Some results on siphon computation for deadlock prevention in resource allocation systems modeled with Petri nets

Siphons are related to liveness properties of Petri net models. This relation is strong in the case of resource allocation systems (RAS). Siphons can be used in these systems in order to both, characterize and prevent/avoid deadlock situations. However, the computation of these structural components can be very time consuming or, even, impossible. Moreover, if, in general, the complete enumeration of the set of minimal siphons must be avoided (there can exist an exponential number of such components), some deadlock prevention methods rely on its (complete or partial) computation and enumeration. In the paper we show how the special syntactical constraints of some classes of resource allocation systems (we will concentrate on S-4 PR) can help in developing specific implementations to compute siphons in a very efficient way.