Kernel mechanisms for distributed real-time programs

The design of a kernel for distributed real-time programs is described. This design allows a distributed real-time program to be configured by interconnecting ports of component processes. This configuration is specified separately from the programs of individual processes, permitting easy reconfiguration of programs. The kernel provides mechanisms for both asynchronous and synchronous communication. A variety of mechanisms is provided for specifying real-time constraints. A novel aspect of this design is the provision of a structure called process clone that incorporates redundant computation for fault tolerance. This redundancy is provided such that it is transparent to application programs, and is used by the kernel to ensure continuity of operation in the presence of failures. Implementing this kernel poses many problems. The authors discuss some of these and present solutions that have been adopted in a prototype implementation of the kernel