deadlocktest.java

模拟操作系统的进程死锁

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class DeadLockTest extends JFrame {
	
	private String choose;
	private int current;
	private String[][] input = new String[3][3]; 
    private int num[][] = new int[3][3];
    private String[] resinput = new String[3];
    private String[] srequest = new String[3];  
    private String[][] firstinput = new String[3][3];
    private int first[][] = new int[3][3];
    private int resource[] = new int[3]; 
    private int request[][] = new int[3][3];
    private int thread[] = new int[3];
    private int need[][] = new int[3][3];
    private int available[] = new int[3];
    
    public DeadLockTest()
    {
    	for( int k = 0 ; k < 3 ; k++ )
    	  {
    	  	resinput[k] = 
    	          JOptionPane.showInputDialog("请输入第"+(k+1)+"类资源的总数量:");
    	    resource[k] = Integer.parseInt( resinput[k] ) ;      
    	  }       
    	for( int i = 0 ; i < 3 ; i++ )
    	   
    	   	for( int j = 0 ; j < 3 ; j++ )
    	    {
    	       input[i][j] = 
    	          JOptionPane.showInputDialog("请输入第个"+ (i+1) +"进程的所需要第"+ (j+1) +"类资源个数:");
    	       num[i][j] = Integer.parseInt( input[i][j] ) ; 
    	       firstinput[i][j] = 
    	          JOptionPane.showInputDialog("请输入第个"+ (i+1) +"进程的开始有"+ (j+1) +"类的资源数:");
    	       first[i][j] = Integer.parseInt( firstinput[i][j] ) ; 	
    	   	}
    	   	choose = new String();
    		choose = 
    	          JOptionPane.showInputDialog("输入申请资源的进程:"); 
    	    current  = Integer.parseInt( choose ) - 1 ;       	
    	   
    	for( int r = 0 ; r < 3 ; r++ )
    	  {
    	  	srequest[r] = 
    	          JOptionPane.showInputDialog("请输入首次申请第"+(r+1)+"类资源的数量:");
    	    request[current][r] = Integer.parseInt( srequest[r] ) ;      
    	  } 
    	for ( int n = 0 ; n < 3 ; n++ )
           for( int m = 0; m< 3 ; m++ )
           
           	 need[n][m] = num[n][m] - first[n][m];
           	 
         
        available[0] = resource[0] - ( first[0][0] + first[1][0] + first[2][0]);   	 
        available[1] = resource[1] - ( first[0][1] + first[1][1] + first[2][1]);
        available[2] = resource[2] - ( first[0][2] + first[1][2] + first[2][2]);
    }
    
    public void run()
    {   
        
    	if( request[current][0] <= need[current][0]&&request[current][1] <= need[current][1]&&request[current][2] <= need[current][2])
    	 {
    	   	 if( request[current][0] <= available[0]&&request[current][1] <= available[1]&&request[current][2] <= available[2])
    	     {
    	     	for(int i = 0 ; i < 3 ;i++ )
    	     	{
    	     		available[i] = available[i] - request[current][i];
    	     	    first[current][i] = first[current][i] + request[current][i];
    	     	    need[current][i] = need[current][i] - request[current][i];
    	     	}
    	     if( !issafe() )
    	     {
    	     	JOptionPane.showMessageDialog( null , "安全序列为;" + thread[current] + thread[1]+ thread[2]);
    	     }
    	    }
    	     else
    	     JOptionPane.showMessageDialog( null , " 无法分配等待:");	
    	   
    	    	
         }
    	else
    	
    	  JOptionPane.showMessageDialog( null , "wrong" );
}
    
    
    public boolean issafe()
    {
    	int work[] = new int[3];
    	boolean finish[] = new boolean[3];
        for( int i = 0 ; i < 3 ; i++ )
        {
        	work[i] = available[i];
        	finish[i] = false;
        }
        for( int i = 0 ; i < 3 ; i++ )
        {
        	
        	 if(finish[i] = false&&need[i][0] <= work[0]&&need[i][1] <= work[1]&&need[i][2] <= work[2])
        	  {
        	  	work[0] = work[0] + first[i][0];
        	    work[1] = work[1] + first[i][1];
        	    work[2] = work[2] + first[i][2];
        	    finish[i] = true;
        	    thread[i+1] = i;
        	    
        	  }
            else break;
        }
        
         if( finish[0] == true && finish[0] == true && finish[0] == true )
         return true;
         else 
         return false;
    }
    public static void main( String args[] )
    {
    	DeadLockTest app = new DeadLockTest();
    	app.run();
    }
}