Higham, LisaKawash, JalalVerwaal, Nathaly2008-02-272008-02-271998-01-01http://hdl.handle.net/1880/45994Process coordination problems have been extensively addressed in the context of sequential consistency. However, modern multiprocessors present a large variety of memory models that are anything but sequentially consistent. In these machines, the ordering constraints on memory accesses are few. We re-address two fundamental process coordination problems in the context of weak memory models. We prove that many models cannot support a solution to the critical section problem without additional powerful synchronization primitives. Nevertheless, we show 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.EngComputer Scienceunknown1998-613-0410.11575/PRISM/30836