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Show CHAPTERS CONCLUSION Boplog is the first logic programming system designed for and implemented on a large-scale shared-memory multiprocessor. Its design emphasizes shared data structures. effective use of large memories. locality. scalability. fast task migration and largely sequential execution. It is targeted for an unenhanced commerciallyavailable multiprocessor of a kind which seems likely to become increasingly popular with time. Boplog's performance is hobbled by an inadequately-optimized implementation and by attempts to overcome frustrating architectural limitations of the Butterfly. Rather than an end in itself, Boplog should instead be viewed as an early effort to identify and confront problems which will impact the implementation of declarative programming paradigms on future machines. The Butterfly is probably a hint of a kind of machine which will have a large impact on the way computers are used, and on the way they are programmed. It represents a pioneering effort in that it combines powerful microprocessors with a communications network capable of supplying high throughput to many processing elements. Already, a successor to the Butterfly is in the design stages; it will use much of the high-level architecture of the Butterfly in a system supporting several thousand processors rather than a few hundred. The Butterfly is difficult to use. Its operating system is new and attempts to provide capabilities which sequential systems do not need. Its user interface is frustratingly fragile, cumbersome, and inadequate. To use the Butterfly in more than a very naive fashion requires intricate knowledge of the operating system and memory management system as well as the underlying architecture and specific |
