On the Input Acceptance of Transactional Memory

We present the Input Acceptance of Transactional Memory (TM). Despite the large interest for performance of TMs, no existing research work has investigated the impact of solving a conflict that does not need to be solved. Traditional solutions for a TM to be correct is to delay or abort a transaction as soon as it presents a risk to violate consistency. Both alternatives are costly and should be avoided if consistency is actually preserved. To address this problem, we introduce the input acceptance of a TM as its ability to commit transactions, we upper-bound the input acceptance of existing TMs and propose a new TM with higher input acceptance.