packaged for wip by pho.
Software Transactional Memory: a modular composable concurrency
abstraction. See
* Composable memory transactions, by Tim Harris, Simon Marlow,
Simon Peyton Jones, and Maurice Herlihy, in /ACM Conference on
Principles and Practice of Parallel Programming/
2005. http://research.microsoft.com/Users/simonpj/papers/stm/index.htm
