1 /*
   2  * Copyright (c) 2014, 2015, 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  * @test
  26  * @bug 8055008
  27  * @summary Redefine EMCP and non-EMCP methods that are running in an infinite loop
  28  * @library /test/lib
  29  * @modules java.base/jdk.internal.misc
  30  * @modules java.compiler
  31  *          java.instrument
  32  *          jdk.jartool/sun.tools.jar
  33  * @run main RedefineClassHelper
  34  * @run main/othervm -javaagent:redefineagent.jar -XX:TraceRedefineClasses=0x600 RedefineRunningMethods
  35  */
  36 public class RedefineRunningMethods {
  37 
  38     public static String newB =
  39                 "class RedefineRunningMethods$B {" +
  40                 "   static int count1 = 0;" +
  41                 "   static int count2 = 0;" +
  42                 "   public static volatile boolean stop = false;" +
  43                 "  static void localSleep() { " +
  44                 "    try{ " +
  45                 "      Thread.currentThread().sleep(10);" +
  46                 "    } catch(InterruptedException ie) { " +
  47                 "    } " +
  48                 " } " +
  49                 "   public static void infinite() { " +
  50                 "       System.out.println(\"infinite called\");" +
  51                 "   }" +
  52                 "   public static void infinite_emcp() { " +
  53                 "       while (!stop) { count2++; localSleep(); }" +
  54                 "   }" +
  55                 "}";
  56 
  57     public static String evenNewerB =
  58                 "class RedefineRunningMethods$B {" +
  59                 "   static int count1 = 0;" +
  60                 "   static int count2 = 0;" +
  61                 "   public static volatile boolean stop = false;" +
  62                 "  static void localSleep() { " +
  63                 "    try{ " +
  64                 "      Thread.currentThread().sleep(1);" +
  65                 "    } catch(InterruptedException ie) { " +
  66                 "    } " +
  67                 " } " +
  68                 "   public static void infinite() { }" +
  69                 "   public static void infinite_emcp() { " +
  70                 "       System.out.println(\"infinite_emcp now obsolete called\");" +
  71                 "   }" +
  72                 "}";
  73 
  74     static class B {
  75         static int count1 = 0;
  76         static int count2 = 0;
  77         public static volatile boolean stop = false;
  78         static void localSleep() {
  79           try{
  80             Thread.currentThread().sleep(10);//sleep for 10 ms
  81           } catch(InterruptedException ie) {
  82           }
  83         }
  84 
  85         public static void infinite() {
  86             while (!stop) { count1++; localSleep(); }
  87         }
  88         public static void infinite_emcp() {
  89             while (!stop) { count2++; localSleep(); }
  90         }
  91     }
  92 
  93 
  94     public static void main(String[] args) throws Exception {
  95 
  96         new Thread() {
  97             public void run() {
  98                 B.infinite();
  99             }
 100         }.start();
 101 
 102         new Thread() {
 103             public void run() {
 104                 B.infinite_emcp();
 105             }
 106         }.start();
 107 
 108         RedefineClassHelper.redefineClass(B.class, newB);
 109 
 110         System.gc();
 111 
 112         B.infinite();
 113 
 114         // Start a thread with the second version of infinite_emcp running
 115         new Thread() {
 116             public void run() {
 117                 B.infinite_emcp();
 118             }
 119         }.start();
 120 
 121         for (int i = 0; i < 20 ; i++) {
 122             String s = new String("some garbage");
 123             System.gc();
 124         }
 125 
 126         RedefineClassHelper.redefineClass(B.class, evenNewerB);
 127         System.gc();
 128 
 129         for (int i = 0; i < 20 ; i++) {
 130             B.infinite();
 131             String s = new String("some garbage");
 132             System.gc();
 133         }
 134 
 135         B.infinite_emcp();
 136 
 137         // purge should clean everything up.
 138         B.stop = true;
 139 
 140         for (int i = 0; i < 20 ; i++) {
 141             B.infinite();
 142             String s = new String("some garbage");
 143             System.gc();
 144         }
 145     }
 146 }