1989 Reports

An Overview of the Synthesis Operating System

Pu, Calton; Massalin, Henry

An operating system (OS) maps a model of computation, defined by its kernel interface, onto the underlying hardware. A. simple and intuitive model of computation makes it easy for programmers to write applications. An efficient implementation of the mapping makes the applications run fast. Typical OS interfaces for von Neumann hardware include processes (CPU), address spaces (memory), and I/O devices (I/O). An OS for distributed and multiprocessor systems must support parallel processing and inter-process communications. Designed for the distributed and multiprocessor systems of today and tomorrow, Synthesis is an example of the new generation of OS's. The Synthesis model of computation based on macro dataflow makes parallel programming easy. The Synthesis implementation uses innovative ideas from areas as different as compilers and control systems, Kernel Code Synthesis. Reduced Synchronization, Fine-Grain Scheduling, and Valued Redundancy provide high performance. Emulation of guest OS's in Synthesis allow existing software written for other OS's to run on Synthesis with little or no modification. Using hardware and software emulating a SUN-3/160 running SUN OS, the current version of Synthesis kernel achieves several times to several dozen times speed up for UNIX kernel calls.