1 /*
   2  * Copyright (c) 2016, 2018, Oracle and/or its affiliates. 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 /**
  26  * @test
  27  * @bug 8148175
  28  * @run main/othervm/timeout=300  -XX:+UseG1GC -Xbatch -Xmx128m PreserveFPRegistersTest
  29  */
  30 public class PreserveFPRegistersTest {
  31 
  32     public static void main(String... args) throws InterruptedException {
  33         new PreserveFPRegistersTest().go();
  34     }
  35 
  36     public final Object[][] storage;
  37 
  38     /**
  39      * Number of objects per region.
  40      */
  41     public final int K = 10;
  42 
  43     /**
  44      * Length of object array: sizeOf(Object[N]) ~= regionSize / K .
  45      */
  46     public final int N;
  47 
  48     /**
  49      * How many regions involved into testing.
  50      */
  51     public final int regionCount;
  52 
  53     PreserveFPRegistersTest() {
  54         long regionSize = 1_000_000; //WB.g1RegionSize();
  55 
  56         Runtime rt = Runtime.getRuntime();
  57         long used = rt.totalMemory() - rt.freeMemory();
  58         long totalFree = rt.maxMemory() - used;
  59         regionCount = (int) ( (totalFree / regionSize) * 0.9);
  60         int refSize = 4;
  61 
  62         N = (int) ((regionSize / K ) / refSize) - 5;
  63         storage = new Object[regionCount * K][];
  64         for (int i = 0; i < storage.length; i++) {
  65             storage[i] = new Object[N];
  66         }
  67     }
  68 
  69     public void go() throws InterruptedException {
  70         final float FINAL = getValue();
  71 
  72         for (int to = 0; to < regionCount; to++) {
  73             Object celebrity = storage[to * K];
  74             for (int from = 0; from < regionCount; from++) {
  75                 for (int rn = 0; rn != 100; rn++) {
  76                     storage[getY(to, from, rn)][getX(to, from, rn)] = celebrity;
  77                 }
  78                 if (FINAL != getValue()) {
  79                     throw new AssertionError("Final value has changed: " + FINAL + " != " + getValue());
  80                 }
  81             }
  82         }
  83 
  84         System.out.println("TEST PASSED");
  85     }
  86 
  87     public float getValue() {
  88         return 6;
  89     }
  90 
  91     private int getX(int to, int from, int rn) {
  92         return (rn*regionCount + to) % N;
  93     }
  94 
  95     private int getY(int to, int from, int rn) {
  96         return ((rn*regionCount + to) / N + from * K) % (regionCount*K) ;
  97     }
  98 }