import gc | |
import sys | |
import unittest | |
import UserList | |
import weakref | |
import operator | |
from test import test_support | |
# Used in ReferencesTestCase.test_ref_created_during_del() . | |
ref_from_del = None | |
class C: | |
def method(self): | |
pass | |
class Callable: | |
bar = None | |
def __call__(self, x): | |
self.bar = x | |
def create_function(): | |
def f(): pass | |
return f | |
def create_bound_method(): | |
return C().method | |
def create_unbound_method(): | |
return C.method | |
class TestBase(unittest.TestCase): | |
def setUp(self): | |
self.cbcalled = 0 | |
def callback(self, ref): | |
self.cbcalled += 1 | |
class ReferencesTestCase(TestBase): | |
def test_basic_ref(self): | |
self.check_basic_ref(C) | |
self.check_basic_ref(create_function) | |
self.check_basic_ref(create_bound_method) | |
self.check_basic_ref(create_unbound_method) | |
# Just make sure the tp_repr handler doesn't raise an exception. | |
# Live reference: | |
o = C() | |
wr = weakref.ref(o) | |
repr(wr) | |
# Dead reference: | |
del o | |
repr(wr) | |
def test_basic_callback(self): | |
self.check_basic_callback(C) | |
self.check_basic_callback(create_function) | |
self.check_basic_callback(create_bound_method) | |
self.check_basic_callback(create_unbound_method) | |
def test_multiple_callbacks(self): | |
o = C() | |
ref1 = weakref.ref(o, self.callback) | |
ref2 = weakref.ref(o, self.callback) | |
del o | |
self.assertTrue(ref1() is None, | |
"expected reference to be invalidated") | |
self.assertTrue(ref2() is None, | |
"expected reference to be invalidated") | |
self.assertTrue(self.cbcalled == 2, | |
"callback not called the right number of times") | |
def test_multiple_selfref_callbacks(self): | |
# Make sure all references are invalidated before callbacks are called | |
# | |
# What's important here is that we're using the first | |
# reference in the callback invoked on the second reference | |
# (the most recently created ref is cleaned up first). This | |
# tests that all references to the object are invalidated | |
# before any of the callbacks are invoked, so that we only | |
# have one invocation of _weakref.c:cleanup_helper() active | |
# for a particular object at a time. | |
# | |
def callback(object, self=self): | |
self.ref() | |
c = C() | |
self.ref = weakref.ref(c, callback) | |
ref1 = weakref.ref(c, callback) | |
del c | |
def test_proxy_ref(self): | |
o = C() | |
o.bar = 1 | |
ref1 = weakref.proxy(o, self.callback) | |
ref2 = weakref.proxy(o, self.callback) | |
del o | |
def check(proxy): | |
proxy.bar | |
self.assertRaises(weakref.ReferenceError, check, ref1) | |
self.assertRaises(weakref.ReferenceError, check, ref2) | |
self.assertRaises(weakref.ReferenceError, bool, weakref.proxy(C())) | |
self.assertTrue(self.cbcalled == 2) | |
def check_basic_ref(self, factory): | |
o = factory() | |
ref = weakref.ref(o) | |
self.assertTrue(ref() is not None, | |
"weak reference to live object should be live") | |
o2 = ref() | |
self.assertTrue(o is o2, | |
"<ref>() should return original object if live") | |
def check_basic_callback(self, factory): | |
self.cbcalled = 0 | |
o = factory() | |
ref = weakref.ref(o, self.callback) | |
del o | |
self.assertTrue(self.cbcalled == 1, | |
"callback did not properly set 'cbcalled'") | |
self.assertTrue(ref() is None, | |
"ref2 should be dead after deleting object reference") | |
def test_ref_reuse(self): | |
o = C() | |
ref1 = weakref.ref(o) | |
# create a proxy to make sure that there's an intervening creation | |
# between these two; it should make no difference | |
proxy = weakref.proxy(o) | |
ref2 = weakref.ref(o) | |
self.assertTrue(ref1 is ref2, | |
"reference object w/out callback should be re-used") | |
o = C() | |
proxy = weakref.proxy(o) | |
ref1 = weakref.ref(o) | |
ref2 = weakref.ref(o) | |
self.assertTrue(ref1 is ref2, | |
"reference object w/out callback should be re-used") | |
self.assertTrue(weakref.getweakrefcount(o) == 2, | |
"wrong weak ref count for object") | |
del proxy | |
self.assertTrue(weakref.getweakrefcount(o) == 1, | |
