Randomized two-process wait-free test-and-set

We present the first explicit, and currently simplest, randomized algorithm for two-process wait-free test-and-set. It is implemented with two 4-valued single writer single reader atomic variables. A test-and-set takes at most 11 expected elementary steps, while a reset takes exactly 1 elementary step. Based on a finite-state analysis, the proofs of… (More)