First-class reactive programs for CPS

Abstract

Cyber-Physical Systems (CPS) are comprised of a network of devices that vary widely in complexity, ranging from simple sensors to autonomous robots. Traditionally, controlling and sensing these devices happens through API communication, in either push or pull-based fashion. We argue that the computational power of these devices is converging to the point where they can do autonomous computations. This allows application programmers to run programs locally on the sensors, thereby reducing the communication and workload of more central command and control entities. This work introduces the Potato framework that aims to make programming CPS systems intuitively easy and fast. Potato is based on three essential mechanisms: failure handling by means of leasing, distribution by means of first-class reactive programs, and intentional retroactive designation of the network by means of capabilities and dynamic properties. In this paper we focus on the reactive capabilities of our framework. Potato enables programmers to create and deploy first-class reactive programs on CPS devices at run time, abstracting away from the API approach. Each node in the network is equipped with a minimal actor-based middleware that can execute first-class reactive programs. We have implemented Potato as a library in Elixir and have used it to implement several small examples.