There is an increasing focus on software parallelisation and scalability through multi-threaded programming these days. This is most clearly evident through the number of articles on these subjects popping up in blogs, magazines, and journals.

One such article I recently read was in Dr. Dobb's, written by Herb Sutter, and entitled Sharing Is The Root Of All Contention. Herb talks about the obvious concurrency impediments that are directly visible in code, but he also talks in-depth about the more elusive concurrency impediments that are hidden in the software layers and underlying hardware.

Here is Herb's fantastic breakdown matrix of "contention penalties" which summarises the main thrust of his article quite well (I'm not sure why it was included as a blurry image rather than a table, but it's like that in the original article):

Check out the full article for some great detail on each of these areas: Sharing Is The Root Of All Contention, by Herb Sutter