Distributed real-time systems play a very important role in our modern society. They are used in aircraft control, communication systems, military command and control systems, factory automation and robotics. However, satisfying the rigid timing requirements of various real-time activities in distributed real-time often requires ad hoc methods to tune the systems runtime behavior.

The object of Real-Time Mach is to develop a real-time version of the Mach kernel which provides users with a predictable and reliable distributed real-time computing environment. In this paper, we describe a real-time thread model, real-time synchronization, and the ITDS scheduler in Real-Time Mach. We also discuss the implementation issues, a real-time toolset, and the current status of the system.