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Editing: save_env.py
import builtins import locale import os import sys import threading from test import support from test.support import os_helper from test.libregrtest.utils import print_warning class SkipTestEnvironment(Exception): pass # 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 support.environment_altered attribute 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. """ 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', 'urllib.requests._url_tempfiles', 'urllib.requests._opener', ) def get_module(self, name): # function for restore() methods return sys.modules[name] def try_get_module(self, name): # function for get() methods try: return self.get_module(name) except KeyError: raise SkipTestEnvironment def get_urllib_requests__url_tempfiles(self): urllib_request = self.try_get_module('urllib.request') return list(urllib_request._url_tempfiles) def restore_urllib_requests__url_tempfiles(self, tempfiles): for filename in tempfiles: os_helper.unlink(filename) def get_urllib_requests__opener(self): urllib_request = self.try_get_module('urllib.request') return urllib_request._opener def restore_urllib_requests__opener(self, opener): urllib_request = self.get_module('urllib.request') urllib_request._opener = opener def get_asyncio_events__event_loop_policy(self): self.try_get_module('asyncio') return support.maybe_get_event_loop_policy() def restore_asyncio_events__event_loop_policy(self, policy): asyncio = self.get_module('asyncio') 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): warnings = self.try_get_module('warnings') return id(warnings.filters), warnings.filters, warnings.filters[:] def restore_warnings_filters(self, saved_filters): warnings = self.get_module('warnings') 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): shutil = self.try_get_module('shutil') # 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 = self.get_module('shutil') shutil._ARCHIVE_FORMATS = saved[0] shutil._ARCHIVE_FORMATS.clear() shutil._ARCHIVE_FORMATS.update(saved[1]) def get_shutil_unpack_formats(self): shutil = self.try_get_module('shutil') return shutil._UNPACK_FORMATS, shutil._UNPACK_FORMATS.copy() def restore_shutil_unpack_formats(self, saved): shutil = self.get_module('shutil') shutil._UNPACK_FORMATS = saved[0] shutil._UNPACK_FORMATS.clear() shutil._UNPACK_FORMATS.update(saved[1]) def get_logging__handlers(self): logging = self.try_get_module('logging') # _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): logging = self.try_get_module('logging') # _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): multiprocessing_process = self.try_get_module('multiprocessing.process') # 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): multiprocessing_process = self.get_module('multiprocessing.process') multiprocessing_process._dangling.clear() multiprocessing_process._dangling.update(saved) def get_sysconfig__CONFIG_VARS(self): # make sure the dict is initialized sysconfig = self.try_get_module('sysconfig') 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 = self.get_module('sysconfig') sysconfig._CONFIG_VARS = saved[1] sysconfig._CONFIG_VARS.clear() sysconfig._CONFIG_VARS.update(saved[2]) def get_sysconfig__INSTALL_SCHEMES(self): sysconfig = self.try_get_module('sysconfig') return (id(sysconfig._INSTALL_SCHEMES), sysconfig._INSTALL_SCHEMES, sysconfig._INSTALL_SCHEMES.copy()) def restore_sysconfig__INSTALL_SCHEMES(self, saved): sysconfig = self.get_module('sysconfig') 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 = os_helper.TESTFN if fn not in saved_value and (fn + '/') not in saved_value: if os.path.isfile(fn): os_helper.unlink(fn) elif os.path.isdir(fn): os_helper.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): warnings = self.try_get_module('warnings') return warnings.showwarning def restore_warnings_showwarning(self, fxn): warnings = self.get_module('warnings') 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 = [] for name, get, restore in self.resource_info(): try: original = get() except SkipTestEnvironment: continue self.saved_values.append((name, get, restore, original)) return self def __exit__(self, exc_type, exc_val, exc_tb): saved_values = self.saved_values self.saved_values = None # Some resources use weak references support.gc_collect() for name, get, restore, original in saved_values: current = get() # Check for changes to the resource's value if current != original: support.environment_altered = True restore(original) if not self.quiet and not self.pgo: print_warning( f"{name} was modified by {self.testname}\n" f" Before: {original}\n" f" After: {current} ") return False
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