Stubborn Transaction Reduction (with Proofs)

TL;DR

This paper introduces a dynamic transaction reduction technique that leverages the same commutativity detection as stubborn set POR, demonstrating through implementation and case studies that it can outperform POR in reducing interleavings in model checking.

Contribution

The paper shows how dynamic transaction reduction can incorporate the same commutativity detection as stubborn set POR and demonstrates its practical advantages over static TR and POR.

Findings

Dynamic TR can surpass POR in reducing interleavings.

Dynamic TR effectively uses commutativity detection from stubborn set POR.

Implementation in LTSmin shows practical efficiency gains.

Abstract

The exponential explosion of parallel interleavings remains a fundamental challenge to model checking of concurrent programs. Both partial-order reduction (POR) and transaction reduction (TR) decrease the number of interleavings in a concurrent system. Unlike POR, transactions also reduce the number of intermediate states. Modern POR techniques, on the other hand, offer more dynamic ways of identifying commutative behavior, a crucial task for obtaining good reductions. We show that transaction reduction can use the same dynamic commutativity as found in stubborn set POR. We also compare reductions obtained by POR and TR, demonstrating with several examples that these techniques complement each other. With an implementation of the dynamic transactions in the model checker LTSmin, we compare its effectiveness with the original static TR and two POR approaches. Several inputs, including realistic case studies, demonstrate that the new dynamic TR can surpass POR in practice.