"wrong weak ref count for object after deleting proxy") | |
def test_proxy_reuse(self): | |
o = C() | |
proxy1 = weakref.proxy(o) | |
ref = weakref.ref(o) | |
proxy2 = weakref.proxy(o) | |
self.assertTrue(proxy1 is proxy2, | |
"proxy object w/out callback should have been re-used") | |
def test_basic_proxy(self): | |
o = C() | |
self.check_proxy(o, weakref.proxy(o)) | |
L = UserList.UserList() | |
p = weakref.proxy(L) | |
self.assertFalse(p, "proxy for empty UserList should be false") | |
p.append(12) | |
self.assertEqual(len(L), 1) | |
self.assertTrue(p, "proxy for non-empty UserList should be true") | |
with test_support.check_py3k_warnings(): | |
p[:] = [2, 3] | |
self.assertEqual(len(L), 2) | |
self.assertEqual(len(p), 2) | |
self.assertIn(3, p, "proxy didn't support __contains__() properly") | |
p[1] = 5 | |
self.assertEqual(L[1], 5) | |
self.assertEqual(p[1], 5) | |
L2 = UserList.UserList(L) | |
p2 = weakref.proxy(L2) | |
self.assertEqual(p, p2) | |
## self.assertEqual(repr(L2), repr(p2)) | |
L3 = UserList.UserList(range(10)) | |
p3 = weakref.proxy(L3) | |
with test_support.check_py3k_warnings(): | |
self.assertEqual(L3[:], p3[:]) | |
self.assertEqual(L3[5:], p3[5:]) | |
self.assertEqual(L3[:5], p3[:5]) | |
self.assertEqual(L3[2:5], p3[2:5]) | |
def test_proxy_unicode(self): | |
# See bug 5037 | |
class C(object): | |
def __str__(self): | |
return "string" | |
def __unicode__(self): | |
return u"unicode" | |
instance = C() | |
self.assertIn("__unicode__", dir(weakref.proxy(instance))) | |
self.assertEqual(unicode(weakref.proxy(instance)), u"unicode") | |
def test_proxy_index(self): | |
class C: | |
def __index__(self): | |
return 10 | |
o = C() | |
p = weakref.proxy(o) | |
self.assertEqual(operator.index(p), 10) | |
def test_proxy_div(self): | |
class C: | |
def __floordiv__(self, other): | |
return 42 | |
def __ifloordiv__(self, other): | |
return 21 | |
o = C() | |
p = weakref.proxy(o) | |
self.assertEqual(p // 5, 42) | |
p //= 5 | |
self.assertEqual(p, 21) | |
# The PyWeakref_* C API is documented as allowing either NULL or | |
# None as the value for the callback, where either means "no | |
# callback". The "no callback" ref and proxy objects are supposed | |
# to be shared so long as they exist by all callers so long as | |
# they are active. In Python 2.3.3 and earlier, this guarantee | |
# was not honored, and was broken in different ways for | |
# PyWeakref_NewRef() and PyWeakref_NewProxy(). (Two tests.) | |
def test_shared_ref_without_callback(self): | |
self.check_shared_without_callback(weakref.ref) | |
def test_shared_proxy_without_callback(self): | |
self.check_shared_without_callback(weakref.proxy) | |
def check_shared_without_callback(self, makeref): | |
o = Object(1) | |
p1 = makeref(o, None) | |
p2 = makeref(o, None) | |
self.assertTrue(p1 is p2, "both callbacks were None in the C API") | |
del p1, p2 | |
p1 = makeref(o) | |
p2 = makeref(o, None) | |
self.assertTrue(p1 is p2, "callbacks were NULL, None in the C API") | |
del p1, p2 | |
p1 = makeref(o) | |
p2 = makeref(o) | |
self.assertTrue(p1 is p2, "both callbacks were NULL in the C API") | |
del p1, p2 | |
p1 = makeref(o, None) | |
p2 = makeref(o) | |
self.assertTrue(p1 is p2, "callbacks were None, NULL in the C API") | |
def test_callable_proxy(self): | |
o = Callable() | |
ref1 = weakref.proxy(o) | |
self.check_proxy(o, ref1) | |
self.assertTrue(type(ref1) is weakref.CallableProxyType, | |
"proxy is not of callable type") | |
ref1('twinkies!') | |
self.assertTrue(o.bar == 'twinkies!', | |
"call through proxy not passed through to original") | |
ref1(x='Splat.') | |
self.assertTrue(o.bar == 'Splat.', | |
"call through proxy not passed through to original") | |
# expect due to too few args | |
self.assertRaises(TypeError, ref1) | |
# expect due to too many args | |
self.assertRaises(TypeError, ref1, 1, 2, 3) | |
def check_proxy(self, o, proxy): | |
o.foo = 1 | |
self.assertTrue(proxy.foo == 1, | |
"proxy does not reflect attribute addition") | |
o.foo = 2 | |
self.assertTrue(proxy.foo == 2, | |
"proxy does not reflect attribute modification") | |
