  In this paper, we introduce Continuation Passing C (CPC), a programming
language for concurrent systems in which native and cooperative threads are
unified and presented to the programmer as a single abstraction. The CPC
compiler uses a compilation technique, based on the CPS transform, that yields
efficient code and an extremely lightweight representation for contexts. We
provide a proof of the correctness of our compilation scheme. We show in
particular that lambda-lifting, a common compilation technique for functional
languages, is also correct in an imperative language like C, under some
conditions enforced by the CPC compiler. The current CPC compiler is mature
enough to write substantial programs such as Hekate, a highly concurrent
BitTorrent seeder. Our benchmark results show that CPC is as efficient, while
using significantly less space, as the most efficient thread libraries
available.

Programming Languages