Python 2.x - sleep call at millisecond level on Windows

Question

I was given some very good hints in this forum about how to code a clock object in Python 2. I\'ve got some code working now. It\'s a clock that \'ticks\' at 60 FPS:

Answer 1

You can temporarily lower the timer period to the wPeriodMin value returned by timeGetDevCaps. The following defines a timer_resolution context manager that calls the timeBeginPeriod and timeEndPeriod functions.

import timeit
import contextlib
import ctypes
from ctypes import wintypes

winmm = ctypes.WinDLL('winmm')

class TIMECAPS(ctypes.Structure):
    _fields_ = (('wPeriodMin', wintypes.UINT),
                ('wPeriodMax', wintypes.UINT))

def _check_time_err(err, func, args):
    if err:
        raise WindowsError('%s error %d' % (func.__name__, err))
    return args

winmm.timeGetDevCaps.errcheck = _check_time_err
winmm.timeBeginPeriod.errcheck = _check_time_err
winmm.timeEndPeriod.errcheck = _check_time_err

@contextlib.contextmanager
def timer_resolution(msecs=0):
    caps = TIMECAPS()
    winmm.timeGetDevCaps(ctypes.byref(caps), ctypes.sizeof(caps))
    msecs = min(max(msecs, caps.wPeriodMin), caps.wPeriodMax)
    winmm.timeBeginPeriod(msecs)
    yield
    winmm.timeEndPeriod(msecs)

def min_sleep():
    setup = 'import time'
    stmt = 'time.sleep(0.001)'
    return timeit.timeit(stmt, setup, number=1000)

Example

>>> min_sleep()
15.6137827

>>> with timer_resolution(msecs=1): min_sleep()
...
1.2827173000000016

The original timer resolution is restored after the with block:

>>> min_sleep()
15.6229814