import unittest
import contextvars
from contextlib import contextmanager, ExitStack
from test.support import (
catch_unraisable_exception, import_helper,
gc_collect)
# Skip this test if the _testcapi module isn't available.
_testcapi = import_helper.import_module('_testcapi')
class TestDictWatchers(unittest.TestCase):
# types of watchers testcapimodule can add:
EVENTS = 0 # appends dict events as strings to global event list
ERROR = 1 # unconditionally sets and signals a RuntimeException
SECOND = 2 # always appends "second" to global event list
def add_watcher(self, kind=EVENTS):
return _testcapi.add_dict_watcher(kind)
def clear_watcher(self, watcher_id):
_testcapi.clear_dict_watcher(watcher_id)
@contextmanager
def watcher(self, kind=EVENTS):
wid = self.add_watcher(kind)
try:
yield wid
finally:
self.clear_watcher(wid)
def assert_events(self, expected):
actual = _testcapi.get_dict_watcher_events()
self.assertEqual(actual, expected)
def watch(self, wid, d):
_testcapi.watch_dict(wid, d)
def unwatch(self, wid, d):
_testcapi.unwatch_dict(wid, d)
def test_set_new_item(self):
d = {}
with self.watcher() as wid:
self.watch(wid, d)
d["foo"] = "bar"
self.assert_events(["new:foo:bar"])
def test_set_existing_item(self):
d = {"foo": "bar"}
with self.watcher() as wid:
self.watch(wid, d)
d["foo"] = "baz"
self.assert_events(["mod:foo:baz"])
def test_clone(self):
d = {}
d2 = {"foo": "bar"}
with self.watcher() as wid:
self.watch(wid, d)
d.update(d2)
self.assert_events(["clone"])
def test_no_event_if_not_watched(self):
d = {}
with self.watcher() as wid:
d["foo"] = "bar"
self.assert_events([])
def test_del(self):
d = {"foo": "bar"}
with self.watcher() as wid:
self.watch(wid, d)
del d["foo"]
self.assert_events(["del:foo"])
def test_pop(self):
d = {"foo": "bar"}
with self.watcher() as wid:
self.watch(wid, d)
d.pop("foo")
self.assert_events(["del:foo"])
def test_clear(self):
d = {"foo": "bar"}
with self.watcher() as wid:
self.watch(wid, d)
d.clear()
self.assert_events(["clear"])
def test_dealloc(self):
d = {"foo": "bar"}
with self.watcher() as wid:
self.watch(wid, d)
del d
self.assert_events(["dealloc"])
def test_object_dict(self):
class MyObj: pass
o = MyObj()
with self.watcher() as wid:
self.watch(wid, o.__dict__)
o.foo = "bar"
o.foo = "baz"
del o.foo
self.assert_events(["new:foo:bar", "mod:foo:baz", "del:foo"])
with self.watcher() as wid:
self.watch(wid, o.__dict__)
for _ in range(100):
o.foo = "bar"
self.assert_events(["new:foo:bar"] + ["mod:foo:bar"] * 99)
def test_unwatch(self):
d = {}
with self.watcher() as wid:
self.watch(wid, d)
d["foo"] = "bar"
self.unwatch(wid, d)
d["hmm"] = "baz"
self.assert_events(["new:foo:bar"])
def test_error(self):
d = {}
with self.watcher(kind=self.ERROR) as wid:
self.watch(wid, d)
with catch_unraisable_exception() as cm:
d["foo"] = "bar"
self.assertIn(
"Exception ignored in "
"PyDict_EVENT_ADDED watcher callback for <dict at ",
cm.unraisable.err_msg
)
self.assertIsNone(cm.unraisable.object)
self.assertEqual(str(cm.unraisable.exc_value), "boom!")
self.assert_events([])
def test_dealloc_error(self):
d = {}
with self.watcher(kind=self.ERROR) as wid:
self.watch(wid, d)
with catch_unraisable_exception() as cm:
del d
self.assertEqual(str(cm.unraisable.exc_value), "boom!")
def test_two_watchers(self):
d1 = {}
d2 = {}
with self.watcher() as wid1:
with self.watcher(kind=self.SECOND) as wid2:
self.watch(wid1, d1)
self.watch(wid2, d2)
d1["foo"] = "bar"
d2["hmm"] = "baz"
self.assert_events(["new:foo:bar", "second"])
def test_watch_non_dict(self):
with self.watcher() as wid:
with self.assertRaisesRegex(ValueError, r"Cannot watch non-dictionary"):
self.watch(wid, 1)
def test_watch_out_of_range_watcher_id(self):
d = {}
with self.assertRaisesRegex(ValueError, r"Invalid dict watcher ID -1"):
self.watch(-1, d)
with self.assertRaisesRegex(ValueError, r"Invalid dict watcher ID 8"):
self.watch(8, d) # DICT_MAX_WATCHERS = 8
def test_watch_unassigned_watcher_id(self):
d = {}
with self.assertRaisesRegex(ValueError, r"No dict watcher set for ID 3"):
self.watch(3, d)
def test_unwatch_non_dict(self):
with self.watcher() as wid:
with self.assertRaisesRegex(ValueError, r"Cannot watch non-dictionary"):
self.unwatch(wid, 1)
def test_unwatch_out_of_range_watcher_id(self):
d = {}
with self.assertRaisesRegex(ValueError, r"Invalid dict watcher ID -1"):
self.unwatch(-1, d)
with self.assertRaisesRegex(ValueError, r"Invalid dict watcher ID 8"):
self.unwatch(8, d) # DICT_MAX_WATCHERS = 8
def test_unwatch_unassigned_watcher_id(self):
d = {}
with self.assertRaisesRegex(ValueError, r"No dict watcher set for ID 3"):
self.unwatch(3, d)
def test_clear_out_of_range_watcher_id(self):
with self.assertRaisesRegex(ValueError, r"Invalid dict watcher ID -1"):
self.clear_watcher(-1)
with self.assertRaisesRegex(ValueError, r"Invalid dict watcher ID 8"):
self.clear_watcher(8) # DICT_MAX_WATCHERS = 8
def test_clear_unassigned_watcher_id(self):
with self.assertRaisesRegex(ValueError, r"No dict watcher set for ID 3"):
self.clear_watcher(3)
class TestTypeWatchers(unittest.TestCase):
# types of watchers testcapimodule can add:
TYPES = 0 # appends modified types to global event list
ERROR = 1 # unconditionally sets and signals a RuntimeException
WRAP = 2 # appends modified type wrapped in list to global event list
# duplicating the C constant
TYPE_MAX_WATCHERS = 8
def add_watcher(self, kind=TYPES):
return _testcapi.add_type_watcher(kind)
def clear_watcher(self, watcher_id):
_testcapi.clear_type_watcher(watcher_id)
@contextmanager
def watcher(self, kind=TYPES):
wid = self.add_watcher(kind)
try:
yield wid
finally:
self.clear_watcher(wid)
def assert_events(self, expected):
actual = _testcapi.get_type_modified_events()
self.assertEqual(actual, expected)
def watch(self, wid, t):
_testcapi.watch_type(wid, t)
def unwatch(self, wid, t):
_testcapi.unwatch_type(wid, t)
def test_watch_type(self):
class C: pass
with self.watcher() as wid:
self.watch(wid, C)
C.foo = "bar"
self.assert_events([C])
def test_event_aggregation(self):
class C: pass
with self.watcher() as wid:
self.watch(wid, C)
C.foo = "bar"
C.bar = "baz"
# only one event registered for both modifications
self.assert_events([C])
def test_lookup_resets_aggregation(self):
class C: pass
with self.watcher() as wid:
self.watch(wid, C)
C.foo = "bar"
# lookup resets type version tag
self.assertEqual(C.foo, "bar")
C.bar = "baz"
# both events registered
self.assert_events([C, C])
def test_unwatch_type(self):
class C: pass
with self.watcher() as wid:
self.watch(wid, C)
C.foo = "bar"
self.assertEqual(C.foo, "bar")
self.assert_events([C])
self.unwatch(wid, C)
C.bar = "baz"
self.assert_events([C])
def test_clear_watcher(self):
class C: pass
# outer watcher is unused, it's just to keep events list alive
with self.watcher() as _:
with self.watcher() as wid:
self.watch(wid, C)
C.foo = "bar"
self.assertEqual(C.foo, "bar")
self.assert_events([C])
C.bar = "baz"
# Watcher on C has been cleared, no new event
self.assert_events([C])
def test_watch_type_subclass(self):
class C: pass
class D(C): pass
with self.watcher() as wid:
self.watch(wid, D)
C.foo = "bar"
self.assert_events([D])
def test_error(self):
class C: pass
with self.watcher(kind=self.ERROR) as wid:
self.watch(wid, C)
with catch_unraisable_exception() as cm:
C.foo = "bar"
self.assertEqual(
cm.unraisable.err_msg,
f"Exception ignored in type watcher callback #1 for {C!r}",
)
self.assertIs(cm.unraisable.object, None)
self.assertEqual(str(cm.unraisable.exc_value), "boom!")
