Back to the future!

[Ludovic Courtès]

Hello!

There’s a brand new (ice-9 futures) module implementing futures:

  
http://git.sv.gnu.org/cgit/guile.git/commit/?id=0d4e6ca38f1c51f5f92effc7d97c8b69eb85d071

(There used to be an implementation of futures in libguile, but it was
never included in a release because of various bugs.)

It basically does the job, though there are a couple of minor FIXMEs or
TODOs.

The implementation was inspired by that of libgomp, the GNU OpenMP
run-time support library.  It uses a pool of threads, normally one per
CPU core minus one, and offloads expression evaluation to them.  On a
single-core machine, you get an empty thread pool, meaning that futures
are evaluated sequentially, upon ‘touch’.

Feedback welcome!  :-)

Thanks,
Ludo’.