Soundness in negotiations

Javier Esparza (1) , Denis Kuperberg (1, 2, 3, 4) , Anca Muscholl (5) , Igor Walukiewicz (5)

1 TUM - Technische Universität Munchen - Technical University Munich - Université Technique de Munich
2 PLUME - Preuves et Langages
3 LIP - Laboratoire de l'Informatique du Parallélisme
4 CNRS - Centre National de la Recherche Scientifique
5 LaBRI - Laboratoire Bordelais de Recherche en Informatique

Negotiations are a formalism for describing multiparty distributed cooperation. Alternatively, they can be seen as a model of concurrency with synchronized choice as communication primitive. Well-designed negotiations must be sound, meaning that, whatever its current state, the negotiation can still be completed. In a former paper, Esparza and Desel have shown that deciding soundness of a negotiation is PSPACE-complete, and in PTIME if the negotiation is determinis-tic. They have also provided an algorithm for an intermediate class of acyclic, non-deterministic negotiations, but left the complexity of the soundness problem open. In the first part of this paper we study two further analysis problems for sound acyclic deter-ministic negotiations, called the race and the omission problem, and give polynomial algorithms. We use these results to provide the first polynomial algorithm for some analysis problems of workflow nets with data previously studied by Trcka, van der Aalst, and Sidorova. In the second part we solve the open question of Esparza and Desel's paper. We show that soundness of acyclic, weakly non-deterministic negotiations is in PTIME, and that checking soundness is already NP-complete for slightly more general classes.

Mots clés: Negotiations; workflows; soundness; verification; concurrency

Domaines: Calcul parallèle, distribué et partagé [cs.DC]

Javier Esparza, Denis Kuperberg, Anca Muscholl, Igor Walukiewicz. Soundness in negotiations. Logical Methods in Computer Science, 2018, ⟨10.4230/LIPIcs⟩. ⟨hal-01891179⟩