title: If nodejs uses non blocking IO, how is fs.readFileSync implemented?
body: <p>I see a lot of synchronous functions in the <a href="http://nodejs.org/api/fs.html">file system library</a>. such as <code>fs.readFileSync(filename, [options])</code>. </p>
  
  <p>How (and why) are these functions implemented if node has async/non-blocking IO and no sleep method - and can I use the same mechanism to implement other synchronous functions?</p>