1 /*
   2  * Copyright (c) 2017, 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
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  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
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  22  */
  23 
  24 /*
  25  * @test ArraysNewInstanceBug
  26  * @bug 8182397
  27  * @summary race in setting array_klass field for component mirror with mirror update for klass
  28  * @modules java.base/jdk.internal.misc
  29  * @run main/othervm -Xcomp ArraysNewInstanceBug
  30  */
  31 
  32 // This test crashes in compiled code with race, because the compiler generates code that assumes this ordering.
  33 import java.lang.reflect.Array;
  34 import java.net.URL;
  35 import java.net.URLClassLoader;
  36 
  37 public class ArraysNewInstanceBug implements Runnable {
  38     static Class<?>[] classes;
  39 
  40     int start;
  41 
  42     ArraysNewInstanceBug(int start) {
  43         this.start = start;
  44     }
  45 
  46     String[] result;
  47 
  48     public void run() {
  49         result = new String[classes.length];
  50         System.err.print('.');
  51         for (int i = start; i < classes.length; i++) {
  52             result[i] = Array.newInstance(classes[i], 0).getClass().getName();
  53         }
  54     }
  55 
  56     public static void main(String[] args) throws Throwable {
  57         Class<?> c = ArraysNewInstanceBug.class;
  58         ClassLoader apploader =  c.getClassLoader();
  59         for (int iter = 0; iter < 10 ; iter++) {  // 10 is enough to get it to crash on my machine.
  60             System.err.print('[');
  61             classes = new Class<?>[1000];
  62             String urlpath = "file://" + System.getProperty("test.classes") + "/";
  63             for (int i = 0; i < classes.length; i++) {
  64                 ClassLoader loader = new URLClassLoader(new URL[] { new URL(urlpath) }, apploader.getParent());
  65                 classes[i] = loader.loadClass(c.getSimpleName());
  66             }
  67             System.err.print(']');
  68             System.err.print('(');
  69             int threadCount = 64;
  70             Thread[] threads = new Thread[threadCount];
  71             for (int i = 0; i < threads.length; i++) {
  72                 threads[i] = new Thread(new ArraysNewInstanceBug(i));
  73             }
  74             for (int i = 0; i < threads.length; i++) {
  75                 threads[i].start();
  76             }
  77             for (int i = 0; i < threads.length; i++) {
  78                 threads[i].join();
  79             }
  80             System.err.print(')');
  81         }
  82     }
  83 }