Viewing file:  refleak.py (8 KB) -rw-r--r--
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import os
import re
import sys
import warnings
from inspect import isabstract
from test import support
try:
from _abc import _get_dump
except ImportError:
import weakref
def _get_dump(cls):
# Reimplement _get_dump() for pure-Python implementation of
# the abc module (Lib/_py_abc.py)
registry_weakrefs = set(weakref.ref(obj) for obj in cls._abc_registry)
return (registry_weakrefs, cls._abc_cache,
cls._abc_negative_cache, cls._abc_negative_cache_version)
def dash_R(ns, test_name, test_func):
"""Run a test multiple times, looking for reference leaks.
Returns:
False if the test didn't leak references; True if we detected refleaks.
"""
# This code is hackish and inelegant, but it seems to do the job.
import copyreg
import collections.abc
if not hasattr(sys, 'gettotalrefcount'):
raise Exception("Tracking reference leaks requires a debug build "
"of Python")
# Avoid false positives due to various caches
# filling slowly with random data:
warm_caches()
# Save current values for dash_R_cleanup() to restore.
fs = warnings.filters[:]
ps = copyreg.dispatch_table.copy()
pic = sys.path_importer_cache.copy()
try:
import zipimport
except ImportError:
zdc = None # Run unmodified on platforms without zipimport support
else:
zdc = zipimport._zip_directory_cache.copy()
abcs = {}
for abc in [getattr(collections.abc, a) for a in collections.abc.__all__]:
if not isabstract(abc):
continue
for obj in abc.__subclasses__() + [abc]:
abcs[obj] = _get_dump(obj)[0]
# bpo-31217: Integer pool to get a single integer object for the same
# value. The pool is used to prevent false alarm when checking for memory
# block leaks. Fill the pool with values in -1000..1000 which are the most
# common (reference, memory block, file descriptor) differences.
int_pool = {value: value for value in range(-1000, 1000)}
def get_pooled_int(value):
return int_pool.setdefault(value, value)
nwarmup, ntracked, fname = ns.huntrleaks
fname = os.path.join(support.SAVEDCWD, fname)
repcount = nwarmup + ntracked
# Pre-allocate to ensure that the loop doesn't allocate anything new
rep_range = list(range(repcount))
rc_deltas = [0] * repcount
alloc_deltas = [0] * repcount
fd_deltas = [0] * repcount
getallocatedblocks = sys.getallocatedblocks
gettotalrefcount = sys.gettotalrefcount
fd_count = support.fd_count
# initialize variables to make pyflakes quiet
rc_before = alloc_before = fd_before = 0
if not ns.quiet:
print("beginning", repcount, "repetitions", file=sys.stderr)
print(("1234567890"*(repcount//10 + 1))[:repcount], file=sys.stderr,
flush=True)
dash_R_cleanup(fs, ps, pic, zdc, abcs)
for i in rep_range:
test_func()
dash_R_cleanup(fs, ps, pic, zdc, abcs)
# dash_R_cleanup() ends with collecting cyclic trash:
# read memory statistics immediately after.
alloc_after = getallocatedblocks()
rc_after = gettotalrefcount()
fd_after = fd_count()
if not ns.quiet:
print('.', end='', file=sys.stderr, flush=True)
rc_deltas[i] = get_pooled_int(rc_after - rc_before)
alloc_deltas[i] = get_pooled_int(alloc_after - alloc_before)
fd_deltas[i] = get_pooled_int(fd_after - fd_before)
alloc_before = alloc_after
rc_before = rc_after
fd_before = fd_after
if not ns.quiet:
print(file=sys.stderr)
# These checkers return False on success, True on failure
def check_rc_deltas(deltas):
# Checker for reference counters and memory blocks.
#
# bpo-30776: Try to ignore false positives:
#
# [3, 0, 0]
# [0, 1, 0]
# [8, -8, 1]
#
# Expected leaks:
#
# [5, 5, 6]
# [10, 1, 1]
return all(delta >= 1 for delta in deltas)
def check_fd_deltas(deltas):
return any(deltas)
failed = False
for deltas, item_name, checker in [
(rc_deltas, 'references', check_rc_deltas),
(alloc_deltas, 'memory blocks', check_rc_deltas),
(fd_deltas, 'file descriptors', check_fd_deltas)
]:
# ignore warmup runs
deltas = deltas[nwarmup:]
if checker(deltas):
msg = '%s leaked %s %s, sum=%s' % (
test_name, deltas, item_name, sum(deltas))
print(msg, file=sys.stderr, flush=True)
with open(fname, "a") as refrep:
print(msg, file=refrep)
refrep.flush()
failed = True
return failed
def dash_R_cleanup(fs, ps, pic, zdc, abcs):
import copyreg
import collections.abc
# Restore some original values.
warnings.filters[:] = fs
copyreg.dispatch_table.clear()
copyreg.dispatch_table.update(ps)
sys.path_importer_cache.clear()
sys.path_importer_cache.update(pic)
try:
import zipimport
except ImportError:
pass # Run unmodified on platforms without zipimport support
else:
zipimport._zip_directory_cache.clear()
zipimport._zip_directory_cache.update(zdc)
# clear type cache
sys._clear_type_cache()
# Clear ABC registries, restoring previously saved ABC registries.
abs_classes = [getattr(collections.abc, a) for a in collections.abc.__all__]
abs_classes = filter(isabstract, abs_classes)
for abc in abs_classes:
for obj in abc.__subclasses__() + [abc]:
for ref in abcs.get(obj, set()):
if ref() is not None:
obj.register(ref())
obj._abc_caches_clear()
clear_caches()
def clear_caches():
# Clear the warnings registry, so they can be displayed again
for mod in sys.modules.values():
if hasattr(mod, '__warningregistry__'):
del mod.__warningregistry__
# Flush standard output, so that buffered data is sent to the OS and
# associated Python objects are reclaimed.
for stream in (sys.stdout, sys.stderr, sys.__stdout__, sys.__stderr__):
if stream is not None:
stream.flush()
# Clear assorted module caches.
# Don't worry about resetting the cache if the module is not loaded
try:
distutils_dir_util = sys.modules['distutils.dir_util']
except KeyError:
pass
else:
distutils_dir_util._path_created.clear()
re.purge()
try:
_strptime = sys.modules['_strptime']
except KeyError:
pass
else:
_strptime._regex_cache.clear()
try:
urllib_parse = sys.modules['urllib.parse']
except KeyError:
pass
else:
urllib_parse.clear_cache()
try:
urllib_request = sys.modules['urllib.request']
except KeyError:
pass
else:
urllib_request.urlcleanup()
try:
linecache = sys.modules['linecache']
except KeyError:
pass
else:
linecache.clearcache()
try:
mimetypes = sys.modules['mimetypes']
except KeyError:
pass
else:
mimetypes._default_mime_types()
try:
filecmp = sys.modules['filecmp']
except KeyError:
pass
else:
filecmp._cache.clear()
try:
struct = sys.modules['struct']
except KeyError:
pass
else:
struct._clearcache()
try:
doctest = sys.modules['doctest']
except KeyError:
pass
else:
doctest.master = None
try:
ctypes = sys.modules['ctypes']
except KeyError:
pass
else:
ctypes._reset_cache()
try:
typing = sys.modules['typing']
except KeyError:
pass
else:
for f in typing._cleanups:
f()
support.gc_collect()
def warm_caches():
# char cache
s = bytes(range(256))
for i in range(256):
s[i:i+1]
# unicode cache
[chr(i) for i in range(256)]
# int cache
list(range(-5, 257))
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