Coarse-Grained Transactions

Traditional transactional memory systems suffer from overly conservative conflict detection, yielding so-called false conflicts, because they are based on fine-grained, low-level read/write conflicts. In response, the recent trend has been toward integrating various abstract data-type libraries using ad-hoc methods of high-level conflict detection. These proposals have led to improved performance but a lack of a unified theory has led to confusion in the literature. We clarify these recent proposals by defining a generalization of transactional memory in which a transaction consists of rained (abstract data-type) operations rather than simple memory read/write operations. We provide semantics for both pessimistic (e.g. transactional boosting) and optimistic (e.g. traditional TMs and recent alternatives) execution. We show that both are included in the standard atomic semantics, yet find that the choice imposes different requirements on the coarse-grained operations: pessimistic requir...

• Type: Conference
• Year: 2010
• Where: POPL
• Authors: Eric Koskinen, Matthew Parkinson, Maurice Herlihy
• Keywords: Memory Read/write Operations, Pessimistic Requires Operations, POPL 2010, Programming Languages, Traditional Transactional Memory