/*

 * Copyright (c) 2012, 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

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 * questions.

 */

/*

 * @test Humongous.java

 * @bug 7168848

 * @summary G1: humongous object allocations should initiate marking cycles when necessary

 * @run main/othervm -Xms100m -Xmx100m -XX:+PrintGC -XX:G1HeapRegionSize=1m -XX:+UseG1GC  HumongousAlloc

 *

 */

import java.lang.management.GarbageCollectorMXBean;

import java.lang.management.ManagementFactory;

import java.util.List;

public class HumongousAlloc {

    public static byte[] dummy;

    private static int sleepFreq = 40;

    private static int sleepTime = 1000;

    private static double size = 0.75;

    private static int iterations = 50;

    private static int MB = 1024 * 1024;

    public static void allocate(int size, int sleepTime, int sleepFreq) throws InterruptedException {

        System.out.println("Will allocate objects of size: " + size

                + " bytes and sleep for " + sleepTime

                + " ms after every " + sleepFreq + "th allocation.");

        int count = 0;

        while (count < iterations) {

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

                dummy = new byte[size - 16];

            }

            Thread.sleep(sleepTime);

            count++;

        }

    }

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

        allocate((int) (size * MB), sleepTime, sleepFreq);

        List<GarbageCollectorMXBean> collectors = ManagementFactory.getGarbageCollectorMXBeans();

        for (GarbageCollectorMXBean collector : collectors) {

            if (collector.getName().contains("G1 Old")) {

               long count = collector.getCollectionCount();

                if (count > 0) {

                    throw new RuntimeException("Failed: FullGCs should not have happened. The number of FullGC run is " + count);

                }

                else {

                    System.out.println("Passed.");

                }

            }

        }

    }

}