On the complexity of linearizability

Abstract

It was previously shown that the problem of verifying whether a finite concurrent system is linearizable can be done with an $$\mathsf{EXPSPACE}$$ complexity. However, the best known lower bound is $$\mathsf{PSPACE}$$ -hardness, and can be obtained using a reduction from control-state reachability to linearizability. In this paper, we close the complexity gap between the $$\mathsf{PSPACE}$$ lower bound and the $$\mathsf{EXPSPACE}$$ upper bound, and show that linearizability is $$\mathsf{EXPSPACE}$$ -complete.