[Twisted-Python] Shutting down a service...

[Chaz.]

I have a problem I am trying to solve and hope that someone can see an
obvious way (particularly since I am new with Twisted).

My system is composed of 4 different services: an ftp server, a
multicast server, a XML-RPC facility and a service made of a proprietary
 protocol. The problem I am having is when I shut down the system I have
to close down nicely which means that I have to send out a few "I am
leaving" messages, etc.

The issue is that I can terminate because I get an RPC shutdown request,
but also the service getting a SIGINT. Is there some convenient
"Twisted" way to capture sigint (or any signals) and route them to
shutdown services in my application?

Thanks in advance,
Chaz.