/*

 * 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.

 *

 */

/* @test

 * @bug 4607272 6842687

 * @summary Unit test for AsynchronousChannelGroup

 */

import java.nio.ByteBuffer;

import java.nio.channels.*;

import java.net.*;

import java.util.*;

import java.util.concurrent.*;

import java.util.concurrent.atomic.*;

/**

 * Tests that the completion handler is invoked by a thread with

 * the expected identity.

 */

public class Identity {

    static final Random rand = new Random();

    static final CountDownLatch done = new CountDownLatch(1);

    static final AtomicBoolean failed = new AtomicBoolean(false);

    static void fail(String msg) {

        failed.set(true);

        done.countDown();

        throw new RuntimeException(msg);

    }

    // thread-local identifies the thread

    private static final ThreadLocal<Integer> myGroup =

        new ThreadLocal<Integer>() {

            @Override protected Integer initialValue() {

                return Integer.valueOf(-1);

            }

        };

    // creates a ThreadFactory that constructs groups with the given identity

    static final ThreadFactory createThreadFactory(final int groupId) {

        return new ThreadFactory() {

            @Override

            public Thread newThread(final Runnable r) {

                Thread t = new Thread(new Runnable() {

                    public void run() {

                        myGroup.set(groupId);

                        r.run();

                    }});

                t.setDaemon(true);

                return t;

            }

        };

    }

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

        // create listener to accept connections

        final AsynchronousServerSocketChannel listener =

            AsynchronousServerSocketChannel.open()

                .bind(new InetSocketAddress(0));

        listener.accept((Void)null, new CompletionHandler<AsynchronousSocketChannel,Void>() {

            public void completed(final AsynchronousSocketChannel ch, Void att) {

                listener.accept((Void)null, this);

                final ByteBuffer buf = ByteBuffer.allocate(100);

                ch.read(buf, (Void)null, new CompletionHandler<Integer,Void>() {

                    public void completed(Integer bytesRead, Void att) {

                        buf.clear();

                        ch.read(buf, (Void)null, this);

                    }

                    public void failed(Throwable exc, Void att) {

                    }

                });

            }

            public void failed(Throwable exc, Void att) {

            }

        });

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

        SocketAddress sa = new InetSocketAddress(InetAddress.getLocalHost(), port);

        // create 3-10 channels, each in its own group

        final int groupCount = 3 + rand.nextInt(8);

        final AsynchronousSocketChannel[] channel = new AsynchronousSocketChannel[groupCount];

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

            ThreadFactory factory = createThreadFactory(i);

            AsynchronousChannelGroup group;

            if (rand.nextBoolean()) {

                int nThreads = 1 + rand.nextInt(10);

                group = AsynchronousChannelGroup.withFixedThreadPool(nThreads, factory);

            } else {

                ExecutorService pool = Executors.newCachedThreadPool(factory);

                group = AsynchronousChannelGroup.withCachedThreadPool(pool, rand.nextInt(5));

            }

            // create channel in group and connect it to the server

            AsynchronousSocketChannel ch = AsynchronousSocketChannel.open(group);

            ch.connect(sa).get();

            channel[i] = ch;

        }

        // randomly write to each channel, ensuring that the completion handler

        // is always invoked by a thread with the right identity.

        final AtomicInteger writeCount = new AtomicInteger(100);

        channel[0].write(getBuffer(), 0, new CompletionHandler<Integer,Integer>() {

            public void completed(Integer bytesWritten, Integer groupId) {

                if (bytesWritten != 1)

                    fail("Expected 1 byte to be written");

                if (!myGroup.get().equals(groupId))

                    fail("Handler invoked by thread with the wrong identity");

                if (writeCount.decrementAndGet() > 0) {

                    int id = rand.nextInt(groupCount);

                    channel[id].write(getBuffer(), id, this);

                } else {

                    done.countDown();

                }

            }

            public void failed(Throwable exc, Integer groupId) {

                fail(exc.getMessage());

            }

        });

        // wait until

        done.await();

        if (failed.get())

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

    }

    static ByteBuffer getBuffer() {

        ByteBuffer buf;

        if (rand.nextBoolean()) {

            buf = ByteBuffer.allocateDirect(1);

        } else {

            buf = ByteBuffer.allocate(1);

        }

        buf.put((byte)0);

        buf.flip();

        return buf;

    }

}