Poster: connecting PGAS and traditional HPC languages.

Chapel is a high-level parallel programming language that implements a partitioned global address space model (PGAS). Programs written in this programming model have traditionally been self-contained entities written entirely in one language. On our poster, we present BRAID, which enables Chapel programs to call functions and instantiate objects written in C, C++, Fortran 77-2008, Java and Python. Our tool creates language bindings that are binary-compatible with those generated by the Babel language interoperability tool. The scientific community maintains a large amount of code written in traditional languages. With the help of our tool, users will gain access to their existing codebase with minimal effort and through a well-defined interface. The language bindings are designed to provide a good combination of performance and flexibility (including transparent access to distributed arrays). Knowing the demands of the target audience, we support the full Babel array API. A particular contribution is that we expose Chapel's distributed data types through our interface and make them accessible to external functions implemented in traditional serial programming languages. The advantages of our approach are highlighted by benchmarks that compare the performance of pure Chapel programs with that of hybrid versions that call subroutines implemented in Babel-supported languages inside of parallel loops. We also present our vision for interoperability with other PGAS languages such as UPC and X10.