问题
I have a python script that calls a USB-based data-acquisition C# dotnet executable. The main python script does many other things, e.g. it controls a stepper motor. We would like to check the relative timing of various operations, for that purpose the dotnet exe generates a log with timestamps from C# Stopwatch.GetTimestamp(), which as far as I know yields the same number as calls to win32 API QueryPerformanceCounter().
Now I would like to get similar numbers from the python script. time.clock() returns such values, unfortunately it subtracts the value obtained at the time of 1st call to time.clock(). How can I get around this? Is it easy to call QueryPerformanceCounter() from some existing python module or do I have to write my own python extension in C?
I forgot to mention, the python WMI module by Tim Golden does this: wmi.WMI().Win32_PerfRawData_PerfOS_System()[0].Timestamp_PerfTime , but it is too slow, some 48ms overhead. I need something with <=1ms overhead. time.clock() seems to be fast enough, as is c# Stopwatch.GetTimestamp().
TIA, Radim
回答1:
Have you tried using ctypes?
from ctypes import *
val = c_int64()
windll.Kernel32.QueryPerformanceCounter(byref(val))
print val.value
回答2:
You could just call the C# StopWatch class directly from Python couldn't you? Maybe a small wrapper is needed (don't know Python/C# interop details - sorry) - if you are already using C# for data acquisition, doing the same for timings via Stopwatch should be simpler than anything else you can do.
来源：https://stackoverflow.com/questions/4430227/python-on-win32-how-to-get-absolute-timing-cpu-cycle-count