/*
 * Copyright (c) 2017, 2018, Red Hat, Inc. 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.
 *
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/**
 * @test TestElasticTLAB
 * @key gc
 * @requires vm.gc.Epsilon
 * @summary Epsilon is able to work with/without elastic TLABs
 *
 * @run main/othervm -Xmx1g -XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC -XX:-EpsilonElasticTLAB                               TestElasticTLAB
 * @run main/othervm -Xmx1g -XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC -XX:+EpsilonElasticTLAB -XX:EpsilonTLABElasticity=1   TestElasticTLAB
 * @run main/othervm -Xmx1g -XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC -XX:+EpsilonElasticTLAB -XX:EpsilonTLABElasticity=1.1 TestElasticTLAB
 * @run main/othervm -Xmx1g -XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC -XX:+EpsilonElasticTLAB -XX:EpsilonTLABElasticity=2.0 TestElasticTLAB
 * @run main/othervm -Xmx1g -XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC -XX:+EpsilonElasticTLAB -XX:EpsilonTLABElasticity=42  TestElasticTLAB
 * @run main/othervm -Xmx1g -XX:+UnlockExperimentalVMOptions -XX:+UseEpsilonGC -XX:+EpsilonElasticTLAB -XX:EpsilonTLABElasticity=100 TestElasticTLAB
 */

import java.util.Random;

public class TestElasticTLAB {

  static long SEED = Long.getLong("seed", System.nanoTime());
  static int COUNT = Integer.getInteger("count", 3000); // ~500 MB allocation

  static byte[][] arr;

  public static void main(String[] args) throws Exception {
    Random r = new Random(SEED);

    arr = new byte[COUNT * 100][];
    for (int c = 0; c < COUNT; c++) {
      arr[c] = new byte[c * 100];
      for (int v = 0; v < c; v++) {
        arr[c][v] = (byte)(r.nextInt(255) & 0xFF);
      }
    }

    r = new Random(SEED);
    for (int c = 0; c < COUNT; c++) {
      byte[] b = arr[c];
      if (b.length != (c * 100)) {
        throw new IllegalStateException("Failure: length = " + b.length + ", need = " + (c*100));
      }
      for (int v = 0; v < c; v++) {
        byte actual = b[v];
        byte expected = (byte)(r.nextInt(255) & 0xFF);
        if (actual != expected) {
          throw new IllegalStateException("Failure: expected = " + expected + ", actual = " + actual);
        }
      }
    }
  }
}