On 30/09/10 14:36, Chris Withers wrote:
Indeed, but, as I keep saying, I need to build a scheduler that's resilient to errors in the tasks its running ;-)
Sure.
Most prominent is reactor.callLater.
...which I'm not actually using, it was just a small-as-possible way I could simulate the failure mode (rather than the specific failure) I need to protect against.
Ah.
Actually, what appears to work is simply changing `loop` to not be an async fuction:
def loop(): try: doStuff() except Exception,e: log.err(None,'Unhandled scheduled exception')
looper = task.LoopingCall(loop) looper.start(1.0) reactor.run()
This appears to solve most of the problems: - the schedule now keeps running regardless - exceptions in doStuff and below get logged
However, it now has the problem that if doStuff *does* return a deferred and it errbacks, the I get the ugly:
Well, you could do this, which is more Twist-y, and Glyph suggested: def loop(): d = defer.maybeDeferred(doStuff, *args) d.addErrback(log.err) This will call doStuff, converting return/exception into callback/errback, or if the call returns a deferred itself, just return that. FWIW, you say "if doStuff does return a deferred"; I presume you don't really have a single call returning both normal and deferred values, and it's actually several different function calls to different pieces of work.
Is there any way I can get both errbacks *and* exceptions handled nicely in my `loop` call?
I think you want maybeDeferred, as above.