[firstname.lastname@example.org: Re: [Zope-Checkins] CVS:
Zope/lib/python/nt_svcutils - service.py:184.108.40.206]
tim.peters at gmail.com
Wed Apr 20 17:52:29 EDT 2005
>>> However, a service can stop also stop by its own accord.
>> I don't think ZRS ever does that, and am not sure how I could write
>> code to do it. Does a Zope service ever decide to "stop by its own
> By that, I simply mean "terminate with a zero exit code". Obviously not "of
> its own accord", but it has nothing to do with the service framework. This
> also includes "terminate with non-zero exit code too many times" - you will
> not be called in this case either.
>>> The question, then, is under what cases should the onStop()
>>> calls be made? It sounds to me like you want it called only when that
>>> external request comes in.
>> Maybe. In the end, by whatever means a service gets shut down
>> (external, internal, whatever), I want to see the subclass onStop()
>> method called exactly once.
> My patch does not do that. If Zope terminates "of its own accord", then
> your hook is never called. This means that patch is suitable if you need
> onStop to actually trigger the stop process, but not to be notified of
> normal shutdown.
> Having that method called exactly once in all circumstances is a little more
> tricky, and would probably involve a maintaining a flag - it must be called
> in SvcStop to *trigger* the shutdown, or if shutdown is "normal" (ie, not
> triggered by us), then it must be called as the main run-loop terminates -
> but not both times.
>> Seems to work fine for the ZRS-related services too, although I didn't
>> get into the "restarting too frequently" branch. Thank you. If
>> nobody objects in the next 10 minutes, then, I'll check this in (and
>> port to Zope trunk (2.8) too).
> I did test the "too frequently" branch - but note that as above, that patch
> will *not* have your function be called when Zope just sys.exits. If that
> is suitable, go for it :)
Bet you were wondering when you'd see new text <wink>.
Thing is, ZRS has nothing in particular to do with Zope. It runs
independently of Zope, and may run on boxes that don't even have a
Zope installed. It has no UI at all, it's just a couple of services
that run infinite loops. The only way it stops on Windows is as a
result of someone clicking "stop" in the Windows Services GUI, or by
running "XYZservice.py stop" from a DOS box, or by getting a stop
request via, e.g., Windows shutdown. In those cases I want onStop()
called exactly once, and that's what's happening now, so I'm happy.
AFAICT, the ZRS services are the only ones we have that override
onStop(); if so, there's no other case to look at. Good enough for
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