import java.awt.*;  
import java.awt.image.*;  
import java.awt.event.*; 
import java.util.*;  
import java.applet.*;  
import java.net.*;  
import java.awt.Component.*; 
import java.awt.Color.*; 
import java.awt.Graphics; 
import java.util.Random; 
import java.lang.Math; 
import java.awt.event.WindowListener; 


// example Thread producer consumer 
// implemented by Dr. Roger Webster 
public class producerconsumer extends Applet
{
        Frame window;
        Button openbutton;
        Button closebutton;
		TextArea textarea = new TextArea(24, 80);
		public Producer b;
		public Consumer c;

	public void init() 
	{		
		b = new Producer("The Producer");
		b.start();
		c = new Consumer("The Consumer", b);
		c.start();
      //  	openbutton = new Button("KILL Producer");
      //  	closebutton = new Button("KILL Consumer");
       // 	this.add(openbutton);
       // 	this.add(closebutton);
        	window = new Frame ("Webster's Sample Java Thread Window");
        	window.reshape (100, 100, 400, 400);
	  	textarea.setFont(new Font("Helvetica", Font.PLAIN, 12));
	  	textarea.setEditable(false);
        	window.add("Center", textarea);
        	textarea.appendText("Java Producer Consumer Lockstep Synchronization Thread example\n");
        	window.show();

  	}

        public void stop() 
        {
                	window.dispose();
			b.killme();
			c.killme();
        }

        // action -  a button pressed.
        public boolean action(Event event, Object arg) 
        {
                if (event.target == closebutton)
                {
                        //window.hide();
				c.killme();

                }
                if (event.target == openbutton)
                {
                       	b.killme();
 			//	window.show();
                }

                return true;
        }

        // user presses a mouse button.
        public boolean mouseDown(Event e, int x, int y) 
        {
                return true;
        }

	class Producer extends Thread
	{ 
		long mytime;	
  	  	boolean keeprunning = true;
		private int mystring = 0;

		public Producer (String name)
		{
			super (name);
	
		}//end constructor

		public void killme()
		{
		 	keeprunning = false;
		}
		public synchronized void putmessage()
		{
		 	try
			{
				if (mystring == 1)
				{
				   textarea.appendText("Producer is " + "waiting" +"\n"); 
				   System.out.println("Producer is "+ "waiting" +"\n");
				   wait();
				}
			}
			catch (Exception e) 
			  { System.out.println("exception in thread " + e.toString());}

			mystring = 1; //new java.util.Date().toString();
			textarea.appendText(this.getName()+ " Produced "+ mystring + " \n");
			System.out.println(this.getName()+ " Produced "+ mystring +"\n");

			notify();
		}
		public synchronized int getmessage()
		{
			int s;
			try
			{
				if (mystring == 0)
				 {  
					textarea.appendText("Consumer "+ "waiting" +"\n"); 
					System.out.println("Consumer "+ "waiting" +"\n");
					wait();
				 }
			}
			catch (Exception e) 
			  { System.out.println("exception in thread " + e.toString());}


			s = mystring;
			mystring = 0;
			textarea.appendText("Consumer consumed: "+s+ " \n");
			System.out.println( "Consumer consumed: "+ s +"\n");
			notify();
		 	return (s);
		}

		public void run()
		{
			while (keeprunning)
			{
				this.putmessage();
				try
				{
					mytime = (long)(Math.random() * 10000);
					Thread.sleep(mytime);
				}
				catch (Exception e) 
				{ System.out.println("exception in thread sleep" + e.toString());}

			}

		}//end run

	}//end mythread

	class Consumer extends Thread
	{ 
		long mytime;	
  	  	boolean keeprunning = true;
		Producer producer;
		int consumerstring;

		public Consumer (String name, Producer p)
		{
			super(name);
			producer = p;

		}//end constructor

		public void killme()
		{
		 	keeprunning = false;
		}

		public void run()
		{
			while (keeprunning)
			{
				
				consumerstring = producer.getmessage();
	
				try
				{
					mytime = (long)(Math.random() * 1000);
					Thread.sleep(mytime);
				}
				catch (Exception e) 
				{ System.out.println("exception in thread sleep" + e.toString());}

			}

		}//end run

	}//end mythread

}//end applet