cpython-lru_cache-weakref: Tools/scripts/find

annotate Tools/scripts/find_recursionlimit.py @ 58689:514b56efd89a 3.1

Merged revisions 77962 via svnmerge from svn+ssh://pythondev@svn.python.org/python/branches/py3k ................ r77962 | r.david.murray | 2010-02-04 11:41:57 -0500 (Thu, 04 Feb 2010) | 17 lines Merged revisions 77943,77959-77960 via svnmerge from svn+ssh://pythondev@svn.python.org/python/trunk ........ r77943 | r.david.murray | 2010-02-03 08:36:23 -0500 (Wed, 03 Feb 2010) | 2 lines Explicitly mention the default value for formatdate's usegmt parameter. ........ r77959 | nick.coghlan | 2010-02-04 07:43:58 -0500 (Thu, 04 Feb 2010) | 1 line Issue 6760: Clarify args handling for subprocess.Popen. Patch by Chris Rebert ........ r77960 | r.david.murray | 2010-02-04 11:33:31 -0500 (Thu, 04 Feb 2010) | 2 lines Add Chris Rebert to ACKS for issue 6760 Popen doc improvements. ........ ................

author	R. David Murray <rdmurray@bitdance.com>
date	Thu, 04 Feb 2010 16:44:31 +0000
parents	029d69659b5f
children	bcf030f73eee fcfe324663a6

rev	line source
56889 029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	1 #! /usr/bin/env python
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	2 """Find the maximum recursion limit that prevents interpreter termination.
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	3
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	4 This script finds the maximum safe recursion limit on a particular
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	5 platform. If you need to change the recursion limit on your system,
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	6 this script will tell you a safe upper bound. To use the new limit,
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	7 call sys.setrecursionlimit().
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	8
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	9 This module implements several ways to create infinite recursion in
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	10 Python. Different implementations end up pushing different numbers of
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	11 C stack frames, depending on how many calls through Python's abstract
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	12 C API occur.
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	13
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	14 After each round of tests, it prints a message:
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	15 "Limit of NNNN is fine".
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	16
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	17 The highest printed value of "NNNN" is therefore the highest potentially
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	18 safe limit for your system (which depends on the OS, architecture, but also
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	19 the compilation flags). Please note that it is practically impossible to
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	20 test all possible recursion paths in the interpreter, so the results of
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	21 this test should not be trusted blindly -- although they give a good hint
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	22 of which values are reasonable.
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	23
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	24 NOTE: When the C stack space allocated by your system is exceeded due
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	25 to excessive recursion, exact behaviour depends on the platform, although
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	26 the interpreter will always fail in a likely brutal way: either a
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	27 segmentation fault, a MemoryError, or just a silent abort.
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	28
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	29 NB: A program that does not use __methods__ can set a higher limit.
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	30 """
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	31
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	32 import sys
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	33 import itertools
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	34
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	35 class RecursiveBlowup1:
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	36 def __init__(self):
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	37 self.__init__()
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	38
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	39 def test_init():
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	40 return RecursiveBlowup1()
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	41
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	42 class RecursiveBlowup2:
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	43 def __repr__(self):
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	44 return repr(self)
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	45
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	46 def test_repr():
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	47 return repr(RecursiveBlowup2())
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	48
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	49 class RecursiveBlowup4:
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	50 def __add__(self, x):
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	51 return x + self
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	52
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	53 def test_add():
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	54 return RecursiveBlowup4() + RecursiveBlowup4()
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	55
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	56 class RecursiveBlowup5:
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	57 def __getattr__(self, attr):
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	58 return getattr(self, attr)
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	59
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	60 def test_getattr():
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	61 return RecursiveBlowup5().attr
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	62
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	63 class RecursiveBlowup6:
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	64 def __getitem__(self, item):
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	65 return self[item - 2] + self[item - 1]
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	66
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	67 def test_getitem():
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	68 return RecursiveBlowup6()[5]
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	69
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	70 def test_recurse():
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	71 return test_recurse()
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	72
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	73 def test_cpickle(_cache={}):
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	74 import io
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	75 try:
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	76 import _pickle
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	77 except ImportError:
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	78 print("cannot import _pickle, skipped!")
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	79 return
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	80 l = None
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	81 for n in itertools.count():
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	82 try:
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	83 l = _cache[n]
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	84 continue # Already tried and it works, let's save some time
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	85 except KeyError:
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	86 for i in range(100):
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	87 l = [l]
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	88 _pickle.Pickler(io.BytesIO(), protocol=-1).dump(l)
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	89 _cache[n] = l
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	90
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	91 def check_limit(n, test_func_name):
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	92 sys.setrecursionlimit(n)
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	93 if test_func_name.startswith("test_"):
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	94 print(test_func_name[5:])
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	95 else:
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	96 print(test_func_name)
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	97 test_func = globals()[test_func_name]
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	98 try:
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	99 test_func()
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	100 # AttributeError can be raised because of the way e.g. PyDict_GetItem()
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	101 # silences all exceptions and returns NULL, which is usually interpreted
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	102 # as "missing attribute".
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	103 except (RuntimeError, AttributeError):
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	104 pass
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	105 else:
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	106 print("Yikes!")
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	107
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	108 limit = 1000
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	109 while 1:
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	110 check_limit(limit, "test_recurse")
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	111 check_limit(limit, "test_add")
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	112 check_limit(limit, "test_repr")
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	113 check_limit(limit, "test_init")
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	114 check_limit(limit, "test_getattr")
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	115 check_limit(limit, "test_getitem")
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	116 check_limit(limit, "test_cpickle")
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	117 print("Limit of %d is fine" % limit)
029d69659b5f Merged revisions 75373 via svnmerge from Georg Brandl <georg@python.org> parents: diff changeset	118 limit = limit + 100

Mercurial > cpython-lru_cache-weakref

annotate Tools/scripts/find_recursionlimit.py @ 58689:514b56efd89a 3.1