memory.java

java程序写系统的服务

package org.tanukisoftware.wrapper.test;

/*
 * Copyright (c) 1999, 2006 Tanuki Software Inc.
 * 
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of the Java Service Wrapper and associated
 * documentation files (the "Software"), to deal in the Software
 * without  restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sub-license,
 * and/or sell copies of the Software, and to permit persons to
 * whom the Software is furnished to do so, subject to the
 * following conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES 
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 
 * NON-INFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT 
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 * 
 * 
 * Portions of the Software have been derived from source code
 * developed by Silver Egg Technology under the following license:
 * 
 * Copyright (c) 2001 Silver Egg Technology
 * 
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without 
 * restriction, including without limitation the rights to use, 
 * copy, modify, merge, publish, distribute, sub-license, and/or 
 * sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following 
 * conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 */

// $Log: Memory.java,v $
// Revision 1.5  2006/02/24 05:45:59  mortenson
// Update the copyright.
//
// Revision 1.4  2005/05/23 02:39:30  mortenson
// Update the copyright information.
//
// Revision 1.3  2004/01/16 04:41:55  mortenson
// The license was revised for this version to include a copyright omission.
// This change is to be retroactively applied to all versions of the Java
// Service Wrapper starting with version 3.0.0.
//
// Revision 1.2  2003/04/03 04:05:22  mortenson
// Fix several typos in the docs.  Thanks to Mike Castle.
//
// Revision 1.1  2003/02/03 06:55:29  mortenson
// License transfer to TanukiSoftware.org
//

import java.io.FileWriter;
import java.io.IOException;
import java.io.Writer;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;

/**
 *
 *
 * @author Leif Mortenson <[e-mail]>
 * @version $Revision: 1.5 $
 */
public class Memory implements Runnable
{
    private Writer m_writer;
    private Thread m_runner;
    
    /*---------------------------------------------------------------
     * Runnable Method
     *-------------------------------------------------------------*/
    public void run()
    {
        if ( m_runner == null )
        {
            // This is the runner
            m_runner = Thread.currentThread();
        }
        else
        {
            System.out.println("Stopping..." );
            // This is the shutdown hook.  Sloppy code, but simple :-)
            m_runner = null;
            return;
        }
        
        long startTime = System.currentTimeMillis();
        long lastTest = startTime;
        try
        {
            m_writer.write( "--> Starting Memory Log\n" );
            m_writer.flush();
    
            while( m_runner != null )
            {
                long now = System.currentTimeMillis();
                System.out.println( "Running for " + ( now - startTime ) + "ms..." );
                
                if ( now - lastTest > 15000 )
                {
                    Runtime rt = Runtime.getRuntime();
                    System.gc();
                    long totalMemory = rt.totalMemory();
                    long freeMemory = rt.freeMemory();
                    long usedMemory = totalMemory - freeMemory;
                    
                    m_writer.write( "total memory=" + pad( totalMemory, 10 )
                        + ", used=" + pad( usedMemory, 10 )
                        + ", free=" + pad( freeMemory, 10 ) + "\n" );
                    m_writer.flush();
                    
                    lastTest = now;
                }
                
                try
                {
                    Thread.sleep( 250 );
                }
                catch ( InterruptedException e )
                {
                }
            }
            
            m_writer.write( "<-- Stopping Memory Log\n" );
            m_writer.flush();
            m_writer.close();
        }
        catch ( IOException e )
        {
            e.printStackTrace();
        }
    }
    
    /*---------------------------------------------------------------
     * Methods
     *-------------------------------------------------------------*/
    private static final String PADDING = "                ";
    private String pad( long n, int len )
    {
        String s = Long.toString( n );
        int sLen = s.length();
        if ( sLen < len )
        {
            s = s + PADDING.substring( 0, len - sLen );
        }
        return s;
    }
    /*---------------------------------------------------------------
     * Main Method
     *-------------------------------------------------------------*/
    public static void main(String[] args)
    {
        System.out.println("Memory Tester Running...");
        
        // Locate the add and remove shutdown hook methods using reflection so
        //  that this class can be compiled on 1.2.x versions of java.
        Method addShutdownHookMethod;
        try {
            addShutdownHookMethod =
                Runtime.class.getMethod("addShutdownHook", new Class[] {Thread.class});
        } catch (NoSuchMethodException e) {
            System.out.println("Shutdown hooks not supported by current JVM.");
            addShutdownHookMethod = null;
        }
        
        Memory app = new Memory();
        
        // Create a Writer for the memory output
        try
        {
            app.m_writer = new FileWriter( "memory.log" );
        }
        catch ( IOException e )
        {
            e.printStackTrace();
            return;
        }
        
        // Register a shutdown hook using reflection.
        if (addShutdownHookMethod != null) {
            Runtime runtime = Runtime.getRuntime();
            Thread hook = new Thread( app, "shutdown-hook" );
            try {
                addShutdownHookMethod.invoke(runtime, new Object[] {hook});
            } catch (IllegalAccessException e) {
                System.out.println("Unable to register shutdown hook: " + e.getMessage());
            } catch (InvocationTargetException e) {
                System.out.println("Unable to register shutdown hook: " + e.getMessage());
            }
        }
        
        // Start the runner
        new Thread( app, "runner" ).start();
    }
}