/*

 * Copyright 2008-2009 Sun Microsystems, Inc.  All Rights Reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.

 *

 * This code 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

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

 * CA 95054 USA or visit www.sun.com if you need additional information or

 * have any questions.

 */

/* @test

 * @bug 6834246

 * @summary Stress test connections through the loopback interface

 */

import java.nio.ByteBuffer;

import java.net.*;

import java.nio.channels.*;

import java.util.Random;

import java.io.IOException;

public class StressLoopback {

    static final Random rand = new Random();

    public static void main(String[] args) throws Exception {

        // setup listener

        AsynchronousServerSocketChannel listener =

            AsynchronousServerSocketChannel.open().bind(new InetSocketAddress(0));

        int port =((InetSocketAddress)(listener.getLocalAddress())).getPort();

        InetAddress lh = InetAddress.getLocalHost();

        SocketAddress remote = new InetSocketAddress(lh, port);

        // create sources and sinks

        int count = 2 + rand.nextInt(9);

        Source[] source = new Source[count];

        Sink[] sink = new Sink[count];

        for (int i=0; i<count; i++) {

            AsynchronousSocketChannel ch = AsynchronousSocketChannel.open();

            ch.connect(remote).get();

            source[i] = new Source(ch);

            sink[i] = new Sink(listener.accept().get());

        }

        // start the sinks and sources

        for (int i=0; i<count; i++) {

            sink[i].start();

            source[i].start();

        }

        // let the test run for a while

        Thread.sleep(20*1000);

        // wait until everyone is done

        boolean failed = false;

        long total = 0L;

        for (int i=0; i<count; i++) {

            long nwrote = source[i].finish();

            long nread = sink[i].finish();

            if (nread != nwrote)

                failed = true;

            System.out.format("%d -> %d (%s)\n",

                nwrote, nread, (failed) ? "FAIL" : "PASS");

            total += nwrote;

        }

        if (failed)

            throw new RuntimeException("Test failed - see log for details");

        System.out.format("Total sent %d MB\n", total / (1024L * 1024L));

    }

    /**

     * Writes bytes to a channel until "done". When done the channel is closed.

     */

    static class Source {

        private final AsynchronousByteChannel channel;

        private final ByteBuffer sentBuffer;

        private volatile long bytesSent;

        private volatile boolean finished;

        Source(AsynchronousByteChannel channel) {

            this.channel = channel;

            int size = 1024 + rand.nextInt(10000);

            this.sentBuffer = (rand.nextBoolean()) ?

                ByteBuffer.allocateDirect(size) : ByteBuffer.allocate(size);

        }

        void start() {

            sentBuffer.position(0);

            sentBuffer.limit(sentBuffer.capacity());

                public void completed(Integer nwrote, Void att) {

                    bytesSent += nwrote;

                    if (finished) {

                        closeUnchecked(channel);

                    } else {

                        sentBuffer.position(0);

                        sentBuffer.limit(sentBuffer.capacity());

                    }

                }

                public void failed(Throwable exc, Void att) {

                    exc.printStackTrace();

                    closeUnchecked(channel);

                }

                public void cancelled(Void att) {

                }

            });

        }

        long finish() {

            finished = true;

            waitUntilClosed(channel);

            return bytesSent;

        }

    }

    /**

     * Read bytes from a channel until EOF is received.

     */

    static class Sink {

        private final AsynchronousByteChannel channel;

        private final ByteBuffer readBuffer;

        private volatile long bytesRead;

        Sink(AsynchronousByteChannel channel) {

            this.channel = channel;

            int size = 1024 + rand.nextInt(10000);

            this.readBuffer = (rand.nextBoolean()) ?

                ByteBuffer.allocateDirect(size) : ByteBuffer.allocate(size);

        }

        void start() {

                public void completed(Integer nread, Void att) {

                    if (nread < 0) {

                        closeUnchecked(channel);

                    } else {

                        bytesRead += nread;

                        readBuffer.clear();

                    }

                }

                public void failed(Throwable exc, Void att) {

                    exc.printStackTrace();

                    closeUnchecked(channel);

                }

                public void cancelled(Void att) {

                }

            });

        }

        long finish() {

            waitUntilClosed(channel);

            return bytesRead;

        }

    }

    static void waitUntilClosed(Channel c) {

        while (c.isOpen()) {

            try {

                Thread.sleep(100);

            } catch (InterruptedException ignore) { }

        }

    }

    static void closeUnchecked(Channel c) {

        try {

            c.close();

        } catch (IOException ignore) { }

    }

}