/*

 * 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

 * or visit www.oracle.com if you need additional information or have any

 * questions.

 */

/* @test

 * @summary Unit test for AsynchronousSocketChannel

 */

import java.nio.ByteBuffer;

import java.nio.channels.*;

import java.net.*;

import java.util.List;

import java.util.concurrent.Future;

import java.util.concurrent.ThreadFactory;

import java.lang.management.BufferPoolMXBean;

import java.lang.management.ManagementFactory;

/**

 * Heap buffers must be substituted with direct buffers when doing I/O. This

 * test creates a scenario on Windows that challenges the per-thread buffer

 * cache and quickly leads to an OutOfMemoryError if temporary buffers are

 * not returned to the native heap.

 */

public class Leaky {

    static final int K = 1024;

    static class Connection {

        private final AsynchronousSocketChannel client;

        private final SocketChannel peer;

        private final ByteBuffer dst;

        private Future<Integer> readResult;

        Connection(AsynchronousChannelGroup group) throws Exception {

            ServerSocketChannel ssc =

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

            InetAddress lh = InetAddress.getLocalHost();

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

            SocketAddress remote = new InetSocketAddress(lh, port);

            client = AsynchronousSocketChannel.open(group);

            client.connect(remote).get();

            peer = ssc.accept();

            ssc.close();

            dst = ByteBuffer.allocate(K*K);

        }

        void startRead() {

            dst.clear();

            readResult = client.read(dst);

        }

        void write() throws Exception {

            peer.write(ByteBuffer.wrap("X".getBytes()));

        }

        void finishRead() throws Exception {

            readResult.get();

        }

    }

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

        ThreadFactory threadFactory = new ThreadFactory() {

            @Override

            public Thread newThread(Runnable r) {

                Thread t = new Thread(r);

                t.setDaemon(true);

                return t;

            }

        };

        AsynchronousChannelGroup group =

            AsynchronousChannelGroup.withFixedThreadPool(4, threadFactory);

        final int CONNECTION_COUNT = 10;

        Connection[] connections = new Connection[CONNECTION_COUNT];

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

            connections[i] = new Connection(group);

        }

        for (int i=0; i<1024; i++) {

            // initiate reads

            for (Connection conn: connections) {

                conn.startRead();

            }

            // write data so that the read can complete

            for (Connection conn: connections) {

                conn.write();

            }

            // complete read

            for (Connection conn: connections) {

                conn.finishRead();

            }

        }

        // print summary of buffer pool usage

        List<BufferPoolMXBean> pools =

            ManagementFactory.getPlatformMXBeans(BufferPoolMXBean.class);

        for (BufferPoolMXBean pool: pools)

            System.out.format("         %8s             ", pool.getName());

        System.out.println();

        for (int i=0; i<pools.size(); i++)

            System.out.format("%6s %10s %10s  ",  "Count", "Capacity", "Memory");

        System.out.println();

        for (BufferPoolMXBean pool: pools) {

            System.out.format("%6d %10d %10d  ",

                pool.getCount(), pool.getTotalCapacity(), pool.getMemoryUsed());

        }

        System.out.println();

    }

}