Randomized naming using wait-free shared variables

Abstract.

A naming protocol assigns unique names (keys) to every process out of a set of communicating processes. We construct a randomized wait-free naming protocol using wait-free atomic read/write registers (shared variables) as process intercommunication primitives. Each process has its own private register and can read all others. The addresses/names each one uses for the others are possibly different: Processes p and q address the register of process r in a way not known to each other. For $n$ processes and $\epsilon > 0$, the protocol uses a name space of size $(1+\epsilon)n$ and $O(n \log n \log \log n)$ running time (read/writes to shared bits) with probability at least $1-o(1)$, and $O(n \log^2 n)$ overall expected running time. The protocol is based on the wait-free implementation of a novel $\alpha$-Test&SetOnce object that randomly and fast selects a winner from a set of q contenders with probability at least $\alpha$ in the face of the strongest possible adaptive adversary.