Code to copy:


/************** File name: Semaphore.java ***************/
import java.util.Date;

class Semaphore
{
private int sem;

public synchronized void swait()
{
  while (sem <= 0)
  {
   try
   {
    wait(500);
   } catch (Exception e)
   {
    System.exit(0);
   }
   ;
  } // II end while
  sem--; // II decrease value of sem
}// end swait
  //

public synchronized void signal()
{
  sem++;
  notify();
} // end signal
  //
  // constructor

public Semaphore(int intval)
{
  sem = intval; // initialize attribute sem
} // end class Semaphore
}

/************** File name: Producer.java ***************/
class Producer extends Thread
{
SharedBuffer buffer;
Semaphore full;
Semaphore empty;
Semaphore mutex;

Producer(SharedBuffer b, Semaphore f, Semaphore e, Semaphore m)
{
  buffer = b;
  full = f;
  empty = e;
  mutex = m;
}

public void run()
{
  try
  {
   char value = 'a';
   while (true)
   {
    empty.swait();
    mutex.swait();
    buffer.insert(value);
    System.out.println("Producer Value:" + value);
    mutex.signal();
    full.signal();
    Thread.sleep(100);
    value += 2;
    if(value > 100 )
    {
     value = 0;
    }
   }
  } catch (InterruptedException e)
  {
   System.out.println("Producer: But I wasn't done!!!");
  }
}
}


/************** File name: Consumer.java ***************/

class Consumer extends Thread {
    SharedBuffer buffer;
    Semaphore full;
    Semaphore empty;
    Semaphore mutex;

    Consumer(SharedBuffer b, Semaphore f, Semaphore e, Semaphore m) {
        buffer = b;
        full = f;
        empty = e;
        mutex = m;
    }

    public void run() {
        try {
          char value;
          while(true) {
            full.swait();
            mutex.swait();
            value = buffer.retrieve();
            mutex.signal();
            empty.signal();
            System.out.println("Consumer Value: " + value);
            Thread.sleep(200);
          }
        } catch (InterruptedException e) {
          System.out.println("Consumer: But I wasn't done!!!");
      }
    }
}


/************** File name: SharedBuffer.java ***************/
// Create a class named SharedBuffer
class SharedBuffer
{
// Create an array of type char
private char[] buffer;

private int in = 0;
private int out = 0;
private int count = 0;
private int size;

SharedBuffer(int size)
{
  this.size = size;
  buffer = new char[size];
}

public void insert(char o)
{
  buffer[in] = o;
  ++count;
  in = (in + 1) % size;
}

public char retrieve()
{
  int ret_val = buffer[out];
  --count;
  out = (out + 1) % size;
  return ((char) ret_val);
}
}


/************** File name: ProdconSync.java ***************/
// Create a class named ProdconSync
public class ProdconSync
{
// number of slots in buffer
static final int N = 100;
static SharedBuffer sharedBuff = new SharedBuffer(N);

// Create a main method to run the program.
public static void main(String args[])
{
  Semaphore mutex = new Semaphore(1);
  Semaphore full = new Semaphore(0);
  Semaphore empty = new Semaphore(N);

  Producer prod = new Producer(sharedBuff, mutex, full, empty);
  Consumer cons = new Consumer(sharedBuff, mutex, full, empty);
  prod.start();
  cons.start();

} // end main
} // end class ProdconSync