A Practical Transactional Memory Interface (original) (raw)

Hardware transactional memory (HTM) is becoming widely available on modern platforms. However, software using HTM requires at least two carefully-coordinated code paths: one for transactions, and at least one for when transactions either fail, or are not supported at all. We present the MCMS interface that allows a simple design of fast concurrent data structures. MCMS-based code can execute fast when HTM support is provided, but it also executes well on platforms that do not support HTM, and it handles transaction failures as well. To demonstrate the advantage of such an abstraction, we designed MCMS-based linked-list and tree algorithms. The list algorithm outperforms all known lock-free linked-lists by a factor of up to X2.15. The tree algorithm builds on Ellen et al. [7] and outperforms it by a factor of up to X1.37. Both algorithms are considerably simpler than their lock-free counterparts.