del o.foo | |
self.assertTrue(not hasattr(proxy, 'foo'), | |
"proxy does not reflect attribute removal") | |
proxy.foo = 1 | |
self.assertTrue(o.foo == 1, | |
"object does not reflect attribute addition via proxy") | |
proxy.foo = 2 | |
self.assertTrue( | |
o.foo == 2, | |
"object does not reflect attribute modification via proxy") | |
del proxy.foo | |
self.assertTrue(not hasattr(o, 'foo'), | |
"object does not reflect attribute removal via proxy") | |
def test_proxy_deletion(self): | |
# Test clearing of SF bug #762891 | |
class Foo: | |
result = None | |
def __delitem__(self, accessor): | |
self.result = accessor | |
g = Foo() | |
f = weakref.proxy(g) | |
del f[0] | |
self.assertEqual(f.result, 0) | |
def test_proxy_bool(self): | |
# Test clearing of SF bug #1170766 | |
class List(list): pass | |
lyst = List() | |
self.assertEqual(bool(weakref.proxy(lyst)), bool(lyst)) | |
def test_getweakrefcount(self): | |
o = C() | |
ref1 = weakref.ref(o) | |
ref2 = weakref.ref(o, self.callback) | |
self.assertTrue(weakref.getweakrefcount(o) == 2, | |
"got wrong number of weak reference objects") | |
proxy1 = weakref.proxy(o) | |
proxy2 = weakref.proxy(o, self.callback) | |
self.assertTrue(weakref.getweakrefcount(o) == 4, | |
"got wrong number of weak reference objects") | |
del ref1, ref2, proxy1, proxy2 | |
self.assertTrue(weakref.getweakrefcount(o) == 0, | |
"weak reference objects not unlinked from" | |
" referent when discarded.") | |
# assumes ints do not support weakrefs | |
self.assertTrue(weakref.getweakrefcount(1) == 0, | |
"got wrong number of weak reference objects for int") | |
def test_getweakrefs(self): | |
o = C() | |
ref1 = weakref.ref(o, self.callback) | |
ref2 = weakref.ref(o, self.callback) | |
del ref1 | |
self.assertTrue(weakref.getweakrefs(o) == [ref2], | |
"list of refs does not match") | |
o = C() | |
ref1 = weakref.ref(o, self.callback) | |
ref2 = weakref.ref(o, self.callback) | |
del ref2 | |
self.assertTrue(weakref.getweakrefs(o) == [ref1], | |
"list of refs does not match") | |
del ref1 | |
self.assertTrue(weakref.getweakrefs(o) == [], | |
"list of refs not cleared") | |
# assumes ints do not support weakrefs | |
self.assertTrue(weakref.getweakrefs(1) == [], | |
"list of refs does not match for int") | |
def test_newstyle_number_ops(self): | |
class F(float): | |
pass | |
f = F(2.0) | |
p = weakref.proxy(f) | |
self.assertTrue(p + 1.0 == 3.0) | |
self.assertTrue(1.0 + p == 3.0) # this used to SEGV | |
def test_callbacks_protected(self): | |
# Callbacks protected from already-set exceptions? | |
# Regression test for SF bug #478534. | |
class BogusError(Exception): | |
pass | |
data = {} | |
def remove(k): | |
del data[k] | |
def encapsulate(): | |
f = lambda : () | |
data[weakref.ref(f, remove)] = None | |
raise BogusError | |
try: | |
encapsulate() | |
except BogusError: | |
pass | |
else: | |
self.fail("exception not properly restored") | |
try: | |
encapsulate() | |
except BogusError: | |
pass | |
else: | |
self.fail("exception not properly restored") | |
def test_sf_bug_840829(self): | |
# "weakref callbacks and gc corrupt memory" | |
# subtype_dealloc erroneously exposed a new-style instance | |
# already in the process of getting deallocated to gc, | |
# causing double-deallocation if the instance had a weakref | |
# callback that triggered gc. | |
# If the bug exists, there probably won't be an obvious symptom | |
# in a release build. In a debug build, a segfault will occur | |
# when the second attempt to remove the instance from the "list | |
# of all objects" occurs. | |
import gc | |
class C(object): | |
pass | |
c = C() | |
wr = weakref.ref(c, lambda ignore: gc.collect()) | |
del c | |
# There endeth the first part. It gets worse. | |
del wr | |
c1 = C() | |
c1.i = C() | |
wr = weakref.ref(c1.i, lambda ignore: gc.collect()) | |
c2 = C() | |
c2.c1 = c1 | |
del c1 # still alive because c2 points to it | |
