Tales from the jungle

Abstract

We rely on a computational infrastructure that is a densely interwined mass of software and hardware: programming languages, network protocols, operating systems, and processors. It has accumulated great complexity, from a combination of engineering design decisions, contingent historical choices, and sheer scale, yet it is defined at best by prose specifications, or, all too often, just by the common implementations. Can we do better? More specifically, can we apply rigorous methods to this mainstream infrastructure, taking the accumulated complexity seriously, and if we do, does it help? My colleagues and I have looked at these questions in several contexts: the TCP/IP network protocols with their Sockets API; programming language design, including the Java module system and the C11/C++11 concurrency model; the hardware concurrency behaviour of x86, IBM POWER, and ARM multiprocessors; and compilation of concurrent code.