A Language for Embedded and Cyber-Physical Systems

Abstract

As computers continue to advance, they are becoming more capable of sensing, interacting, and communicating with both the physical and cyber world in significant ways. Medical devices responsible for a person’s well-being, electronic braking systems in automotive applications, and industrial control systems are examples of the many Cyber-Physical Systems (CPS) that utilize these computing capabilities. Given the potential consequences of software related failures in such systems, a high degree of safety, security, and reliability is often required. Programming languages are one of the primary tools used by programmers to develop embedded and cyber-physical systems. They provide a programmer with the ability to transform complex designs into machine executable code. Of equal importance is their ability to help detect and avoid programming mistakes. For decades, embedded and cyber-physical systems have been developed predominantly with the C programming language—in large part, due to its expressive power and ability to program low-level characteristics of these systems that other languages can’t. Although a powerful and widely used language, its type and memory unsafe pointers are a common source of programming errors. Pretzel is a hypothetical programming language that addresses memory safety and type safety issues commonly found in C/C++ pointers while attempting to maintain comparable performance and expressiveness. To achieve this, Pretzel’s type system provides a cohesive set of three distinct reference types; each with varying degrees of flexibility and runtime overhead. Additionally, the design also proposes techniques to minimize the performance impact of automatic reference counting.