Democratizing transactional programming

Abstract. The transaction abstraction is arguably one of the most appealing middleware paradigms. It lies typically between the programmer of a concurrent or distributed application on the one hand, and the operating system with the underlying network on the other hand. It encapsulates the complex internals of failure recovery and concurrency control, significantly simplifying thereby the life of a non-expert programmer. Yet, some programmers are indeed experts and, for those, the transaction abstraction turns out to be inherently restrictive in its classic form. We argue for a genuine democratization of the paradigm, with different transactional semantics to be used by different programmers and composed within the same application. 1 A Brief History of Transaction The transaction abstraction is in essence a middleware paradigm: it allows multiple processes running on one or more processors (machines) to interact. The transaction abstraction lies typically between the programmer of concurrent an