[cdi-dev] CDI + transactions query

[Marina Vatkina]

Pete Muir wrote:
> On 24 Aug 2012, at 22:17, Jens Schumann wrote:
>
>   
>> Am 22.08.12 17:44 schrieb "Pete Muir" unter <pmuir at bleepbleep.org.uk>:
>>
>>     
>>>> Admittedly this is a gut reaction, I read through the Jira and the doc
>>>> you linked to though, and used my JEE experience to draw analogies, do
>>>> let me know if I got the wrong end of the stick please!
>>>>         
>>> No, I think this is right.
>>>
>>> In that case, what I would suggest we do is:
>>>
>>> * explicitly make controlling transactions from observers non-portable
>>> (which allows implementors to experiment with such a feature without
>>> breaking spec compliance)
>>> * raise a feature request in CDI to consider adding something like what
>>> you describe in the future
>>>       
>> Maybe I misunderstand the current wording, but wouldn't it be possible to
>> explicitly specify certain scenarios?
>>     
>
> It certainly would, if we know what the right way to specify it is. If you know how to specify it, please please please please come up with a proposal (I suggest writing it on the issue) and then I can help you work out the spec changes.
>
>   
>> For instance I would expect that
>> IN_PROGRESS (and maybe BEFORE_COMPLETION) observers and their dependencies
>> should be able to start and commit/rollback a new transaction (RequiresNew
>> semantics).
>>
>> On the other hand I would also expect that AFTER_COMPLETION/AFTER_FAILRE
>> observers and their dependencies may never directly initiate, commit or
>> rollback JTA transactions.
>>     
>
> Ok, I'm no TX expert, so I need to rely on people who are, like you, and Tom et al from our TX team.
>   

You can mark a transaction for rollback inside the beforeCompletion 
callback.

BeforCompletion callback is part of the transaction commit process, so 
it's too late to request a commit. Nested transactions are not required 
to be supported, but you should be able to suspend/resume an active 
transaction to run a RequiresNew logic.

AfterCompletion callback is called after all transaction processing has 
been finished.
>   
>> I tried to find a few more answers to this in the current JTA/JTS specs.
>> However both specs are very thin in this regard. Do you know who can
>> answer which limitations apply to JTA Transaction Synchronization
>> beforeCompletion/afterCompletion callbacks? The JTA spec 3.3.2 has no
>> answer.
>>     
>
> Marina, now in cc, is JTA spec lead IIRC.
>   

Paul Parkinson is (cc-ed) ;)

-marina
> Thanks!