/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"""
10import time
11
12TEST_TIME = 1.0
13
14def 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
35if __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