Steve Schafer wrote: > On Fri, 09 Jan 2009 11:01:18 -0200, you wrote: > >> I'm writing a program that will read medical signs >>from many patients. It's important to have a precise >> measure of the time interval between some signs, and >> that can't depend on adjustments of time. (Supose >> my software is running midnight at the end of a year >> with leap seconds. I would get wrong time intervals.) > > If you really need that level of accuracy, there is nothing available on > an off-the-shelf machine that will do the job. You need an independent > timekeeping source of some kind, one that is not subject to the vagaries
I'm not sure that the original question implied *that* level of need. Linux has High-Resolution Timers (HRTs) that may be appropriate. See the manpage for clock_gettime(), which defines these HRTs: CLOCK_REALTIME System-wide real-time clock. Setting this clock requires appropriate privi- leges. CLOCK_MONOTONIC Clock that cannot be set and represents monotonic time since some unspeci- fied starting point. CLOCK_PROCESS_CPUTIME_ID High-resolution per-process timer from the CPU. CLOCK_THREAD_CPUTIME_ID Thread-specific CPU-time clock. CLOCK_MONOTONIC, in particular, looks suitable. Using it could be a matter of just a few quick likes in FFI. I don't know if Windows has similar features. -- John _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe