1 /*

     2  * Copyright (c) 2012, 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 7196045

    28  * @bug 8014294

    29  * @summary Possible JVM deadlock in ThreadTimesClosure when using HotspotInternal non-public API.

    30  * @run main/othervm -XX:+UsePerfData -Xmx32m ThreadCpuTimesDeadlock

    31  */

    32 

    33 import java.lang.management.ManagementFactory;

    34 import javax.management.JMException;

    35 import javax.management.MBeanServer;

    36 import javax.management.MalformedObjectNameException;

    37 import javax.management.ObjectName;

    38 

    39 public class ThreadCpuTimesDeadlock {

    40 

    41     public static byte[] dummy;

    42     public static long duration = 10 * 1000;

    43     private static final String HOTSPOT_INTERNAL = "sun.management:type=HotspotInternal";

    44 

    45     public static void main(String[] args) {

    46 

    47         MBeanServer server = ManagementFactory.getPlatformMBeanServer();

    48         ObjectName objName= null;

    49         try {

    50             ObjectName hotspotInternal = new ObjectName(HOTSPOT_INTERNAL);

    51             try {

    52                 server.registerMBean(new sun.management.HotspotInternal(), hotspotInternal);

    53             } catch (JMException e) {

    54                 throw new RuntimeException("HotSpotWatcher: Failed to register the HotspotInternal MBean" + e);

    55             }

    56             objName= new ObjectName("sun.management:type=HotspotThreading");

    57 

    58         } catch (MalformedObjectNameException e1) {

    59             throw new RuntimeException("Bad object name" + e1);

    60         }

    61 

    62         // Thread that allocs memory to generate GC's

    63         Thread allocThread = new Thread() {

    64           public void run() {

    65             while (true) {

    66               dummy = new byte[4096];

    67             }

    68           }

    69         };

    70 

    71         allocThread.setDaemon(true);

    72         allocThread.start();

    73 

    74         long endTime = System.currentTimeMillis() + duration;

    75         long i = 0;

    76         while (true) {

    77             try {

    78                 server.getAttribute(objName, "InternalThreadCpuTimes");

    79             } catch (Exception ex) {

    80                 System.err.println("Exception while getting attribute: " + ex);

    81             }

    82             i++;

    83             if (i % 10000 == 0) {

    84                 System.out.println("Successful iterations: " + i);

    85             }

    86             if (System.currentTimeMillis() > endTime) {

    87                 break;

    88             }

    89         }

    90         System.out.println("PASSED.");

    91     }

    92 }