在OSX上，Windows的QueryPerformanceCounter相当于什么？

Question

我正在将一个库从Windows移植到* NIX（目前是OSX），现在有人可以使用什么功能代替Microsoft的QueryPerformanceCounter和QueryPerformanceFrequency？

Answer 1

On OSX mach_absolute_time and mach_timebase_info are the best equivalents to Win32 QueryPerformance* functions.

See http://developer.apple.com/library/mac/#qa/qa1398/_index.html

Answer 2

http://www.tin.org/bin/man.cgi?section=3&topic=clock_gettime (and the other functions mentioned there) - it's Posix! Will fall back to worse counters if HPET is not existent. (shouldn't be a problem though)

http://en.wikipedia.org/wiki/High_Precision_Event_Timer

Resolution should be about +10Mhz.

Answer 3

Try boost's ptime for portable high-resolution timing.

Update (prompted, 2 years on, by Mark's comment below):

These days I'd use a std::chrono::high_resolution_clock ; example .

Answer 4

他询问了OS X.使用CoreAudio中的这些API：

AudioConvertHostTimeToNanos(AudioGetCurrentHostTime())

Answer 5

Back in the day you had either uclock or you delved into assembler to read the RDTSC .

G.