/*
 * @(#)Ping.java	1.2 01/12/13
 * Connect to each of a list of hosts and measure the time required to complete
 * the connection.  This example uses a selector and two additional threads in
 * order to demonstrate non-blocking connects and the multithreaded use of a
 * selector.
 *
 * Copyright (c) 2001, 2002, Oracle and/or its affiliates. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * Redistribution and use in source and binary forms, with or 
 * without modification, are permitted provided that the following 
 * conditions are met:
 *
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 * 
 * -Redistributions of source code must retain the above copyright  
 * notice, this  list of conditions and the following disclaimer.
 *
 * -Redistribution in binary form must reproduct the above copyright
 * notice, this list of conditions and the following disclaimer in
 * the documentation and/or other materials provided with the
 * 
 * -Redistribution in binary form must reproduct the above copyright 
 * notice, this list of conditions and the following disclaimer in 
 * the documentation and/or other materials provided with the 
 * distribution.
 *
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 * contributors may be used to endorse or promote products derived
 * 
 * Neither the name of Oracle nor the names of 
 * contributors may be used to endorse or promote products derived 
 * from this software without specific prior written permission.
 *
 * This software is provided "AS IS," without a warranty of any
 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND
 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY
 * EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY
 * DAMAGES OR LIABILITIES  SUFFERED BY LICENSEE AS A RESULT OF  OR
 * RELATING TO USE, MODIFICATION OR DISTRIBUTION OF THE SOFTWARE OR
 * ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE
 * FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT,
 * SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF
 * THE USE OF OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN
 * 
 * This software is provided "AS IS," without a warranty of any 
 * kind. ALL EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND 
 * WARRANTIES, INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, 
 * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY 
 * EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY 
 * DAMAGES OR LIABILITIES  SUFFERED BY LICENSEE AS A RESULT OF  OR 
 * RELATING TO USE, MODIFICATION OR DISTRIBUTION OF THE SOFTWARE OR 
 * ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE 
 * FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, 
 * SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER 
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF 
 * THE USE OF OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN 
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 *
 * You acknowledge that Software is not designed, licensed or
 * intended for use in the design, construction, operation or
 * maintenance of any nuclear facility.
 * 
 * You acknowledge that Software is not designed, licensed or 
 * intended for use in the design, construction, operation or 
 * maintenance of any nuclear facility. 
 */

import java.io.*;
import java.net.*;
import java.nio.*;
import java.nio.channels.*;
import java.nio.charset.*;
import java.util.*;
import java.util.regex.*;


public class Ping {

    // The default daytime port
    static int DAYTIME_PORT = 13;

    // The port we'll actually use
    static int port = DAYTIME_PORT;


    // Representation of a ping target
    //
    // 
    static class Target {

        InetSocketAddress address;
        SocketChannel channel;
        Exception failure;
        long connectStart;
        long connectFinish = 0;
        boolean shown = false;
	InetSocketAddress address;
	SocketChannel channel;
	Exception failure;
	long connectStart;
	long connectFinish = 0;
	boolean shown = false;

        Target(String host) {
            try {
                address = new InetSocketAddress(InetAddress.getByName(host),
                                                port);
            } catch (IOException x) {
                failure = x;
            }
        }
	Target(String host) {
	    try {
		address = new InetSocketAddress(InetAddress.getByName(host),
						port);
	    } catch (IOException x) {
		failure = x;
	    }
	}

        void show() {
            String result;
            if (connectFinish != 0)
                result = Long.toString(connectFinish - connectStart) + "ms";
            else if (failure != null)
                result = failure.toString();
            else
                result = "Timed out";
            System.out.println(address + " : " + result);
            shown = true;
        }
	void show() {
	    String result;
	    if (connectFinish != 0)
		result = Long.toString(connectFinish - connectStart) + "ms";
	    else if (failure != null)
		result = failure.toString();
	    else
		result = "Timed out";
	    System.out.println(address + " : " + result);
	    shown = true;
	}

    }


    // Thread for printing targets as they're heard from
    //
    static class Printer
        extends Thread
	extends Thread
    {
        LinkedList pending = new LinkedList();
	LinkedList pending = new LinkedList();

