graceful restart under runit

["Dražen Kačar" <dave@fly.srk.fer.hr>]

Say I have a TCP server which listens on incoming connections on some TCP
port. Occasionaly I'd like to install and run a new version of the server
executable. Server source is under my control, for all intents and
purposes.

Normally I'd use SIGUSR1 to make the server close socket on which it
listens, finish processing current client sessions (depending on the
protocol, that might take seconds, minutes or hours) and exit.

Right after sending SIGUSR1 I'd start the new server version which would
just work for all new client connections.

If the server is managed by runit, things get complicated because runit
won't start the new server until the old one exits, so I either have to
abort existing client connections or suffer some time without service.

Is there a way to get around this?

-- 
 .-.   .-.    Yes, I am an agent of Satan, but my duties are largely
(_  \ /  _)   ceremonial.
     |
     |        dave@fly.srk.fer.hr