com.sun.jmx.remote.generic.ServerSynchroMessageConnectionImpl Maven / Gradle / Ivy

/*
 * @(#)file      ServerSynchroMessageConnectionImpl.java
 * @(#)author    Sun Microsystems, Inc.
 * @(#)version   1.5
 * @(#)lastedit  07/03/08
 * @(#)build     @BUILD_TAG_PLACEHOLDER@
 *
 * 
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
 * 
 * Copyright (c) 2007 Sun Microsystems, Inc. All Rights Reserved.
 * 
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 * Public License Version 2 only ("GPL") or the Common Development and
 * Distribution License("CDDL")(collectively, the "License"). You may not use
 * this file except in compliance with the License. You can obtain a copy of the
 * License at http://opendmk.dev.java.net/legal_notices/licenses.txt or in the 
 * LEGAL_NOTICES folder that accompanied this code. See the License for the 
 * specific language governing permissions and limitations under the License.
 * 
 * When distributing the software, include this License Header Notice in each
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 * or in the LEGAL_NOTICES folder that accompanied this code.
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 * accompanied this code.
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package com.sun.jmx.remote.generic;

import java.util.Map;
import java.util.HashMap;
import java.util.Iterator;
import java.io.IOException;
import java.io.InterruptedIOException;
import javax.security.auth.Subject;

import javax.management.remote.generic.ConnectionClosedException;
import javax.management.remote.generic.*;
import javax.management.remote.message.*;
import com.sun.jmx.remote.generic.DefaultConfig;
import com.sun.jmx.remote.opt.util.ThreadService;
import com.sun.jmx.remote.opt.util.ClassLogger;
import com.sun.jmx.remote.opt.internal.ClientCommunicatorAdmin;
import com.sun.jmx.remote.opt.util.EnvHelp;

public class ServerSynchroMessageConnectionImpl implements ServerSynchroMessageConnection {

    public ServerSynchroMessageConnectionImpl(MessageConnection mc, Map env) 
	throws IOException {
	if (mc == null) {
	    throw new IllegalArgumentException("Null message connection.");
	}
	
	this.env = env;

	waitConnectedState = DefaultConfig.getTimeoutForWaitConnectedState(env);

	this.serverAdmin = DefaultConfig.getServerAdmin(this.env);

	connection = mc;
    }

    public void connect(Map env) throws IOException {
        synchronized(stateLock) {
	    if (state != UNCONNECTED) {
		waitConnected();
		return;
	    } else {
		state = CONNECTING;
	    }
	}

	connection.connect(env);
	
	connection = serverAdmin.connectionOpen(connection);

        synchronized(stateLock) {
	    if (state != CONNECTING) {
		// closed by another thread
		try {
		    connection.close();
		} catch (Exception e) {
		    // OK Already closed.
		}
		throw new IOException("The connecting is stooped by another thread.");
	    }

	    state = CONNECTED;
	    stateLock.notifyAll();
	}
    }

    public void sendOneWay(Message msg) throws IOException {
	if (logger.traceOn()) {
	    logger.trace("sendOneWay", "Send a message without response.");
	}

	waitConnected();

	synchronized(connectionLock) {
	    connection.writeMessage(msg);
	}
    }

    public void setCallback(SynchroCallback cb) {
	if (logger.traceOn()) {
	    logger.trace("setCallback", "be called.");
	}

	if (callback != null) {
	    throw new IllegalArgumentException("The callback has been assigned.");
	}

	if (cb == null) {
	    throw new IllegalArgumentException("Null callback.");
	}
	callback = cb;

	threads = new ThreadService(DefaultConfig.getServerMinThreads(env),
				    DefaultConfig.getServerMaxThreads(env));

	reader = new MessageReader();
	threads.handoff(reader);
    }

    public String getConnectionId() {
	return connection.getConnectionId();
    }

    public void close() throws IOException {
	if (logger.traceOn()) {
	    logger.trace("close", "Closing this SynchroMessageConnection.");
	}

	synchronized(stateLock) {
	    if (state == TERMINATED) {
		return;
	    }

	    state = TERMINATED;

	    if (logger.traceOn()) {
		logger.trace("close", "Close the callback reader.");
	    }
	    if (reader != null) {
		reader.stop();
	    }

	    if (threads != null) {
		threads.terminate();

		threads = null;
	    }

	    if (logger.traceOn()) {
		logger.trace("close", "Closing the underlying connection.");
	    }
	    if (connection != null) {
		connection.close();
	    }

	    serverAdmin.connectionClosed(connection);

