1 /*
   2  * Copyright (c) 2016, Red Hat, Inc. and/or its affiliates.
   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  * @test TestHumongous
  25  * @summary test reclaim of humongous object
  26  * @run main/othervm -Xint -XX:+UseShenandoahGC -XX:ShenandoahHeapRegionSize=1M TestHumongous
  27  */
  28 
  29 public class TestHumongous {
  30     // Shenandoah heap memory region size = 1 M
  31     private static int M = 1024 * 1024;
  32     public static void main(String[] args) {
  33         // Construct a humongous object (oop) just fits multiple regions
  34         // 8 bytes for object header, 8 bytes for brooks pointer
  35         int size = 2 * M  - 8 - 8;
  36         // The oop spans 2 regions
  37         char[] ch = new char[size];
  38         for (int index = 0; index < 10; index ++) {
  39             ch[index] = 'A';
  40         }
  41 
  42         System.out.print(ch[1]);
  43         ch = null;
  44         // Force a GC to clean up above object
  45         System.gc();
  46     }
  47 }
  48