1 /*

     2  * Copyright (c) 2016, 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 

    26 package jdk.management.jfr.internal;

    27 

    28 import java.util.Collections;

    29 import java.util.List;

    30 import java.util.Map;

    31 import java.util.Set;

    32 import java.util.concurrent.Callable;

    33 

    34 import jdk.jfr.internal.management.ManagementSupport;

    35 import jdk.management.jfr.FlightRecorderMXBean;

    36 import jdk.management.jfr.SettingDescriptorInfo;

    37 import sun.management.spi.PlatformMBeanProvider;

    38 

    39 public final class FlightRecorderMXBeanProvider extends PlatformMBeanProvider {

    40 

    41     private final static class SingleMBeanComponent

    42             implements PlatformComponent<FlightRecorderMXBean> {

    43         private final String objectName;

    44         private final Class<FlightRecorderMXBean> mbeanInterface;

    45 

    46         public SingleMBeanComponent(String objectName,

    47                                     Class<FlightRecorderMXBean> mbeanInterface) {

    48             this.objectName = objectName;

    49             this.mbeanInterface = mbeanInterface;

    50         }

    51 

    52         @Override

    53         public Set<String> mbeanInterfaceNames() {

    54             return Collections.singleton(mbeanInterface.getName());

    55         }

    56 

    57         @Override

    58         public Map<String, FlightRecorderMXBean> nameToMBeanMap() {

    59             FlightRecorderMXBean bean = getFlightRecorderMXBean();

    60             if (bean != null) {

    61                 return Collections.singletonMap(objectName, bean);

    62             } else {

    63                 return Collections.emptyMap();

    64             }

    65         }

    66 

    67         @Override

    68         public String getObjectNamePattern() {

    69             return objectName;

    70         }

    71 

    72         @Override

    73         public Set<Class<? extends FlightRecorderMXBean>> mbeanInterfaces() {

    74             return Collections.singleton(mbeanInterface);

    75         }

    76     }

    77 

    78     private static Callable<FlightRecorderMXBean> flightRecorderMXBeanFactory;

    79 

    80     private static volatile FlightRecorderMXBean flightRecorderMXBean;

    81 

    82     private static FlightRecorderMXBean getFlightRecorderMXBean() {

    83         FlightRecorderMXBean bean = flightRecorderMXBean;

    84         if (bean == null) {

    85             SettingDescriptorInfo.from(null); // Sets flightRecorderMXBeanFactory under <clinit> lock

    86             synchronized (flightRecorderMXBeanFactory) {

    87                 bean = flightRecorderMXBean;

    88                 if (bean != null) {

    89                     return bean;

    90                 }

    91                 try {

    92                     bean = flightRecorderMXBean = flightRecorderMXBeanFactory.call();

    93                 } catch (Exception e) {

    94                     ManagementSupport.logError("Could not create Flight Recorder "

    95                             + "instance for MBeanServer. " + e.getMessage());

    96                 }

    97             }

    98         }

    99         return bean;

   100     }

   101 

   102     public static void setFlightRecorderMXBeanFactory(Callable<FlightRecorderMXBean> factory) {

   103         flightRecorderMXBeanFactory = factory;

   104     }

   105 

   106     @Override

   107     public List<PlatformComponent<?>> getPlatformComponentList() {

   108         String objectName = FlightRecorderMXBean.MXBEAN_NAME;

   109         Class<FlightRecorderMXBean> mbeanInterface = FlightRecorderMXBean.class;

   110         return Collections.singletonList(new SingleMBeanComponent(objectName, mbeanInterface));

   111     }

   112 }