heimdallr: Improving Compile Time Correctness Checking for Message Passing with Rust

Abstract

Message passing is the foremost parallelization method used in high-performance computing (HPC). Parallel programming in general and especially message passing strongly increase the complexity and susceptibility to errors of programs. The de-facto standard technologies used to realize message passing applications in HPC are MPI with C/C++ or Fortran code. These technologies offer high performance but do not come with many compile-time correctness guarantees and are quite error-prone. This paper presents our work on a message passing library implemented in Rust that focuses on compile-time correctness checks. In our design, we apply Rust’s memory and concurrency safety features to a message passing context and show how common error classes from MPI applications can be avoided with this approach.

Problems with the type safety of transmitted messages can be mitigated through the use of generic programming concepts at compile time and completely detected during runtime using data serialization methods. Our library is able to use Rust’s memory safety features to achieve data buffer safety for non-blocking message passing operations at compile time.

A performance comparison between our proof of concept implementation and MPI is included to evaluate the practicality of our approach. While the performance of MPI could not be beaten, the results still are promising. Moreover, we are able to achieve clear improvements in the aspects of correctness and usability.