def _tcp_proc(self, addrinfo, task=None):
        """
        Internal use only.
        """
        task.set_daemon()
        sock = addrinfo.tcp_sock
        while 1:
            try:
                conn, addr = yield sock.accept()
            except ssl.SSLError as err:
                logger.debug('SSL connection failed: %s', str(err))
                continue
            except GeneratorExit:
                break
            except:
                logger.debug(traceback.format_exc())
                continue
            SysTask(self._tcp_conn_proc, conn, addrinfo)

  原文：http://www.codingdict.com/sources/py/traceback/2706.html