iogate.java

只是一个简单模拟操作系统

/*
 * IOGate.java
 *
 * Created on 2006年3月15日, 下午9:53
 *
 *Each IODevice have a IOGate
 */

package os.iodevice;

/**
 *
 * @author Vernkin
 */
import os.process.*;


public class IOGate
{

        /**IOGate name**/
        String name;
    
	/**For outer programe,whether the IO devides is busy or not**/
	private boolean isFree = true;
	
	/**For IODriver,whether finish the last task**/
	private boolean isFinished = false;
	
	/**The basic unit of data is int**/
	private int data;
        
        private int interrupt_num;
	
	/**The MyProcess Object**/
	private MyProcess mp;
        
        
        private static IOGate printer = new IOGate("Printer");
        private static IOGate console = new IOGate("Console");
	
	
	/**Empty Constructor**/
	private IOGate(String name){
            this.name = name;
            isFree = true;
            isFinished = false;
	}
        
        public static IOGate getInstance(String device_name){
            if(device_name.equalsIgnoreCase("Printer"))
                return printer;
            else if(device_name.equalsIgnoreCase("Console"))
                return console;
            else{
                System.out.println("Init IOGate : Unknown IO Device "+device_name);
                System.exit(1);
                return null;
            }
        }
	
	
	/***************************************************************
	******************* For Outer Program **************************                         
	****************************************************************/
	
	
	/**Print a message to certain io devide
	 *
	 *@param p determine that io device
	 *
	 *@return If operates succesfully,return true,else false
	 *(Operates succesfully means change the ioGate status)
	 ***/
	public boolean managerOutput(MyProcess p,int data,int num){
                interrupt_num = num;
                mp = p;
		this.data = data;
		isFree = false;
		
		return true;
	}
	
	public boolean managerReadyToUse(){
		return isFree && !isFinished;
	}
	
	
	/**Whether the formal work is not responed**/
	public boolean managerRemainWork(){
		return isFinished;
	}
	
	
	public void managerResponseOK(){
		isFinished = false;
		System.out.println(name + " of manager response OK!");
	}
	
	
	/***************************************************************
	*********************** For IODriver ***************************                         
	****************************************************************/
	
	/**Whether **/
	public boolean driverHaveTask(){
		return !isFree && !isFinished;
	}
	
	
	
	
	public void driverSetData(int data){
		this.data = data;
		driverFinishWork();
	}
	
	
	/**finish the work at last**/
	public void driverFinishWork(){
            isFree = true;
            isFinished = true;
            System.out.println(name+" finish work");
	}
        
        public String getIOGateName(){
            return name;
        }
        
        public int getInterruptNum(){
            return interrupt_num;
        }
        
        public MyProcess getProcess(){
		return mp;
	}
               	
	
	public int getData(){
		return data;	
	}
        
        public void rest(int millsec){
            if(millsec<5000)
                millsec = 5000;
            try{
         //       System.out.println("IOGate Rest");
                Thread.sleep(millsec);          
            }catch(InterruptedException e){
                System.out.println(e.getMessage());
            }
        }
}