Software Control Synchronization Primitives for Mass Service Like Real Time Systems

Abstract In last years many high level language synchronization primitives (semaphores, critical regions, messages, monitors etc.) were invented. The primitives are intended to be used in operating systems and/or in real time programming. The variety of tools reflects, it seems, not only the state of the art. It is likely that due to various reasons (hardware limitations, response time etc.) the decision what primitives are to be used (or invented) depends on the problem to be solved. If the response time need not be too short and a greater overhead of an supervisory program is admissible more sophisticated means can be used. Moreover some means can reflect the situation and the intuition in some area of applications better than others. In the paper synchronization constructs for discrete system control software are discussed. The constructs were used with success in practical applications. The constructs are based on a list of jobs to be performed together with the conditions which must be satisfied before the job is performed. In order to program the parallel and sequential tasks easily it is possible to call a process “in parallel” as well as like a sub routine. The tools described below are very powerful and flexible in use. Their properties were verified in a machine tool workshop control software. The constructs seem to be useful in many real time systems especially in production process control software.