/*
 * Copyright (c) 2013, OpenCloudDB/MyCAT and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software;Designed and Developed mainly by many Chinese 
 * opensource volunteers. 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.
 * 
 * Any questions about this component can be directed to it's project Web address 
 * https://code.google.com/p/opencloudb/.
 *
 */
package com.talent.nio.utils;

import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * 
 * @filename: com.talent.nio.utils.SystemTimer
 * @copyright: Copyright (c)2010
 * @company: talent
 * @author: 谭耀武
 * @version: 1.0
 * @create time: 2013年9月25日 上午9:22:56
 * @record <table cellPadding="3" cellSpacing="0" style="width:600px">
 *         <thead style="font-weight:bold;background-color:#e3e197">
 *         <tr>
 *         <td>date</td>
 *         <td>author</td>
 *         <td>version</td>
 *         <td>description</td>
 *         </tr>
 *         </thead> <tbody style="background-color:#ffffeb">
 *         <tr>
 *         <td>2013年9月25日</td>
 *         <td>谭耀武</td>
 *         <td>1.0</td>
 *         <td>create</td>
 *         </tr>
 *         </tbody>
 *         </table>
 */
public class SystemTimer
{
    private static Logger log = LoggerFactory.getLogger(SystemTimer.class);

    /**
     * 
     */
    public SystemTimer()
    {
    	
    }

    /**
     * @param args
     */
    public static void main(String[] args)
    {
    }

    private final static ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor();
    private static final long tickUnit = Long.parseLong(System.getProperty("notify.systimer.tick", "10"));
    private static volatile long time = System.currentTimeMillis();

    private static class TimerTicker implements Runnable
    {
        @Override
        public void run()
        {
            time = System.currentTimeMillis();
        }
    }

    public static long currentTimeMillis()
    {
//    	return System.currentTimeMillis();
        return time;
    }

    static
    {
        executor.scheduleAtFixedRate(new TimerTicker(), tickUnit, tickUnit, TimeUnit.MILLISECONDS);
        Runtime.getRuntime().addShutdownHook(new Thread()
        {
            @Override
            public void run()
            {
                executor.shutdown();
            }
        });
    }
}