Are wait-free algorithms fast?

  • Authors:
  • Hagit Attiya;Nancy Lynch;Nir Shavit

  • Affiliations:
  • Technion–Israel Institute of Technology, Haifa, Israel;Massachusetts Institute of Technology, Cambridge;Tel Aviv Univ., Tel Aviv, Israel

  • Venue:
  • Journal of the ACM (JACM)
  • Year:
  • 1994

Quantified Score

Hi-index 0.00

Visualization

Abstract

The time complexity of wait-free algorithms in “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 &OHgr;(log n) time separation between the wait-free and non-wait-free computation models. On the positive side, we present an O(log n) time wait-free approximate agreement algorithm; the complexity of this algorithm is within a small constant of the lower bound.