classification
Title: multiprocessing Server's shutdown method useless send message to manager
Type: behavior Stage:
Components: Library (Lib) Versions: Python 3.6, Python 3.5
process
Status: open Resolution:
Dependencies: Superseder:
Assigned To: Nosy List: davin, jnoller, pitrou, sbt, stevezh
Priority: normal Keywords:

Created on 2017-11-13 06:00 by stevezh, last changed 2017-11-13 06:00 by stevezh.

Messages (1)
msg306142 - (view) Author: stevezh (stevezh) * Date: 2017-11-13 06:00
When shutdown the manager, Server's handle_request will send back message to the manager, so is useless for the Server's shutdown method send back "None" to the manager?

Source code from Lib/multiprocessing/managers.py:

    def shutdown(self, c):
        '''
        Shutdown this process
        '''
        try:
            util.debug('manager received shutdown message')
            # Is useless here?
            c.send(('#RETURN', None))
        except:
            import traceback
            traceback.print_exc()
        finally:
            self.stop_event.set()

Server's handle_request may throw and catch exception because the conn is closed in _finalize_manager() after Server's shutdown method returns.

code from handle_request():

        try:
            c.send(msg)
        except Exception as e:
            try:
                c.send(('#TRACEBACK', format_exc()))
            except Exception:
                pass

code from _finalize_manager():

            try:
                conn = _Client(address, authkey=authkey)
                try:
                    dispatch(conn, None, 'shutdown')
                finally:
                    conn.close()
            except Exception:
                pass

Also the Server's shutdown method only used by manager class.
History
Date User Action Args
2017-11-13 06:00:30stevezhcreate