/*

 * Copyright (c) 2009, 2010, 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

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

 * questions.

 */

/* @test

 * @bug 6543863 6842687

 * @summary Try to cause a deadlock between (Asynchronous)FileChannel.close

 *   and FileLock.release

 */

import java.io.*;

import java.nio.file.Path;

import static java.nio.file.StandardOpenOption.*;

import java.nio.channels.*;

import java.util.concurrent.*;

public class ReleaseOnCloseDeadlock {

    private static final int LOCK_COUNT = 1024;

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

        File blah = File.createTempFile("blah", null);

        blah.deleteOnExit();

        try {

            for (int i=0; i<100; i++) {

                test(blah.toPath());

            }

        } finally {

            blah.delete();

        }

    }

    static void test(Path file) throws IOException {

        FileLock[] locks = new FileLock[LOCK_COUNT];

        FileChannel fc = FileChannel.open(file, READ, WRITE);

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

            locks[i] = fc.lock(i, 1, true);

        }

        tryToDeadlock(fc, locks);

        AsynchronousFileChannel ch = AsynchronousFileChannel.open(file, READ, WRITE);

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

            try {

                locks[i] = ch.lock(i, 1, true).get();

            } catch (InterruptedException x) {

                throw new RuntimeException(x);

            } catch (ExecutionException x) {

                throw new RuntimeException(x);

            }

        }

        tryToDeadlock(ch, locks);

    }

    static void tryToDeadlock(final Channel channel, FileLock[] locks)

        throws IOException

    {

        // start thread to close the file (and invalidate the locks)

        Thread closer = new Thread(

            new Runnable() {

                public void run() {

                    try {

                        channel.close();

                    } catch (IOException ignore) {

                        ignore.printStackTrace();

                    }

                }});

        closer.start();

        // release the locks explicitly

        for (int i=0; i<locks.length; i++) {

            try {

                locks[i].release();

            } catch (ClosedChannelException ignore) { }

        }

        // we are done when closer has terminated

        while (closer.isAlive()) {

            try {

                closer.join();

            } catch (InterruptedException ignore) { }

        }

    }

}