self.assert_events([])
def test_two_watchers(self):
class C1: pass
class C2: pass
with self.watcher() as wid1:
with self.watcher(kind=self.WRAP) as wid2:
self.assertNotEqual(wid1, wid2)
self.watch(wid1, C1)
self.watch(wid2, C2)
C1.foo = "bar"
C2.hmm = "baz"
self.assert_events([C1, [C2]])
def test_all_watchers(self):
class C: pass
with ExitStack() as stack:
last_wid = -1
# don't make assumptions about how many watchers are already
# registered, just go until we reach the max ID
while last_wid < self.TYPE_MAX_WATCHERS - 1:
last_wid = stack.enter_context(self.watcher())
self.watch(last_wid, C)
C.foo = "bar"
self.assert_events([C])
def test_watch_non_type(self):
with self.watcher() as wid:
with self.assertRaisesRegex(ValueError, r"Cannot watch non-type"):
self.watch(wid, 1)
def test_watch_out_of_range_watcher_id(self):
class C: pass
with self.assertRaisesRegex(ValueError, r"Invalid type watcher ID -1"):
self.watch(-1, C)
with self.assertRaisesRegex(ValueError, r"Invalid type watcher ID 8"):
self.watch(self.TYPE_MAX_WATCHERS, C)
def test_watch_unassigned_watcher_id(self):
class C: pass
with self.assertRaisesRegex(ValueError, r"No type watcher set for ID 1"):
self.watch(1, C)
def test_unwatch_non_type(self):
with self.watcher() as wid:
with self.assertRaisesRegex(ValueError, r"Cannot watch non-type"):
self.unwatch(wid, 1)
def test_unwatch_out_of_range_watcher_id(self):
class C: pass
with self.assertRaisesRegex(ValueError, r"Invalid type watcher ID -1"):
self.unwatch(-1, C)
with self.assertRaisesRegex(ValueError, r"Invalid type watcher ID 8"):
self.unwatch(self.TYPE_MAX_WATCHERS, C)
def test_unwatch_unassigned_watcher_id(self):
class C: pass
with self.assertRaisesRegex(ValueError, r"No type watcher set for ID 1"):
self.unwatch(1, C)
def test_clear_out_of_range_watcher_id(self):
with self.assertRaisesRegex(ValueError, r"Invalid type watcher ID -1"):
self.clear_watcher(-1)
with self.assertRaisesRegex(ValueError, r"Invalid type watcher ID 8"):
self.clear_watcher(self.TYPE_MAX_WATCHERS)
def test_clear_unassigned_watcher_id(self):
with self.assertRaisesRegex(ValueError, r"No type watcher set for ID 1"):
self.clear_watcher(1)
def test_no_more_ids_available(self):
with self.assertRaisesRegex(RuntimeError, r"no more type watcher IDs"):
with ExitStack() as stack:
for _ in range(self.TYPE_MAX_WATCHERS + 1):
stack.enter_context(self.watcher())
class TestCodeObjectWatchers(unittest.TestCase):
@contextmanager
def code_watcher(self, which_watcher):
wid = _testcapi.add_code_watcher(which_watcher)
try:
yield wid
finally:
_testcapi.clear_code_watcher(wid)
def assert_event_counts(self, exp_created_0, exp_destroyed_0,
exp_created_1, exp_destroyed_1):
gc_collect() # code objects are collected by GC in free-threaded build
self.assertEqual(
exp_created_0, _testcapi.get_code_watcher_num_created_events(0))
self.assertEqual(
exp_destroyed_0, _testcapi.get_code_watcher_num_destroyed_events(0))
self.assertEqual(
exp_created_1, _testcapi.get_code_watcher_num_created_events(1))
self.assertEqual(
exp_destroyed_1, _testcapi.get_code_watcher_num_destroyed_events(1))
def test_code_object_events_dispatched(self):
# verify that all counts are zero before any watchers are registered
self.assert_event_counts(0, 0, 0, 0)
# verify that all counts remain zero when a code object is
# created and destroyed with no watchers registered
co1 = _testcapi.code_newempty("test_watchers", "dummy1", 0)
self.assert_event_counts(0, 0, 0, 0)
del co1
self.assert_event_counts(0, 0, 0, 0)
# verify counts are as expected when first watcher is registered
with self.code_watcher(0):
self.assert_event_counts(0, 0, 0, 0)
co2 = _testcapi.code_newempty("test_watchers", "dummy2", 0)
self.assert_event_counts(1, 0, 0, 0)
del co2
self.assert_event_counts(1, 1, 0, 0)
# again with second watcher registered
with self.code_watcher(1):
self.assert_event_counts(1, 1, 0, 0)
co3 = _testcapi.code_newempty("test_watchers", "dummy3", 0)
self.assert_event_counts(2, 1, 1, 0)
del co3
self.assert_event_counts(2, 2, 1, 1)
# verify counts are reset and don't change after both watchers are cleared
co4 = _testcapi.code_newempty("test_watchers", "dummy4", 0)
self.assert_event_counts(0, 0, 0, 0)
del co4
self.assert_event_counts(0, 0, 0, 0)
def test_error(self):
with self.code_watcher(2):
with catch_unraisable_exception() as cm:
co = _testcapi.code_newempty("test_watchers", "dummy0", 0)
self.assertEqual(
cm.unraisable.err_msg,
f"Exception ignored in "
f"PY_CODE_EVENT_CREATE watcher callback for {co!r}"
)
self.assertIsNone(cm.unraisable.object)
self.assertEqual(str(cm.unraisable.exc_value), "boom!")
