[Twisted-Python] Remote PB calls in ApplicationService.stopService

[Glyph Lefkowitz]

On Saturday, August 2, 2003, at 05:55 AM, Moshe Zadka wrote:

> BTW, currently that feature is not in the new Application code I'm 
> working
> on. I could add it, but when we discussed it I didn't know of anybody
> using that feature. It seems a bit too dangerous to allow a buggy 
> remote
> side to delay our shutdown by a long amount of time [depending on PB
> timeouts]. I humbly suggest that an architecture which depends on being
> able to send "one last message" is probably flawed.

There are a couple of different use-cases here that need to be 
separated; for example, shutting down an active thread pool requires 
waiting, otherwise you will deadlock - and yes, this is due to the fact 
that OS threads are a basically flawed concept, but we've been over 
that one before :).

Sometimes it's also useful to be able to send out a descriptive message 
before dying, like, "The service is going down!  Please hurry up."  I 
admit that the deferred-from-stopService is probably not the best way 
to handle this, though; there should be a different canonical way to 
shut down a Twisted server that allows those sorts of messages to be 
sent.

However, as long as the deferred in the latter case always comes with 
the timeout, I think the use cases are about equivalent.  Thoughts?