Upper and Lower Bounds for Deterministic Approximate Objects

Danny Hendler (1) , Adnane Khattabi (2) , Alessia Milani (2) , Corentin Travers (2)

1 BGU - Ben-Gurion University of the Negev
2 LaBRI - Laboratoire Bordelais de Recherche en Informatique

Relaxing the sequential specification of shared objects has been proposed as a promising approach to obtain implementations with better complexity. In this paper, we study the step complexity of relaxed variants of two common shared objects: max registers and counters. In particular, we consider the k-multiplicative-accurate max register and the k-multiplicative-accurate counter, where read operations are allowed to err by a multiplicative factor of k (for some k ∈ N). More accurately, reads are allowed to return an approximate value x of the maximum value v previously written to the max register, or of the number v of increments previously applied to the counter, respectively, such that v/k ≤ x ≤ v • k. We provide upper and lower bounds on the complexity of implementing these objects in a wait-free manner in the shared memory model.

Mots clés: Distributed computing; Distributed algorithms; Concurrent data structures; Relaxed specifications; Shared memory; Fault tolerance

Domaines: Informatique [cs]

Danny Hendler, Adnane Khattabi, Alessia Milani, Corentin Travers. Upper and Lower Bounds for Deterministic Approximate Objects. ICDCS 2021 - 41st IEEE International Conference on Distributed Computing Systems, Jul 2021, Washington (virtual), United States. pp.438-448, ⟨10.1109/ICDCS51616.2021.00049⟩. ⟨hal-03202712v2⟩