Exploring Data Reusing of Failed Transaction

Abstract

Transactional Memory (TM) has been the promising parallel programming technique to relieve the tedious work of synchronizing shared object using lock mechanism. Transaction execution required to be atomic and isolated relative to the whole system. The transaction fails if found violated access to the shared object from other transaction, and it will be re-executed till finally commit successfully; currently, most TM systems are required to restore shared memory's state before reexecution, this cleanup cost and the shared object's opening cost greatly hurdle system's performance. In this paper, we propose a new general transaction iteration's data reusing (TItDR) method which reuses the opened object of failed transaction in the following re-execution. The obvious advantage is that it greatly simplify the opening process if it has been opened in previous failed transaction and most of the cleanup work are no longer needed. TItDR leaves opened object in pseudo-active state and restart the transaction, We talk about conflicts resolution, validation, commit/abort processing problem along with our data reusing method and show that TItDR will not incur more conflicts and more overhead for validation or commit. Both currently proposed software transactional memory (STM) systems and hardware systems (HTM) have much potential data reusing. Our test result is based on STM implementation, which shows 40% performance improvement on average.