/*

 * Copyright (c) 2003, 2008, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

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

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

 *

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

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

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

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

 * accompanied this code).

 *

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

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

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

 *

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

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 */

package sun.management;

import java.lang.management.ManagementFactory;

import java.lang.management.MemoryMXBean;

import java.lang.management.MemoryUsage;

import java.lang.management.MemoryNotificationInfo;

import java.lang.management.MemoryManagerMXBean;

import java.lang.management.MemoryPoolMXBean;

import javax.management.ObjectName;

import javax.management.MBeanNotificationInfo;

import javax.management.Notification;

import javax.management.openmbean.CompositeData;

/**

 * Implementation class for the memory subsystem.

 * Standard and committed hotspot-specific metrics if any.

 *

 * ManagementFactory.getMemoryMXBean() returns an instance

 * of this class.

 */

class MemoryImpl extends NotificationEmitterSupport

                 implements MemoryMXBean {

    private final VMManagement jvm;

    private static MemoryPoolMXBean[] pools = null;

    private static MemoryManagerMXBean[] mgrs = null;

    /**

     * Constructor of MemoryImpl class

     */

    MemoryImpl(VMManagement vm) {

        this.jvm = vm;

    }

    public int getObjectPendingFinalizationCount() {

        return sun.misc.VM.getFinalRefCount();

    }

    public void gc() {

        Runtime.getRuntime().gc();

    }

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

    public MemoryUsage getHeapMemoryUsage() {

        return getMemoryUsage0(true);

    }

    public MemoryUsage getNonHeapMemoryUsage() {

        return getMemoryUsage0(false);

    }

    public boolean isVerbose() {

        return jvm.getVerboseGC();

    }

    public void setVerbose(boolean value) {

        Util.checkControlAccess();

        setVerboseGC(value);

    }

    // The current Hotspot implementation does not support

    // dynamically add or remove memory pools & managers.

    static synchronized MemoryPoolMXBean[] getMemoryPools() {

        if (pools == null) {

            pools = getMemoryPools0();

        }

        return pools;

    }

    static synchronized MemoryManagerMXBean[] getMemoryManagers() {

        if (mgrs == null) {

            mgrs = getMemoryManagers0();

        }

        return mgrs;

    }

    private static native MemoryPoolMXBean[] getMemoryPools0();

    private static native MemoryManagerMXBean[] getMemoryManagers0();

    private native MemoryUsage getMemoryUsage0(boolean heap);

    private native void setVerboseGC(boolean value);

    private final static String notifName =

        "javax.management.Notification";

    private final static String[] notifTypes = {

        MemoryNotificationInfo.MEMORY_THRESHOLD_EXCEEDED,

        MemoryNotificationInfo.MEMORY_COLLECTION_THRESHOLD_EXCEEDED

    };

    private final static String[] notifMsgs  = {

        "Memory usage exceeds usage threshold",

        "Memory usage exceeds collection usage threshold"

    };

    public MBeanNotificationInfo[] getNotificationInfo() {

        return new MBeanNotificationInfo[] {

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

        };

    }

    private static String getNotifMsg(String notifType) {

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

            if (notifType == notifTypes[i]) {

                return notifMsgs[i];

            }

        }

        return "Unknown message";

    }

    private static long seqNumber = 0;

    private static long getNextSeqNumber() {

        return ++seqNumber;

    }

    static void createNotification(String notifType,

                                   String poolName,

                                   MemoryUsage usage,

                                   long count) {

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

        if (!mbean.hasListeners()) {

            // if no listener is registered.

            return;

        }

        long timestamp = System.currentTimeMillis();

        String msg = getNotifMsg(notifType);

        Notification notif = new Notification(notifType,

                                              mbean.getObjectName(),

                                              getNextSeqNumber(),

                                              timestamp,

                                              msg);

        MemoryNotificationInfo info =

            new MemoryNotificationInfo(poolName,

                                       usage,

                                       count);

        CompositeData cd =

            MemoryNotifInfoCompositeData.toCompositeData(info);

        notif.setUserData(cd);

        mbean.sendNotification(notif);

    }

    public ObjectName getObjectName() {

        return Util.newObjectName(ManagementFactory.MEMORY_MXBEAN_NAME);

    }

}