With regard to your last quesiton... look at clock.h. I believe most of these calls are safe in the kernel or even in an interrupt task. As far as a periodic call back you may want to attach yourself to an interrupt and install an interrupt service routine. I doubt anything else would give you the reliability you are looking for. -Phil -----Original Message----- From: Sean Morrell [mailto:smorrell@artlogic.com] Sent: Friday, March 08, 2002 10:19 AM To: darwin-kernel@lists.apple.com Subject: Need quick and reliable thread or timer I am writing an audio driver and would like to perform a very small amount of work at least every millisecond, with no more variance than a tenth of a millsecond. What mechanisms can be employed here? Can a thread be used? Can the priority be raised high enough to ensure it is running once every millsecond? Is there a timer as accurate as a Time Manager Task in OS 9? Thanks, Sean _______________________________________________ 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. _______________________________________________ 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.