two transactions under the same XA cordinator to the same resource

Hello,

I was wonderring how the XA-driver will behave, if it is asked to perform an update to a row in a db within the same xa-transaction, where it is asked to perform a read to the same row.

coordinator
|
--T1: asking to update R1
|
--T2: asking to read R1

Will the Xa rollback, deadlock or commit?

Rashi

This depends, but not on XA.

What is the transaction isolation level and does T1 commit the updates ?