Re: [boost] Low-level precision timer proposal

From: Jeff Garland (jeff_at_[hidden])
Date: 2006-06-26 08:44:02

Pavel Vozenilek wrote:
> "Philippe Vaucher" wrote:
> 
>>  As I understand it, QueryPerformanceCounter has a hardware defined
>>> resolution that
>>> can be queried by calling QueryPerformanceFrequency.  QPF provides the
>>> counts
>>> per second.  You should be able to use this to more simply construct the
>>> time_duration.
> 
> The measurement will be exact if the execution
> runs on single processor. On multiprocessor there's
> always chance that the thread moves elsewhere
> and the measured value will be slightly different.

Yeah, isn't there something I read in the MSDN pages about giving QPC thread 
affinity to solve this issue?  Given the number of dual core chips making 
their way into the world now this is certain to be a serious problem.

Jeff