DispatcherN.java

/*
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 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
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/*
 * This source code is provided to illustrate the usage of a given feature
 * or technique and has been deliberately simplified. Additional steps
 * required for a production-quality application, such as security checks,
 * input validation and proper error handling, might not be present in
 * this sample code.
 */


import java.io.*;
import java.nio.channels.*;
import java.util.*;

/**
 * A Multi-threaded dispatcher.
 * <P>
 * In this example, one thread does accepts, and the second
 * does read/writes.
 *
 * @author Mark Reinhold
 * @author Brad R. Wetmore
 */
class DispatcherN implements Dispatcher {

    private Selector sel;

    DispatcherN() throws IOException {
        sel = Selector.open();
    }

    public void run() {
        for (;;) {
            try {
                dispatch();
            } catch (IOException x) {
                x.printStackTrace();
            }
        }
    }

    private Object gate = new Object();

    private void dispatch() throws IOException {
        sel.select();
        for (Iterator i = sel.selectedKeys().iterator(); i.hasNext(); ) {
            SelectionKey sk = (SelectionKey)i.next();
            i.remove();
            Handler h = (Handler)sk.attachment();
            h.handle(sk);
        }
        synchronized (gate) { }
    }

    public void register(SelectableChannel ch, int ops, Handler h)
            throws IOException {
        synchronized (gate) {
            sel.wakeup();
            ch.register(sel, ops, h);
        }
    }

}