In this paper we study the ability of shared object types to implement Consensus in asynchronous shared-memory systems where at most one process may crash. More specifically, we consider the following question: Let n ≥ 3 and S be a set of object types that can be used to solve one-resilient Consensus among n processes. Can S always be used to solve one-resilient Consensus among n - 1 processes? We prove that for n = 3 the answer is negative, even if S consists only of deterministic types. (This strengthens an earlier result by the first author proving the same fact for nondeterministic types.) We also prove that, in contrast, for n > 3 the answer to the above question is affirmative.
['Wai-Kau Lo', 'Vassos Hadzilacos']
On the power of shared object types to implement one-resilient Consensus