gui.java

Reader Writer Problem to solve synchronization issues

// Methods to control the Gui thru Reader and Writer threads.


/*---------------------------------------------*/

public synchronized void   start_to_mutex_db(int tnum)
{
	tn=tnum;
        Currentimg = RWimg[tn];
	Currentpos[tn][0]=init[tn][0];
	Currentpos[tn][1]=init[tn][1];

 object_move(init[tnum][0],init[tnum][1],
		mutexdb[tn][0],mutexdb[tn][1],move[3]);
}



public synchronized void   db_to_start(int tnum)
{
   	tn=tnum;
        Currentimg = RWimg[tn];
	Currentpos[tn][0]=dbtop[0];
	Currentpos[tn][1]=dbtop[1];

 object_move(Currentpos[tn][0],Currentpos[tn][1],
                init[tn][0],init[tn][1],move[2]);

}

/*---------------------------------------------*/

public synchronized void   mutex_lock(int tnum)
{

   	tn=tnum;
        Currentimg = RWimg[tn];
	Current_mutexlock=mutexlock;

 	Graphics g=getGraphics();

        g.clearRect(Currentpos[tn][0],Currentpos[tn][1],
                Currentimg.getWidth(this),Currentimg.getHeight(this));

	Currentpos[tn][0]=mutexbottom[0];
	Currentpos[tn][1]=mutexbottom[1];
        g.drawImage(Currentimg,mutexbottom[0],mutexbottom[1],this);

        g.clearRect(mutex[0],mutex[1],
                Current_mutexlock.getWidth(this),
			Current_mutexlock.getHeight(this));

        g.drawImage(mutexlock,mutex[0],mutex[1],this);
        g.dispose();
}

public synchronized void   mutex_unlock(int tnum, int num)
{
	int abc;
 	Graphics g=getGraphics();
   	tn=tnum;
	abc=num;
        Currentimg = RWimg[tn];
	Current_mutexlock=mutexunlock;

        	g.clearRect(mutex[0],mutex[1],
                	Current_mutexlock.getWidth(this),
				Current_mutexlock.getHeight(this));

        	g.drawImage(mutexunlock,mutex[0],mutex[1],this);

	if (num==1)
	{
        	g.dispose();
        	object_move(mutexbottom[0],mutexbottom[1],
			mutexright[tn][0],mutexright[tn][1],move[0]);
	}
	else if(num==2)
	{
        	g.clearRect(Currentpos[tn][0],Currentpos[tn][1],
	                Currentimg.getWidth(this),Currentimg.getHeight(this));

		Currentpos[tn][0]=mutexdb[tn][0];
		Currentpos[tn][1]=mutexdb[tn][1];

	       g.drawImage(Currentimg,Currentpos[tn][0],Currentpos[tn][1],this);
		g.dispose();
                object_move(mutexdb[tn][0],mutexdb[tn][1],
				init[tn][0],init[tn][1],move[3]);

	}
}

/*---------------------------------------------*/

public synchronized void   db_lock(int tnum)
{
        tn=tnum;
        Currentimg = RWimg[tn];
	Current_dblock=dblock;

 	Graphics g=getGraphics();

        g.clearRect(Currentpos[tn][0],Currentpos[tn][1],
	             Currentimg.getWidth(this),Currentimg.getHeight(this));

        g.clearRect(db[0],db[1],
               	Current_dblock.getWidth(this),
			Current_dblock.getHeight(this));
        g.drawImage(dblock,db[0],db[1],this);



	Currentpos[tn][0]=dbbottom[0];
	Currentpos[tn][1]=dbbottom[1];
        g.drawImage(Currentimg,Currentpos[tn][0],Currentpos[tn][1],this);

        g.dispose();


}
public synchronized void   db_unlock(int tnum)
{
	Graphics g=getGraphics();
        tn=tnum;
        Currentimg = RWimg[tn];
	Current_dblock=dbunlock;

        g.clearRect(Currentpos[tn][0],Currentpos[tn][1],
               	Currentimg.getWidth(this),
			Currentimg.getHeight(this));

	Currentpos[tn][0]=dbtop[0];
	Currentpos[tn][1]=dbtop[1];
        g.drawImage(Currentimg,Currentpos[tn][0],Currentpos[tn][1],this);


        g.clearRect(db[0],db[1],
               	Current_dblock.getWidth(this),
			Current_dblock.getHeight(this));
        g.drawImage(dbunlock,db[0],db[1],this);
        g.dispose();
}

/*---------------------------------------------*/

public synchronized void   db_down_to_mutex(int tnum)
{
        tn=tnum;
        Currentimg = RWimg[tn];
	object_move(dbbottom[0],dbbottom[1],
			mutexbottom[0],mutexbottom[1],move[0]);

}
public synchronized void   db_up_to_mutex(int tnum)
{
        tn=tnum;
        Currentimg = RWimg[tn];
	object_move(dbtop[0],dbtop[1],
			mutexbottom[0],mutexbottom[1],move[0]);
}


public synchronized void   dbase_to_mutex(int tnum)
{
  	tn=tnum;
	Currentimg = RWimg[tn];
        object_move(dbasepos[tn][0],dbasepos[tn][1],
                        mutexdb[tn][0],mutexdb[tn][1],move[1]);

}
public synchronized void   dbase_to_db(int tnum)
{
  	tn=tnum;
 	Currentimg = RWimg[tn];
        object_move(dbasepos[tn][0],dbasepos[tn][1],
                        dbbottom[0],dbbottom[1],move[3]);
}

