1 /*
   2  * Copyright (c) 2013, 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 8023472
  28  * @summary C2 optimization breaks with G1
  29  *
  30  * @run main/othervm -Xbatch -XX:+IgnoreUnrecognizedVMOptions -XX:-TieredCompilation
  31  *      -Dcount=100000 compiler.gcbarriers.G1CrashTest
  32  *
  33  * @author pbiswal@palantir.com
  34  */
  35 
  36 package compiler.gcbarriers;
  37 
  38 public class G1CrashTest {
  39     static Object[] set = new Object[11];
  40 
  41     public static void main(String[] args) throws InterruptedException {
  42         for (int j = 0; j < Integer.getInteger("count"); j++) {
  43             Object key = new Object();
  44             insertKey(key);
  45             if (j > set.length / 2) {
  46                 Object[] oldKeys = set;
  47                 set = new Object[2 * set.length - 1];
  48                 for (Object o : oldKeys) {
  49                     if (o != null)
  50                         insertKey(o);
  51                 }
  52             }
  53         }
  54     }
  55 
  56     static void insertKey(Object key) {
  57         int hash = key.hashCode() & 0x7fffffff;
  58         int index = hash % set.length;
  59         Object cur = set[index];
  60         if (cur == null)
  61             set[index] = key;
  62         else
  63             insertKeyRehash(key, index, hash, cur);
  64     }
  65 
  66     static void insertKeyRehash(Object key, int index, int hash, Object cur) {
  67         int loopIndex = index;
  68         int firstRemoved = -1;
  69         do {
  70             if (cur == "dead")
  71                 firstRemoved = 1;
  72             index--;
  73             if (index < 0)
  74                 index += set.length;
  75             cur = set[index];
  76             if (cur == null) {
  77                 if (firstRemoved != -1)
  78                     set[firstRemoved] = "dead";
  79                 else
  80                     set[index] = key;
  81                 return;
  82             }
  83         } while (index != loopIndex);
  84         if (firstRemoved != -1)
  85             set[firstRemoved] = null;
  86     }
  87 }