Christopher Diggins Object Oriented Template Library (OOTL) http://www.ootl.org ----- Original Message ----- From: "Michael Walter" <michael.walter@gmail.com> To: <boost@lists.boost.org> Sent: Friday, February 11, 2005 10:15 PM Subject: Re: [boost] Re: Re: Re: Re: Profiling Library suggestion
On Fri, 11 Feb 2005 19:57:56 -0500, Preston A. Elder <prez@neuromancy.net> wrote:
On Fri, 11 Feb 2005 19:30:36 -0500, christopher diggins wrote: [...] std::clock() and I assume QueryPerformanceCounter() give you an amount of clock ticks. This number is only incremented when the CPU works on your task. AFAIK your assumption is wrong.
Can you point me to documentation which supports your assertion?
The only problem with QueryPerformanceCounter() is that it can "jump" on some chipsets.
I believe this problem is perhaps not restricted to QueryPerformanceCounter() but to any counter counting mechanism, as the problem is at the chipset level not the API level.
A good idea is to use a "control timer" with lower frequency (or just timeBeginPeriod() + timeGetTime(), if its precision is good enough for the task).
I am not sure what you mean by a control timer, but I do have a workaround for the QueryPerformanceCounter() issue in http://www.cdiggins.com/profiler/v2/high_resolution_timer.hpp Thanks for the feedback, Christopher