title: issue with stream_select() in PHP
body: <p>I am using stream_select() but it returns 0 number of descriptors after few seconds and my function while there is still data to be read.</p>
  
  <p>An unusual thing though is that if you set the time out as 0 then I always get the number of descriptors as zero. </p>
  
  <pre><code>$num = stream_select($read, $w, $e, 0);
  </code></pre>