DragonFly BSD
DragonFly commits List (threaded) for 2005-04
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cvs commit: src/usr.sbin/dntpd client.c client.h defs.h main.c system.c

From: Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxxxxx>
Date: Tue, 26 Apr 2005 00:01:43 -0700 (PDT)

dillon      2005/04/26 00:01:43 PDT

DragonFly src repository

  Modified files:
    usr.sbin/dntpd       client.c client.h defs.h main.c system.c 
  Do not try to collect offset data if a prior offset correction is still
  in progress.  Since we do not compensate for the prior offset correction,
  any corrections based on data accumulated while the prior correction is
  active will overshoot or undershoot.
  Offset calculations are based on compensated real time rather then
  uncompensated real time, which is why this is a problem.  Frequency
  corrections are based on uncompensated real time and do not have any
  similar issue.  It would be even better, but more difficult, to adapt
  the offset correction code to use uncompensated real time and then take
  the compensation into account, but this is a considerably more complex
  equation to get right.
  There is still another problem and that is the offset error will continue
  to build when the frequency is not corrected, potentially resulting in a
  longer sync-up time.  On the positive side, the offset correction is based
  on a standard deviation that only requires a minimum of 4 samples.
  Correct a minor compiler warning.
  Revision  Changes    Path
  1.8       +19 -12    src/usr.sbin/dntpd/client.c
  1.6       +6 -4      src/usr.sbin/dntpd/client.h
  1.8       +1 -0      src/usr.sbin/dntpd/defs.h
  1.7       +3 -3      src/usr.sbin/dntpd/main.c
  1.5       +17 -0     src/usr.sbin/dntpd/system.c


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