[Pythonmac-SIG] Microseconds.py

[Just van Rossum]

I just learned in comp.sys.mac.programmer.whatever that there exists a
toolbox function called Microseconds(). Apparently it is not really precise
up to the Microsecond, but still a whole lot more precise than TickCount().
Thanks to Jack's wonderful calldll module, I was able to interface it in a
matter of minutes (but won't run on 68k ;-).

This might be useful for better profiling, where TickCount is really
somewhat too course.

Just


# Microseconds.py
import calldll
import struct

_InterfaceLib = calldll.getlibrary('InterfaceLib')

_Microseconds = calldll.newcall(_InterfaceLib.Microseconds,
		'None', 'InString')

def Microseconds():
	"""erm, don't try this at home..."""
	a = '\0' * 8
	_Microseconds(a)
	h, l = struct.unpack('LL', a)
	return float((h << 32) | l)


def _test():
	import Evt
	while 1:
		print Microseconds() / 1000000.0,
		print Evt.TickCount() / 60.0


if __name__ == "__main__":
	_test()