/*

 * 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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 */

/* @test

 * @bug 4625907

 * @summary Testing force()

 * @run main/othervm Force

 */

import java.io.*;

import java.nio.*;

import java.util.*;

import java.nio.channels.*;

public class Force {

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

        Random random = new Random();

        long filesize = random.nextInt(3*1024*1024);

        int cut = random.nextInt((int)filesize);

        File file = File.createTempFile("Blah", null);

        file.deleteOnExit();

        try (RandomAccessFile raf = new RandomAccessFile(file, "rw")) {

            raf.setLength(filesize);

            FileChannel fc = raf.getChannel();

            MappedByteBuffer mbb = fc.map(FileChannel.MapMode.READ_WRITE, cut, filesize-cut);

            mbb.force();

        }

        // improve chance that mapped buffer will be unmapped

        System.gc();

        Thread.sleep(500);

    }

}