Fast, Scalable Synchronization with Minimal Hardware Support (Extended Abstract)

This paper concerns synchronization under read/write atomicity in shared memory multiprocessors. We present a new algorithm for N-process mutual exclusion that requires only read and write operations and that has O(log² N ) time complexity, where "time" is measured by counting remote memory references. The time complexity of this algorithm is better than that of all prior solutions to the mutual exclusion problem that are based upon atomic read and write instructions; in fact, the time complexity of most prior solutions is unbounded. Performance studies are presented that show that our mutual exclusion algorithm exhibits scalable performance under heavy contention. In the second part of the paper, we discuss two extensions of our mutual exclusion algorithm. In the first extension, we modify the algorithm so that in the absence of conte..