Verification of Concurrent Programs Using Petri Net Unfoldings

Given a verification problem for a concurrent program (with a fixed number of threads) over infinite data domains, we can construct a model checking problem for an abstraction of the concurrent program through a Petri net (a problem which can be solved using McMillan’s unfoldings technique). We present a method of abstraction refinement which translates Floyd/Hoare-style proofs for sample traces into additional synchronization constraints for the Petri net.