def test_dealloc_error(self):
co = _testcapi.code_newempty("test_watchers", "dummy0", 0)
with self.code_watcher(2):
with catch_unraisable_exception() as cm:
del co
gc_collect()
self.assertEqual(str(cm.unraisable.exc_value), "boom!")
def test_clear_out_of_range_watcher_id(self):
with self.assertRaisesRegex(ValueError, r"Invalid code watcher ID -1"):
_testcapi.clear_code_watcher(-1)
with self.assertRaisesRegex(ValueError, r"Invalid code watcher ID 8"):
_testcapi.clear_code_watcher(8) # CODE_MAX_WATCHERS = 8
def test_clear_unassigned_watcher_id(self):
with self.assertRaisesRegex(ValueError, r"No code watcher set for ID 1"):
_testcapi.clear_code_watcher(1)
def test_allocate_too_many_watchers(self):
with self.assertRaisesRegex(RuntimeError, r"no more code watcher IDs available"):
_testcapi.allocate_too_many_code_watchers()
class TestFuncWatchers(unittest.TestCase):
@contextmanager
def add_watcher(self, func):
wid = _testcapi.add_func_watcher(func)
try:
yield
finally:
_testcapi.clear_func_watcher(wid)
def test_func_events_dispatched(self):
events = []
def watcher(*args):
events.append(args)
with self.add_watcher(watcher):
def myfunc():
pass
self.assertIn((_testcapi.PYFUNC_EVENT_CREATE, myfunc, None), events)
myfunc_id = id(myfunc)
new_code = self.test_func_events_dispatched.__code__
myfunc.__code__ = new_code
self.assertIn((_testcapi.PYFUNC_EVENT_MODIFY_CODE, myfunc, new_code), events)
new_defaults = (123,)
myfunc.__defaults__ = new_defaults
self.assertIn((_testcapi.PYFUNC_EVENT_MODIFY_DEFAULTS, myfunc, new_defaults), events)
new_defaults = (456,)
_testcapi.set_func_defaults_via_capi(myfunc, new_defaults)
self.assertIn((_testcapi.PYFUNC_EVENT_MODIFY_DEFAULTS, myfunc, new_defaults), events)
new_kwdefaults = {"self": 123}
myfunc.__kwdefaults__ = new_kwdefaults
self.assertIn((_testcapi.PYFUNC_EVENT_MODIFY_KWDEFAULTS, myfunc, new_kwdefaults), events)
new_kwdefaults = {"self": 456}
_testcapi.set_func_kwdefaults_via_capi(myfunc, new_kwdefaults)
self.assertIn((_testcapi.PYFUNC_EVENT_MODIFY_KWDEFAULTS, myfunc, new_kwdefaults), events)
# Clear events reference to func
events = []
del myfunc
self.assertIn((_testcapi.PYFUNC_EVENT_DESTROY, myfunc_id, None), events)
def test_multiple_watchers(self):
events0 = []
def first_watcher(*args):
events0.append(args)
events1 = []
def second_watcher(*args):
events1.append(args)
with self.add_watcher(first_watcher):
with self.add_watcher(second_watcher):
def myfunc():
pass
event = (_testcapi.PYFUNC_EVENT_CREATE, myfunc, None)
self.assertIn(event, events0)
self.assertIn(event, events1)
def test_watcher_raises_error(self):
class MyError(Exception):
pass
def watcher(*args):
raise MyError("testing 123")
with self.add_watcher(watcher):
with catch_unraisable_exception() as cm:
def myfunc():
pass
self.assertEqual(
cm.unraisable.err_msg,
f"Exception ignored in "
f"PyFunction_EVENT_CREATE watcher callback for {repr(myfunc)[1:-1]}"
)
self.assertIsNone(cm.unraisable.object)
def test_dealloc_watcher_raises_error(self):
class MyError(Exception):
pass
def watcher(*args):
raise MyError("testing 123")
def myfunc():
pass
with self.add_watcher(watcher):
with catch_unraisable_exception() as cm:
del myfunc
self.assertIsInstance(cm.unraisable.exc_value, MyError)
def test_clear_out_of_range_watcher_id(self):
with self.assertRaisesRegex(ValueError, r"invalid func watcher ID -1"):
