1 /*

     2  * Copyright (c) 2018, 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.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 package jdk.jfr.jmx;

    26 

    27 import java.lang.management.ManagementFactory;

    28 import java.net.URL;

    29 import java.net.URLClassLoader;

    30 

    31 import javax.management.MBeanAttributeInfo;

    32 import javax.management.MBeanInfo;

    33 import javax.management.MBeanServer;

    34 import javax.management.ObjectName;

    35 

    36 import jdk.jfr.Recording;

    37 import jdk.jfr.consumer.RecordedClassLoader;

    38 import jdk.jfr.consumer.RecordedEvent;

    39 import jdk.management.jfr.FlightRecorderMXBean;

    40 import jdk.test.lib.jfr.Events;

    41 

    42 /**

    43  * @test

    44  * @key jfr

    45  * @summary Verifies that attributes in FlightRecorderMXBean can be inspected

    46  *          without causing a memory leak.

    47  * @requires vm.hasJFR

    48  * @library /test/lib /test/jdk

    49  * @run main/othervm jdk.jfr.jmx.TestFlightRecorderMXBeanLeak

    50  */

    51 public class TestFlightRecorderMXBeanLeak {

    52 

    53     private static final String CLASS_LOADER_NAME = "Test Leak";

    54     private static final String TEST_CLASS = "jdk.jfr.jmx.TestFlightRecorderMXBeanLeak$FlightRecorderMXBeanLoader";

    55 

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

    57         URL url = FlightRecorderMXBeanLoader.class.getProtectionDomain().getCodeSource().getLocation();

    58         URLClassLoader loader = new URLClassLoader(CLASS_LOADER_NAME, new URL[] { url }, null);

    59         Class<?> clazz = Class.forName(TEST_CLASS, true, loader);

    60         clazz.newInstance();

    61         loader.close();

    62         clazz = null;

    63         loader = null;

    64         System.gc();

    65         System.gc();

    66 

    67         try (Recording r = new Recording()) {

    68             r.enable("jdk.ClassLoaderStatistics").with("period", "endChunk");

    69             r.start();

    70             r.stop();

    71             for (RecordedEvent e : Events.fromRecording(r)) {

    72                 RecordedClassLoader o = e.getValue("classLoader");

    73                 if (o != null) {

    74                     System.out.println("Class loader: type=" + o.getType().getName() + " name=" + o.getName());

    75                     if (CLASS_LOADER_NAME.equals(o.getName())) {

    76                         throw new Exception("Memory Leak. Class loader '" + CLASS_LOADER_NAME + "' should not be on the heap!");

    77                     }

    78                 }

    79             }

    80         }

    81     }

    82 

    83     public static class FlightRecorderMXBeanLoader {

    84         public FlightRecorderMXBeanLoader() throws Exception {

    85             ObjectName objectName = new ObjectName(FlightRecorderMXBean.MXBEAN_NAME);

    86             MBeanServer platformMBeanServer = ManagementFactory.getPlatformMBeanServer();

    87             MBeanInfo mBeanInfo = platformMBeanServer.getMBeanInfo(objectName);

    88             System.out.println("Inspecting FlightRecorderMXBeann:");

    89             for (MBeanAttributeInfo attributeInfo : mBeanInfo.getAttributes()) {

    90                 Object value = platformMBeanServer.getAttribute(objectName, attributeInfo.getName());

    91                 System.out.println(attributeInfo.getName() + " = " + value);

    92             }

    93         }

    94     }

    95 }