Add support for accumulating frequency and time offset without changing
the reference parameters and calling the local parameter change
handlers.
This will allow an unsynchronized source to operate below other sources
in order to stabilize the clock.
Replace struct timeval with struct timespec as the main data type for
timestamps. This will allow the NTP code to work with timestamps in
nanosecond resolution.
In addition to the system driver handling add new modes to slew or step
the system clock for leap second, or ignore it completely. This can be
configured with leapsecmode directive.
This will be used to set the kernel adjtimex() variables to allow other
applications running on the system to know if the system clock is
synchronized and the estimated error and the maximum error.
Rework makestep to cancel accumulated offset and step with the new
offset instead of accumulating new offset first, canceling all
accumulated offset and making the step.
This avoids two large frequency changes to initiate and cancel a slew
before making the step.
Add a new change type and use it when an unexpected time jump is
detected in the scheduler to reset reference times, offset and slewing,
NCR instances (with their polling interval), synchronization status, and
drop all sourcestats, manual, refclock and RTC samples.
This should make the recovery more graceful if the estimated jump has a
large error (e.g. select didn't timeout, or after system suspend).
We want to correct the offset quickly, but we also want to keep the
frequency error caused by the correction itself low.
Define correction rate as the area of the region bounded by the graph of
offset corrected in time. Set the rate so that the time needed to correct
an offset equal to the current sourcestats stddev will be equal to the
update interval (assuming linear adjustment). The offset and the
time needed to make the correction are inversely proportional.
This is only a suggestion and it's up to the system driver how the
adjustment will be executed.
This is needed to keep sourcestats accurate when the actual frequency is
different from the requested frequency due to clamping (or possibly
rounding in future system drivers).
None of the current handlers really need it and with temperature
compensation enabled it would be necessary to undo the compensation
before passing it to the handlers.
A new tempcomp directive can be used to specify a file for reading
current temperature, update interval and compensation coefficients. The
clock frequency corrections are applied in local module and are invisible
in upper layers. The measurements and corrections can be logged to
tempcomp.log file.
Leap second status is accepted and forwarded to clients if majority
of selectable sources agree. The actual insertion/deletion is supported
only on Linux now.
This is a verbatim copy of the files at that stage of the repository that was
built from the CVS import. It allows future development to see a bit of recent
history, but without carrying around the baggage going back to 1997. If that
is really required, git grafts can be used.
