Interprocess Communication in MARS

This paper outlines the interprocess communication mechanisms developed in the MARS (MAintainable Real-time System) project. Since additional requirements in the time domain have to be fulfilled by real-time systems, only a few of the traditional communication mechanisms are feasible for real-time applications. The approach taken in MARS meets the real-time communication requirements by using periodic messages, a deterministic medium access strategy, and a simple datagram protocol. Reliability requirements are met by repetitive sending of messages on a broadcast-bus. On top of efficient message handling routines within the kernel, high-level C/MARS language constructs provide a powerful and easy to use interface to the application programmer. The applicability of the C/MARS language constructs is not limited to certain fields of real-time processing but they are designed for general use.