ABSTRACT

The occam [Inm84a, Inm84b, Inm95, Bar92] programming language is a concurrent programming Language based on the CSP [Hoa78, Hoa85, Ros97] process algebra. CSP provides a rigorous parallel model, whereby parallel processes engage in synchronous events. A process may also select between several events on other (external choice). In occam, CSP events appear mostly as channels (wherewo processes synchronise and data is copied) and at the ends of PARallel blocks — to ensure that l nested parallel processes have terminated. occam was developed between Oxford University and Inmos, with the Transputer [Inm93] in mind. The Transputer combined an on-chip micro-coded scheduler with on-chip external communications (on DS links), resulting in highly scalable multi-processor platforms for parallel processing.The T9000 Transputer additionally provided a virtual channel capability, allowing several virtual inks to be multiplexed into one physical link [MTW93]. Coupled with crossbar routing, namely theC104, this provided a solid platform for the distribution and execution of occam programs.Then we can have a look at the RMoX operating sysyem and its architecture.