title: What's the number should be the "n" of new CyclicBarrier(n)?
body: <p>Recently I learned CyclicBarrier, but here's a question:</p>
  
  <p>Code:</p>
  
  <pre><code>public class Main {
      public static CyclicBarrier c;
  
      public static void main(String[] agrs){
          int threadsCount = 5;
          c = new CyclicBarrier(threadsCount + 1);
          // make 5 A threads to run
      }
  }
  
  public class A implements Runnable {
  
      public void run(){
          // do something
         Main.c.await();
          // do something
      }
  }
  </code></pre>
  
  <p>In about code, I wonder that why I must initialize CyclicBarrier by (threadsCount + 1) but not (threadsCount), since I never invoke await() in the main method?</p>