Prof. Dr. Javier Esparza

Abstract:

We characterize the complexity of the safety verification problem for parameterized systems consisting of a leader process and arbitrarily many anonymous and identical contributors. Processes communicate through a shared, bounded-value register. While each operation on the register is atomic, there is no synchronization primitive to execute a sequence of operations atomically. The model is inspired by distributed algorithms implemented on sensor networks.We analyse the complexity of the safety verification problem when processes are modeled by finite-state machines, pushdown machines, and Turing machines. Our proofs use combinatorial characterizations of computations in the model, and in case of pushdown-systems, some novel language-theoretic constructions of independent interest.

(Joint work with  Rupak Majumdar and Pierre Ganty)