RTC questions

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From
Benny Prijono <bennylp@switchlab.net>
Date
16 Mar 2001 03:38:34
Subject
RTC questions
Message-ID
3AB1FABF.C16A2E94@switchlab.net

Referenced by

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Dear all,

I'm working on a program which has soft-realtime requirement, that is
to schedule the jobs every 20 miliseconds. But unfortunately, if I use
normal usleep() + gettimeofday(), the schedule is somewhat not
reliable. If I do usleep(20), I've almost always got 30 ms long sleep.
I think this might have something to do with internal kernel timing
precision, which if I recall correctly is 10 ms.

So is there any solution to this problem?

Is there any RTC api in FreeBSD, similar to /dev/rtc in Linux? (with
/dev/rtc, a single program is allowed to program the RTC to any
frequency between 1Hz - 16Khz. The application then can do read() to
/dev/rtc, and it will block until the next RTC tick).

And in general, is there any realtime works being done with FreeBSD?
links?


thanks,
Bennylp

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