package semaphore; import java.util.ArrayList; import java.util.Random; public class Main { public static void main(String arg[]) throws Exception { Random r = new Random(); ArrayList threads = new ArrayList(); Semaphore s = new Semaphore(4); //create some threads for (int i=0; i<10; i++) { MyThread mt = new MyThread(r, i, s); threads.add(mt); } //start all the threads for (Thread t: threads) { t.start(); } } }