Abstract

Programmers face much complexity from the co-existence of “native” (Unix-like) and [language] virtual machine (VM) “managed” run-time environments. Despite historical intentions, language VMs have largely failed to replace Unix processes. In this talk I’ll explore an approach in which Unix processes instead “become VMs”. This means evolving Unix’s user-level services to subsume those of VMs, in a highly compatible way. I’ll describe a system, liballocs, whose design achieves this by exploiting the existing (little-understood) rudiments of reflection and late-binding in modern Unix, while addressing two recurring shortcomings: a lack of semantic metadata (“type information”) and the inability to bind from objects “back” to their metadata. I’ll also describe some applications of liballocs: run-time type-checking, FFI -less language interoperability, dynamically precise debugging, and programmer-friendly disk I/O.