    def _is_any_file_changed(self):
        """Return 1 if there is any source file of sys.modules changed,
        otherwise 0. mtimes is dict to store the last modify time for
        comparing."""
        for filename in self._iter_module_files():
            try:
                mtime = os.stat(filename).st_mtime
            except IOError:
                continue
            old_time = self.mtimes.get(filename, None)
            if old_time is None:
                self.mtimes[filename] = mtime
            elif mtime > old_time:
                logger.info('模块已更新')
                return True
        return False
Return 1 if there is any source file of sys.modules changed,
otherwise 0. mtimes is dict to store the last modify time for
comparing.
biliup/common/reload.py