Parallel External Directed Model Checking with Linear I/O

Shahid Jabbar, Stefan Edelkamp

Abstract: In this paper we present Parallel External A*, a parallel variant of external memory directed model checking. As a model scales up, its successors generation becomes complex and, in turn, starts to impact the running time of the model checker. Probings of our external memory model checker IO-HSF-SPIN revealed that in some of the cases about 70% of the whole running time was consumed in the internal processing. Employing a multiprocessor machine or a cluster of workstations, we can distribute the internal working load of the algorithm on multiple processors. Moreover, assuming a sufficient number of processors and number of open file pointers per process, the I/O complexity is reduced to linear by exploiting a hash-function based state space partition scheme.