1 /*
   2  * Copyright (c) 2017, 2018, Red Hat, Inc. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  */
  23 
  24 /**
  25  * @test TestElasticTLABDecay
  26  * @key gc
  27  * @requires vm.gc.Epsilon
  28  * @summary Epsilon is able to work with/without elastic TLABs
  29  *
  30  * @run main/othervm -Xmx1g -XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC -XX:+EpsilonElasticTLAB -XX:-EpsilonElasticTLABDecay                               TestElasticTLABDecay
  31  * @run main/othervm -Xmx1g -XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC -XX:+EpsilonElasticTLAB -XX:+EpsilonElasticTLABDecay -XX:EpsilonTLABDecayTime=1    TestElasticTLABDecay
  32  * @run main/othervm -Xmx1g -XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC -XX:+EpsilonElasticTLAB -XX:+EpsilonElasticTLABDecay -XX:EpsilonTLABDecayTime=100  TestElasticTLABDecay
  33  */
  34 
  35 import java.util.Random;
  36 
  37 public class TestElasticTLABDecay {
  38 
  39   static long SEED = Long.getLong("seed", System.nanoTime());
  40   static int COUNT = Integer.getInteger("count", 3000); // ~500 MB allocation
  41 
  42   static byte[][] arr;
  43 
  44   public static void main(String[] args) throws Exception {
  45     Random r = new Random(SEED);
  46 
  47     arr = new byte[COUNT * 100][];
  48     for (int c = 0; c < COUNT; c++) {
  49       arr[c] = new byte[c * 100];
  50       for (int v = 0; v < c; v++) {
  51         arr[c][v] = (byte)(r.nextInt(255) & 0xFF);
  52       }
  53       Thread.sleep(5);
  54     }
  55 
  56     r = new Random(SEED);
  57     for (int c = 0; c < COUNT; c++) {
  58       byte[] b = arr[c];
  59       if (b.length != (c * 100)) {
  60         throw new IllegalStateException("Failure: length = " + b.length + ", need = " + (c*100));
  61       }
  62       for (int v = 0; v < c; v++) {
  63         byte actual = b[v];
  64         byte expected = (byte)(r.nextInt(255) & 0xFF);
  65         if (actual != expected) {
  66           throw new IllegalStateException("Failure: expected = " + expected + ", actual = " + actual);
  67         }
  68       }
  69     }
  70   }
  71 }