Am 21.05.2014 09:31, schrieb Noel Grandin:
> On 2014-05-20 21:11, Karsten Blees wrote:
>>   * implement Mac OSX version using mach_absolute_time
>>
>>
> 
> 
> Note that unlike the Windows and Linux APIs, mach_absolute_time does not do 
> correction for frequency-scaling

I don't have a MAC so I can't test any of this, but supposedly 
mach_timebase_info() returns the frequency of mach_absolute_time(), so you 
could do similar frequency-scaling as I do for Windows with 
QueryPerformanceFrequency().

> and cross-CPU synchronization with the TSC.
> 

The TSC is synchronized across cores and sockets on modern x86 hardware [1] (at 
least since Intel Nehalem, i.e. all Core i[357] processors). On older machines, 
I would expect the OS API to choose a more appropriate time source, e.g. the 
HPET. I'm not proposing to use asm("rdtsc") or anything like that...

[1] 
https://software.intel.com/en-us/articles/best-timing-function-for-measuring-ipp-api-timing

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