Python code coverage for Tools/pybench/systimes.py

#	count	content
1	n/a	#!/usr/bin/env python
2	n/a
3	n/a	""" systimes() user and system timer implementations for use by
4	n/a	pybench.
5	n/a
6	n/a	This module implements various different strategies for measuring
7	n/a	performance timings. It tries to choose the best available method
8	n/a	based on the platform and available tools.
9	n/a
10	n/a	On Windows, it is recommended to have the Mark Hammond win32
11	n/a	package installed. Alternatively, the Thomas Heller ctypes
12	n/a	packages can also be used.
13	n/a
14	n/a	On Unix systems, the standard resource module provides the highest
15	n/a	resolution timings. Unfortunately, it is not available on all Unix
16	n/a	platforms.
17	n/a
18	n/a	If no supported timing methods based on process time can be found,
19	n/a	the module reverts to the highest resolution wall-clock timer
20	n/a	instead. The system time part will then always be 0.0.
21	n/a
22	n/a	The module exports one public API:
23	n/a
24	n/a	def systimes():
25	n/a
26	n/a	Return the current timer values for measuring user and system
27	n/a	time as tuple of seconds (user_time, system_time).
28	n/a
29	n/a	Copyright (c) 2006, Marc-Andre Lemburg (mal@egenix.com). See the
30	n/a	documentation for further information on copyrights, or contact
31	n/a	the author. All Rights Reserved.
32	n/a
33	n/a	"""
34	n/a
35	n/a	from __future__ import print_function
36	n/a
37	n/a	import time, sys
38	n/a
39	n/a	#
40	n/a	# Note: Please keep this module compatible to Python 1.5.2.
41	n/a	#
42	n/a	# TODOs:
43	n/a	#
44	n/a	# * Add ctypes wrapper for new clock_gettime() real-time POSIX APIs;
45	n/a	# these will then provide nano-second resolution where available.
46	n/a	#
47	n/a	# * Add a function that returns the resolution of systimes()
48	n/a	# values, ie. systimesres().
49	n/a	#
50	n/a
51	n/a	### Choose an implementation
52	n/a
53	n/a	SYSTIMES_IMPLEMENTATION = None
54	n/a	USE_CTYPES_GETPROCESSTIMES = 'ctypes GetProcessTimes() wrapper'
55	n/a	USE_WIN32PROCESS_GETPROCESSTIMES = 'win32process.GetProcessTimes()'
56	n/a	USE_RESOURCE_GETRUSAGE = 'resource.getrusage()'
57	n/a	USE_PROCESS_TIME_CLOCK = 'time.clock() (process time)'
58	n/a	USE_WALL_TIME_CLOCK = 'time.clock() (wall-clock)'
59	n/a	USE_WALL_TIME_TIME = 'time.time() (wall-clock)'
60	n/a
61	n/a	if sys.platform[:3] == 'win':
62	n/a	# Windows platform
63	n/a	try:
64	n/a	import win32process
65	n/a	except ImportError:
66	n/a	try:
67	n/a	import ctypes
68	n/a	except ImportError:
69	n/a	# Use the wall-clock implementation time.clock(), since this
70	n/a	# is the highest resolution clock available on Windows
71	n/a	SYSTIMES_IMPLEMENTATION = USE_WALL_TIME_CLOCK
72	n/a	else:
73	n/a	SYSTIMES_IMPLEMENTATION = USE_CTYPES_GETPROCESSTIMES
74	n/a	else:
75	n/a	SYSTIMES_IMPLEMENTATION = USE_WIN32PROCESS_GETPROCESSTIMES
76	n/a	else:
77	n/a	# All other platforms
78	n/a	try:
79	n/a	import resource
80	n/a	except ImportError:
81	n/a	pass
82	n/a	else:
83	n/a	SYSTIMES_IMPLEMENTATION = USE_RESOURCE_GETRUSAGE
84	n/a
85	n/a	# Fall-back solution
86	n/a	if SYSTIMES_IMPLEMENTATION is None:
87	n/a	# Check whether we can use time.clock() as approximation
88	n/a	# for systimes()
89	n/a	start = time.clock()
90	n/a	time.sleep(0.1)
91	n/a	stop = time.clock()
92	n/a	if stop - start < 0.001:
93	n/a	# Looks like time.clock() is usable (and measures process
94	n/a	# time)
95	n/a	SYSTIMES_IMPLEMENTATION = USE_PROCESS_TIME_CLOCK
96	n/a	else:
97	n/a	# Use wall-clock implementation time.time() since this provides
98	n/a	# the highest resolution clock on most systems
99	n/a	SYSTIMES_IMPLEMENTATION = USE_WALL_TIME_TIME
100	n/a
101	n/a	### Implementations
102	n/a
103	n/a	def getrusage_systimes():
104	n/a	return resource.getrusage(resource.RUSAGE_SELF)[:2]
105	n/a
106	n/a	def process_time_clock_systimes():
107	n/a	return (time.clock(), 0.0)
108	n/a
109	n/a	def wall_clock_clock_systimes():
110	n/a	return (time.clock(), 0.0)
111	n/a
112	n/a	def wall_clock_time_systimes():
113	n/a	return (time.time(), 0.0)
114	n/a
115	n/a	# Number of clock ticks per second for the values returned
116	n/a	# by GetProcessTimes() on Windows.
