A layered architecture for simulating distributed operating systems

One of the main problems to be solved by the designers of policies and algorithms for distributed systems or multiprocessors is their test and evaluation. The solution adopted in the paper is based on the design and construction of a software test bed. DASS, a simulation system to test and design distributed algorithms, is presented. With it, the designer can work in an environment similar to a real network but with increased flexibility enabling change to the parameters or the network itself. The system is implemented, in C language, on a VAX/VMS as a concurrent program composed of a variable number of processes. The creation and synchronization system calls are borrowed from the C/UNIX library available on VMS