/*

 * Copyright (c) 2001, 2006, 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

 * @summary The FileChannel file locking

 */

import java.io.*;

import java.nio.channels.*;

/**

 * Testing FileChannel's lock method.

 */

public class Lock {

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

        if (args.length > 0) {

            if(args[0].equals("1")) {

                MadWriter mw = new MadWriter(args[1], false);

            } else {

                MadWriter mw = new MadWriter(args[1], true);

            }

            return;

        }

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

        blah.deleteOnExit();

        RandomAccessFile raf = new RandomAccessFile(blah, "rw");

        raf.write(1);

        raf.close();

        test1(blah, "1");

        test1(blah, "2");

        test2(blah, true);

        test2(blah, false);

        test3(blah);

        blah.delete();

    }

    private static void test2(File blah, boolean b) throws Exception {

        RandomAccessFile raf = new RandomAccessFile(blah, "rw");

        FileChannel channel = raf.getChannel();

        FileLock lock;

        if (b)

            lock = channel.lock();

        else

            lock = channel.tryLock();

        lock.release();

        channel.close();

    }

    static void test1(File blah, String str) throws Exception {

        // Grab the lock

        RandomAccessFile fis = new RandomAccessFile(blah, "rw");

        FileChannel fc = fis.getChannel();

        FileLock lock = null;

        if (str.equals("1")) {

            lock = fc.lock(0, 10, false);

            if (lock == null)

                throw new RuntimeException("Lock should not return null");

            try {

                FileLock lock2 = fc.lock(5, 10, false);

                throw new RuntimeException("Overlapping locks allowed");

            } catch (OverlappingFileLockException e) {

                // Correct result

            }

        }

        // Exec the tamperer

        String command = System.getProperty("java.home") +

            File.separator + "bin" + File.separator + "java";

        String testClasses = System.getProperty("test.classes");

        if (testClasses != null)

            command += " -cp " + testClasses;

        command += " Lock " + str + " " + blah;

        Process p = Runtime.getRuntime().exec(command);

        BufferedReader in = new BufferedReader

            (new InputStreamReader(p.getInputStream()));

        String s;

        int count = 0;

        while ((s = in.readLine()) != null) {

            if (!s.equals("good")) {

                if (File.separatorChar == '/') {

                    // Fails on windows over NFS...

                    throw new RuntimeException("Failed: "+s);

                }

            }

            count++;

        }

        if (count == 0) {

            in = new BufferedReader(new InputStreamReader(p.getErrorStream()));

            while ((s = in.readLine()) != null) {

                System.err.println("Error output: " + s);

            }

            throw new RuntimeException("Failed, no output");

        }

        // Clean up

        if (lock != null) {

            /* Check multiple releases */

            lock.release();

            lock.release();

        }

        fc.close();

        fis.close();

    }

    // The overlap check for file locks should be JVM-wide

    private static void test3(File blah) throws Exception {

        FileChannel fc1 = new RandomAccessFile(blah, "rw").getChannel();

        FileChannel fc2 = new RandomAccessFile(blah, "rw").getChannel();

        // lock via one channel, and then attempt to lock the same file

        // using a second channel

        FileLock fl1 = fc1.lock();

        try {

            fc2.tryLock();

            throw new RuntimeException("Overlapping locks allowed");

        } catch (OverlappingFileLockException x) {

        }

        try {

            fc2.lock();

            throw new RuntimeException("Overlapping locks allowed");

        } catch (OverlappingFileLockException x) {

        }

        // release lock and the attempt to lock with the second channel

        // should succeed.

        fl1.release();

        FileLock fl2 = fc2.lock();

        try {

            fc1.lock();

            throw new RuntimeException("Overlapping locks allowed");

        } catch (OverlappingFileLockException x) {

        }

        fc1.close();

        fc2.close();

    }

}

class MadWriter {

    public MadWriter(String s, boolean b) throws Exception {

        File f = new File(s);

        RandomAccessFile fos = new RandomAccessFile(f, "rw");

        FileChannel fc = fos.getChannel();

        if (fc.tryLock(10, 10, false) == null) {

            System.out.println("bad: Failed to grab adjacent lock");

        }

        FileLock lock = fc.tryLock(0, 10, false);

        if (lock == null) {

            if (b)

                System.out.println("bad");

            else

                System.out.println("good");

        } else {

            if (b)

                System.out.println("good");

            else

                System.out.println("bad");

        }

        fc.close();

        fos.close();

    }

}