Protection and synchronisation in a message-switched system

Abstract

We present a language, the Task Graph Language for the centralized representation of distributed control in the Mininet distributed operating system. This context-free language allows a programmer to specify the inter-process communication between a suite of distributed processes in the form of a Task Graph (centralized representation) and to have the constraints of the Task Graph enforced at run-time by coöperating Token Lists, one at each task (distributed control). The language allows the specification of connectivity (which tasks can send messages to which), sequencing (which messages must precede or follow one another), concurrency (which messages can be sent without regard to order), and mutual exclusion (which message sequences incident on a single task must be non-interfering).