/*

 * Copyright (c) 2008, 2009, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 * questions.

 */

/* @test

 * @bug 4607272 6842687

 * @summary Unit test for AsynchronousChannelGroup

 * @build Restart

 * @run main/othervm -XX:-UseVMInterruptibleIO Restart

 */

import java.nio.channels.*;

import java.net.*;

import java.util.*;

import java.util.concurrent.*;

import java.util.concurrent.atomic.*;

import java.io.IOException;

/**

 * Exercise replacement of threads in the thread pool when completion handlers

 * terminate due to errors or runtime exceptions.

 */

public class Restart {

    static final Random rand = new Random();

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

        // thread group for thread pools

        final ThreadGroup tg = new ThreadGroup("test");

        // keep track of the number of threads that terminate

        final AtomicInteger exceptionCount = new AtomicInteger(0);

        final Thread.UncaughtExceptionHandler ueh =

            new Thread.UncaughtExceptionHandler() {

                public void uncaughtException(Thread t, Throwable e) {

                    exceptionCount.incrementAndGet();

                }

            };

        ThreadFactory factory = new ThreadFactory() {

            @Override

            public Thread newThread(Runnable r) {

                Thread t = new Thread(tg, r);

                t.setUncaughtExceptionHandler(ueh);

                return t;

            }

        };

        // group with fixed thread pool

        int nThreads = 1 + rand.nextInt(4);

        AsynchronousChannelGroup group =

            AsynchronousChannelGroup.withFixedThreadPool(nThreads, factory);

        testRestart(group, 100);

        group.shutdown();

        // group with custom thread pool

        ExecutorService pool = Executors.newCachedThreadPool(factory);

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

        testRestart(group, 100);

        group.shutdown();

        // give time for threads to terminate

        Thread.sleep(3000);

        int actual = exceptionCount.get();

        if (actual != 200)

            throw new RuntimeException(actual + " exceptions, expected: " + 200);

    }

    static void testRestart(AsynchronousChannelGroup group, int count)

        throws Exception

    {

        AsynchronousServerSocketChannel listener =

            AsynchronousServerSocketChannel.open(group)

                .bind(new InetSocketAddress(0));

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

            final CountDownLatch latch = new CountDownLatch(1);

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

                public void completed(AsynchronousSocketChannel ch, Void att) {

                    try {

                        ch.close();

                    } catch (IOException ignore) { }

                    latch.countDown();

                    // throw error or runtime exception

                    if (rand.nextBoolean()) {

                        throw new Error();

                    } else {

                        throw new RuntimeException();

                    }

                }

                public void failed(Throwable exc, Void att) {

                }

            });

            // establish loopback connection which should cause completion

            // handler to be invoked.

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

            AsynchronousSocketChannel ch = AsynchronousSocketChannel.open();

            InetAddress lh = InetAddress.getLocalHost();

            ch.connect(new InetSocketAddress(lh, port)).get();

            ch.close();

            // wait for handler to be invoked

            latch.await();

        }

        // clean-up

        listener.close();

    }

}