/*

 * Copyright (c) 2016, 2018, Red Hat, Inc. All rights reserved.

 *

 * 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 TestAllocHumongousFragment

 * @summary Make sure Shenandoah can recover from humongous allocation fragmentation

 * @key gc

 * @requires vm.gc.Shenandoah & !vm.graal.enabled

 *

 *

 * @run main/othervm -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -Xms1g -XX:ShenandoahTargetNumRegions=2048 -XX:ShenandoahGCHeuristics=aggressive -XX:+ShenandoahOOMDuringEvacALot -XX:+ShenandoahVerify TestAllocHumongousFragment

 * @run main/othervm -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -Xms1g -XX:ShenandoahTargetNumRegions=2048 -XX:ShenandoahGCHeuristics=aggressive -XX:+ShenandoahAllocFailureALot  -XX:+ShenandoahVerify TestAllocHumongousFragment

 * @run main/othervm -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -Xms1g -XX:ShenandoahTargetNumRegions=2048 -XX:ShenandoahGCHeuristics=aggressive -XX:+ShenandoahOOMDuringEvacALot                       TestAllocHumongousFragment

 * @run main/othervm -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -Xms1g -XX:ShenandoahTargetNumRegions=2048 -XX:ShenandoahGCHeuristics=aggressive -XX:+ShenandoahAllocFailureALot                        TestAllocHumongousFragment

 *

 * @run main/othervm -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -Xms1g -XX:ShenandoahTargetNumRegions=2048 -XX:ShenandoahGCHeuristics=adaptive     -XX:+ShenandoahVerify TestAllocHumongousFragment

 *

 * @run main/othervm -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -Xms1g -XX:ShenandoahTargetNumRegions=2048 -XX:ShenandoahGCHeuristics=adaptive     TestAllocHumongousFragment

 * @run main/othervm -Xlog:gc -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -Xms1g -XX:ShenandoahTargetNumRegions=2048 -XX:ShenandoahGCHeuristics=static       TestAllocHumongousFragment

 */

import java.util.*;

import java.util.concurrent.*;

public class TestAllocHumongousFragment {

    static final long TARGET_MB = Long.getLong("target", 30_000); // 30 Gb allocations

    static final long LIVE_MB   = Long.getLong("occupancy", 700); // 700 Mb alive

    static volatile Object sink;

    static List<int[]> objects;

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

        final int min = 128 * 1024;

        final int max = 16 * 1024 * 1024;

        final long count = TARGET_MB * 1024 * 1024 / (16 + 4 * (min + (max - min) / 2));

        objects = new ArrayList<>();

        long current = 0;

        Random r = new Random();

        for (long c = 0; c < count; c++) {

            while (current > LIVE_MB * 1024 * 1024) {

                int idx = ThreadLocalRandom.current().nextInt(objects.size());

                int[] remove = objects.remove(idx);

                current -= remove.length * 4 + 16;

            }

            int[] newObj = new int[min + r.nextInt(max - min)];

            current += newObj.length * 4 + 16;

            objects.add(newObj);

            sink = new Object();

            System.out.println("Allocated: " + (current / 1024 / 1024) + " Mb");

        }

    }

}