A Testbed of Non-determinism in Educational Context

Non-determinism is a fundamental concept in automata theory, algorithms and parallelism. Dijkstra's guarded commands as well as Hoare's CSP alternative primitives are means for overcome of the intrinsic for parallel systems non-determinism. The fiberOS is an educational non-preemptive cooperative exokernel. It represents an implementation of a simple CSP machine using Windows fibers. The key CSP objects such processes and channels are supported as well as CSP parallel, alternative and communications primitives. This paper presents an implementation of CSP alternative command in fiberOS. Two-channel and n-channel versions of this command are supported. The first version is for introductory purposes, while the second one is STL (C++ Standard Library) based. Both of them are truly non-deterministic and could be used to profound study of that fundamental concept.