class BoundedBuffer {
    private int front = 0, back = 0, count = 0;
    private int NoOfElems;
    private int [] Elements;

    public BoundedBuffer( int size ) {
	NoOfElems = size;
	Elements = new int[NoOfElems];
    } // BoundedBuffer

    public int query() {
	return count;
    } // query

    public synchronized void insert( int elem ) {
	while ( count == NoOfElems ) {
	    try {
		wait();
	    } catch( InterruptedException ex ) {
	    } // try
	} // while

	Elements[back] = elem;
	back = ( back + 1 ) % NoOfElems;
	count += 1;

	notify();
    } // insert

    public synchronized int remove() {
	int elem;

	while ( count == 0 ) {
	    try {
		wait();
	    } catch( InterruptedException ex ) {
	    } // try
	} // while

	elem = Elements[front];
	front = ( front + 1 ) % NoOfElems;
	count -= 1;

	notify();
	return elem;
    } // remove
} // BoundedBuffer

class Consumer extends Thread {
    private BoundedBuffer buf;

    public Consumer( BoundedBuffer buf ) {
	this.buf = buf;
    } // Consumer

    public void run() {
	for ( ;; ) {
	    int elem = buf.remove();
	  if ( elem == -1 ) break;
	    System.out.println( "Consumer:" + this + " value:" + elem );
	} // for
    } // run
} // Consumer

class Producer extends Thread {
    private BoundedBuffer buf;

    public Producer( BoundedBuffer buf ) {
	this.buf = buf;
    } // Producer

    public void run() {
	int NoOfElems = 40;

	for ( int i = 1; i <= NoOfElems; i += 1 ) {
	    int elem = (int)(Math.random() * 100);
	    System.out.println( "Producer:" + this + " value:" + elem );
	    buf.insert( elem );
	} // for
    } // run
} // Producer

public class BB {
    public static void main( String[] args ) throws InterruptedException {
	int NoOfCons = 3, NoOfProds = 4, i;
	BoundedBuffer buf = new BoundedBuffer( 5 );
	Consumer[] cons  = new Consumer[NoOfCons];
	Producer[] prods = new Producer[NoOfProds];

	for ( i = 0; i < NoOfCons; i += 1 ) {
	    cons[i] = new Consumer( buf );
	    cons[i].start();
	} // for
	for ( i = 0; i < NoOfProds; i += 1 ) {
	    prods[i] = new Producer( buf );
	    prods[i].start();
	} // for
	for ( i = 0; i < NoOfProds; i += 1 ) {
	    prods[i].join();
	} // for
	for ( i = 0; i < NoOfCons; i += 1 ) {
	    buf.insert( -1 );
	} // for
	for ( i = 0; i < NoOfCons; i += 1 ) {
	    cons[i].join();
	} // for
	System.out.println( "successful completion" );
    } // main
} // BB