Section: New Results

Decidability results on the verification of phaser programs

Participant : Ludovic Henrio.

Together with Ahmed Rezine and Zeinab Ganjei (Linköping University) we investigated the possibility to analyze programs with phasers (a construct for synchronizing processes that generalizes locks, barrier, and publish-subscribe patterns). They work with signal and wait messages from the processes (comparing the number of wait and signal received to synchronize the processes). We proved that in many conditions, if the number of phasers or processes cannot be bounded, or if the difference between the number of signal and the number of wait signal is unbounded, then many reachability problems are undecidable. We also proposed fragments where these problems become decidable, and proposed an analysis algorithm in these cases. The results have been published in TACAS 2019 [11].