A method, apparatus, and computer readable article of manufacture for executing a transaction by a processor apparatus that includes a plurality of hardware threads. The method includes the steps of: executing, by the processor apparatus using the plurality of hardware threads, a main software thread for executing the transaction and a helper software thread for executing a barrier function; and deciding, by the processor apparatus, whether or not the barrier function is required to be executed when the main software thread encounters a transactional load or store operation that requires the main software thread to read or write data.