gcc/libjava/gnu/java/rmi/server/UnicastConnectionManager.java

/*
  Copyright (c) 1996, 1997, 1998, 1999 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
 
GNU Classpath 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 for more details.

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along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
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As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
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terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
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or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
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exception statement from your version. */

package gnu.java.rmi.server;

import java.rmi.server.RMISocketFactory;
import java.rmi.server.RMIServerSocketFactory;
import java.rmi.server.RMIClientSocketFactory;
import java.rmi.RemoteException;
import gnu.java.rmi.server.UnicastConnection;
import java.util.Hashtable;
import java.net.Socket;
import java.net.ServerSocket;
import java.io.IOException;
import java.io.ObjectOutput;
import java.io.ObjectInput;
import java.lang.Thread;
import java.lang.Runnable;
import java.net.InetAddress;
import java.net.UnknownHostException;

public class UnicastConnectionManager
	implements Runnable, ProtocolConstants {

private static String localhost;
// use different maps for server/client type UnicastConnectionManager
private static Hashtable servers = new Hashtable();
private static Hashtable clients = new Hashtable();

// make serverThread volatile for poll
private volatile Thread serverThread;
private ServerSocket ssock;
String serverName;
int serverPort;
private RMIServerSocketFactory serverFactory;
private RMIClientSocketFactory clientFactory;

static {
        try {
                //Use host address instead of host name to avoid name resolving issues
                //localhost = InetAddress.getLocalHost().getHostName();
                localhost = InetAddress.getLocalHost().getHostAddress();
        }
        catch (UnknownHostException _) {
                localhost = "localhost";
        }
}

private UnicastConnectionManager(String host, int port, RMIClientSocketFactory csf) {
	ssock = null;
	serverName = host;
	serverPort = port;
	serverFactory = null;
	clientFactory = csf;
}

private UnicastConnectionManager(int port, RMIServerSocketFactory ssf) {
	try {
		ssock = ssf.createServerSocket(port);
		serverPort = ssock.getLocalPort();
	}
	catch (IOException _) {
		try {
			ssock = ssf.createServerSocket(0);
			serverPort = ssock.getLocalPort();
		}
		catch (IOException __) {
			ssock = null;
			serverPort = 0;
		}
	}
	serverName = localhost;
	serverFactory = ssf;
	clientFactory = null;
}

/**
 * Return a client connection manager which will connect to the given
 * host/port.
 */
public static synchronized UnicastConnectionManager getInstance(String host, int port, RMIClientSocketFactory csf) {
//System.out.println("getInstance: " + host + "," + port + "," + csf);
	if (csf == null) {
		csf = RMISocketFactory.getSocketFactory();
	}
	// change host name to host address to avoid name resolving issues
	try{
    	host = InetAddress.getByName(host).getHostAddress();
    }catch(Exception _){}
    
	TripleKey key = new TripleKey(host, port, csf);
	UnicastConnectionManager man = (UnicastConnectionManager)clients.get(key);
	if (man == null) {
		man = new UnicastConnectionManager(host, port, csf);
		clients.put(key, man);
	}
	return (man);
}

/**
 * Return a server connection manager which will accept connection on the
 * given port.
 */
public static synchronized UnicastConnectionManager getInstance(int port, RMIServerSocketFactory ssf) {
//System.out.println("getInstance: " + port + "," + ssf);
	if (ssf == null) {
		ssf = RMISocketFactory.getSocketFactory();
	}
	TripleKey key = new TripleKey(localhost, port, ssf);
	UnicastConnectionManager man = (UnicastConnectionManager)servers.get(key);
	if (man == null) {
		man = new UnicastConnectionManager(port, ssf);
		// The provided port might not be the set port.
		key.port = man.serverPort;
		servers.put(key, man);
	}
	return (man);
}

/**
 * Get a connection from this manager.
 */
public UnicastConnection getConnection() throws IOException {
	if (ssock == null) {
		return (getClientConnection());
	}
	else {
		return (getServerConnection());
	}
}

/**
 * Accept a connection to this server.
 */
private UnicastConnection getServerConnection() throws IOException {
	Socket sock = ssock.accept();
	UnicastConnection conn = new UnicastConnection(this, sock);
	conn.acceptConnection();
//System.out.println("Server connection " + conn);
	return (conn);
}

/**
 * Make a conection from this client to the server.
 */
private UnicastConnection getClientConnection() throws IOException {
	Socket sock = clientFactory.createSocket(serverName, serverPort);
	UnicastConnection conn = new UnicastConnection(this, sock);
	conn.makeConnection(DEFAULT_PROTOCOL);
//System.out.println("Client connection " + conn);
	return (conn);
}

/**
 * Discard a connection when we're done with it - maybe it can be
 * recycled.
 */
public void discardConnection(UnicastConnection conn) {
//System.out.println("Discarding connection " + conn);
	conn.disconnect();
}

/**
 * Start a server on this manager if it's a server socket and we've not
 * already got one running.
 */
public void startServer() {
	synchronized(this) {
		if (ssock == null || serverThread != null) {
			return;
		}
		serverThread = new Thread(this);
	}
	serverThread.start();
}

/**
 * Stop a server on this manager
 */
public void stopServer() {
    synchronized(this) {
    	if(serverThread != null){
    	    serverThread = null;
    	    try{
    	        ssock.close();
    	    }catch(Exception _){}
    	}
    }
}

/**
 * Server thread for connection manager.
 */
public void run() {
	for (;serverThread != null;) { // if serverThread==null, then exit thread
		try {
//System.out.println("Waiting for connection on " + serverPort);
			UnicastConnection conn = getServerConnection();
			// use a thread pool to improve performance
			// (new Thread(conn)).start();
			ConnectionRunnerPool.dispatchConnection(conn);
		}
		catch (Exception e) {
			// e.printStackTrace();
		}
	}
}

/**
 * Serialization routine.
 */
void write(ObjectOutput out) throws IOException {
        out.writeUTF(serverName);
        out.writeInt(serverPort);
}

/**
 * Serialization routine.
 */
static UnicastConnectionManager read(ObjectInput in) throws IOException {
        String host = in.readUTF();
        int port = in.readInt();
	RMIClientSocketFactory csf = ((RMIObjectInputStream)in).manager.clientFactory;
        return (getInstance(host, port, csf));
}

}

/**
 * This is use as the hashkey for the client/server connections.
 */
class TripleKey {

String host;
int port;
Object other;

TripleKey(String host, int port, Object other) {
	this.host = host;
	this.port = port;
	this.other = other;
}

/**
 * Hash code just include the host and other - we ignore the port since
 * this has unusual matching behaviour.
 */
public int hashCode() {
	return (host.hashCode() ^ other.hashCode());
}

public boolean equals(Object obj) {
	if (obj instanceof TripleKey) {
		TripleKey other = (TripleKey)obj;
		if (this.host.equals(other.host) &&
		    this.other == other.other &&
		    (this.port == other.port || this.port == 0 || other.port == 0)) {
			return (true);
		}
	}
	return (false);
}

}