Transactional memory going mainstream with Intel Haswell

Intel has announced that its Haswell architecture, due to ship some time in 2013, will include hardware support for transactional memory.

Transactional memory is a promising technique designed to make the creation of reliable multithreaded programs easier. It does this by using a transactional model wherein complex operations can be performed concurrently, in isolation from each other, with those operations either completing or being undone as if they'd never been started—a model that developers are already familiar with from database programming.

Haswell's transactional support, which Intel is calling Transactional Synchronization Extensions (TSX), come in two parts. Hardware Lock Elision (HLE) allows easy conversion of lock-based programs into transactional programs in a way that's backwards compatible with current processors. Restricted Transactional Memory (RTM) is a more complete transactional memory implementation.