/*

 * Copyright (c) 2018, 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.

 */

package nsk.stress.jni;

class GarbageGenerator extends Thread {

    class Garbage {

        Garbage() {

            this(1024);

        }

        Garbage(int m) {

            memory = new byte[m];

        }

        void setNext(Garbage n) {

            next = n;

        }

        Garbage getNext() {

            return next;

        }

        protected void finalize() {

        }

        private Garbage next;

        private byte[] memory;

    }

    class GarbageRing {

        GarbageRing() {

            attachment = new Garbage(0);

        }

        void add(int size) {

            Garbage head = attachment.getNext();

            Garbage g = new Garbage(size);

            if (head != null) {

                Garbage oldNext = head.getNext();

                if (oldNext != null) {

                    g.setNext(oldNext);

                    head.setNext(g);

                    attachment.setNext(g);

                } else {

                    g.setNext(head);

                    head.setNext(g);

                }

            } else

                attachment.setNext(g);

        }

        void discard() {

            attachment.setNext(null);

        }

        private byte[] memory;

        private Garbage attachment;

    }

    public void run() {

        GarbageRing gr = new GarbageRing();

        int g = 0;

        while (!done) {

            for (g = 0; g < ringSize; g++) {

                gr.add(allocSize);

            }

            gr.discard();

            try {

                sleep(interval);

            } catch (InterruptedException e) {

            }

        }

        if (DEBUG) System.out.println("GarbageRing::run(): done");

    }

    public void setAllocSize(int i) {

        allocSize = i;

    }

    public int getAllocSize() {

        return allocSize;

    }

    public void setInterval(int i) {

        interval = i;

    }

    public int getInterval() {

        return interval;

    }

    public void halt() {

        done = true;

    }

    private int allocSize = 10000;

    private int ringSize = 50;

    private int interval = 1000;

    private boolean done = false;

    final private static boolean DEBUG = false;

}