Time and related disasters in software (y2k38)

There are some opportunities to simplify:

• BIND now targets POSIX, which gives us much more useful guarantees about the behaviour of time_t, so we can replace most uses of isc_stdtime_t.

• ISO C has adopted struct timespec so we can use that instead of isc_time_t. It is used for C's timed mutex and thread sleep.

  • This will need some care, though, because isc_time_t has unsigned members, whereas struct timespec is signed, for instance, long tv_nsec.
  • On the other hand, 64 bit nanoseconds since the epoch is much easier to use than struct timespec or isc_time_t

• Most uses of time in BIND should probably be changed to use CLOCK_MONOTONIC instead of wall time