package Lab3;

import java.util.concurrent.Semaphore;

public class Exercise5 {

    int waitingCustomers = 0;

    public Semaphore availableSeats = new Semaphore(5);
    public Semaphore lock = new Semaphore(1);


    public class Customer extends Thread{
        void customerComesIn() throws InterruptedException {
            // TODO: 3/29/20 Synchronize this method, invoked by a Customer thread
            availableSeats.acquire();
            lock.acquire();
            waitingCustomers++;
            lock.release();
        }

        @Override
        public void run() {
            try {
                customerComesIn();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    public class Barber extends Thread{
        void barber() throws InterruptedException {
            // TODO: 3/29/20 Synchronize this method, invoked by Barber thread
            lock.acquire();
            if (waitingCustomers > 0) {
                System.out.println("Haircut...");
                waitingCustomers--;
                availableSeats.release();
            }
            lock.release();
        }

        @Override
        public void run() {
            try {
                barber();
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }


    public static void main(String[] args) {
        // TODO: 3/29/20 Synchronize the scenario

    }
}