Is a GUID unique 100% of the time?

Question

Is a GUID unique 100% of the time?

Will it stay unique over multiple threads?

Answer 1

Guids are statistically unique. The odds of two different clients generating the same Guid are infinitesimally small (assuming no bugs in the Guid generating code). You may as well worry about your processor glitching due to a cosmic ray and deciding that 2+2=5 today.

Multiple threads allocating new guids will get unique values, but you should get that the function you are calling is thread safe. Which environment is this in?