/*

 * 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.

 *

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 */

/* @test

 * @bug 4938372 6541641

 * @summary Flushing dirty pages prior to unmap can cause Cleaner thread to

 *          abort VM if memory system has pages locked

 * @run main/othervm ExpandingMap

 */

import java.io.File;

import java.io.RandomAccessFile;

import java.io.IOException;

import java.nio.ByteBuffer;

import java.nio.channels.FileChannel;

import java.util.ArrayList;

/**

 * Test case provided by submitter of 4938372.

 */

public class ExpandingMap {

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

        int initialSize = 20480*1024;

        int maximumMapSize = 16*1024*1024;

        int maximumFileSize = 300000000;

        File file = File.createTempFile("exp", "tmp");

        file.deleteOnExit();

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

        f.setLength(initialSize);

        FileChannel fc = f.getChannel();

        ByteBuffer[] buffers = new ByteBuffer[128];

        System.out.format("map %d -> %d\n", 0, initialSize);

        buffers[0] = fc.map(FileChannel.MapMode.READ_WRITE, 0, initialSize);

        int currentBuffer = 0;

        int currentSize = initialSize;

        int currentPosition = 0;

        ArrayList<String> junk = new ArrayList<String>();

        while (currentPosition+currentSize < maximumFileSize) {

            int inc = Math.max(1000*1024, (currentPosition+currentSize)/8);

            int size = currentPosition+currentSize+inc;

            f.setLength(size);

            while (currentSize+inc > maximumMapSize) {

                if (currentSize < maximumMapSize) {

                    System.out.format("map %d -> %d\n", currentPosition,

                        (currentPosition + maximumMapSize));

                    buffers[currentBuffer] = fc.map(FileChannel.MapMode.READ_WRITE,

                        currentPosition, maximumMapSize);

                    fillBuffer(buffers[currentBuffer], currentSize);

                }

                currentPosition += maximumMapSize;

                inc = currentSize+inc-maximumMapSize;

                currentSize = 0;

                currentBuffer++;

                if (currentBuffer == buffers.length) {

                    ByteBuffer[] old = buffers;

                    buffers = new ByteBuffer[currentBuffer+currentBuffer/2];

                    System.arraycopy(old, 0, buffers, 0, currentBuffer);                                        }

            }

            currentSize += inc;

            if (currentSize > 0) {

                System.out.format("map %d -> %d\n", currentPosition,

                    (currentPosition + currentSize));

                buffers[currentBuffer] = fc.map(FileChannel.MapMode.READ_WRITE,

                     currentPosition, currentSize);

                fillBuffer(buffers[currentBuffer], currentSize-inc);

            }

            // busy loop needed to reproduce issue

            long t = System.currentTimeMillis();

            while (System.currentTimeMillis() < t+500) {

                junk.add(String.valueOf(t));

                if (junk.size() > 100000) junk.clear();

            }

        }

        fc.close();

        // cleanup the ref to mapped buffers so they can be GCed

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

            buffers[i] = null;

        System.gc();

        // Take a nap to wait for the Cleaner to cleanup those unrefed maps

        Thread.sleep(1000);

        System.out.println("TEST PASSED");

    }

    static void fillBuffer(ByteBuffer buf, int from) {

        int limit = buf.limit();

        for (int i=from; i<limit; i++) {

            buf.put(i, (byte)i);

        }

    }

}