_testcapi.clear_func_watcher(-1)
with self.assertRaisesRegex(ValueError, r"invalid func watcher ID 8"):
_testcapi.clear_func_watcher(8) # FUNC_MAX_WATCHERS = 8
def test_clear_unassigned_watcher_id(self):
with self.assertRaisesRegex(ValueError, r"no func watcher set for ID 1"):
_testcapi.clear_func_watcher(1)
def test_allocate_too_many_watchers(self):
with self.assertRaisesRegex(RuntimeError, r"no more func watcher IDs"):
_testcapi.allocate_too_many_func_watchers()
class TestContextObjectWatchers(unittest.TestCase):
@contextmanager
def context_watcher(self, which_watcher):
wid = _testcapi.add_context_watcher(which_watcher)
try:
switches = _testcapi.get_context_switches(which_watcher)
except ValueError:
switches = None
try:
yield switches
finally:
_testcapi.clear_context_watcher(wid)
def assert_event_counts(self, want_0, want_1):
self.assertEqual(len(_testcapi.get_context_switches(0)), want_0)
self.assertEqual(len(_testcapi.get_context_switches(1)), want_1)
def test_context_object_events_dispatched(self):
# verify that all counts are zero before any watchers are registered
self.assert_event_counts(0, 0)
# verify that all counts remain zero when a context object is
# entered and exited with no watchers registered
ctx = contextvars.copy_context()
ctx.run(self.assert_event_counts, 0, 0)
self.assert_event_counts(0, 0)
# verify counts are as expected when first watcher is registered
with self.context_watcher(0):
self.assert_event_counts(0, 0)
ctx.run(self.assert_event_counts, 1, 0)
self.assert_event_counts(2, 0)
# again with second watcher registered
with self.context_watcher(1):
self.assert_event_counts(2, 0)
ctx.run(self.assert_event_counts, 3, 1)
self.assert_event_counts(4, 2)
# verify counts are reset and don't change after both watchers are cleared
ctx.run(self.assert_event_counts, 0, 0)
self.assert_event_counts(0, 0)
def test_callback_error(self):
ctx_outer = contextvars.copy_context()
ctx_inner = contextvars.copy_context()
unraisables = []
def _in_outer():
with self.context_watcher(2):
with catch_unraisable_exception() as cm:
ctx_inner.run(lambda: unraisables.append(cm.unraisable))
unraisables.append(cm.unraisable)
try:
ctx_outer.run(_in_outer)
self.assertEqual([x.err_msg for x in unraisables],
["Exception ignored in Py_CONTEXT_SWITCHED "
f"watcher callback for {ctx!r}"
for ctx in [ctx_inner, ctx_outer]])
self.assertEqual([str(x.exc_value) for x in unraisables],
["boom!", "boom!"])
finally:
# Break reference cycle
unraisables = None
def test_clear_out_of_range_watcher_id(self):
with self.assertRaisesRegex(ValueError, r"Invalid context watcher ID -1"):
_testcapi.clear_context_watcher(-1)
with self.assertRaisesRegex(ValueError, r"Invalid context watcher ID 8"):
_testcapi.clear_context_watcher(8) # CONTEXT_MAX_WATCHERS = 8
def test_clear_unassigned_watcher_id(self):
with self.assertRaisesRegex(ValueError, r"No context watcher set for ID 1"):
_testcapi.clear_context_watcher(1)
def test_allocate_too_many_watchers(self):
with self.assertRaisesRegex(RuntimeError, r"no more context watcher IDs available"):
_testcapi.allocate_too_many_context_watchers()
def test_exit_base_context(self):
ctx = contextvars.Context()
_testcapi.clear_context_stack()
with self.context_watcher(0) as switches:
ctx.run(lambda: None)
self.assertEqual(switches, [ctx, None])
if __name__ == "__main__":
unittest.main()
Codebase Browser
cpython