[python-win32] time. delay oddities

[Ray S]

With the pure Python code below, I get results like:
micro sec: 1.0 12.2 154.8
micro sec: 0.9 11.3 156.0
when requesting 0, 10 and 160 us, which seems reasonable - PII600 Win2K Py2.2.

On Linux with a 2GHz Py2.3 it seems to always return 0.0

Additionally, I don't see why mydelay works as it does; I have tried other 
methods today, including an rdtsc DLL, and all other methodologies tried 
are limited by overhead of the call to ctypes (for rdstc or waitabletimer) 
or  ~200ms clock granularity (averages, ignoring the randomness of MS timing).
Can someone explain it? Does it work the same on other machines?


Code snipped from:
http://edily.progiciels-bpi.ca/showfile.html?name=courriel/c%C3%A9duleur&index=1

CODE:

mytime = time.clock#time ## optimization
sleep = time.sleep
clock = time.clock

def mydelay(delay):
     global logical_time
     physical_time = mytime()
     try:
         logical_time = logical_time + delay
     except NameError:
         logical_time = physical_time + delay
     if logical_time > physical_time:
         ## apparently only done when delays are > ~.001s
         sleep(logical_time - physical_time)
         #sleep(.001) ## same as above for small delays
         #print (logical_time - physical_time) *1000. ## print ms
         #sleep(.0001) ## same as sleep(0)!


p = 0.
d1 = 0.
d2 = 0.
looped = 0.
howMany = 100
for i in range(20):
     ## timer for pass in a for loop
     t1 = clock()
     for j in range(howMany):
         pass
     p += (clock()-t1)

     t1 = clock()
     mydelay(.000001)
     for j in range(howMany):
         mydelay(.00001)     ## ~minumum useable ~10us
     d1 += (clock()-t1)

     t1 = clock()
     for j in range(howMany):
         mydelay(.00016)
     d2 += (clock()-t1)

     looped+= howMany
     print 'micro sec: %.1f %.1f %.1f' % (1000000*p/looped, 
1000000*d1/looped, 1000000*(d2)/looped)