Quasi-Linearizability is Undecidable

Abstract. Quasi-linearizability is a quantitative relaxation of linearizability. It preserves the intuition of the standard notion of linearizability and permits more flexibility. The decidability of quasi-linearizability has been remaining open in general for a bounded number of processes. In this paper we show that the problem of whether a library is quasilinearizable with respect to a regular sequential specification is undecidable for a bounded number of processes. This is proved by reduction from the k-Z decision problem of a k-counter machine, a known undecidable problem. The key idea of the proof is to establish a correspondence between the quasi-sequential specification of quasi-linearizability and the set of all unadmitted runs of the k-counter machines.

• Type: Journal
• Year: 2015
• Where: APLAS
• Authors: Chao Wang, Yi Lv, Gaoang Liu, Peng Wu 0002
• Keywords: APLAS 2015, Programming Languages