A Time Complexity Bound for Adaptive Mutual Exclusion

We consider the time complexity of adaptive mutual exclusion algorithms, where "time" is measured by counting the number of remote memory references required per critical-section access. We establish a lower bound that precludes a deterministic algorithm with O(log k) time complexity (in fact, any deterministic o(k) algorithm), where k is "point contention." In contrast, we show that expected O(log k) time is possible using randomization.