10 Jan
2009
10 Jan
'09
12:22 p.m.
On Sat, 10 Jan 2009 15:04:36 +0100, you wrote:
POSIX realtime extensions have been developed to be high reliable.
I think people are missing the details here. Yes, the built-in real-time clocks have excellent long-term accuracy. They run UTC-based correction algorithms using NTP, and are thus traceable to TAI. However, they offer no guarantees on interval measurements, and the correction algorithms can cause the measurement of a time interval of an hour or so duration to be off by +/- 1 sec, especially within the first few hours after a cold boot. If you care about leap seconds, you should certainly care about that magnitude of error. Steve Schafer Fenestra Technologies Corp. http://www.fenestra.com/