title: Multiprocessing in tornado
body: <p>I want to have two non-blocking processes running synchronously, the one is a while True loop which caches data every minute, and the second one is a code such below:</p>
  <pre><code>def create_and_start_app():
      app = Application([
          ('/dashboard', Dashboard)
      ],
      debug=RuntimeConfig.DEBUG_MODE)
      http_server = HTTPServer(app)
      http_server.listen(RuntimeConfig.APP_PORT)
      print(f'Listening on http:/{RuntimeConfig.APP_HOST}:{RuntimeConfig.APP_PORT}')
      IOLoop.current().start()
  </code></pre>
  <p>I tried <code>IOLoop.current.spawn_call_back</code> approach and also <code>concurrent.futures.ThreadPoolExecutor</code> but it seems I didn't get the point of documentation because every approach I test, blocks with while True in caching method and program doesn't execute next process. Thank you if you show me a sample code which fits into this case.</p>