1 /*
   2  * Copyright (c) 2017, 2018, Red Hat, Inc. All rights reserved.
   3  *
   4  * This code is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 only, as
   6  * published by the Free Software Foundation.
   7  *
   8  * This code is distributed in the hope that it will be useful, but WITHOUT
   9  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  10  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  11  * version 2 for more details (a copy is included in the LICENSE file that
  12  * accompanied this code).
  13  *
  14  * You should have received a copy of the GNU General Public License version
  15  * 2 along with this work; if not, write to the Free Software Foundation,
  16  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  17  *
  18  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  19  * or visit www.oracle.com if you need additional information or have any
  20  * questions.
  21  *
  22  */
  23 
  24 /*
  25  * @test TestHumongousThreshold
  26  * @key gc
  27  *
  28  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g                                      -XX:+ShenandoahVerify TestHumongousThreshold
  29  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -XX:ShenandoahHumongousThreshold=50  -XX:+ShenandoahVerify TestHumongousThreshold
  30  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -XX:ShenandoahHumongousThreshold=90  -XX:+ShenandoahVerify TestHumongousThreshold
  31  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -XX:ShenandoahHumongousThreshold=99  -XX:+ShenandoahVerify TestHumongousThreshold
  32  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -XX:ShenandoahHumongousThreshold=100 -XX:+ShenandoahVerify TestHumongousThreshold
  33  *
  34  * @run main/othervm -XX:+UnlockDiagnosticVMOptions -XX:+UnlockExperimentalVMOptions -XX:+UseShenandoahGC -Xmx1g -XX:ShenandoahHumongousThreshold=90  -XX:ShenandoahGCHeuristics=aggressive TestHumongousThreshold
  35  */
  36 
  37 import java.util.Random;
  38 
  39 public class TestHumongousThreshold {
  40 
  41     static final long TARGET_MB = Long.getLong("target", 20_000); // 20 Gb allocation
  42 
  43     static volatile Object sink;
  44 
  45     public static void main(String[] args) throws Exception {
  46         final int min = 0;
  47         final int max = 384 * 1024;
  48         long count = TARGET_MB * 1024 * 1024 / (16 + 4 * (min + (max - min) / 2));
  49 
  50         Random r = new Random();
  51         for (long c = 0; c < count; c++) {
  52             sink = new int[min + r.nextInt(max - min)];
  53         }
  54     }
  55 
  56 }