Fine real-time processing in distributed systems

A simple communication mechanism for real-time operating systems is proposed to support communicating real-time processes in distributed systems. To extract the primitive requirements for a communication mechanism, communicating real-time processes are classified and discussed. Then a communication mechanism is designed to meet these requirements. The proposed mechanism handles communication messages with interrupt-level priority cooperatively with the real-time scheduler which are working in the target real-time operating system. Although the proposed mechanism is independent to the target operating systems and communicating devices, the article shows the implementation of this mechanism as an additional subsystem for RT-Linux, a real-time extended Linux, to support Ethernet. Some performance evaluations show that this implementation is enough fast to communicate and to synchronize between two real-time processes which is running on different computers. Also an experimental result shows that two robot systems are successfully controlled cooperatively connected with Ethernet. These results shows the proposed mechanism is quite efficient to build communicating real-time processes in distributed systems.