Major Description
Here's the code for ObjectStore.commitTransaction() and ObjectStore.rollbackTransaction():
public boolean commitTransaction() { assert (openTrasactionCalls >= 1); if (!currentTransaction.isActive()) { throw new RuntimeException( "Commit is called, but transaction is not active. Either there are" + " mismatching open and close calls or rollback was called in the same trasaction"); } openTrasactionCalls--; if ((openTrasactionCalls == 0) && currentTransaction.isActive()) { transactionStatus = TXN_STATUS.COMMITED; currentTransaction.commit(); } return true; } public void rollbackTransaction() { if (openTrasactionCalls < 1) { return; } openTrasactionCalls = 0; if (currentTransaction.isActive() && transactionStatus != TXN_STATUS.ROLLBACK) { transactionStatus = TXN_STATUS.ROLLBACK; // could already be rolled back currentTransaction.rollback(); } }
Now suppose a nested transaction throws an exception which results
in the nested pseudo-transaction calling rollbackTransaction(). This causes
rollbackTransaction() to rollback the actual transaction, as well as to set
openTransactionCalls=0 and transactionStatus = TXN_STATUS.ROLLBACK.
Suppose also that this nested transaction squelches the original exception.
In this case the stack will unwind and the caller will eventually try to commit the
transaction by calling commitTransaction() which will see that currentTransaction.isActive() returns
FALSE and will throw a RuntimeException. The fix for this problem is
that commitTransaction() needs to first check transactionStatus and return immediately
if transactionStatus==TXN_STATUS.ROLLBACK.
