To detect forward time jumps, use a timestamp made before calling
select() instead of the first timeout in the queue. Also, if the timeout
value is modified by select() (e.g. on Linux) use it to get a more
accurate estimate of the elapsed time.
With cmdport 0 and port 0, it's now possible that there is no descriptor
watched or timer running, i.e. chronyd doing nothing and only waiting to
be terminated. Replace the assertion with LOG_FATAL to exit properly.
With special reference update modes, the timeout handlers may add or
remove file descriptors from the read fd set, so it needs to be copied
for select() call after they are dispatched. Also, they can now request
quit, so the exit flag needs to be checked before select() to avoid
hanging.
It could be triggered by delayed name resolving as it adds multiple new
timeouts which can be called in the same dispatching if the DNS responses
are slower than initial delay and sampling separation.
Compare number of dispatched events also with current number of
timeouts.
If more timeouts were handled than there were in the timer queue on
start, assume some code is scheduling timeouts with negative delays and
abort. Make the actual limit higher in case the machine is temporarily
overloaded and dispatching the handlers takes more time than was delay
of a scheduled timeout.
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.
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.