/*---------------------------------------------*/

public synchronized void   dbase_data(int tnum, int val)
{
	Graphics g=getGraphics();
        tn=tnum;
	readval[tn]=val;
	 g.clearRect(datapos[tn][0],datapos[tn][1],
                textbox.getWidth(this),textbox.getHeight(this));
	g.drawImage(textbox,datapos[tn][0],datapos[tn][1],this);

 	if((tn==0)||(tn==3))
        g.setColor(Color.red);
        else if((tn==2)||(tn==4))
        g.setColor(Color.blue);
        else
        g.setColor(Color.green);

   	g.setFont(new Font("Helvetica",Font.BOLD,14));
	g.drawString(String.valueOf(readval[tn]),datapos[tn][0]+15,datapos[tn][1]+18);
	g.dispose();
}

public synchronized void   read_dbase(int tnum)
{
// code to move from mutexright to dbase;
	tn=tnum;
 	Currentimg = RWimg[tn];
	object_move(mutexright[tn][0],mutexright[tn][1],
                        dbasepos[tn][0],dbasepos[tn][1],move[2]);
}


public synchronized void   db_to_dbase(int tnum)
{
// code to move from dbbottom to dbase;
	tn=tnum;
	 Currentimg = RWimg[tn];
	object_move(dbbottom[0],dbbottom[1],
                        dbasepos[tn][0],dbasepos[tn][1],move[2]);

}

public synchronized void   write_dbase(int tnum, int val)
{
	writeval=val;

	Graphics g=getGraphics();
  	g.clearRect(writebox[0],writebox[1],
                textbox.getWidth(this),textbox.getHeight(this));
        g.drawImage(textbox,writebox[0],writebox[1],this);
	
	g.setFont(new Font("Helvetica",Font.BOLD,14));
        g.drawString(String.valueOf(writeval),writebox[0]+15,writebox[1]+18);
	g.dispose();
}
/*---------------------------------------------*/

public synchronized void   rc_plus_minus(int tnum, int val1)
{
	rcval=val1;
	tn=tnum;
	Currentimg=RWimg[tn];
        object_move(mutexbottom[0],mutexbottom[1],
			mutexright[tn][0],mutexright[tn][1],move[0]);

	Graphics g=getGraphics();
        tn=tnum;
         g.clearRect(rcpos[0],rcpos[1],
                textbox.getWidth(this),textbox.getHeight(this));
        g.drawImage(textbox,rcpos[0],rcpos[1],this);
   	g.setFont(new Font("Helvetica",Font.BOLD,14));
        g.drawString(String.valueOf(rcval),rcpos[0]+15,rcpos[1]+18);
        g.dispose();
}


public synchronized void   rc_one_db(int tnum)
{
  	tn=tnum;
        Currentimg=RWimg[tn];
        object_move(mutexright[tn][0],mutexright[tn][1],
                        dbleft[0],dbleft[1],move[0]);

}

public synchronized void   rc_zero_db(int tnum)
{
	tn=tnum;
	Currentimg=RWimg[tn];
	object_move(mutexright[tn][0],mutexright[tn][1],
			dbbottom[0],dbbottom[1],move[0]);
}

public synchronized void   rc_not_one_zero(int tnum)
{
  	tn=tnum;
        Currentimg=RWimg[tn];
        object_move(mutexright[tn][0],mutexright[tn][1],
                        mutexbottom[0],mutexbottom[1],move[0]);

}

public synchronized void   rc_one_zero(int tnum,int cas)
{
	int cases;
// add rc=1,0 flashing code; flash only when rc=0,1;
       	tn=tnum;
	cases=cas;
	Color color[]= {Color.red,Color.green,Color.blue};

	Graphics g=getGraphics();


	if(cases==1)
	{
	 blinkerflag=true;
	 while(blinkerflag==true)
	  {
	  for(int i=0;i<3;i++)
	   {
        	g.clearRect(rcpos[0],rcpos[1],
	                textbox.getWidth(this),textbox.getHeight(this));
        	g.drawImage(textbox,rcpos[0],rcpos[1],this);
		g.setColor(color[i]);
        	g.setFont(new Font("Helvetica",Font.BOLD,14));
        	g.drawString(String.valueOf(rcval),rcpos[0]+15,rcpos[1]+18);
		pause(100);
	    }
	   } 
 	}
	else if (cases==2)
	
	   for (int j= 0; j<5; j++)
	   {
	      for(int i=0;i<3;i++)
	      {
        	g.clearRect(rcpos[0],rcpos[1],
	                textbox.getWidth(this),textbox.getHeight(this));
        	g.drawImage(textbox,rcpos[0],rcpos[1],this);
		g.setColor(color[i]);
        	g.setFont(new Font("Helvetica",Font.BOLD,14));
        	g.drawString(String.valueOf(rcval),rcpos[0]+15,rcpos[1]+18);
		pause(100);
	      }
	    }
	  
	        g.dispose();
}

/*---------------------------------------------*/
public final void updatescale(int scal)
{
	scale=scal;
// 	System.out.println("New Scale : "+scale);
}
	
public final void rc_reset()
{
	blinkerflag=false;
	Graphics g=getGraphics();
		g.clearRect(rcpos[0],rcpos[1],
                        textbox.getWidth(this),textbox.getHeight(this));
                g.drawImage(textbox,rcpos[0],rcpos[1],this);

	 	g.setColor(Color.black);
                g.setFont(new Font("Helvetica",Font.BOLD,14));
                g.drawString(String.valueOf(rcval),rcpos[0]+15,rcpos[1]+18);

	g.dispose();
		
}

}// end public class Gui