepository classLoaderWithRepository;
    
    private boolean terminated = false;
    
    private final String connectionId;

    private final ServerCommunicatorAdmin serverCommunicatorAdmin;
    // Method IDs for doOperation
    //---------------------------

    private final static int
        ADD_NOTIFICATION_LISTENERS                              = 1;
    private final static int
        ADD_NOTIFICATION_LISTENER_OBJECTNAME                    = 2;
    private final static int
        CREATE_MBEAN                                            = 3;
    private final static int
        CREATE_MBEAN_PARAMS                                     = 4;
    private final static int
        CREATE_MBEAN_LOADER                                     = 5;
    private final static int
        CREATE_MBEAN_LOADER_PARAMS                              = 6;
    private final static int
        GET_ATTRIBUTE                                           = 7;
    private final static int
        GET_ATTRIBUTES                                          = 8;
    private final static int
        GET_DEFAULT_DOMAIN                                      = 9;
    private final static int
        GET_DOMAINS                                             = 10;
    private final static int
        GET_MBEAN_COUNT                                         = 11;
    private final static int
        GET_MBEAN_INFO                                          = 12;
    private final static int
        GET_OBJECT_INSTANCE                                     = 13;
    private final static int
        INVOKE                                                  = 14;
    private final static int
        IS_INSTANCE_OF                                          = 15;
    private final static int
        IS_REGISTERED                                           = 16;
    private final static int
        QUERY_MBEANS                                            = 17;
    private final static int
        QUERY_NAMES                                             = 18;
    private final static int
        REMOVE_NOTIFICATION_LISTENER                            = 19;
    private final static int
        REMOVE_NOTIFICATION_LISTENER_FILTER_HANDBACK            = 20;
    private final static int
        REMOVE_NOTIFICATION_LISTENER_OBJECTNAME                 = 21;
    private final static int
        REMOVE_NOTIFICATION_LISTENER_OBJECTNAME_FILTER_HANDBACK = 22;
    private final static int
        SET_ATTRIBUTE                                           = 23;
    private final static int
        SET_ATTRIBUTES                                          = 24;
    private final static int
        UNREGISTER_MBEAN                                        = 25;

    // SERVER NOTIFICATION
    //--------------------
    private ServerNotifForwarder serverNotifForwarder;
    private Map env;
    
    // TRACES & DEBUG
    //---------------

    private static String objects(final Object[] objs) {
        if (objs == null)
            return "null";
        else
            return Arrays.asList(objs).toString();
    }

    private static String strings(final String[] strs) {
	return objects(strs);
    }

    private static final ClassLogger logger =
	new ClassLogger("javax.management.remote.rmi", "RMIConnectionImpl");
}