systemmonitor.java

来自「java pos,你可以直接编译运行,」· Java 代码 · 共 156 行

/*
 * Copyright (c) 2000 jPOS.org.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *    "This product includes software developed by the jPOS project 
 *    (http://www.jpos.org/)". Alternately, this acknowledgment may 
 *    appear in the software itself, if and wherever such third-party 
 *    acknowledgments normally appear.
 *
 * 4. The names "jPOS" and "jPOS.org" must not be used to endorse 
 *    or promote products derived from this software without prior 
 *    written permission. For written permission, please contact 
 *    [e-mail].
 *
 * 5. Products derived from this software may not be called "jPOS",
 *    nor may "jPOS" appear in their name, without prior written
 *    permission of the jPOS project.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  
 * IN NO EVENT SHALL THE JPOS PROJECT OR ITS CONTRIBUTORS BE LIABLE FOR 
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the jPOS Project.  For more
 * information please see <http://www.jpos.org/>.
 */

package org.jpos.util;

import java.io.PrintStream;

/**
 * Periodically dumps Thread and memory usage
 * @author [e-mail]
 * @version $Id: SystemMonitor.java,v 1.9 2004/08/13 15:05:49 apr Exp $
 * @see Logger
 */
public class SystemMonitor implements Runnable, LogSource, Loggeable
{
    private Logger logger = null;
    private String realm  = null;
    private int sleepTime = 0;
    private int delay     = 0;
    private Thread thread = null;

    /**
     * noargs constructor
     */
    public SystemMonitor () {
        super();
    }
    /**
     * @param sleepTime sleep
     * @param logger current logger
     * @param realm  instance realm
     */
    public SystemMonitor (int sleepTime, Logger logger, String realm) {
        setLogger (logger, realm);
        this.sleepTime = sleepTime;
        startThread();
    }
    
    private void startThread() {
        if (thread != null)
            thread.interrupt();
        else if (sleepTime > 0) {
            thread = new Thread(this);
            thread.setName ("SystemMonitor");
            thread.setPriority (Thread.MIN_PRIORITY);
            thread.start();
        }
    }

    /**
     * @param sleepTime new sleepTime;
     */
    public void setSleepTime (int sleepTime) {
        this.sleepTime = sleepTime;
        startThread();
    }

    void dumpThreads (ThreadGroup g, PrintStream p, String indent) {
        Thread[] list = new Thread[g.activeCount()+5];
        int nthreads = g.enumerate(list);
        for (int i=0; i<nthreads; i++) 
            p.println (indent + list[i]);
    }

    public void showThreadGroup (ThreadGroup g, PrintStream p, String indent) {
        if (g.getParent() != null)
            showThreadGroup (g.getParent(), p, indent + "  ");
        else
            dumpThreads (g, p, indent + "    ");
    }

    public void run() {
        for (;;) {
            Logger.log (new LogEvent (this, "SystemMonitor", this));
            try {
                long expected = System.currentTimeMillis() + sleepTime;
                Thread.sleep (sleepTime);
                delay = (int) (System.currentTimeMillis() - expected);
            } catch (InterruptedException e) { }
        }
    }
    public void dump (PrintStream p, String indent) {
        String newIndent = indent + "  ";
        Runtime r = Runtime.getRuntime();
        p.println (indent + "<memory>");
        p.println (newIndent+" freeMemory="+r.freeMemory());
        p.println (newIndent+"totalMemory="+r.totalMemory());
        p.println (newIndent+"inUseMemory="+(r.totalMemory()-r.freeMemory()));
        p.println (indent + "</memory>");
        p.println (indent + "<threads>");
        p.println (newIndent+"      delay="+delay+" ms");
        p.println (newIndent+"    threads="+Thread.activeCount());
        showThreadGroup (Thread.currentThread().getThreadGroup(), p, newIndent);
        p.println (indent + "</threads>");
        NameRegistrar.getInstance().dump (p, indent);
    }
    public void setLogger (Logger logger, String realm) {
        this.logger = logger;
        this.realm  = realm;
    }
    public String getRealm () {
        return realm;
    }
    public Logger getLogger() {
        return logger;
    }
}