Efficient goal scheduling in a concurrent logic language using type-based dependency analysis

  • Kazuhiko Ohno
  • Masahiko Ikawa
  • Masahiro Goshimai
  • Shin-ichiro Mori
  • Hiroshi Nakashima
  • Shinji Tomita
Session 6
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1345)


In the execution model of concurrent logic languages like KL1, each goal is regarded as a unit of concurrent execution. Although this fine-grained concurrency control enables flexible concurrent/parallel programming, its overhead also causes inefficiency in its implementation. We propose an efficient goal scheduling scheme using the result of static analysis. In this scheme, we obtain precise dependency relations among goals using type-based dependency analysis. Then each set of goals without concurrency is compiled into one thread, a sequence of statically ordered goals, to reduce the overhead of goal scheduling. Since stacks are used to hold goal environments for each thread, the number of garbage collection is also reduced. The result of preliminary evaluation shows our scheme considerably reduces goal scheduling overhead and thus it achieves 1.3–3 times speedup.


Logic Program Garbage Collection Dynamic Schedule Apparent Dependency Guard Horn Clause 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1997

Authors and Affiliations

  • Kazuhiko Ohno
    • 1
  • Masahiko Ikawa
    • 2
  • Masahiro Goshimai
    • 1
  • Shin-ichiro Mori
    • 1
  • Hiroshi Nakashima
    • 3
  • Shinji Tomita
    • 1
  1. 1.Kyoto UniversityJapan
  2. 2.Mitsubishi Electric CorporationJapan
  3. 3.Toyohashi University of TechnologyJapan

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