On 2 Jun 2011, at 13:19, Scott Marlow wrote:

On 06/02/2011 05:31 AM, Mircea Markus wrote:

On 1 Jun 2011, at 20:49, Scott Marlow wrote:

I posted a message on the as7-dev ml
(http://lists.jboss.org/pipermail/jboss-as7-dev/2011-May/002254.html),
about switching to use the TransactionSynchronizationRegistry.

Does Infinispan currently register Transaction synchronization objects?
yes
 Does Infinispan currently register synchronizations via
TransactionSynchronizationRegistry (TSR)?
no, we register synchronizations through transaction.registerSynchronization

I'm trying to get a sense for, what would happen if container managed
(AS7) session beans were registered with the active JTA transaction via
the TSR.

If AS7 switches to use the TSR, I think that Infinispan might need to
ensure that it doesn't attempt to register with the TX too late.
right. One way to go  is by making the registration code pluggable.

I should point out that I believe its only a problem, to call Transaction.registerSynchronization() after the point, where the ordering cannot be correct.  However, no such checking is performed if no components are registering their syncs via TransactionSynchronizationRegistry.

So, another question, how likely would it be, that an application would see Infinispan registering a sync via Transaction.registerSynchronization(), after the transaction commit has been initiated?
ATM Infinispan allows the registration if the transaction is in one of the following states: Status.STATUS_ACTIVE || Status.STATUS_PREPARING. If tx is in any other state the sync won't be registered and a exception is instead sent to the user.  

If Transaction.registerSynchronization() will always be called by Infinispan before the transaction commits.  We shouldn't have to be as concerned about support for registering the Infinispan syncs with TransactionSynchronizationRegistry.

If the answer is we aren't sure or Transaction.registerSynchronization() could happen after the transaction commit has been started, we should have it be pluggable.

From Jonathan's comment[1] I understand that "interposed Synchronizations must be called after non-interposed ones". That seems to be true disregarding tx's status. Or am I wrong?
[1] http://bit.ly/lAJKvm