TunnelTest class

public class TunnelTest {
    public static void main(String[] args) {
        Tunnel portTunnel = new Tunnel(10);

        for(int j = 1;j<= 15; j++) {
            new Thread(new Car(portTunnel, j)).start();
            try {
                Thread.sleep(200);
            } catch(InterruptedException e) {

            }
        }
    }


}

class Car implements Runnable {

    //properties
    private Tunnel t;
    private int num;

    //constructor
    public Car(Tunnel t1, int n) {
        t = t1;
        num = n;
    }

    public void run() {
        t.waitTunnel(num);

        try {
            Thread.sleep(10000);
        } catch (InterruptedException e) {
            System.out.println("Car "+ num + " is crossing the tunnel");
        }


        t.signalTunnel(num);
    }
}

class Tunnel {

    //properties
    private int count;

    //constructor
    public Tunnel(int c) {
        count = c;
    }

    //critical resource
    public synchronized void waitTunnel(int n){
        // if count is zero the process must wait
        while(count == 0)
            try{
                wait();
            } catch(InterruptedException e){}

         // otherwise the process can continue
         count--;
         System.out.println("Car " +n+ " has Entered. " +  count + " spaces left in tunnel.");

    }

    public synchronized void signalTunnel(int n) {
         count++;
         System.out.println("Car "+n+" has left. " +  count + " spaces left in tunnel.");
         notify();

    }
}