A Proof System for a PGAS Language
Due to advances in hardware architectures such as multi-core/multi-threaded architectures, various refinements of the parallel programming models such as distributed shared space, global address space and partitioned global address space (PGAS) etc., are widely prevalent in programming languages designed for high performance computing. In this paper, we shall discuss a preliminary work on a proof system for such a language. The language referred to as PGAS 0, is essentially an object-oriented language with features such as statically fixed set of places, asynchronous creation of activities, futures, atomics for synchronization etc. Many of the features of PGAS 0 are taken from the new experimental language X10 (built around Java) under design at IBM. The language distinguishes between local and remote data access with reference to threads. The atomic is the only construct that can be used for synchronization in PGAS 0 and is executed in a mutually exclusive manner at a place. One of the main safety properties of a PGAS 0 program is that a thread should not access non-local data object directly by dereferencing but use the construct future to obtain remote data. We shall describe the semantics of PGAS 0 and illustrate a proof system for the same with the motivation of establishing locality of data (an extremely useful from performance perspective). Further, we show how the same proof system can be used for establishing other concurrency properties.
KeywordsProof System Future Activity Object Instance Proof Outline Distribute Shared Memory
Unable to display preview. Download preview PDF.
- 1.Ábrahám, E., de Boer, F.S., de Roever, W.-P., Steffen, M.: An assertion based proof system for multithreaded java. TCS 331 (2005)Google Scholar
- 3.Apt, K.R., Francez, N., de Roever, W.P.: A proof system for communicating sequential processes. ACM TOPLAS 2(3) (1980)Google Scholar
- 4.Charles, P., Donawa, C., Ebcioglu, K., Grothoff, C., Kielstra, A., von Praun, C., Saraswat, V., Sarkar, V.: X10: An object-oriented approach to non-uniform cluster computing. In: OOPSLA (2005)Google Scholar
- 6.Flanagan, C., Felleisen, M.: The semantics of future and an application. J. Funct. Program. 9(1) (1999)Google Scholar
- 7.Koymans, R., Shyamasundar, R.K., Gerth, R., de Roever, W.P., Arun-Kumar, S.: Compositional semantics for real-time distributed programming language. Information and Computation 79(3) (December 1988)Google Scholar
- 8.Kundaji, R.N., Shyamasundar, R.K.: Refinement calculus: A basis for translation, validation, debugging and certification. TCS 354 (2006)Google Scholar
- 9.Liblit, B., Aiken, A.: Type system for distributed data structures. In: POPL (2000)Google Scholar
- 10.Owicki, S., Gries, D.: An axiomatic proof technique for parallel programs. Acta Informatica 6(4) (1976)Google Scholar
- 12.UPC language specifications, v1.2. Technical Report LBNL-59208, Berkeley National Lab. (2005)Google Scholar
- 13.Welc, A., Jagannathan, S., Hosking, A.: Safe futures for java. In: OOPSLA (2005)Google Scholar