MemoryUtil.java

/*
 * Copyright (c) 2004, 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.
 *
 * 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
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

/*
 * @bug     4982289
 * @summary Utility class.
 * @author Mandy Chung
 */

import java.lang.management.*;
import java.util.*;

public class MemoryUtil {

    private static String INDENT = "    ";
    private static String formatSize(String name, long value) {
        StringBuffer buf = new StringBuffer(name + " = " + value);
        if (value > 0) {
            buf.append(" (" + (value >> 10) + "K)");
        }
        return buf.toString();
    }
    public static void printMemoryUsage(MemoryUsage usage) {
        System.out.println(INDENT + formatSize("Initial size  ", usage.getInit()));
        System.out.println(INDENT + formatSize("Used size     ", usage.getUsed()));
        System.out.println(INDENT + formatSize("Committd size ", usage.getCommitted()));
        System.out.println(INDENT + formatSize("Max size      ", usage.getMax()));
    }

    public static void printMemoryPool(MemoryPoolMXBean pool) {
        System.out.println(INDENT + "Memory Pool name: " + pool.getName());
        System.out.println(INDENT + "Type: " + pool.getType());
        System.out.println(INDENT + "Memory Usage: " +
            pool.getUsage());
        System.out.println(INDENT + "Threshold: " +
            (pool.isUsageThresholdSupported() ? pool.getUsageThreshold() : -1));
        System.out.print(INDENT + "Manager = [");
        String[] mgrs = pool.getMemoryManagerNames();
        for (int i = 0; i < mgrs.length; i++) {
            System.out.print(mgrs[i]);
            if (i < (mgrs.length - 1)) {
                System.out.print(" | ");
            }
        }
        System.out.println("]");
    }

    public static void printMemoryPools(List pools) {
        ListIterator iter = pools.listIterator();
        System.out.println(INDENT + "Number of memory pools = " + pools.size());
        while (iter.hasNext()) {
            MemoryPoolMXBean pool = (MemoryPoolMXBean) iter.next();
            printMemoryPool(pool);
        }
    }

    public static void printMemoryManager(MemoryManagerMXBean mgr) {
        if (mgr instanceof GarbageCollectorMXBean) {
            GarbageCollectorMXBean gc = (GarbageCollectorMXBean) mgr;
            System.out.println(INDENT + "Garbage Collector name: " + gc.getName());
            System.out.println(INDENT + "GC Count: " + gc.getCollectionCount());
            System.out.println(INDENT + "GC Time : " + gc.getCollectionTime());
        } else {
            System.out.println(INDENT + "Memory Manager name: " + mgr.getName());
        }

        System.out.print("Pool = [");
        String[] pools = mgr.getMemoryPoolNames();
        for (int i = 0; i < pools.length; i++) {
            System.out.print(INDENT + pools[i]);
            if (i < (pools.length - 1)) {
                System.out.print(" | ");
            }
        }
        System.out.println("]");
    }

    public static void printMemoryManagers(List managers) {
        ListIterator iter = managers.listIterator();
        System.out.println(INDENT + "Number of memory managers = " +
            managers.size());
        while (iter.hasNext()) {
            MemoryManagerMXBean mgr = (MemoryManagerMXBean) iter.next();
            printMemoryManager(mgr);
        }
    }

    public static void printMemoryNotificationInfo
        (MemoryNotificationInfo minfo, String type) {
        System.out.print("Notification for " + minfo.getPoolName());
        System.out.print(" [type = " + type);
        System.out.println(" count = " + minfo.getCount() + "]");
        System.out.println(INDENT + "usage = " + minfo.getUsage());
    }
}