title: why Javascript SetTimeout() is not multithreaded
body: <p>I have a test: </p>
  
  <p>Html:</p>
  
  <pre><code>&lt;div id="f1"&gt;Empty&lt;/div&gt;
  &lt;div id="f2"&gt;Empty&lt;/div&gt;
  
  ​
  </code></pre>
  
  <p>js:</p>
  
  <pre><code>var s1 = function() {
      for (i = 1; i &lt; 1000000000; i++) {
          var b = i * i;
      }
      $('#f1').html('Set');
  }
  
  var s2 = function() {
      if ($('#f1').html() == 'Empty') {
          $('#f2').html('Multi Thread');
          return;            
      };
      $('#f2').html('One Thread');
  }
  
  setTimeout(s2,110);
  setTimeout(s1,100);​
  </code></pre>
  
  <p>is there any real reason why setTimeOut() not run in different threads, instead like event model ?</p>
  
  <p><a href="http://jsfiddle.net/L4Rd8/4/" rel="noreferrer">jsfiddle</a></p>