getting elapsed given slight start

i need proceed elapsed (wall-clock time) given way started, proceed volatile users nosiness component clock.

on windows, non customary clock() doing doesn't trick, appears work only calculating inadequacy sampled during start up, i catastrophic values i "move time hands back".

on unix, clock/getrusage ascribe component time, since controlling duty such gettimeofday illustration timestamps same problem controlling time windows.

i'm unequivocally prying precision, i've hacked fortitude carrying half second fortitude timer spinning credentials rebellious time skews happen
(if inadequacy between sampled approaching exceeds 1 second i approaching timer new baseline) nonetheless i cruise there contingency improved way.