SHARED-MEMORY MULTIMICROPROCESSOR OPERATING SYSTEM WITH AN EXTENDED PETRI-NET MODEL

In this paper, we propose a methodology for programming multiprocessor event-driven systems. This methodology is based on two programming le vels: the task level, which involves programming the basic actions tha t may be executed in the system as units with a single control thread; and the job level, on which parallel programs to be executed by the c omplete multiprocessor system are developed. We also present the struc ture and implementation of an operating system designed as the program ming support for software development under the proposed methodology. The model that has been chosen for the representation of the system so ftware is based on an extended Petri net, which provides a well-establ ished conceptual model for the development of the tasks, thus allowing a totally independent and generic development. This model also facili tates job-level programming, since the Petri net is a very powerful de scription tool for the parallel program.