concurrent.py 文件源码

def __del__(self):
            if not self._log_traceback:
                # set_exception() was not called, or result() or exception()
                # has consumed the exception
                return

            tb = traceback.format_exception(*self._exc_info)

            app_log.error('Future %r exception was never retrieved: %s',
                          self, ''.join(tb).rstrip())