// SharedCell1.java
// Multiple Threads modify a shared object
// No synchronization
// This is an example of Deitel & Deitel, but turned 
// into an applet.

import java.applet.Applet;
import java.awt.*;

public class SharedCell1 extends Applet{
	TextField producertext, consumertext;
	ProduceInteger1 p;
	ConsumeInteger1 c;
	HoldInteger1 h;

	public void init()
	{
		// Set up the awt components.
		producertext = new TextField(40);
		consumertext = new TextField(40);
		
		add( producertext);
		add( consumertext);
		
		// Set up the shared object.
		h = new HoldInteger1();
		
	}
	
	// Start the two threads.
	public void start(){
		p = new ProduceInteger1(h, this);
		c = new ConsumeInteger1(h, this);

		p.start();
		c.start();
	}

	public void stop(){
		p.stop();
		c.stop();
	}
	// Methods to change the text fields.
	public void setProducerText(String s){
		producertext.setText(s);
		repaint();
	}		

	public void setConsumerText(String s){
		consumertext.setText(s);
		repaint();
	}


}


class ProduceInteger1 extends Thread {
	private HoldInteger1 pHold;
	private SharedCell1 theapplet;

	// Constructor needs to know shared object and applet.
	public ProduceInteger1( HoldInteger1 h,SharedCell1 s)
	{
		pHold = h;
		theapplet = s;
	}

	public void run()
	{
		// Count to 10 in shared object. 
		// Sleep random amounts of time to let consumer in.
		
		for( int count = 0; count < 10; count++)
		{
			pHold.setSharedInt(count);
			theapplet.setProducerText("Producer set sharedInt to " + count);
			
			try {
				sleep( (int) (Math.random() * 3000));
			}
			catch( InterruptedException e) {
				
			}
		}
	}
}

class ConsumeInteger1 extends Thread {
	private HoldInteger1 cHold;
	private SharedCell1 theapplet;

	// This thread needs to know the shared object and the applet.
	public ConsumeInteger1( HoldInteger1 h, SharedCell1 s)
	{
		theapplet = s;
		cHold = h;
	}

	// Go out 10 times and retrieve whatever is in the 
	// shared object. Sleep random amounts of time to
	// let consumer in.
	public void run()
	{
		int val;
	
		val = cHold.getSharedInt();
		theapplet.setConsumerText("Consumer gets " + val);
	
		while( val != 9 ) {
			try {
				sleep( (int) (Math.random() * 3000));
			}
			catch( InterruptedException e) {
			}

		val = cHold.getSharedInt();
		theapplet.setConsumerText("Consumer retrieves " + val);

		}
	}
}

class HoldInteger1 {
	// Container for one integer, with methods
	// for setting and retrieving it.
	private int sharedInt;

	public void setSharedInt( int val )
	{
		sharedInt = val;
	}

	public int getSharedInt()
	{
		return sharedInt;
	}
}