	    // clean
	    if (logger.traceOn()) {
		logger.trace("close", "Clean all threads waiting theire responses.");
	    }

	    stateLock.notify();
	}
    }

    /**
     * Returns the underlying asynchronous trasport.
     */
    public MessageConnection getAsynchroConnection() {
	return connection;
    }

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

    private class MessageReader implements Runnable {
	public MessageReader() {
	}
	    
	public void run() {
	    try {
		executingThread = Thread.currentThread();

		Message msg;
	    
		while(!stopped()) {
		    if (logger.traceOn()) {
			logger.trace("MessageReader-run", "Waiting a coming message...");
		    }

		    msg = null;
		    
		    try {
			msg = (Message)connection.readMessage();
		    } catch (Exception e) {
			if (stopped()) {
			    break;
			}

			callback.connectionException(e);

			// if rconnected, a new reader should be created.
			break;
		    }

		    if (stopped()) {		
			break;
		    }
		    
		    threads.handoff(new RemoteJob(msg));
		    
		    if (msg instanceof CloseMessage) {
			break;
		    }
		}
	    } catch (Exception eee) {
		// need to stop
		if (logger.traceOn()) logger.trace("MessageReader-run", "stops.");
	    }

	    synchronized(stateLock) {
		executingThreadInterrupted = true;
	    }

	    if (logger.traceOn()) {
		logger.trace("MessageReader-run", "ended.");
	    }
	}

	public void stop() {
	    if (logger.traceOn()) {
		logger.trace("MessageReader-terminated", "be called.");
	    }

	    synchronized(stateLock) {
		if (Thread.currentThread() != executingThread
		    && executingThread != null &&
		    !executingThreadInterrupted) {

		    executingThreadInterrupted = true;
		    
		    executingThread.interrupt();
		}
	    }

	    if (logger.traceOn()) {
		logger.trace("MessageReader-terminated", "done.");
	    }
	}

	private boolean stopped() {
	    synchronized(stateLock) {
		return (state != CONNECTED || executingThreadInterrupted);
	    }
	}

	private Thread executingThread;

	// This flag is used to ensure that we interrupt the executingThread
	// only when it is running in this MessageReader object.
	private boolean executingThreadInterrupted = false;
    }

    private class RemoteJob implements Runnable {
	public RemoteJob(Message msg) {
	    this.msg = msg;
	}

	public void run() {
	    if (logger.traceOn()) {
		logger.trace("RemoteJob-run", "Receive a new request.");
	    }

	    try {
	       Message resp = callback.execute(msg);

	       if (resp != null) {
		   synchronized(connectionLock) {
		       connection.writeMessage(resp);
		   }
	       }
	    } catch (Exception ie) {
		synchronized(stateLock) {
		    if (state != CONNECTED && callback != null) {
			// inform the callback
			callback.connectionException(ie);
		    }
		}
	    }
	}

	private Message msg;
    }

    public Subject getSubject() {
	return serverAdmin.getSubject(connection);
    }

//----------------------------------------------
// private methods
//----------------------------------------------
    private void waitConnected() throws IOException {
	synchronized(stateLock) {
	    if (state == CONNECTED) {
		return;
	    } else if (state != CONNECTING) {
		throw new IOException("The connection was closed or failed.");
	    }

	    final long startTime = System.currentTimeMillis();
	    long remainingTime = waitConnectedState;

	    while (state == CONNECTING &&
		   waitConnectedState > 0) {

		try {
		    stateLock.wait(remainingTime);
		} catch (InterruptedException ire) {
		    break;
		}

		remainingTime = waitConnectedState - 
		    (System.currentTimeMillis() - startTime);
	    }
		    
	    if (state != CONNECTED) {
		throw new IOException("The connection is not connected.");
	    } else {
		return;
	    }
	}
    }

//----------------------------------------------
// private variables
//----------------------------------------------
    /**
     * This lock used to ensures no concurrent writes
     */
    private transient int[] connectionLock = new int[0];
    private transient MessageConnection connection;

    private transient ServerAdmin serverAdmin = null;

    private Map env;

    private transient SynchroCallback callback;
    private transient ThreadService threads;
    private transient MessageReader reader;

    // state issues
    private static final int UNCONNECTED = 1;
    private static final int CONNECTING = 2;
    private static final int CONNECTED = 3;
    private static final int FAILED = 4;
    private static final int TERMINATED = 5;

    private int state = UNCONNECTED;

    /**
     * Used to control access to the state variable, including
     * ensuring that only one thread manages state transitions.
     */
    private int[] stateLock = new int[0];

    private long  waitConnectedState;

    private final ClassLogger logger = new ClassLogger(
	     "javax.management.remote.misc", "SynchroMessageConnectionImpl");
}