Are wait-free algorithms fast?

Hagit Attiya, Nancy Lynch, Nir Shavit

Research output: Contribution to journalConference articlepeer-review


The time complexity of wait-free algorithms in so-called normal executions, where no failures occur and processes operate at approximately the same speed, is considered. A lower bound of log n on the time complexity of any wait-free algorithm that achieves approximate agreement among n processes is proved. In contrast, there exists a non-wait-free algorithm that solves this problem in constant time. This implies an Ω(log n)-time separation between the wait-free and non-wait-free computation models. An O(log n)-time wait-free approximate agreement algorithm is presented. Its complexity is within a small constant of the lower bound.

Original languageEnglish
Pages (from-to)55-64
Number of pages10
JournalIEEE Transactions on Industry Applications
Issue number1 pt 1
StatePublished - Jan 1991
Externally publishedYes
Event1989 Industry Applications Society Annual Meeting - San Diego, CA, USA
Duration: 1 Oct 19895 Oct 1989

Cite this