Implementing Software Transactional Memory, Correctly

In recent years there has been much interest in the idea of concurrent programming using transactional memory, for example as provided in STM Haskell. While programmers are provided with a simple high-level model of transactions in terms of a stop-the-world semantics, the low-level implementation is rather more complex, involving subtle techniques that allow multiple transactions to execute concurrently. In this article, we take the first steps towards a formally verified implementation of transactional memory. In particular, we present a stripped-down, idealised concurrent language inspired by STM Haskell, and show how a low-level implementation of this language can be justified with respect to a high-level semantics, by means of a compiler and its correctness theorem, validated using QuickCheck and HPC.