Re: [weld-dev] AfterBeanDiscovery and observer resolver cache
Hi Jozef,
I think clearing the cache at the end of the Weld bootstrap process is not enough to solve
that particular problem since a CDI extension can hold on to the ABD reference and invoke
addObserverMethod later (multiple times) which causes the same problem I described below.
There's no indication to the caller of addObserverMethod that it's in fact too
late to call that method.
Since an ABD event reference can always escape (can be used outside the method that
observes it) it seems this issue should be resolved (although it admittedly is an edge
case).
Cheers,
Christian
On 2014-03-04, at 11:29 AM, Jozef Hartinger <jharting(a)redhat.com> wrote:
Hi Christian,
this sounds like a bug. All the resolution caches should be cleared at the very end of
Weld's bootstrap sequence (after ABD observers are called). (see
https://github.com/weld/core/blob/master/impl/src/main/java/org/jboss/wel...)
Jozef
On 03/04/2014 04:36 PM, Christian Sadilek wrote:
> Hi everyone,
>
> CDI extensions can observe the AfterBeanDiscovery event to register observer methods
(addObserverMethod). However, when an event is first fired, the observers for that event
are resolved and then cached (in TypeSafeResolver). All future calls to addObserverMethod
for an already fired event with corresponding qualifiers will have no effect because the
observer result is read from cache and not recomputed.
>
> >From an API perspective that's unfortunate because addObserverMethod will
only work until an event (with corresponding qualifiers) is fired and there is no
indication to the caller of that method that it didn't have any effect when invoked
after that.
>
> Possible solutions:
>
> - Provide some public API to clear/recompute that part the observer cache. Maybe that
exists? I couldn't find it which is why I am using the private API and Reflection :(.
Also let AfterBeanDiscovery.addObserverMethod fail in that case with the advice to reset
the cache.
>
> - Recompute the corresponding part of the cache when addObserverMethod is called
(seems preferable).
>
> OpenWebBeans doesn't have this issue as their NotificationManager will simply add
the new ObserverMethod to a ConcurrentHashMap that is also accessed when an event is
fired.
>
> What do you think? Can this already be done or is there another solution?
>
> Cheers,
> Christian
>
>
>
>
>
>
>
> _______________________________________________
> weld-dev mailing list
> weld-dev(a)lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/weld-dev