# Now when subtype_dealloc gets called on c2, it's not enough just | |
# that c2 is immune from gc while the weakref callbacks associated | |
# with c2 execute (there are none in this 2nd half of the test, btw). | |
# subtype_dealloc goes on to call the base classes' deallocs too, | |
# so any gc triggered by weakref callbacks associated with anything | |
# torn down by a base class dealloc can also trigger double | |
# deallocation of c2. | |
del c2 | |
def test_callback_in_cycle_1(self): | |
import gc | |
class J(object): | |
pass | |
class II(object): | |
def acallback(self, ignore): | |
self.J | |
I = II() | |
I.J = J | |
I.wr = weakref.ref(J, I.acallback) | |
# Now J and II are each in a self-cycle (as all new-style class | |
# objects are, since their __mro__ points back to them). I holds | |
# both a weak reference (I.wr) and a strong reference (I.J) to class | |
# J. I is also in a cycle (I.wr points to a weakref that references | |
# I.acallback). When we del these three, they all become trash, but | |
# the cycles prevent any of them from getting cleaned up immediately. | |
# Instead they have to wait for cyclic gc to deduce that they're | |
# trash. | |
# | |
# gc used to call tp_clear on all of them, and the order in which | |
# it does that is pretty accidental. The exact order in which we | |
# built up these things manages to provoke gc into running tp_clear | |
# in just the right order (I last). Calling tp_clear on II leaves | |
# behind an insane class object (its __mro__ becomes NULL). Calling | |
# tp_clear on J breaks its self-cycle, but J doesn't get deleted | |
# just then because of the strong reference from I.J. Calling | |
# tp_clear on I starts to clear I's __dict__, and just happens to | |
# clear I.J first -- I.wr is still intact. That removes the last | |
# reference to J, which triggers the weakref callback. The callback | |
# tries to do "self.J", and instances of new-style classes look up | |
# attributes ("J") in the class dict first. The class (II) wants to | |
# search II.__mro__, but that's NULL. The result was a segfault in | |
# a release build, and an assert failure in a debug build. | |
del I, J, II | |
gc.collect() | |
def test_callback_in_cycle_2(self): | |
import gc | |
# This is just like test_callback_in_cycle_1, except that II is an | |
# old-style class. The symptom is different then: an instance of an | |
# old-style class looks in its own __dict__ first. 'J' happens to | |
# get cleared from I.__dict__ before 'wr', and 'J' was never in II's | |
# __dict__, so the attribute isn't found. The difference is that | |
# the old-style II doesn't have a NULL __mro__ (it doesn't have any | |
# __mro__), so no segfault occurs. Instead it got: | |
# test_callback_in_cycle_2 (__main__.ReferencesTestCase) ... | |
# Exception exceptions.AttributeError: | |
# "II instance has no attribute 'J'" in <bound method II.acallback | |
# of <?.II instance at 0x00B9B4B8>> ignored | |
class J(object): | |
pass | |
class II: | |
def acallback(self, ignore): | |
self.J | |
I = II() | |
I.J = J | |
I.wr = weakref.ref(J, I.acallback) | |
del I, J, II | |
gc.collect() | |
def test_callback_in_cycle_3(self): | |
import gc | |
# This one broke the first patch that fixed the last two. In this | |
# case, the objects reachable from the callback aren't also reachable | |
# from the object (c1) *triggering* the callback: you can get to | |
# c1 from c2, but not vice-versa. The result was that c2's __dict__ | |
# got tp_clear'ed by the time the c2.cb callback got invoked. | |
class C: | |
def cb(self, ignore): | |
self.me | |
self.c1 | |
self.wr | |
c1, c2 = C(), C() | |
c2.me = c2 | |
c2.c1 = c1 | |
c2.wr = weakref.ref(c1, c2.cb) | |
del c1, c2 | |
gc.collect() | |
def test_callback_in_cycle_4(self): | |
import gc | |
# Like test_callback_in_cycle_3, except c2 and c1 have different | |
# classes. c2's class (C) isn't reachable from c1 then, so protecting | |
# objects reachable from the dying object (c1) isn't enough to stop | |
# c2's class (C) from getting tp_clear'ed before c2.cb is invoked. | |
# The result was a segfault (C.__mro__ was NULL when the callback | |
# tried to look up self.me). | |
class C(object): | |
def cb(self, ignore): | |
self.me | |
self.c1 | |
self.wr | |
