Nivat-Processing Systems: Decision Problems Related to Protection and Synchronization

The paper introduces a model for processing systems which proi ides ‘environment’ to the abstract notion of process as introduced by Nicst [ 131. X basic componcllt of the model is ;I protection mechanism which is general enough to capture as particular instances known protection strategies [e.g. take. grant, create, parameter passing) [5. 8. 91. Decision problems associated with these systems are discussed for both cases: processe\ with intinite and tinite hehaviours. Solvability results a+e obtained for the safety problem: as a corollary we get the solvability result of Beauquier in the context of his processes [I 1. IJnsolf ability results arc also derived. A concept of compatibilit) is Introduced for processes acting in parallel su )jcct to s~mc \ynchroniration condition. &‘c show that the traversing from rational to algebraic s>\tt’m$ can take the c~~mpatibility problem from solvable to unsolvable.