How to ensure a timestamp is always unique?

Question

I\'m using timestamps to temporally order concurrent changes in my program, and require that each timestamp of a change be unique. However, I\'ve discovered that simply call

Answer 1

It can't be guaranteed to be unique, but is perhaps using ticks is granular enough?

A single tick represents one hundred nanoseconds or one ten-millionth of a second. There are 10,000 ticks in a millisecond.