class D: | |
pass | |
c1, c2 = D(), C() | |
c2.me = c2 | |
c2.c1 = c1 | |
c2.wr = weakref.ref(c1, c2.cb) | |
del c1, c2, C, D | |
gc.collect() | |
def test_callback_in_cycle_resurrection(self): | |
import gc | |
# Do something nasty in a weakref callback: resurrect objects | |
# from dead cycles. For this to be attempted, the weakref and | |
# its callback must also be part of the cyclic trash (else the | |
# objects reachable via the callback couldn't be in cyclic trash | |
# to begin with -- the callback would act like an external root). | |
# But gc clears trash weakrefs with callbacks early now, which | |
# disables the callbacks, so the callbacks shouldn't get called | |
# at all (and so nothing actually gets resurrected). | |
alist = [] | |
class C(object): | |
def __init__(self, value): | |
self.attribute = value | |
def acallback(self, ignore): | |
alist.append(self.c) | |
c1, c2 = C(1), C(2) | |
c1.c = c2 | |
c2.c = c1 | |
c1.wr = weakref.ref(c2, c1.acallback) | |
c2.wr = weakref.ref(c1, c2.acallback) | |
def C_went_away(ignore): | |
alist.append("C went away") | |
wr = weakref.ref(C, C_went_away) | |
del c1, c2, C # make them all trash | |
self.assertEqual(alist, []) # del isn't enough to reclaim anything | |
gc.collect() | |
# c1.wr and c2.wr were part of the cyclic trash, so should have | |
# been cleared without their callbacks executing. OTOH, the weakref | |
# to C is bound to a function local (wr), and wasn't trash, so that | |
# callback should have been invoked when C went away. | |
self.assertEqual(alist, ["C went away"]) | |
# The remaining weakref should be dead now (its callback ran). | |
self.assertEqual(wr(), None) | |
del alist[:] | |
gc.collect() | |
self.assertEqual(alist, []) | |
def test_callbacks_on_callback(self): | |
import gc | |
# Set up weakref callbacks *on* weakref callbacks. | |
alist = [] | |
def safe_callback(ignore): | |
alist.append("safe_callback called") | |
class C(object): | |
def cb(self, ignore): | |
alist.append("cb called") | |
c, d = C(), C() | |
c.other = d | |
d.other = c | |
callback = c.cb | |
c.wr = weakref.ref(d, callback) # this won't trigger | |
d.wr = weakref.ref(callback, d.cb) # ditto | |
external_wr = weakref.ref(callback, safe_callback) # but this will | |
self.assertTrue(external_wr() is callback) | |
# The weakrefs attached to c and d should get cleared, so that | |
# C.cb is never called. But external_wr isn't part of the cyclic | |
# trash, and no cyclic trash is reachable from it, so safe_callback | |
# should get invoked when the bound method object callback (c.cb) | |
# -- which is itself a callback, and also part of the cyclic trash -- | |
# gets reclaimed at the end of gc. | |
del callback, c, d, C | |
self.assertEqual(alist, []) # del isn't enough to clean up cycles | |
gc.collect() | |
self.assertEqual(alist, ["safe_callback called"]) | |
self.assertEqual(external_wr(), None) | |
del alist[:] | |
gc.collect() | |
self.assertEqual(alist, []) | |
def test_gc_during_ref_creation(self): | |
self.check_gc_during_creation(weakref.ref) | |
def test_gc_during_proxy_creation(self): | |
self.check_gc_during_creation(weakref.proxy) | |
def check_gc_during_creation(self, makeref): | |
thresholds = gc.get_threshold() | |
gc.set_threshold(1, 1, 1) | |
gc.collect() | |
class A: | |
pass | |
def callback(*args): | |
pass | |
referenced = A() | |
a = A() | |
a.a = a | |
a.wr = makeref(referenced) | |
try: | |
# now make sure the object and the ref get labeled as | |
# cyclic trash: | |
a = A() | |
weakref.ref(referenced, callback) | |
finally: | |
gc.set_threshold(*thresholds) | |
def test_ref_created_during_del(self): | |
# Bug #1377858 | |
# A weakref created in an object's __del__() would crash the | |
# interpreter when the weakref was cleaned up since it would refer to | |
# non-existent memory. This test should not segfault the interpreter. | |
class Target(object): | |
def __del__(self): | |
global ref_from_del | |
ref_from_del = weakref.ref(self) | |
w = Target() | |
def test_init(self): | |
