1 /*

     2  * Copyright (c) 2003, 2008, 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 sun.management;

    27 

    28 import java.lang.management.ManagementFactory;

    29 import java.lang.management.MemoryMXBean;

    30 import java.lang.management.MemoryUsage;

    31 import java.lang.management.MemoryNotificationInfo;

    32 import java.lang.management.MemoryManagerMXBean;

    33 import java.lang.management.MemoryPoolMXBean;

    34 import javax.management.ObjectName;

    35 import javax.management.MBeanNotificationInfo;

    36 import javax.management.Notification;

    37 import javax.management.openmbean.CompositeData;

    38 

    39 /**

    40  * Implementation class for the memory subsystem.

    41  * Standard and committed hotspot-specific metrics if any.

    42  *

    43  * ManagementFactory.getMemoryMXBean() returns an instance

    44  * of this class.

    45  */

    46 class MemoryImpl extends NotificationEmitterSupport

    47                  implements MemoryMXBean {

    48 

    49     private final VMManagement jvm;

    50 

    51     private static MemoryPoolMXBean[] pools = null;

    52     private static MemoryManagerMXBean[] mgrs = null;

    53 

    54     /**

    55      * Constructor of MemoryImpl class

    56      */

    57     MemoryImpl(VMManagement vm) {

    58         this.jvm = vm;

    59     }

    60 

    61     public int getObjectPendingFinalizationCount() {

    62         return jdk.internal.misc.VM.getFinalRefCount();

    63     }

    64 

    65     public void gc() {

    66         Runtime.getRuntime().gc();

    67     }

    68 

    69     // Need to make a VM call to get coherent value

    70     public MemoryUsage getHeapMemoryUsage() {

    71         return getMemoryUsage0(true);

    72     }

    73 

    74     public MemoryUsage getNonHeapMemoryUsage() {

    75         return getMemoryUsage0(false);

    76     }

    77 

    78     public boolean isVerbose() {

    79         return jvm.getVerboseGC();

    80     }

    81 

    82     public void setVerbose(boolean value) {

    83         Util.checkControlAccess();

    84 

    85         setVerboseGC(value);

    86     }

    87 

    88     // The current Hotspot implementation does not support

    89     // dynamically add or remove memory pools & managers.

    90     static synchronized MemoryPoolMXBean[] getMemoryPools() {

    91         if (pools == null) {

    92             pools = getMemoryPools0();

    93         }

    94         return pools;

    95     }

    96     static synchronized MemoryManagerMXBean[] getMemoryManagers() {

    97         if (mgrs == null) {

    98             mgrs = getMemoryManagers0();

    99         }

   100         return mgrs;

   101     }

   102     private static native MemoryPoolMXBean[] getMemoryPools0();

   103     private static native MemoryManagerMXBean[] getMemoryManagers0();

   104     private native MemoryUsage getMemoryUsage0(boolean heap);

   105     private native void setVerboseGC(boolean value);

   106 

   107     private final static String notifName =

   108         "javax.management.Notification";

   109     private final static String[] notifTypes = {

   110         MemoryNotificationInfo.MEMORY_THRESHOLD_EXCEEDED,

   111         MemoryNotificationInfo.MEMORY_COLLECTION_THRESHOLD_EXCEEDED

   112     };

   113     private final static String[] notifMsgs  = {

   114         "Memory usage exceeds usage threshold",

   115         "Memory usage exceeds collection usage threshold"

   116     };

   117 

   118     public MBeanNotificationInfo[] getNotificationInfo() {

   119         return new MBeanNotificationInfo[] {

   120             new MBeanNotificationInfo(notifTypes, notifName, "Memory Notification")

   121         };

   122     }

   123 

   124     private static String getNotifMsg(String notifType) {

   125         for (int i = 0; i < notifTypes.length; i++) {

   126             if (notifType == notifTypes[i]) {

   127                 return notifMsgs[i];

   128             }

   129         }

   130         return "Unknown message";

   131     }

   132 

   133     private static long seqNumber = 0;

   134     private static long getNextSeqNumber() {

   135         return ++seqNumber;

   136     }

   137 

   138     static void createNotification(String notifType,

   139                                    String poolName,

   140                                    MemoryUsage usage,

   141                                    long count) {

   142         MemoryImpl mbean = (MemoryImpl) ManagementFactory.getMemoryMXBean();

   143         if (!mbean.hasListeners()) {

   144             // if no listener is registered.

   145             return;

   146         }

   147         long timestamp = System.currentTimeMillis();

   148         String msg = getNotifMsg(notifType);

   149         Notification notif = new Notification(notifType,

   150                                               mbean.getObjectName(),

   151                                               getNextSeqNumber(),

   152                                               timestamp,

   153                                               msg);

   154         MemoryNotificationInfo info =

   155             new MemoryNotificationInfo(poolName,

   156                                        usage,

   157                                        count);

   158         CompositeData cd =

   159             MemoryNotifInfoCompositeData.toCompositeData(info);

   160         notif.setUserData(cd);

   161         mbean.sendNotification(notif);

   162     }

   163 

   164     public ObjectName getObjectName() {

   165         return Util.newObjectName(ManagementFactory.MEMORY_MXBEAN_NAME);

   166     }

   167 

   168 }