G'day Wally, This is a fairly common misconception. The fact that the Funnel enforces 'single' treading does not mean that you can't write a mutliple thread layer. Check out IOSerialFamily. The IOSerialBSDClient.cpp launches to funneled threads as well as at least one client thread and sometimes a driver thread. All of these threads interact quite happily in one instance of a serial port. Godfrey On Monday, May 12, 2003, at 01:31 US/Pacific, Wally Crooze wrote: This system will be multithreaded as it is required to do work in the background and keep synchronized with each other as well as normal vfs / vnode requests. So I will have to look more into sys/lock.h and read the TechNote. _______________________________________________ darwin-kernel mailing list | darwin-kernel@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.