[SOLVED] How do I obtain CPU cycle count in Win32?

How do I obtain CPU cycle count in Win32?

In Win32, is there any way to get a unique cpu cycle count or something similar that would be uniform for multiple processes/languages/systems/etc.

I'm creating some log files, but have to produce multiple logfiles because we're hosting the .NET runtime, and I'd like to avoid calling from one to the other to log. As such, I was thinking I'd just produce two files, combine them, and then sort them, to get a coherent timeline involving cross-world calls.

However, GetTickCount does not increase for every call, so that's not reliable. Is there a better number, so that I get the calls in the right order when sorting?

Edit: Thanks to @Greg that put me on the track to QueryPerformanceCounter, which did the trick.

Solution

You can use the RDTSC CPU instruction (assuming x86). This instruction gives the CPU cycle counter, but be aware that it will increase very quickly to its maximum value, and then reset to 0. As the Wikipedia article mentions, you might be better off using the QueryPerformanceCounter function.