engine.py 文件源码

def _notifysleep(self, delay):
        """Sleeps up to delay number of seconds, but will schedule an
        immediate new event queue check if an event notification is received
        from PostgreSQL.

        """
        conn = connection.connection
        if conn:
            try:
                select.select([conn], [], [], delay)
            except select.error as err:
                if err.args[0] != errno.EINTR:
                    raise
            try:
                conn.poll()
            except OperationalError:
                connection.connection = None
                self._listen()
                return
            if conn.notifies:
                self._logger.debug("got event notification from database")
                self._schedule_next_queuecheck()
                del conn.notifies[:]
        else:
            time.sleep(delay)