Modular Synthesis of Deadlock-Free Control Structures

This paper introduces a modular synthesis approach of arbitrarily large deadlock-free control structures. The synthesis rules are designed to preserve some properties of the modules. The properties preserved in the synthesized control structures are liveness and boundedness, the two most important properties of any control structure. This motivates to choose a model of the modules whose live-and-boundedness can be trivially assured. We introduce regular nets as the model of the modules, since the structure of these nets guarantees live-and-boundedness once the invariants are marked with tokens. The concept of net labeling plays a vital role in the present synthesis procedure. The boolean expressions, called net labels are attached to the transitions of the regular nets to define the synthesis rules for interconnecting the individual modules to form arbitrarily large live-and-bounded structure.