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Diffstat (limited to 'Tools/pybench')
| -rw-r--r-- | Tools/pybench/systimes.py | 197 |
1 files changed, 197 insertions, 0 deletions
diff --git a/Tools/pybench/systimes.py b/Tools/pybench/systimes.py new file mode 100644 index 0000000..79d249f --- /dev/null +++ b/Tools/pybench/systimes.py @@ -0,0 +1,197 @@ +#!/usr/bin/env python + +""" systimes() user and system timer implementations for use by + pybench. + + This module implements various different strategies for measuring + performance timings. It tries to choose the best available method + based on the platforma and available tools. + + On Windows, it is recommended to have the Mark Hammond win32 + package installed. Alternatively, the Thomas Heller ctypes + packages can also be used. + + On Unix systems, the standard resource module provides the highest + resolution timings. Unfortunately, it is not available on all Unix + platforms. + + If no supported timing methods based on process time can be found, + the module reverts to the highest resolution wall-time timer + instead. The system time part will then always be 0.0. + + The module exports one public API: + + def systimes(): + + Return the current timer values for measuring user and system + time as tuple of seconds (user_time, system_time). + + Copyright (c) 2006, Marc-Andre Lemburg (mal@egenix.com). See the + documentation for further information on copyrights, or contact + the author. All Rights Reserved. + +""" +import time, sys, struct + +# +# Note: Please keep this module compatible to Python 1.5.2. +# +# TODOs: +# +# * Add ctypes wrapper for new clock_gettime() real-time POSIX APIs; +# these will then provide nano-second resolution where available. +# +# * Add a function that returns the resolution of systimes() +# values, ie. systimesres(). +# + +### Choose an implementation + +SYSTIMES_IMPLEMENTATION = None +USE_CTYPES_GETPROCESSTIMES = 'cytpes GetProcessTimes() wrapper' +USE_WIN32PROCESS_GETPROCESSTIMES = 'win32process.GetProcessTimes()' +USE_RESOURCE_GETRUSAGE = 'resource.getrusage()' +USE_PROCESS_TIME_CLOCK = 'time.clock() (process time)' +USE_WALL_TIME_CLOCK = 'time.clock() (wall-time)' +USE_WALL_TIME_TIME = 'time.time() (wall-time)' + +if sys.platform[:3] == 'win': + # Windows platform + try: + import win32process + except ImportError: + try: + import ctypes + except ImportError: + # Use the wall-time implementation time.clock(), since this + # is the highest resolution clock available on Windows + SYSTIMES_IMPLEMENTATION = USE_WALL_TIME_CLOCK + else: + SYSTIMES_IMPLEMENTATION = USE_CTYPES_GETPROCESSTIMES + else: + SYSTIMES_IMPLEMENTATION = USE_WIN32PROCESS_GETPROCESSTIMES +else: + # All other platforms + try: + import resource + except ImportError: + pass + else: + SYSTIMES_IMPLEMENTATION = USE_RESOURCE_GETRUSAGE + +# Fall-back solution +if SYSTIMES_IMPLEMENTATION is None: + # Check whether we can use time.clock() as approximation + # for systimes() + start = time.clock() + time.sleep(0.1) + stop = time.clock() + if stop - start < 0.001: + # Looks like time.clock() is usable (and measures process + # time) + SYSTIMES_IMPLEMENTATION = USE_PROCESS_TIME_CLOCK + else: + # Use wall-time implementation time.time() since this provides + # the highest resolution clock on most systems + SYSTIMES_IMPLEMENTATION = USE_WALL_TIME_TIME + +### Implementations + +def getrusage_systimes(): + return resource.getrusage(resource.RUSAGE_SELF)[:2] + +def process_time_clock_systimes(): + return (time.clock(), 0.0) + +def wall_time_clock_systimes(): + return (time.clock(), 0.0) + +def wall_time_time_systimes(): + return (time.time(), 0.0) + +# Number of clock ticks per second for the values returned +# by GetProcessTimes() on Windows. +# +# Note: Ticks returned by GetProcessTimes() are micro-seconds on +# Windows XP (though the docs say 100ns intervals) +WIN32_PROCESS_TIMES_TICKS_PER_SECOND = 10e6 + +def win32process_getprocesstimes_systimes(): + d = win32process.GetProcessTimes(win32process.GetCurrentProcess()) + # Note: I'm not sure whether KernelTime on Windows is the same as + # system time on Unix - I've yet to see a non-zero value for + # KernelTime on Windows. + return (d['UserTime'] / WIN32_PROCESS_TIMES_TICKS_PER_SECOND, + d['KernelTime'] / WIN32_PROCESS_TIMES_TICKS_PER_SECOND) + +def ctypes_getprocesstimes_systimes(): + creationtime = ctypes.c_ulonglong() + exittime = ctypes.c_ulonglong() + kerneltime = ctypes.c_ulonglong() + usertime = ctypes.c_ulonglong() + rc = ctypes.windll.kernel32.GetProcessTimes( + ctypes.windll.kernel32.GetCurrentProcess(), + ctypes.byref(creationtime), + ctypes.byref(exittime), + ctypes.byref(kerneltime), + ctypes.byref(usertime)) + if not rc: + raise TypeError('GetProcessTimes() returned an error') + return (usertime.value / WIN32_PROCESS_TIMES_TICKS_PER_SECOND, + kerneltime.value / WIN32_PROCESS_TIMES_TICKS_PER_SECOND) + +# Select the default for the systimes() function + +if SYSTIMES_IMPLEMENTATION is USE_RESOURCE_GETRUSAGE: + systimes = getrusage_systimes + +elif SYSTIMES_IMPLEMENTATION is USE_PROCESS_TIME_CLOCK: + systimes = process_time_clock_systimes + +elif SYSTIMES_IMPLEMENTATION is USE_WALL_TIME_CLOCK: + systimes = wall_time_clock_systimes + +elif SYSTIMES_IMPLEMENTATION is USE_WALL_TIME_TIME: + systimes = wall_time_time_systimes + +elif SYSTIMES_IMPLEMENTATION is USE_WIN32PROCESS_GETPROCESSTIMES: + systimes = win32process_getprocesstimes_systimes + +elif SYSTIMES_IMPLEMENTATION is USE_CTYPES_GETPROCESSTIMES: + systimes = ctypes_getprocesstimes_systimes + +else: + raise TypeError('no suitable systimes() implementation found') + +### Testing + +def some_workload(): + x = 0L + for i in xrange(10000000L): + x = x + 1L + +def test_workload(): + print 'Testing systimes() under load conditions' + t0 = systimes() + some_workload() + t1 = systimes() + print 'before:', t0 + print 'after:', t1 + print 'differences:', (t1[0] - t0[0], t1[1] - t0[1]) + print + +def test_idle(): + print 'Testing systimes() under idle conditions' + t0 = systimes() + time.sleep(1) + t1 = systimes() + print 'before:', t0 + print 'after:', t1 + print 'differences:', (t1[0] - t0[0], t1[1] - t0[1]) + print + +if __name__ == '__main__': + print 'Using %s as timer' % SYSTIMES_IMPLEMENTATION + print + test_workload() + test_idle() |