Enabling the Rust Compiler to Reason about Fork/Join Parallelism via Tapir

Abstract

Rust + Cilk is an extension to the Rust language incorporating Cilk’s keywords for language level parallelism. The Rust + Cilk compiler leverages the Rust compiler’s static verification of data race freedom and the OpenCilk parallelism platform’s strong theoretical guarantees for performance of parallel programs. I compare Rust + Cilk to existing librarybased parallelism solutions in Rust such as Rayon, as well as to C programs parallelized with OpenCilk, based on performance and ergonomics. I find that Rust + Cilk exhibits marginally worse performance than Rayon, although I expect these differences are possible to bridge with further work. Additionally, Rust + Cilk has ergonomic advantages for some kinds of parallel programs. I outline further research that could make Rust + Cilk a more complete and performant system to further take advantage of the benefits language-based parallelism solutions can offer while statically verifying data race freedom.