[ofw] Adding Performance Counters support for WinOF

[Sean Hefty]

>I further discussed it with my manager who worked with the Linux version
>and I was told that on Linux there was a problem with perfquery since it
>was neither thread nor process safe - i.e. calling it concurrently from
>2 or more threads/processes would crash.
>In addition, I can only assume perfquery is an executable.

perfquery is an executable.  I'm not sure what's meant about being thread or
process safe, since it's a stand alone program.

>I also assume that perfquery uses one of the more "lower levels" dlls
>mentioned below in order to get the performance counter information
>(libibumad?).

perfquery sends MADs that query the performance counters.  The counters are
returned in a MAD.  The MAD format and behavior is defined by the IB spec.

>To be more concrete, if I'd want to directly access the counter
>information I'll simply need to link my project against that DLL and
>call an API method - is that assumption correct?

You can send and process your own MADs.  In this case, you can write to any of
MAD libraries.

- Sean