TriggerResize.java

/*
 * Copyright (c) 2017, 2021, 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.
 */

import java.lang.ClassLoader;

public class TriggerResize extends ClassLoader
{
  static private int[] DATA = // bytes for "class TestCase00000 {}"
  {
    -54,    -2,   -70,   -66,     0,     0,     0,    52,    0,     13, //   0
     10,     0,     3,     0,    10,     7,     0,    11,    7,      0, //  10
     12,     1,     0,     6,    60,   105,   110,   105,  116,     62, //  20
      1,     0,     3,    40,    41,    86,     1,     0,     4,    67, //  30
    111,   100,   101,     1,     0,    15,    76,   105,   110,   101, //  40
     78,   117,   109,    98,   101,   114,    84,    97,    98,   108, //  50
    101,     1,     0,    10,    83,   111,   117,   114,    99,   101, //  60
     70,   105,   108,   101,     1,     0,    18,    84,   101,   115, //  70
    116,    67,    97,   115,   101,    48,    48,    48,    48,    48, //  80
     46,   106,    97,   118,    97,    12,     0,     4,     0,     5, //  90
      1,     0,    13,    84,   101,   115,   116,    67,    97,   115, // 100
    101,    48,    48,    48,    48,    48,     1,     0,    16,   106, // 110
     97,   118,    97,    47,   108,    97,   110,   103,    47,    79, // 120
     98,   106,   101,    99,   116,     0,    32,     0,     2,     0, // 130
      3,     0,     0,     0,     0,     0,     1,     0,     0,     0, // 140
      4,     0,     5,     0,     1,     0,     6,     0,     0,     0, // 150
     29,     0,     1,     0,     1,     0,     0,     0,     5,    42, // 160
    -73,     0,     1,   -79,     0,     0,     0,     1,     0,     7, // 170
      0,     0,     0,     6,     0,     1,     0,     0,     0,     1, // 180
      0,     1,     0,     8,     0,     0,     0,     2,     0,     9  // 190
  };

  static private int INDEX1 = 85;
  static private int INDEX2 = 111;
  static private int BASE = 48;

  public TriggerResize()
  {
    super();
  }

  public void load(int index)
  {
    byte[] bytes = new byte[TriggerResize.DATA.length];
    for (int i=0; i<bytes.length; i++)
    {
      bytes[i] = (byte)TriggerResize.DATA[i];
    }

    // replace id "00000" in TestCase00000 to generate new class on the fly
    {
      int byte1 = index % 10;
      int byte2 = index / 10 % 10;
      int byte3 = index / 100 % 10;
      int byte4 = index / 1000 % 10;
      int byte5 = index / 10000 % 10;

      bytes[INDEX1+0] = bytes[INDEX2+0] = (byte)(BASE+byte5);
      bytes[INDEX1+1] = bytes[INDEX2+1] = (byte)(BASE+byte4);
      bytes[INDEX1+2] = bytes[INDEX2+2] = (byte)(BASE+byte3);
      bytes[INDEX1+3] = bytes[INDEX2+3] = (byte)(BASE+byte2);
      bytes[INDEX1+4] = bytes[INDEX2+4] = (byte)(BASE+byte1);
    }

    Class generatedClass = defineClass(bytes, 0, bytes.length);
    resolveClass(generatedClass);
  }

  public static void main(String args[]) throws Exception
  {
    int count = 0;
    if (args.length >= 1) {
      Integer i = Integer.parseInt(args[0]);
      count = i.intValue();
    }

    TriggerResize test = new TriggerResize();
    for (int i = 0; i <= count; i++)
    {
      test.load(i);
    }

    // trigger safepoint to resize the SystemDictionary if needed
    System.gc();
  }
}