parameters: (check_time: int = 500)
docstring: Begins watching source files for changes.
  
      .. versionchanged:: 5.0
         The ``io_loop`` argument (deprecated since version 4.1) has been removed.
docstring_summary: Begins watching source files for changes.
docstring_tokens: Begins watching source files for changes .
function: def start(check_time: int = 500) -> None:
      """Begins watching source files for changes.
  
      .. versionchanged:: 5.0
         The ``io_loop`` argument (deprecated since version 4.1) has been removed.
      """
      io_loop = ioloop.IOLoop.current()
      if io_loop in _io_loops:
          return
      _io_loops[io_loop] = True
      if len(_io_loops) > 1:
          gen_log.warning("tornado.autoreload started more than once in the same process")
      modify_times = {}  # type: Dict[str, float]
      callback = functools.partial(_reload_on_update, modify_times)
      scheduler = ioloop.PeriodicCallback(callback, check_time)
      scheduler.start()
function_tokens: def start ( check_time : int = 500 ) -> None : io_loop = ioloop . IOLoop . current ( ) if io_loop in _io_loops : return _io_loops [ io_loop ] = True if len ( _io_loops ) > 1 : gen_log . warning ( "tornado.autoreload started more than once in the same process" ) modify_times = { } # type: Dict[str, float] callback = functools . partial ( _reload_on_update , modify_times ) scheduler = ioloop . PeriodicCallback ( callback , check_time ) scheduler . start ( )