Question

Greetings, Forum.

I’m working on a program in Python that uses Twisted to manage networking. The basis of this program is a TCP service that is to listen for connections on multiple ports. However, instead of using one Twisted factory to handle a protocol object for each port, I am trying to use a separate factory for each port. The reason for this is to force a separation among the groups of clients connecting to the different ports.

Unfortunately, it appears that this architecture isn’t quite working: clients that connect to one port appear to be available among all the factories (e.g., the protocol class used by each factory includes a ‘self.factory.clients.append (self)’ statement…instead of adding a given client to just the factory for a particular port, the client is added to all factories), and whenever I shutdown service on one port the listeners on all ports also stop.

I’ve been working with Twisted for a short while, and fear I simply don’t fully understand how its factory classes are managed.

My question is: is it simply not possible to have multiple, simultaneous instances of the same factory and same protocol in use across different ports (without these instances stepping on each other’s toes)?

Answer 1

You can definitely do what you want — it’s hard to tell what you’re doing wrong without seeing your code, but I’d bet you have clients = [] in your factory class instead of

self.clients = []

in your factory class’s __init__ method.