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From: Philippe Vaucher (philippe.vaucher_at_[hidden])
Date: 2007-07-20 03:32:13

> I changed it to do m_frequency.QuadPart /= 1000000 in its constructor
> and add to elapsed by doing:
> m_elapsed += posix_time::microseconds(microseconds);

Sounds fair enough, I'll do the same.

In terms of what to do when QueryPerformanceCounter leaps I would
> probably use the GetTickCount value silently so the class just works
> (tm). I'd probably edit the file locally to assert in debug in that case
> just for personal curiosity.

I'll probably do some kind of macro enabling this behavior, like
QPC_SET_AFFINITY which solves the multicore problem.

There was one more problem with QueryPerformanceCounter on some laptops
> including my old one. When the cpu lowered its clock speed to save
> battery power the frequency of the timer changed despite the
> documentation for QueryPerformanceFrequency explicitly saying the
> frequency cannot change while the system is running. I don't have the
> laptop anymore so I doubt we'll be able to make and test a fix.
> Hopefully this isn't common.

Unfortunately I don't see a fix for the speedsteping problem... I think we
can only document it.

About the next versions, I always do a message on the mailing list and I
post it there, sometimes I also upload it to
the vault...

Cheers for your insights. Btw as you seem to work on non-posix and
non-windows system, can you tell me what timeing API there is on those
platforms ? Would it make sense to add a "others" namespace where non-posix
and non-win devices would be ?


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