Scalable join patterns

Abstract

Coordination can destroy scalability in parallel programming. A comprehensive library of scalable synchronization primitives is therefore an essential tool for exploiting parallelism. Unfortunately, such primitives do not easily combine to yield solutions to more complex problems. We demonstrate that a concurrency library based on Fournet and Gonthier's join calculus can provide declarative and scalable coordination. By declarative, we mean that the programmer needs only to write down the constraints of a coordination problem, and the library will automatically derive a correct solution. By scalable, we mean that the derived solutions deliver robust performance both as the number of processors increases, and as the complexity of the coordination problem grows. We validate our claims empirically on seven coordination problems, comparing our generic solution to specialized algorithms from the literature.

The Chemical Approach to Typestate-Oriented Programming

“…Concerning the program level, our framework relies on a standard formulation of the Join Calculus, for which there exist standalone, embedded, and library implementations: native support for join patterns is provided in JoCaml [15], Join Java [27], and in Cω [3,32], among others; library implementations of join patterns are available for C # [41,48], Visual Basic [42], and Scala [23]. Both native and library implementations of join patterns have pros and cons.…”

“…Library implementations of join patterns are (or can be made) available for all mainstream programming languages and therefore integrate more easily with existing code and development environments, but they might be constrained by the syntax and typing discipline of the host language. Nonetheless, carefully crafted implementations can perform and scale remarkably well [48].…”

The chemical approach to typestate-oriented programming

“…Concerning the program level, our framework relies on a standard formulation of the Join Calculus, for which there exist standalone, embedded, and library implementations: native support for join patterns is provided in JoCaml [20], Join Java [28], and in Cω [3,33], among others; library implementations of join patterns are available for C # [42,49], Visual Basic [43], and Scala [24]. Both native and library implementations of join patterns have pros and cons.…”

“…Library implementations of join patterns are (or can be made) available for all mainstream programming languages and therefore integrate more easily with existing code and development environments, but they might be constrained by the syntax and typing discipline of the host language. Nonetheless, carefully crafted implementations can perform and scale remarkably well [49].…”

Reagents

“…Thus, reagents provide a scalable implementation of the join calculus, along the lines of the one developed in previous work with Russo [29].…”