Current File : //snap/core20/2318/lib/python3.8/test/libregrtest/save_env.py
import asyncio
import builtins
import locale
import logging
import os
import shutil
import sys
import sysconfig
import threading
import warnings
from test import support
from test.libregrtest.utils import print_warning
try:
import _multiprocessing, multiprocessing.process
except ImportError:
multiprocessing = None
# Unit tests are supposed to leave the execution environment unchanged
# once they complete. But sometimes tests have bugs, especially when
# tests fail, and the changes to environment go on to mess up other
# tests. This can cause issues with buildbot stability, since tests
# are run in random order and so problems may appear to come and go.
# There are a few things we can save and restore to mitigate this, and
# the following context manager handles this task.
class saved_test_environment:
"""Save bits of the test environment and restore them at block exit.
with saved_test_environment(testname, verbose, quiet):
#stuff
Unless quiet is True, a warning is printed to stderr if any of
the saved items was changed by the test. The attribute 'changed'
is initially False, but is set to True if a change is detected.
If verbose is more than 1, the before and after state of changed
items is also printed.
"""
changed = False
def __init__(self, testname, verbose=0, quiet=False, *, pgo=False):
self.testname = testname
self.verbose = verbose
self.quiet = quiet
self.pgo = pgo
# To add things to save and restore, add a name XXX to the resources list
# and add corresponding get_XXX/restore_XXX functions. get_XXX should
# return the value to be saved and compared against a second call to the
# get function when test execution completes. restore_XXX should accept
# the saved value and restore the resource using it. It will be called if
# and only if a change in the value is detected.
#
# Note: XXX will have any '.' replaced with '_' characters when determining
# the corresponding method names.
resources = ('sys.argv', 'cwd', 'sys.stdin', 'sys.stdout', 'sys.stderr',
'os.environ', 'sys.path', 'sys.path_hooks', '__import__',
'warnings.filters', 'asyncore.socket_map',
'logging._handlers', 'logging._handlerList', 'sys.gettrace',
'sys.warnoptions',
# multiprocessing.process._cleanup() may release ref
# to a thread, so check processes first.
'multiprocessing.process._dangling', 'threading._dangling',
'sysconfig._CONFIG_VARS', 'sysconfig._INSTALL_SCHEMES',
'files', 'locale', 'warnings.showwarning',
'shutil_archive_formats', 'shutil_unpack_formats',
'asyncio.events._event_loop_policy',
)
def get_asyncio_events__event_loop_policy(self):
return support.maybe_get_event_loop_policy()
def restore_asyncio_events__event_loop_policy(self, policy):
asyncio.set_event_loop_policy(policy)
def get_sys_argv(self):
return id(sys.argv), sys.argv, sys.argv[:]
def restore_sys_argv(self, saved_argv):
sys.argv = saved_argv[1]
sys.argv[:] = saved_argv[2]
def get_cwd(self):
return os.getcwd()
def restore_cwd(self, saved_cwd):
os.chdir(saved_cwd)
def get_sys_stdout(self):
return sys.stdout
def restore_sys_stdout(self, saved_stdout):
sys.stdout = saved_stdout
def get_sys_stderr(self):
return sys.stderr
def restore_sys_stderr(self, saved_stderr):
sys.stderr = saved_stderr
def get_sys_stdin(self):
return sys.stdin
def restore_sys_stdin(self, saved_stdin):
sys.stdin = saved_stdin
def get_os_environ(self):
return id(os.environ), os.environ, dict(os.environ)
def restore_os_environ(self, saved_environ):
os.environ = saved_environ[1]
os.environ.clear()
os.environ.update(saved_environ[2])
def get_sys_path(self):
return id(sys.path), sys.path, sys.path[:]
def restore_sys_path(self, saved_path):
sys.path = saved_path[1]
sys.path[:] = saved_path[2]
def get_sys_path_hooks(self):
return id(sys.path_hooks), sys.path_hooks, sys.path_hooks[:]
def restore_sys_path_hooks(self, saved_hooks):
sys.path_hooks = saved_hooks[1]
sys.path_hooks[:] = saved_hooks[2]
def get_sys_gettrace(self):
return sys.gettrace()
def restore_sys_gettrace(self, trace_fxn):
sys.settrace(trace_fxn)
def get___import__(self):
return builtins.__import__
def restore___import__(self, import_):
builtins.__import__ = import_
def get_warnings_filters(self):
return id(warnings.filters), warnings.filters, warnings.filters[:]
def restore_warnings_filters(self, saved_filters):
warnings.filters = saved_filters[1]
warnings.filters[:] = saved_filters[2]
def get_asyncore_socket_map(self):
asyncore = sys.modules.get('asyncore')
