Well, the disruptor have a set of requests that are processed in parallel. Each request have a counter associated with it. Each request also have a step associated with it. A step can depend on an arbitrary number of earlier steps. This dependency based setup of steps can easily be mapped to petri form.
Ok, maybe it isn't that close, but both are some kind of state machines that allow for arbitrary number of dependencies for each state and the mapping from a cycle free petri net to a disruptor is very trivial. Of course, the lack of cycles hobble the expressive power of the nets.