# Issue 3634 | |
# <weakref to class>.__init__() doesn't check errors correctly | |
r = weakref.ref(Exception) | |
self.assertRaises(TypeError, r.__init__, 0, 0, 0, 0, 0) | |
# No exception should be raised here | |
gc.collect() | |
def test_classes(self): | |
# Check that both old-style classes and new-style classes | |
# are weakrefable. | |
class A(object): | |
pass | |
class B: | |
pass | |
l = [] | |
weakref.ref(int) | |
a = weakref.ref(A, l.append) | |
A = None | |
gc.collect() | |
self.assertEqual(a(), None) | |
self.assertEqual(l, [a]) | |
b = weakref.ref(B, l.append) | |
B = None | |
gc.collect() | |
self.assertEqual(b(), None) | |
self.assertEqual(l, [a, b]) | |
class SubclassableWeakrefTestCase(TestBase): | |
def test_subclass_refs(self): | |
class MyRef(weakref.ref): | |
def __init__(self, ob, callback=None, value=42): | |
self.value = value | |
super(MyRef, self).__init__(ob, callback) | |
def __call__(self): | |
self.called = True | |
return super(MyRef, self).__call__() | |
o = Object("foo") | |
mr = MyRef(o, value=24) | |
self.assertTrue(mr() is o) | |
self.assertTrue(mr.called) | |
self.assertEqual(mr.value, 24) | |
del o | |
self.assertTrue(mr() is None) | |
self.assertTrue(mr.called) | |
def test_subclass_refs_dont_replace_standard_refs(self): | |
class MyRef(weakref.ref): | |
pass | |
o = Object(42) | |
r1 = MyRef(o) | |
r2 = weakref.ref(o) | |
self.assertTrue(r1 is not r2) | |
self.assertEqual(weakref.getweakrefs(o), [r2, r1]) | |
self.assertEqual(weakref.getweakrefcount(o), 2) | |
r3 = MyRef(o) | |
self.assertEqual(weakref.getweakrefcount(o), 3) | |
refs = weakref.getweakrefs(o) | |
self.assertEqual(len(refs), 3) | |
self.assertTrue(r2 is refs[0]) | |
self.assertIn(r1, refs[1:]) | |
self.assertIn(r3, refs[1:]) | |
def test_subclass_refs_dont_conflate_callbacks(self): | |
class MyRef(weakref.ref): | |
pass | |
o = Object(42) | |
r1 = MyRef(o, id) | |
r2 = MyRef(o, str) | |
self.assertTrue(r1 is not r2) | |
refs = weakref.getweakrefs(o) | |
self.assertIn(r1, refs) | |
self.assertIn(r2, refs) | |
def test_subclass_refs_with_slots(self): | |
class MyRef(weakref.ref): | |
__slots__ = "slot1", "slot2" | |
def __new__(type, ob, callback, slot1, slot2): | |
return weakref.ref.__new__(type, ob, callback) | |
def __init__(self, ob, callback, slot1, slot2): | |
self.slot1 = slot1 | |
self.slot2 = slot2 | |
def meth(self): | |
return self.slot1 + self.slot2 | |
o = Object(42) | |
r = MyRef(o, None, "abc", "def") | |
self.assertEqual(r.slot1, "abc") | |
self.assertEqual(r.slot2, "def") | |
self.assertEqual(r.meth(), "abcdef") | |
self.assertFalse(hasattr(r, "__dict__")) | |
def test_subclass_refs_with_cycle(self): | |
# Bug #3110 | |
# An instance of a weakref subclass can have attributes. | |
# If such a weakref holds the only strong reference to the object, | |
# deleting the weakref will delete the object. In this case, | |
# the callback must not be called, because the ref object is | |
# being deleted. | |
class MyRef(weakref.ref): | |
pass | |
# Use a local callback, for "regrtest -R::" | |
# to detect refcounting problems | |
def callback(w): | |
self.cbcalled += 1 | |
o = C() | |
r1 = MyRef(o, callback) | |
r1.o = o | |
del o | |
del r1 # Used to crash here | |
self.assertEqual(self.cbcalled, 0) | |
# Same test, with two weakrefs to the same object | |
# (since code paths are different) | |
o = C() | |
r1 = MyRef(o, callback) | |
r2 = MyRef(o, callback) | |
r1.r = r2 | |
r2.o = o | |
del o | |
del r2 | |
del r1 # Used to crash here | |
self.assertEqual(self.cbcalled, 0) | |
class Object: | |
def __init__(self, arg): | |
self.arg = arg | |
def __repr__(self): | |
return "<Object %r>" % self.arg | |
class MappingTestCase(TestBase): | |
COUNT = 10 | |
def test_weak_values(self): | |
# | |
# This exercises d.copy(), d.items(), d[], del d[], len(d). | |
# | |
dict, objects = self.make_weak_valued_dict() | |
for o in objects: | |
self.assertTrue(weakref.getweakrefcount(o) == 1, | |
"wrong number of weak references to %r!" % o) | |
self.assertTrue(o is dict[o.arg], | |
"wrong object returned by weak dict!") | |
items1 = dict.items() | |
items2 = dict.copy().items() | |
