On 1/19/06, Matt Goodall firstname.lastname@example.org wrote:
I have a couple of services. The second is dependent on the first being fully initialised before the second gets set up.
In other words, what is the recommended way of starting services in the
correct order, including waiting for them to get initialised fully, these days?
I actually wrote something like this today, a subclass of MultiService, because my main service was dependant on there being no other services running on the same machine, and I had to implement a PB client/server to ask the other instance to shut down. This is mostly because Windows sucks, and doesn't allow me to just do a "kill <pid>" on the old one, but gave me an excuse to start the PB integration of my app. I just subclassed MultiService and reimplemented startService and stopService appropriately, not chaining my sub-service starts until I was certain I had managed to start my own service, and not stopping my service until my sub-services had stopped.
It's a fairly simple idiom, so it's probably pretty easy to implement yourself, but I'm surprised a generic one hasn't been written yet. Similarly I've had to write a new LoopingService that runs a "setup" callable before looping the main service, and also has a "minimum wait between calls" timer going on it. None of these have been particulalrly difficult.