        Printer() {
            setName("Printer");
            setDaemon(true);
        }
	Printer() {
	    setName("Printer");
	    setDaemon(true);
	}

        void add(Target t) {
            synchronized (pending) {
                pending.add(t);
                pending.notify();
            }
        }
	void add(Target t) {
	    synchronized (pending) {
		pending.add(t);
		pending.notify();
	    }
	}

        public void run() {
            try {
                for (;;) {
                    Target t = null;
                    synchronized (pending) {
                        while (pending.size() == 0)
                            pending.wait();
                        t = (Target)pending.removeFirst();
                    }
                    t.show();
                }
            } catch (InterruptedException x) {
                return;
            }
        }
	public void run() {
	    try {
		for (;;) {
		    Target t = null;
		    synchronized (pending) {
			while (pending.size() == 0)
			    pending.wait();
			t = (Target)pending.removeFirst();
		    }
		    t.show();
		}
	    } catch (InterruptedException x) {
		return;
	    }
	}

    }


    // Thread for connecting to all targets in parallel via a single selector
    //
    // 
    static class Connector
        extends Thread
	extends Thread
    {
        Selector sel;
        Printer printer;
	Selector sel;
	Printer printer;

        // List of pending targets.  We use this list because if we try to
        // register a channel with the selector while the connector thread is
        // blocked in the selector then we will block.
        //
        LinkedList pending = new LinkedList();
	// List of pending targets.  We use this list because if we try to
	// register a channel with the selector while the connector thread is
	// blocked in the selector then we will block.
	//
	LinkedList pending = new LinkedList();

        Connector(Printer pr) throws IOException {
            printer = pr;
            sel = Selector.open();
            setName("Connector");
        }
	Connector(Printer pr) throws IOException {
	    printer = pr;
	    sel = Selector.open();
	    setName("Connector");
	}

        // Initiate a connection sequence to the given target and add the
        // target to the pending-target list
        //
        void add(Target t) {
            SocketChannel sc = null;
            try {
	// Initiate a connection sequence to the given target and add the
	// target to the pending-target list
	//
	void add(Target t) {
	    SocketChannel sc = null;
	    try {

                // Open the channel, set it to non-blocking, initiate connect
                sc = SocketChannel.open();
                sc.configureBlocking(false);
		// Open the channel, set it to non-blocking, initiate connect
		sc = SocketChannel.open();
		sc.configureBlocking(false);

		boolean connected = sc.connect(t.address);

		// Record the time we started
		t.channel = sc;
		t.connectStart = System.currentTimeMillis();

		if (connected) {
		    t.connectFinish = t.connectStart;
		    sc.close();
		    printer.add(t);
		} else {
		    // Add the new channel to the pending list
		    synchronized (pending) {
		        pending.add(t);
		    }

		    // Nudge the selector so that it will process the pending list
		    sel.wakeup();
		}
	    } catch (IOException x) {
		if (sc != null) {
		    try {
			sc.close();
		    } catch (IOException xx) { }
		}
		t.failure = x;
		printer.add(t);
	    }
	}

        // Process any targets in the pending list
        //
        void processPendingTargets() throws IOException {
            synchronized (pending) {
                while (pending.size() > 0) {
                    Target t = (Target)pending.removeFirst();
                    try {
	// Process any targets in the pending list
	//
	void processPendingTargets() throws IOException {
	    synchronized (pending) {
		while (pending.size() > 0) {
		    Target t = (Target)pending.removeFirst();
		    try {

                        // Register the channel with the selector, indicating
                        // interest in connection completion and attaching the
                        // target object so that we can get the target back
                        // after the key is added to the selector's
                        // selected-key set
                        t.channel.register(sel, SelectionKey.OP_CONNECT, t);
			// Register the channel with the selector, indicating
			// interest in connection completion and attaching the
			// target object so that we can get the target back
			// after the key is added to the selector's
			// selected-key set
			t.channel.register(sel, SelectionKey.OP_CONNECT, t);

                    } catch (IOException x) {
		    } catch (IOException x) {

                        // Something went wrong, so close the channel and
                        // record the failure
                        t.channel.close();
                        t.failure = x;
                        printer.add(t);
			// Something went wrong, so close the channel and
			// record the failure
			t.channel.close();
			t.failure = x;
			printer.add(t);

                    }
		    }

                }
            }
        }
		}
	    }
	}

        // Process keys that have become selected
        //
        void processSelectedKeys() throws IOException {
            for (Iterator i = sel.selectedKeys().iterator(); i.hasNext();) {
	// Process keys that have become selected
	//
	void processSelectedKeys() throws IOException {
	    for (Iterator i = sel.selectedKeys().iterator(); i.hasNext();) {

