UsingSemaphore.java

    public static class UsingSemaphore {

        volatile static boolean check = true;
        volatile static boolean producerStarted = false;
        volatile static boolean consumerStarted = false;

        public static void main(String args[]) throws InterruptedException {

            Semaphore semCon = new Semaphore(0);

            Semaphore semProd = new Semaphore(1);

            Queue<Integer> q = new LinkedList<>();


            // Producer lambda
            Runnable producer = () -> {
                while (check) {
                    producerStarted = true;
                    try {
                        semProd.acquire();

                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    try {

                        Random rand = new Random();
                        q.add(rand.nextInt(10));
                    }finally {
                        semCon.release();

                    }
                }
            };
            //Consumer lambda
            Runnable consumer = () -> {
                while (check) {
                    consumerStarted = true;
                    try {

                        semCon.acquire();

                    } catch (InterruptedException e) {
                        // TODO Auto-generated catch block
                        e.printStackTrace();
                    }
                    try {
                        System.out.println("Consumer item " + q.remove());

                    }finally {
                        semProd.release();

                    }
                }
            };

            ThreadGroup pg = new ThreadGroup("PG");
            ThreadGroup cg = new ThreadGroup("CG");

            Thread p1 = new Thread(pg, producer, "p1");

            Thread c1 = new Thread(cg, consumer, "c1");

            producerStarted = false;
            consumerStarted = false;
            check = true;

            p1.start();
            c1.start();

            Thread.sleep(10);
            while (!consumerStarted || !producerStarted) {
                Thread.sleep(1);
            }
            check = false;
            p1.join();
            c1.join();
        }
    }