def METHOD_NAME(self, interval=0.1, req_async=False):
    """Start the loop.
    If async is True make one loop then return.
    """
    while 1:
        self.update_files()
        for fid, file in list(iter(self.files_map.items())):
            self.readfile(file)
        if req_async:
            return
        time.sleep(interval)