Can Expensive Synchronization be Avoided in Weak Memory Models? (Brief Announcement)

Process coordination problems have been extensively addressed in the context of sequential consistency. However, modern shared-memory systems present a large variety of ordering constraints on memory accesses that are much weaker than sequential consistency. We re-addressed two fundamental process coordination problems in the context of weak memory models. We proved that many models cannot support a solution to the critical section problem without additional powerful synchronization primitives. Nevertheless, we showed that certain versions of the producer/consumer problem can be solved even in the weakest models without the need for such powerful instructions. These instructions are expensive, and avoiding their use is desirable for better performance. This brief announcement groups and re-states some of our earlier results [11, 12, 15].