title: What is the synchronization cost of calling a synchronized method from a synchronized method?
body: <p>Is there any difference in performance between this</p>
  
  <pre><code>synchronized void x() {
      y();
  }
  
  synchronized void y() {
  }
  </code></pre>
  
  <p>and this</p>
  
  <pre><code>synchronized void x() {
      y();
  }
  
  void y() {
  }
  </code></pre>