# XXX Making a copy keeps objects alive until __exit__ gets called.
return asyncore and asyncore.socket_map.copy() or {}
def restore_asyncore_socket_map(self, saved_map):
asyncore = sys.modules.get('asyncore')
if asyncore is not None:
asyncore.close_all(ignore_all=True)
asyncore.socket_map.update(saved_map)
def get_shutil_archive_formats(self):
# we could call get_archives_formats() but that only returns the
# registry keys; we want to check the values too (the functions that
# are registered)
return shutil._ARCHIVE_FORMATS, shutil._ARCHIVE_FORMATS.copy()
def restore_shutil_archive_formats(self, saved):
shutil._ARCHIVE_FORMATS = saved[0]
shutil._ARCHIVE_FORMATS.clear()
shutil._ARCHIVE_FORMATS.update(saved[1])
def get_shutil_unpack_formats(self):
return shutil._UNPACK_FORMATS, shutil._UNPACK_FORMATS.copy()
def restore_shutil_unpack_formats(self, saved):
shutil._UNPACK_FORMATS = saved[0]
shutil._UNPACK_FORMATS.clear()
shutil._UNPACK_FORMATS.update(saved[1])
def get_logging__handlers(self):
# _handlers is a WeakValueDictionary
return id(logging._handlers), logging._handlers, logging._handlers.copy()
def restore_logging__handlers(self, saved_handlers):
# Can't easily revert the logging state
pass
def get_logging__handlerList(self):
# _handlerList is a list of weakrefs to handlers
return id(logging._handlerList), logging._handlerList, logging._handlerList[:]
def restore_logging__handlerList(self, saved_handlerList):
# Can't easily revert the logging state
pass
def get_sys_warnoptions(self):
return id(sys.warnoptions), sys.warnoptions, sys.warnoptions[:]
def restore_sys_warnoptions(self, saved_options):
sys.warnoptions = saved_options[1]
sys.warnoptions[:] = saved_options[2]
# Controlling dangling references to Thread objects can make it easier
# to track reference leaks.
def get_threading__dangling(self):
# This copies the weakrefs without making any strong reference
return threading._dangling.copy()
def restore_threading__dangling(self, saved):
threading._dangling.clear()
threading._dangling.update(saved)
# Same for Process objects
def get_multiprocessing_process__dangling(self):
if not multiprocessing:
return None
# Unjoined process objects can survive after process exits
multiprocessing.process._cleanup()
# This copies the weakrefs without making any strong reference
return multiprocessing.process._dangling.copy()
def restore_multiprocessing_process__dangling(self, saved):
if not multiprocessing:
return
multiprocessing.process._dangling.clear()
multiprocessing.process._dangling.update(saved)
def get_sysconfig__CONFIG_VARS(self):
# make sure the dict is initialized
sysconfig.get_config_var('prefix')
return (id(sysconfig._CONFIG_VARS), sysconfig._CONFIG_VARS,
dict(sysconfig._CONFIG_VARS))
def restore_sysconfig__CONFIG_VARS(self, saved):
sysconfig._CONFIG_VARS = saved[1]
sysconfig._CONFIG_VARS.clear()
sysconfig._CONFIG_VARS.update(saved[2])
def get_sysconfig__INSTALL_SCHEMES(self):
return (id(sysconfig._INSTALL_SCHEMES), sysconfig._INSTALL_SCHEMES,
sysconfig._INSTALL_SCHEMES.copy())
def restore_sysconfig__INSTALL_SCHEMES(self, saved):
sysconfig._INSTALL_SCHEMES = saved[1]
sysconfig._INSTALL_SCHEMES.clear()
sysconfig._INSTALL_SCHEMES.update(saved[2])
def get_files(self):
return sorted(fn + ('/' if os.path.isdir(fn) else '')
for fn in os.listdir())
def restore_files(self, saved_value):
fn = support.TESTFN
if fn not in saved_value and (fn + '/') not in saved_value:
if os.path.isfile(fn):
support.unlink(fn)
elif os.path.isdir(fn):
support.rmtree(fn)
_lc = [getattr(locale, lc) for lc in dir(locale)
if lc.startswith('LC_')]
def get_locale(self):
pairings = []
for lc in self._lc:
try:
pairings.append((lc, locale.setlocale(lc, None)))
except (TypeError, ValueError):
continue
return pairings
def restore_locale(self, saved):
for lc, setting in saved:
locale.setlocale(lc, setting)
def get_warnings_showwarning(self):
return warnings.showwarning
def restore_warnings_showwarning(self, fxn):
warnings.showwarning = fxn
def resource_info(self):
for name in self.resources:
method_suffix = name.replace('.', '_')
get_name = 'get_' + method_suffix
restore_name = 'restore_' + method_suffix
yield name, getattr(self, get_name), getattr(self, restore_name)
def __enter__(self):
self.saved_values = dict((name, get()) for name, get, restore
in self.resource_info())
return self
def __exit__(self, exc_type, exc_val, exc_tb):
saved_values = self.saved_values
del self.saved_values
# Some resources use weak references
support.gc_collect()
# Read support.environment_altered, set by support helper functions
self.changed |= support.environment_altered
for name, get, restore in self.resource_info():
current = get()
original = saved_values.pop(name)
# Check for changes to the resource's value
if current != original:
self.changed = True
restore(original)
if not self.quiet and not self.pgo:
print_warning(f"{name} was modified by {self.testname}")
print(f" Before: {original}\n After: {current} ",
file=sys.stderr, flush=True)
return False
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