items1.sort() | |
items2.sort() | |
self.assertTrue(items1 == items2, | |
"cloning of weak-valued dictionary did not work!") | |
del items1, items2 | |
self.assertTrue(len(dict) == self.COUNT) | |
del objects[0] | |
self.assertTrue(len(dict) == (self.COUNT - 1), | |
"deleting object did not cause dictionary update") | |
del objects, o | |
self.assertTrue(len(dict) == 0, | |
"deleting the values did not clear the dictionary") | |
# regression on SF bug #447152: | |
dict = weakref.WeakValueDictionary() | |
self.assertRaises(KeyError, dict.__getitem__, 1) | |
dict[2] = C() | |
self.assertRaises(KeyError, dict.__getitem__, 2) | |
def test_weak_keys(self): | |
# | |
# This exercises d.copy(), d.items(), d[] = v, d[], del d[], | |
# len(d), in d. | |
# | |
dict, objects = self.make_weak_keyed_dict() | |
for o in objects: | |
self.assertTrue(weakref.getweakrefcount(o) == 1, | |
"wrong number of weak references to %r!" % o) | |
self.assertTrue(o.arg is dict[o], | |
"wrong object returned by weak dict!") | |
items1 = dict.items() | |
items2 = dict.copy().items() | |
self.assertTrue(set(items1) == set(items2), | |
"cloning of weak-keyed dictionary did not work!") | |
del items1, items2 | |
self.assertTrue(len(dict) == self.COUNT) | |
del objects[0] | |
self.assertTrue(len(dict) == (self.COUNT - 1), | |
"deleting object did not cause dictionary update") | |
del objects, o | |
self.assertTrue(len(dict) == 0, | |
"deleting the keys did not clear the dictionary") | |
o = Object(42) | |
dict[o] = "What is the meaning of the universe?" | |
self.assertIn(o, dict) | |
self.assertNotIn(34, dict) | |
def test_weak_keyed_iters(self): | |
dict, objects = self.make_weak_keyed_dict() | |
self.check_iters(dict) | |
# Test keyrefs() | |
refs = dict.keyrefs() | |
self.assertEqual(len(refs), len(objects)) | |
objects2 = list(objects) | |
for wr in refs: | |
ob = wr() | |
self.assertIn(ob, dict) | |
self.assertEqual(ob.arg, dict[ob]) | |
objects2.remove(ob) | |
self.assertEqual(len(objects2), 0) | |
# Test iterkeyrefs() | |
objects2 = list(objects) | |
self.assertEqual(len(list(dict.iterkeyrefs())), len(objects)) | |
for wr in dict.iterkeyrefs(): | |
ob = wr() | |
self.assertIn(ob, dict) | |
self.assertEqual(ob.arg, dict[ob]) | |
objects2.remove(ob) | |
self.assertEqual(len(objects2), 0) | |
def test_weak_valued_iters(self): | |
dict, objects = self.make_weak_valued_dict() | |
self.check_iters(dict) | |
# Test valuerefs() | |
refs = dict.valuerefs() | |
self.assertEqual(len(refs), len(objects)) | |
objects2 = list(objects) | |
for wr in refs: | |
ob = wr() | |
self.assertEqual(ob, dict[ob.arg]) | |
self.assertEqual(ob.arg, dict[ob.arg].arg) | |
objects2.remove(ob) | |
self.assertEqual(len(objects2), 0) | |
# Test itervaluerefs() | |
objects2 = list(objects) | |
self.assertEqual(len(list(dict.itervaluerefs())), len(objects)) | |
for wr in dict.itervaluerefs(): | |
ob = wr() | |
self.assertEqual(ob, dict[ob.arg]) | |
self.assertEqual(ob.arg, dict[ob.arg].arg) | |
objects2.remove(ob) | |
self.assertEqual(len(objects2), 0) | |
def check_iters(self, dict): | |
# item iterator: | |
items = dict.items() | |
for item in dict.iteritems(): | |
items.remove(item) | |
self.assertTrue(len(items) == 0, "iteritems() did not touch all items") | |
# key iterator, via __iter__(): | |
keys = dict.keys() | |
for k in dict: | |
keys.remove(k) | |
self.assertTrue(len(keys) == 0, "__iter__() did not touch all keys") | |
# key iterator, via iterkeys(): | |
keys = dict.keys() | |
for k in dict.iterkeys(): | |
keys.remove(k) | |
self.assertTrue(len(keys) == 0, "iterkeys() did not touch all keys") | |
# value iterator: | |
values = dict.values() | |
for v in dict.itervalues(): | |
values.remove(v) | |
self.assertTrue(len(values) == 0, | |
"itervalues() did not touch all values") | |
def test_make_weak_keyed_dict_from_dict(self): | |
o = Object(3) | |
dict = weakref.WeakKeyDictionary({o:364}) | |
self.assertTrue(dict[o] == 364) | |
def test_make_weak_keyed_dict_from_weak_keyed_dict(self): | |
o = Object(3) | |
dict = weakref.WeakKeyDictionary({o:364}) | |
