1 /*
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   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 8165246 8010319
  27  * @summary Test has_previous_versions flag and processing during class unloading.
  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 RedefinePreviousVersions test
  35  */
  36 
  37 import jdk.test.lib.process.ProcessTools;
  38 import jdk.test.lib.process.OutputAnalyzer;
  39 
  40 // package access top-level classes to avoid problem with RedefineClassHelper
  41 // and nested types.
  42 
  43 class RedefinePreviousVersions_B { }
  44 
  45 class RedefinePreviousVersions_Running {
  46     public static volatile boolean stop = false;
  47     public static volatile boolean running = false;
  48     static void localSleep() {
  49         try {
  50             Thread.sleep(10); // sleep for 10 ms
  51         } catch(InterruptedException ie) {
  52         }
  53     }
  54 
  55     public static void infinite() {
  56         running = true;
  57         while (!stop) { localSleep(); }
  58     }
  59 }
  60 
  61 
  62 
  63 public class RedefinePreviousVersions {
  64 
  65     public static String newB =
  66                 "class RedefinePreviousVersions_B {" +
  67                 "}";
  68 
  69     public static String newRunning =
  70         "class RedefinePreviousVersions_Running {" +
  71         "    public static volatile boolean stop = true;" +
  72         "    public static volatile boolean running = true;" +
  73         "    static void localSleep() { }" +
  74         "    public static void infinite() { }" +
  75         "}";
  76 
  77     public static void main(String[] args) throws Exception {
  78 
  79         if (args.length > 0) {
  80 
  81             // java -javaagent:redefineagent.jar -Xlog:stuff RedefinePreviousVersions
  82             ProcessBuilder pb = ProcessTools.createJavaProcessBuilder( "-javaagent:redefineagent.jar",
  83                "-Xlog:redefine+class+iklass+add=trace,redefine+class+iklass+purge=trace",
  84                "RedefinePreviousVersions");
  85             new OutputAnalyzer(pb.start())
  86               .shouldContain("Class unloading: has_previous_versions = false")
  87               .shouldContain("Class unloading: has_previous_versions = true")
  88               .shouldHaveExitValue(0);
  89             return;
  90         }
  91 
  92         // Redefine a class and create some garbage
  93         // Since there are no methods running, the previous version is never added to the
  94         // previous_version_list and the flag _has_previous_versions should stay false
  95         RedefineClassHelper.redefineClass(RedefinePreviousVersions_B.class, newB);
  96 
  97         for (int i = 0; i < 10 ; i++) {
  98             String s = new String("some garbage");
  99             System.gc();
 100         }
 101 
 102         // Start a class that has a method running
 103         new Thread() {
 104             public void run() {
 105                 RedefinePreviousVersions_Running.infinite();
 106             }
 107         }.start();
 108 
 109         while (!RedefinePreviousVersions_Running.running) {
 110             Thread.sleep(10); // sleep for 10 ms
 111         }
 112 
 113         // Since a method of newRunning is running, this class should be added to the previous_version_list
 114         // of Running, and _has_previous_versions should return true at class unloading.
 115         RedefineClassHelper.redefineClass(RedefinePreviousVersions_Running.class, newRunning);
 116 
 117         for (int i = 0; i < 10 ; i++) {
 118             String s = new String("some garbage");
 119             System.gc();
 120         }
 121 
 122         // purge should clean everything up, except Xcomp it might not.
 123         RedefinePreviousVersions_Running.stop = true;
 124 
 125         for (int i = 0; i < 10 ; i++) {
 126             String s = new String("some garbage");
 127             System.gc();
 128         }
 129     }
 130 }