ThreadsCounter

public class Main {

    public static volatile int counter = 100000;

    public static int tc1 = 0;
    public static int tc2 = 0;
    public static int tc3 = 0;
    public static int tc4 = 0;

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

        Thread w1 = new FirstThread();
        Thread w2 = new SecondThread();
        Thread w3 = new ThirdThread();
        Thread w4 = new FourthThread();


        while(counter > 0) {

            if(!w1.isAlive()) {

                w1 = new FirstThread();
                w1.start();
                w1.join();
            }

            if(!w2.isAlive()) {
                w2 = new SecondThread();
                w2.start();
                w2.join();
            }

            if(!w3.isAlive()) {
                w3 = new ThirdThread();
                w3.start();
                w3.join();
            }

            if(!w4.isAlive()) {
                w4 = new FourthThread();
                w4.start();
                w4.join();
            }


            System.out.println("Counter: " + counter);
        }

        Counters();
        Beep();

    }



    static void Counters(){
        System.out.println("Wątek pierwszy wykonał: " + tc1 + " operacji");
        System.out.println("Wątek drugi wykonał: " + tc2 + " operacji");
        System.out.println("Wątek trzeci wykonał: " + tc3 + " operacji");
        System.out.println("Wątek czwarty wykonał: " + tc4 + " operacji");
    }

    static void Beep(){
        if (counter == 0) {

            Toolkit.getDefaultToolkit().beep();

        }
    }


    private static class FirstThread extends Thread {
        public void run() {

            if(counter > 0) counter --;
            tc1++;

        }
    }

    private static class SecondThread extends Thread {
        public void run(){

            if(counter > 0) counter --;
            tc2++;

        }

    }

    private static class ThirdThread extends Thread {
        public void run(){

            if(counter > 0) counter --;
            tc3++;

        }
    }

    private static class FourthThread extends Thread {
        public void run(){

            if(counter > 0) counter --;
            tc4++;

        }


    }


}