Farms, Pipes, Streams and Reforestation: Reasoning about Structured Parallel Processes using Types and Hylomorphisms
The increasing importance of parallelism has motivated the creation of better abstractions for writing parallel software, including structured parallelism using nested algorithmic skeletons. Such approaches provide high-level abstractions that avoid common problems, such as race conditions, and often allow strong cost models to be defined. However, choosing a combination of algorithmic skeletons that yields good parallel speedups for a program on some specific parallel architecture remains a difficult task. In order to achieve this, it is necessary to simultaneously reason both about the costs of different parallel structures and about the semantic equivalences between them. This paper presents a new type-based mechanism that enables strong static reasoning about these properties. We exploit well-known properties of a very general recursion pattern, hylomorphisms, and give a denotational semantics for structured parallel processes in terms of these hylomorphisms. Using our approach, it is possible to determine formally whether it is possible to introduce a desired parallel structure into a program without altering its functional behaviour, and also to choose a version of that parallel structure that minimises some given cost model.
Mon 19 Sep Times are displayed in time zone: Osaka, Sapporo, Tokyo change
10:45 - 12:25: Session 1Research Papers at Noh Theater Chair(s): Akimasa MorihataUniversity of Tokyo, Japan | |||
10:45 - 11:10 Talk | Farms, Pipes, Streams and Reforestation: Reasoning about Structured Parallel Processes using Types and Hylomorphisms Research Papers David Castro-PerezUniversity of St. Andrews, UK, Kevin HammondUniversity of St. Andrews, UK, Susmit SarkarUniversity of St. Andrews, UK DOI | ||
11:10 - 11:35 Talk | Dag-Calculus: A Calculus for Parallel Computation Research Papers Umut A. AcarCarnegie Mellon University, Arthur CharguéraudInria, France, Mike RaineyInria, France, Filip SieczkowskiInria, France DOI | ||
11:35 - 12:00 Talk | A Lambda-Calculus Foundation for Universal Probabilistic Programming Research Papers Johannes BorgströmUppsala University, Sweden, Ugo Dal LagoUniversity of Bologna, France, Andrew D. GordonMicrosoft Research, UK, Marcin SzymczakUniversity of Edinburgh, UK DOI | ||
12:00 - 12:25 Talk | Deriving a Probability Density Calculator (Functional Pearl) Research Papers DOI |