Tools/pybench/clockres.py

   1 #!/usr/bin/env python
   2
   3 """ clockres - calculates the resolution in seconds of a given timer.
   4
   5     Copyright (c) 2006, Marc-Andre Lemburg (mal@egenix.com). See the
   6     documentation for further information on copyrights, or contact
   7     the author. All Rights Reserved.
   8
   9 """
  10 import time
  11
  12 TEST_TIME = 1.0
  13
  14 def clockres(timer):
  15     d = {}
  16     wallclock = time.time
  17     start = wallclock()
  18     stop = wallclock() + TEST_TIME
  19     spin_loops = range(1000)
  20     while 1:
  21         now = wallclock()
  22         if now >= stop:
  23             break
  24         for i in spin_loops:
  25             d[timer()] = 1
  26     values = d.keys()
  27     values.sort()
  28     min_diff = TEST_TIME
  29     for i in range(len(values) - 1):
  30         diff = values[i+1] - values[i]
  31         if diff < min_diff:
  32             min_diff = diff
  33     return min_diff
  34
  35 if __name__ == '__main__':
  36     print 'Clock resolution of various timer implementations:'
  37     print 'time.clock:           %10.3fus' % (clockres(time.clock) * 1e6)
  38     print 'time.time:            %10.3fus' % (clockres(time.time) * 1e6)
  39     try:
  40         import systimes
  41         print 'systimes.processtime: %10.3fus' % (clockres(systimes.processtime) * 1e6)
  42     except ImportError:
  43         pass