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  *  @test

    26  *  @bug 7105883

    27  *  @summary Ensure that JDWP doesn't crash with a null thread group name

    28  *

    29  *  @run build TestScaffold VMConnection TargetListener TargetAdapter

    30  *  @run main NullThreadGroupNameTest

    31  */

    32 import com.sun.jdi.*;

    33 import com.sun.jdi.connect.*;

    34 import com.sun.jdi.event.*;

    35 import com.sun.jdi.request.*;

    36 import com.sun.jdi.VMDisconnectedException;

    37 import java.util.concurrent.CountDownLatch;

    38 import java.util.*;

    39 

    40 class DebugTarget {

    41     public final static String DEBUG_THREAD_NAME = "DebugThread";

    42 

    43     public static void main(String[] args) throws Exception {

    44         DebugThread thread = new DebugThread();

    45         thread.start();

    46         thread.runningLatch.await();

    47         breakpointHere();

    48         thread.breakpointLatch.countDown();

    49     }

    50 

    51     public static void breakpointHere() {

    52         System.out.println("Breakpoint finished!");

    53     }

    54 

    55     static class DebugThread extends Thread {

    56         final CountDownLatch runningLatch = new CountDownLatch(1);

    57         final CountDownLatch breakpointLatch = new CountDownLatch(1);

    58 

    59         public DebugThread() {

    60             super(new ThreadGroup(null), DEBUG_THREAD_NAME);

    61         }

    62 

    63         public void run() {

    64             runningLatch.countDown();

    65             try {

    66                 breakpointLatch.await();

    67             } catch (InterruptedException ie) {

    68                 ie.printStackTrace();

    69             }

    70         }

    71     }

    72 }

    73 

    74 public class NullThreadGroupNameTest extends TestScaffold {

    75 

    76     NullThreadGroupNameTest(String args[]) {

    77         super(args);

    78     }

    79 

    80     public static void main(String[] args) throws Exception {

    81         new NullThreadGroupNameTest(args).startTests();

    82     }

    83 

    84     protected void runTests() throws Exception {

    85         startTo("DebugTarget", "breakpointHere", "()V");

    86 

    87         ThreadReference thread = findThread(DebugTarget.DEBUG_THREAD_NAME);

    88         assertThreadGroupName(thread.threadGroup(), "");

    89 

    90         listenUntilVMDisconnect();

    91     }

    92 

    93     private ThreadReference findThread(String name) {

    94         for (ThreadReference thread : vm().allThreads()) {

    95             if (name.equals(thread.name())) {

    96                 return thread;

    97             }

    98         }

    99         throw new NoSuchElementException("Couldn't find " + name);

   100     }

   101 

   102     private void assertThreadGroupName(ThreadGroupReference threadGroup, String expectedName) {

   103         try {

   104             String name = threadGroup.name();

   105             if (!expectedName.equals(name)) {

   106                 throw new AssertionError("Unexpected thread group name '" + name + "'");

   107             }

   108         } catch (VMDisconnectedException vmde) {

   109             throw new AssertionError("Likely JVM crash with null thread group name", vmde);

   110         }

   111     }

   112 }