4:33 a.m.
Le 18 mars 2015 à 09:58, Romain Manni-Bucau
<rmannibucau(a)gmail.com> a écrit :
2015-03-18 9:55 GMT+01:00 Antoine Sabot-Durand <antoine(a)sabot-durand.net
<mailto:antoine@sabot-durand.net>>:
>
> Le 18 mars 2015 à 09:42, Romain Manni-Bucau <rmannibucau(a)gmail.com
<mailto:rmannibucau@gmail.com>> a écrit :
>
> Hi guys,
>
> think Mark is right and a new API (as fireAsync) would be better for users for:
> - understanding
> - compatibility (think to custom extensions using this flag)
My point here is to avoid making CDI the EJB next by introducing @Async or @Asynchronous
annotation in the spec. This kind of annotation should be shared by other specs and would
have a better fit in concurrency utilities or commons annotations spec.
+1
> that said if we have @Async methods I think async observers are really useless,
isn't it?
@Async is rather useless IMO when you see how easy it is do async operation with Java 8.
On the other hand Async observers are a at a higher level since they are called thru the
Container and that the fire point must know what’s going on at the other side.
don't get it, observer can use j8 then to do its stuff asynchronously so maybe the
feature if finally useless assuming you run on j8.
And how do you make your fire point know that one of its observer will be asynchronous ?
How do you manage event ordering (as we plan to support it for async event as well). I
think we shouldn’t see the event bus as a standard method call but something more featured
(think about parameter injection in observer methods or transactional behavior)
That said saying a method is async is still more elegant than firing it in a pool you
don't control.
fireAsync will have a signature allowing you to pass your own Executor to give you better
control on thread pool
>
>
>
> Romain Manni-Bucau
> @rmannibucau <https://twitter.com/rmannibucau> | Blog
<http://rmannibucau.wordpress.com/> | Github <https://github.com/rmannibucau>
| LinkedIn <https://www.linkedin.com/in/rmannibucau> | Tomitriber
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> 2015-03-18 9:30 GMT+01:00 Arne Limburg <arne.limburg(a)openknowledge.de
<mailto:arne.limburg@openknowledge.de>>:
> Hi Antoine,
>
> The third bullet point in 10.5.1 of the CDI 1.1 spec states that the
> observer method must be called in the same transaction context as the
> event.fire(...) if it is no transactional observer (that is
> TransactionPhase.IN_PROGRESS).
> If the default behavior would be async, we would have to move the
> transaction context to another thread. To my best knowledge this would be
> the only situation in EE where this is the case.
>
> Cheers,
> Arne
>
> Am 18.03.15 09:21 schrieb "Antoine Sabot-Durand" unter
> <antoine(a)sabot-durand.net <mailto:antoine@sabot-durand.net>>:
>
> >Hi Arne,
> >
> >Sorry can you explain why? This value allows observer to be called inside
> >or outside a transaction. What will be the compatibility issue?
> >
> >Antoine
> >
> >
> >> Le 18 mars 2015 à 09:05, Arne Limburg <arne.limburg(a)openknowledge.de
<mailto:arne.limburg@openknowledge.de>> a
> >>écrit :
> >>
> >> Hi to all,
> >>
> >> I think the biggest issue with backward compatibility is, that the
> >>current
> >> @Observes annotation by default has TransactionPhase.IN_PROGRESS.
> >> I think we can¹t deal with this, if the default for observers would be
> >> async. So I think there is no way to specify async as default without
> >> loosing backward compatibility.
> >> Any other thoughts?
> >>
> >> Cheers,
> >> Arne
> >>
> >>
> >> Am 18.03.15 08:48 schrieb "Antoine Sabot-Durand" unter
> >> <antoine(a)sabot-durand.net <mailto:antoine@sabot-durand.net>>:
> >>
> >>> Hi all,
> >>>
> >>> Yesterday we had another meeting to try to find a better solution than
> >>> explicitly activating async event on observer, without no success. I
> >>> understand that we should go on on this feature so what I suggest is to
> >>> have a meeting (an hangout) with people that want to try to find a
> >>>better
> >>> solution. If we find something we¹ll do a last proposal, and in all
> >>>case
> >>> we¹ll adopt the woking solution next week for this point. People
> >>> interested with this please manifest yourself.
> >>>
> >>> If we have to go with opt-in (have to explicitly declare an observer
> >>> supporting async event) we also have to validate the decision to use a
> >>> member in @Observes (as it was decided before) or go back on that as
> >>> mMark keep asking by introducing a new annotation to add on the
> >>>observer
> >>> (@Async or something similar). As I said when we discussed this point,
> >>>I
> >>> prefer the member in @Observes but we may have overlooked issues linked
> >>> to backward compatibility.
> >>> A third solution might be to introduce an @ObserveAsync to declare an
> >>> asynchronous capable observerŠ
> >>>
> >>> I¹m waiting for active feedback from you to find the best solution
> >>>taking
> >>> ALL aspects (not only the technicals one) into account.
> >>>
> >>> Thanks,
> >>>
> >>> Antoine
> >>
> >
>
>
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