How feasible is this?

I'm writing in desperate hope that something like this exists... because
if so, it would make my life a lot easier. I want to be able to:

a) Roll back a transaction

b) Receive a notification when retrying the exact same transaction might
cause different data to be returned from something that was done up to
the point of the rollback; i.e., some result set, update count, etc.
might be different.

It's okay if (b) is overly sensitive. For example, one technically
correct (but disappointing) answer would be to get that notification
immediately on the rollback; but that would cause the application to
spin and retry the same transaction in a loop with no delays, which is
hardly ideal to say the least.

Any ideas on doing better than that?

--
Chris Smith