1 /*
   2  * Copyright (c) 2013, 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 import java.lang.management.ManagementFactory;
  25 import java.lang.ref.WeakReference;
  26 import java.lang.reflect.Field;
  27 import javax.management.MBeanServer;
  28 import javax.management.MBeanServerConnection;
  29 import javax.management.remote.JMXConnector;
  30 import javax.management.remote.JMXConnectorFactory;
  31 import javax.management.remote.JMXConnectorServer;
  32 import javax.management.remote.JMXConnectorServerFactory;
  33 import javax.management.remote.JMXServiceURL;
  34 import javax.management.remote.rmi.RMIConnector;
  35 
  36 /*
  37  * @test
  38  * @bug 6566891
  39  * @summary Check no memory leak on RMIConnector's nullSubjectConn
  40  * @author Shanliang JIANG
  41  * @modules java.management.rmi/javax.management.remote.rmi:open
  42  * @run clean RMIConnectorNullSubjectConnTest
  43  * @run build RMIConnectorNullSubjectConnTest
  44  * @run main RMIConnectorNullSubjectConnTest
  45  */
  46 
  47 public class RMIConnectorNullSubjectConnTest {
  48     public static void main(String[] args) throws Exception {
  49         System.out.println("---RMIConnectorNullSubjectConnTest starting...");
  50 
  51         JMXConnectorServer connectorServer = null;
  52         JMXConnector connectorClient = null;
  53 
  54         try {
  55             MBeanServer mserver = ManagementFactory.getPlatformMBeanServer();
  56             JMXServiceURL serverURL = new JMXServiceURL("rmi", "localhost", 0);
  57             connectorServer = JMXConnectorServerFactory.newJMXConnectorServer(serverURL, null, mserver);
  58             connectorServer.start();
  59 
  60             JMXServiceURL serverAddr = connectorServer.getAddress();
  61             connectorClient = JMXConnectorFactory.connect(serverAddr, null);
  62             connectorClient.connect();
  63 
  64             Field nullSubjectConnField = RMIConnector.class.getDeclaredField("nullSubjectConnRef");
  65             nullSubjectConnField.setAccessible(true);
  66 
  67             WeakReference<MBeanServerConnection> weak =
  68                     (WeakReference<MBeanServerConnection>)nullSubjectConnField.get(connectorClient);
  69 
  70             if (weak != null && weak.get() != null) {
  71                 throw new RuntimeException("nullSubjectConnRef must be null at initial time.");
  72             }
  73 
  74             MBeanServerConnection conn1 = connectorClient.getMBeanServerConnection(null);
  75             MBeanServerConnection conn2 = connectorClient.getMBeanServerConnection(null);
  76             if (conn1 == null) {
  77                 throw new RuntimeException("A connection with null subject should not be null.");
  78             } else if (conn1 != conn2) {
  79                 throw new RuntimeException("The 2 connections with null subject are not equal.");
  80             }
  81 
  82             conn1 = null;
  83             conn2 = null;
  84             int i = 1;
  85             do {
  86                 System.gc();
  87                 Thread.sleep(100);
  88                 weak = (WeakReference<MBeanServerConnection>)nullSubjectConnField.get(connectorClient);
  89             } while ((weak != null && weak.get() != null) && i++ < 60);
  90 
  91             System.out.println("---GC times: " + i);
  92 
  93             if (weak != null && weak.get() != null) {
  94                 throw new RuntimeException("Failed to clean RMIConnector's nullSubjectConn");
  95             } else {
  96                 System.out.println("---RMIConnectorNullSubjectConnTest: PASSED!");
  97             }
  98         } finally {
  99             try {
 100                 connectorClient.close();
 101                 connectorServer.stop();
 102             } catch (Exception e) {
 103             }
 104         }
 105     }
 106 }