title: NSTimer or NSThread in iOs 4 background mode
body: <p>I have to keep a NSThread or NSTimer when my iPhone application goes into background mode. Is it possible ? I have enabled the background modes  in info.plist and opened readstream and writestream  as follows ...(I am using UDP)</p>
  
  <blockquote>
    <p>CFReadStreamSetProperty(readStream, kCFStreamNetworkServiceType,kCFStreamNetworkServiceTypeVoIP);</p>
  
  <pre><code>CFWriteStreamSetProperty(writeStream, kCFStreamNetworkServiceType, kCFStreamNetworkServiceTypeVoIP);
  </code></pre>
  </blockquote>
  
  <p>But when my application goes to background and locked state, NSThread or NSTimer is not calling .  So please suggest me how to achieve background threading in iPhone background locked state ?</p>