Thanks to the work of Mark Heily, both upstream and in Debian, this week saw the arrival of libdispatch in Debian.
libdispatch is the userspace component of Apple’s Grand Central Dispatch technology, designed to help write applications that really take advantage of multicore processors without having to fiddle directly with threads and locking (and getting it terribly wrong).
To get that working on Linux, Mark wrote a userspace implementation of the pthread workqueues and a kqueue compatibility library (libkqueue). He also packaged the Blocks runtime (libblocksruntime) for Debian so as to build libdispatch with Blocks support. That means code using libdispatch must be built with CLang (or llvm-gcc-4.2) rather than gcc, as getting Blocks support in gcc in the near future looks highly improbable.
On Mac OS X and FreeBSD, a kernel-based implementation of the pthread workqueues is used; we don’t have that for Linux yet. The all-userspace implementation we have at the moment works really well; there are some caveats, though, but that’s no reason for not starting to play with libdispatch right now!
Try it out, it’s great. Thanks again, Mark!