OS X :: FreeBSD Adds Support For Snow Leopard's Grand Central Dispatch

Apple's Grand Central Dispatch technology, which debuted in Snow Leopard as a mechanism for optimizing parallelism across multiple cores and processors, has now been ported to FreeBSD. Apple publicly announced plans to release its GCD technology as open source last month; the FreeBSD team demonstrated its early port of the new feature at EuroBSDCon 2009 in Cambridge, UK just days after Apple's announcement. Out of the box support for GCD is scheduled to appear with the release of FreeBSD 8.1. The work required to port Apple's GCD event and concurrency framework to other operating systems is more complex than many other higher-level open source packages because GCD requires integration into the kernel (the core component of the operating system which manages processes, memory, and other hardware).

Most Unix-based software is highly portable between Mac OS X, Linux, and BSD, but significant kernel differences between these systems makes porting low-level, kernel-integrated technologies like GCD more work. In particular, Mac OS X uses a unique kernel design based on a hybrid of Mach and BSD. Porting GCD to FreeBSD required adaptations to account for a more conventional kernel environment without a Mach layer, such as using POSIX semaphores instead of Mach semaphores. FreeBSD's porting efforts should help to make GCD easier to port to other operating systems with conventional Unix or Unix-like kernels, including OpenBSD, NetBSD, Linux, and Solaris..........................