JCA TransactionImporter should be thread safe --------------------------------------------- Key: JBTM-2614 URL: https://issues.jboss.org/browse/JBTM-2614 Project: JBoss Transaction Manager Issue Type: Bug Components: JCA Affects Versions: 5.2.12.Final Reporter: Michael Musgrove Assignee: Michael Musgrove Fix For: 4.17.35, 5.2.13.Final I have a unit test that shows there's a race condition (first observed by [~dmlloyd]) in com.arjuna.ats.internal.jta.transaction.arjunacore.jca.TransactionImporterImple#importTransaction(javax.transaction.xa.Xid, int). If two threads call this method at the same time, two separate transaction objects may be created. Here's the sequence of events: T1: call importTransaction for XID1 T2: call importTransaction for XID1 T1: getImportedTransaction returns null T2: getImportedTransaction returns null T1: create new transaction, add to map T2: create new transaction, add to map (overwriting T1's) There is nothing in the documentation to indicate that this is not a valid situation or that access to the TransactionImporter has to be single-threaded in any way.