Transactional Mutex Locks

Luke Dalessandro, David Dice, Michael L. Scott, Nir Shavit, Michael F. Spear

Abstract: Mutual exclusion (mutex) locks limit concurrency but offer low single-thread latency. Software transactional memory (STM) typically has much higher latency, but scales well. We present transactional mutex locks (TML), which attempt to achieve the best of both worlds for read-dominated workloads. We also propose compiler optimizations that reduce the latency of TML to within a small fraction of mutex overheads.