zeromq/czmq — pull request #566 by mtspencer (2014-07-25 00:48:27+00:00)
Title: Create a monotonic clock function, use where time offsets are computed

Problem: If the system time is set backwards while a czmq application is
running that has timers set on a zloop, those timers will stop
until the system time reaches its previous value.

Solution: Introduce a monotonic clock that is not affected by system time
changes. Use this clock where time offsets are computed.

I've added a simple test to the self test. I built and ran on both Ubuntu 14.04 and Windows 7.