                // Retrieve the next key and remove it from the set
                SelectionKey sk = (SelectionKey)i.next();
                i.remove();
		// Retrieve the next key and remove it from the set
		SelectionKey sk = (SelectionKey)i.next();
		i.remove();

                // Retrieve the target and the channel
                Target t = (Target)sk.attachment();
                SocketChannel sc = (SocketChannel)sk.channel();
		// Retrieve the target and the channel
		Target t = (Target)sk.attachment();
		SocketChannel sc = (SocketChannel)sk.channel();

                // Attempt to complete the connection sequence
                try {
                    if (sc.finishConnect()) {
                        sk.cancel();
                        t.connectFinish = System.currentTimeMillis();
                        sc.close();
                        printer.add(t);
                    }
                } catch (IOException x) {
                    sc.close();
                    t.failure = x;
                    printer.add(t);
                }
            }
        }
		// Attempt to complete the connection sequence
		try {
		    if (sc.finishConnect()) {
			sk.cancel();
			t.connectFinish = System.currentTimeMillis();
			sc.close();
			printer.add(t);
		    }
		} catch (IOException x) {
		    sc.close();
		    t.failure = x;
		    printer.add(t);
		}
	    }
	}

        volatile boolean shutdown = false;
	volatile boolean shutdown = false;

        // Invoked by the main thread when it's time to shut down
        //
        void shutdown() {
            shutdown = true;
            sel.wakeup();
        }
	// Invoked by the main thread when it's time to shut down
	//
	void shutdown() {
	    shutdown = true;
	    sel.wakeup();
	}

        // Connector loop
        //
        public void run() {
            for (;;) {
                try {
                    int n = sel.select();
                    if (n > 0)
                        processSelectedKeys();
                    processPendingTargets();
                    if (shutdown) {
                        sel.close();
                        return;
                    }
                } catch (IOException x) {
                    x.printStackTrace();
                }
            }
        }
	// Connector loop
	//
	public void run() {
	    for (;;) {
		try {
		    int n = sel.select();
		    if (n > 0)
			processSelectedKeys();
		    processPendingTargets();
		    if (shutdown) {
			sel.close();
			return;
		    }
		} catch (IOException x) {
		    x.printStackTrace();
		}
	    }
	}

    }


    public static void main(String[] args)
        throws InterruptedException, IOException
	throws InterruptedException, IOException
    {
        if (args.length < 1) {
            System.err.println("Usage: java Ping [port] host...");
            return;
        }
        int firstArg = 0;
	if (args.length < 1) {
	    System.err.println("Usage: java Ping [port] host...");
	    return;
	}
	int firstArg = 0;

        // If the first argument is a string of digits then we take that
        // to be the port number to use
        if (Pattern.matches("[0-9]+", args[0])) {
            port = Integer.parseInt(args[0]);
            firstArg = 1;
        }
	// If the first argument is a string of digits then we take that
	// to be the port number to use
	if (Pattern.matches("[0-9]+", args[0])) {
	    port = Integer.parseInt(args[0]);
	    firstArg = 1;
	}

        // Create the threads and start them up
        Printer printer = new Printer();
        printer.start();
        Connector connector = new Connector(printer);
        connector.start();
	// Create the threads and start them up
	Printer printer = new Printer();
	printer.start();
	Connector connector = new Connector(printer);
	connector.start();

        // Create the targets and add them to the connector
        LinkedList targets = new LinkedList();
        for (int i = firstArg; i < args.length; i++) {
            Target t = new Target(args[i]);
            targets.add(t);
            connector.add(t);
        }
	// Create the targets and add them to the connector
	LinkedList targets = new LinkedList();
	for (int i = firstArg; i < args.length; i++) {
	    Target t = new Target(args[i]);
	    targets.add(t);
	    connector.add(t);
	}

        // Wait for everything to finish
        Thread.sleep(2000);
        connector.shutdown();
        connector.join();
	// Wait for everything to finish
	Thread.sleep(2000);
	connector.shutdown();
	connector.join();

        // Print status of targets that have not yet been shown
        for (Iterator i = targets.iterator(); i.hasNext();) {
            Target t = (Target)i.next();
            if (!t.shown)
                t.show();
        }
	// Print status of targets that have not yet been shown
	for (Iterator i = targets.iterator(); i.hasNext();) {
	    Target t = (Target)i.next();
	    if (!t.shown)
		t.show();
	}

    }

}