j_synchronization.java.bak

一个十分好的java基础学习的课件

// ////////////////////////////////////////////////////////
// 
// J_Synchronization.java
// 
// Created by Jun-Hai Yong,    on XX xx, xxxx (Date)
// ////////////////////////////////////////////////////////
// Readme:
//      Demonstrating synchronization of threads.
// ////////////////////////////////////////////////////////
// Using this example, please explicitly refer to the book:
//     Jun-Hai Yong. Programming in Java. 
//     Beijing: Tsinghua University Press, 2004.
// 使用本例子，请注明引用:
//     雍俊海. Java 程序设计. 北京: 清华大学出版社, 2004.
// Please note that the author and publisher make no 
// warranty of any kind on the examples provided.
// ////////////////////////////////////////////////////////

class J_Experiment
{
    private int m_temperature, m_pressure;
    
    public void mb_update(int t, int p)
    {
        m_temperature = t;
        m_pressure    = p;
        System.out.println("Update: (" + m_temperature + "(t), " + m_pressure + "(p))");
    } // End of method: mb_update
    
    public void mb_analyze( )
    {
        int t= m_temperature;
        int p= m_pressure;
        if (t!=m_temperature)
        {
            System.out.print("It is very dangerous now: ");
            System.out.println("t(" + t + ") != (" + m_temperature + ")");
            System.exit(0);
        }
        if (p!= m_pressure)
        {
            System.out.print("It is very dangerous now: ");
            System.out.println("p(" + p + ") != (" + m_pressure + ")");
            System.exit(0);
        }
        System.out.println("Analyze: (" + m_temperature + "(t), " + m_pressure + "(p))");
    } // End of method: mb_analyze
} // End of class: J_Experiment

class J_Assistant extends Thread
{
    J_Experiment m_data;
    
    public J_Assistant(J_Experiment d)
    {
        m_data= d;
    } // End of constructor

    public void run( )
    {
        int i, j;
        for(; true; )
        {
            i= (int)(Math.random( ) * 1000);
            j= (int)(Math.random( ) * 1000);
            synchronized(m_data)
            {
                m_data.mb_update(i, j);
            }
        }
    } // End of method: run
} // End of class: J_Assistant

class J_Analyst extends Thread
{
    J_Experiment m_data;
    
    public J_Analyst(J_Experiment d)
    {
        m_data= d;
    } // End of constructor
    
    public void run( )
    {
        int i;
        for(; true; )
        {
            synchronized(m_data)
            {
                m_data.mb_analyze( );
            }
        }
    } // End of method: run
} // End of class: J_Analyst

public class J_Synchronization
{
    
    public static void main( String args[] )
    { 
        J_Experiment data= new J_Experiment( );
        J_Assistant threadA = new J_Assistant(data);
        J_Analyst   threadB = new J_Analyst(data);
        threadA.start( );
        threadB.start( );
    } // End of method: main

}  // End of class: J_Synchronization