Transaction commit and abort cannot be performed from a different Thread

[Peter Beaman]

Documentation for com.persistit.Transaction says that with careful management of ownership of a SessionId, it is possible to complete a transaction in a different thread than the one that began it. However, this is not the case: the second thread receives an IllegalMonitorStateException when attempting to commit or abort the transaction.

The issue is that the TransactionStatus object used to represent transaction state within the TransactionIndex uses a java.util.concurrent.locks.ReentrantLock to represent its in-use state, and only the thread that locked it may unlock it.