Karen.Olack@H.CS.CMU.EDU.UUCP (03/10/87)
Speaker: Robert Halstead Date: March 16, 1987 Time: 2:00 p.m. Place: Wean Hall 8220 Topic: Multilisp: A Language for Parallel Symbolic Computing ABSTRACT Multilisp is an extension of Scheme with additional operators and additional semantics for parallel execution. These have been added without removing side effects from the language. The principal parallelism construct in Multilisp is the "future," which exhibits some features of both eager and lazy evaluation. Current work focuses on making Multilisp a more humane programming environment, on expanding the power of Multilisp to express task scheduling policies, and on measuring the properties of Multilisp programs with the goal of designing a parallel architecture well tailored for efficient Multilisp execution. Multilisp has been implemented, and runs on the shared-memory Concert multiprocessor, using as many as 27 processors. The implementation uses interesting techniques for task scheduling and garbage collection. The task scheduler helps control excessive resource utilization by means of an unfair scheduling policy; the garbage collector uses a multiprocessor algorithm modeled after the incremental garbage collector of Baker. The talk will briefly describe Multilisp, discuss the areas of current activity, and indicate the future direction of the project in the areas of language design, application development, and multiprocessor architecture.