Ticket History #2959: profile library should check high-resolution timestamps if available

With the current profile code, it's possible for a file to be read when
partially written, with the writing of the new file contents being completed
within the same 1-second clock value, causing the profile code not to re-read
the contents. Using a higher-resolution timestamp, available on many systems
now, should help reduce that window. (Checking file sizes should also,
consider doing that separately.)

* configure.in: Check struct stat for fields st_mtimensec,
st_mtimespec.tv_nsec, and st_mtim.tv_usec.
* prof_file.c (profile_update_file_data): If one of them is found, use it as
the fractional part of the timestamp. Do re-read the file if the fractional
parts don't match.
* prof_int.h (struct _prf_data_t): Add new field frac_ts.


To generate a diff of this commit:



cvs diff -r1.177 -r1.178 krb5/src/util/profile/ChangeLog
cvs diff -r1.25 -r1.26 krb5/src/util/profile/configure.in
cvs diff -r1.52 -r1.53 krb5/src/util/profile/prof_file.c
cvs diff -r1.42 -r1.43 krb5/src/util/profile/prof_int.h