117	n/a	#
118	n/a	# Note: Ticks returned by GetProcessTimes() are 100ns intervals on
119	n/a	# Windows XP. However, the process times are only updated with every
120	n/a	# clock tick and the frequency of these is somewhat lower: depending
121	n/a	# on the OS version between 10ms and 15ms. Even worse, the process
122	n/a	# time seems to be allocated to process currently running when the
123	n/a	# clock interrupt arrives, ie. it is possible that the current time
124	n/a	# slice gets accounted to a different process.
125	n/a
126	n/a	WIN32_PROCESS_TIMES_TICKS_PER_SECOND = 1e7
127	n/a
128	n/a	def win32process_getprocesstimes_systimes():
129	n/a	d = win32process.GetProcessTimes(win32process.GetCurrentProcess())
130	n/a	return (d['UserTime'] / WIN32_PROCESS_TIMES_TICKS_PER_SECOND,
131	n/a	d['KernelTime'] / WIN32_PROCESS_TIMES_TICKS_PER_SECOND)
132	n/a
133	n/a	def ctypes_getprocesstimes_systimes():
134	n/a	creationtime = ctypes.c_ulonglong()
135	n/a	exittime = ctypes.c_ulonglong()
136	n/a	kerneltime = ctypes.c_ulonglong()
137	n/a	usertime = ctypes.c_ulonglong()
138	n/a	rc = ctypes.windll.kernel32.GetProcessTimes(
139	n/a	ctypes.windll.kernel32.GetCurrentProcess(),
140	n/a	ctypes.byref(creationtime),
141	n/a	ctypes.byref(exittime),
142	n/a	ctypes.byref(kerneltime),
143	n/a	ctypes.byref(usertime))
144	n/a	if not rc:
145	n/a	raise TypeError('GetProcessTimes() returned an error')
146	n/a	return (usertime.value / WIN32_PROCESS_TIMES_TICKS_PER_SECOND,
147	n/a	kerneltime.value / WIN32_PROCESS_TIMES_TICKS_PER_SECOND)
148	n/a
149	n/a	# Select the default for the systimes() function
150	n/a
151	n/a	if SYSTIMES_IMPLEMENTATION is USE_RESOURCE_GETRUSAGE:
152	n/a	systimes = getrusage_systimes
153	n/a
154	n/a	elif SYSTIMES_IMPLEMENTATION is USE_PROCESS_TIME_CLOCK:
155	n/a	systimes = process_time_clock_systimes
156	n/a
157	n/a	elif SYSTIMES_IMPLEMENTATION is USE_WALL_TIME_CLOCK:
158	n/a	systimes = wall_clock_clock_systimes
159	n/a
160	n/a	elif SYSTIMES_IMPLEMENTATION is USE_WALL_TIME_TIME:
161	n/a	systimes = wall_clock_time_systimes
162	n/a
163	n/a	elif SYSTIMES_IMPLEMENTATION is USE_WIN32PROCESS_GETPROCESSTIMES:
164	n/a	systimes = win32process_getprocesstimes_systimes
165	n/a
166	n/a	elif SYSTIMES_IMPLEMENTATION is USE_CTYPES_GETPROCESSTIMES:
167	n/a	systimes = ctypes_getprocesstimes_systimes
168	n/a
169	n/a	else:
170	n/a	raise TypeError('no suitable systimes() implementation found')
171	n/a
172	n/a	def processtime():
173	n/a
174	n/a	""" Return the total time spent on the process.
175	n/a
176	n/a	This is the sum of user and system time as returned by
177	n/a	systimes().
178	n/a
179	n/a	"""
180	n/a	user, system = systimes()
181	n/a	return user + system
182	n/a
183	n/a	### Testing
184	n/a
185	n/a	def some_workload():
186	n/a	x = 0
187	n/a	for i in range(10000000):
188	n/a	x = x + 1
189	n/a
190	n/a	def test_workload():
191	n/a	print('Testing systimes() under load conditions')
192	n/a	t0 = systimes()
193	n/a	some_workload()
194	n/a	t1 = systimes()
195	n/a	print('before:', t0)
196	n/a	print('after:', t1)
197	n/a	print('differences:', (t1[0] - t0[0], t1[1] - t0[1]))
198	n/a	print()
199	n/a
200	n/a	def test_idle():
201	n/a	print('Testing systimes() under idle conditions')
202	n/a	t0 = systimes()
203	n/a	time.sleep(1)
204	n/a	t1 = systimes()
205	n/a	print('before:', t0)
206	n/a	print('after:', t1)
207	n/a	print('differences:', (t1[0] - t0[0], t1[1] - t0[1]))
208	n/a	print()
209	n/a
210	n/a	if __name__ == '__main__':
211	n/a	print('Using %s as timer' % SYSTIMES_IMPLEMENTATION)
212	n/a	print()
213	n/a	test_workload()
214	n/a	test_idle()