Perhaps there is an option not considered here? What about lock-free structures?

I am by no means an expert in this stuff, but am interested in a peripheral way. I was just reading

http://www.cl.cam.ac.uk/netos/papers/2004-cpwl-submission.pdf

which I got to from:

http://www.cl.cam.ac.uk/research/srg/netos/lock-free/

and they sure do bandy the word "practical" around a lot.

Do the luminaries on this board know if this stuff is robust enough to make its way into current programming languages? Is it even relevant?

It might be too subtle for library use, but perhaps it would make sense if a programming language could use it to provide thread-safe objects, and programmers could mostly ignore threading issues when dealing with those objects.

-Ray