dict2 = weakref.WeakKeyDictionary(dict) | |
self.assertTrue(dict[o] == 364) | |
def make_weak_keyed_dict(self): | |
dict = weakref.WeakKeyDictionary() | |
objects = map(Object, range(self.COUNT)) | |
for o in objects: | |
dict[o] = o.arg | |
return dict, objects | |
def make_weak_valued_dict(self): | |
dict = weakref.WeakValueDictionary() | |
objects = map(Object, range(self.COUNT)) | |
for o in objects: | |
dict[o.arg] = o | |
return dict, objects | |
def check_popitem(self, klass, key1, value1, key2, value2): | |
weakdict = klass() | |
weakdict[key1] = value1 | |
weakdict[key2] = value2 | |
self.assertTrue(len(weakdict) == 2) | |
k, v = weakdict.popitem() | |
self.assertTrue(len(weakdict) == 1) | |
if k is key1: | |
self.assertTrue(v is value1) | |
else: | |
self.assertTrue(v is value2) | |
k, v = weakdict.popitem() | |
self.assertTrue(len(weakdict) == 0) | |
if k is key1: | |
self.assertTrue(v is value1) | |
else: | |
self.assertTrue(v is value2) | |
def test_weak_valued_dict_popitem(self): | |
self.check_popitem(weakref.WeakValueDictionary, | |
"key1", C(), "key2", C()) | |
def test_weak_keyed_dict_popitem(self): | |
self.check_popitem(weakref.WeakKeyDictionary, | |
C(), "value 1", C(), "value 2") | |
def check_setdefault(self, klass, key, value1, value2): | |
self.assertTrue(value1 is not value2, | |
"invalid test" | |
" -- value parameters must be distinct objects") | |
weakdict = klass() | |
o = weakdict.setdefault(key, value1) | |
self.assertIs(o, value1) | |
self.assertIn(key, weakdict) | |
self.assertIs(weakdict.get(key), value1) | |
self.assertIs(weakdict[key], value1) | |
o = weakdict.setdefault(key, value2) | |
self.assertIs(o, value1) | |
self.assertIn(key, weakdict) | |
self.assertIs(weakdict.get(key), value1) | |
self.assertIs(weakdict[key], value1) | |
def test_weak_valued_dict_setdefault(self): | |
self.check_setdefault(weakref.WeakValueDictionary, | |
"key", C(), C()) | |
def test_weak_keyed_dict_setdefault(self): | |
self.check_setdefault(weakref.WeakKeyDictionary, | |
C(), "value 1", "value 2") | |
def check_update(self, klass, dict): | |
# | |
# This exercises d.update(), len(d), d.keys(), in d, | |
# d.get(), d[]. | |
# | |
weakdict = klass() | |
weakdict.update(dict) | |
self.assertEqual(len(weakdict), len(dict)) | |
for k in weakdict.keys(): | |
self.assertIn(k, dict, | |
"mysterious new key appeared in weak dict") | |
v = dict.get(k) | |
self.assertIs(v, weakdict[k]) | |
self.assertIs(v, weakdict.get(k)) | |
for k in dict.keys(): | |
self.assertIn(k, weakdict, | |
"original key disappeared in weak dict") | |
v = dict[k] | |
self.assertIs(v, weakdict[k]) | |
self.assertIs(v, weakdict.get(k)) | |
def test_weak_valued_dict_update(self): | |
self.check_update(weakref.WeakValueDictionary, | |
{1: C(), 'a': C(), C(): C()}) | |
def test_weak_keyed_dict_update(self): | |
self.check_update(weakref.WeakKeyDictionary, | |
{C(): 1, C(): 2, C(): 3}) | |
def test_weak_keyed_delitem(self): | |
d = weakref.WeakKeyDictionary() | |
o1 = Object('1') | |
o2 = Object('2') | |
d[o1] = 'something' | |
d[o2] = 'something' | |
self.assertTrue(len(d) == 2) | |
del d[o1] | |
self.assertTrue(len(d) == 1) | |
self.assertTrue(d.keys() == [o2]) | |
def test_weak_valued_delitem(self): | |
d = weakref.WeakValueDictionary() | |
o1 = Object('1') | |
o2 = Object('2') | |
d['something'] = o1 | |
d['something else'] = o2 | |
self.assertTrue(len(d) == 2) | |
del d['something'] | |
self.assertTrue(len(d) == 1) | |
self.assertTrue(d.items() == [('something else', o2)]) | |
def test_weak_keyed_bad_delitem(self): | |
d = weakref.WeakKeyDictionary() | |
o = Object('1') | |
# An attempt to delete an object that isn't there should raise | |
# KeyError. It didn't before 2.3. | |
self.assertRaises(KeyError, d.__delitem__, o) | |
self.assertRaises(KeyError, d.__getitem__, o) | |
# If a key isn't of a weakly referencable type, __getitem__ and | |
# __setitem__ raise TypeError. __delitem__ should too. | |
self.assertRaises(TypeError, d.__delitem__, 13) | |
self.assertRaises(TypeError, d.__getitem__, 13) | |
self.assertRaises(TypeError, d.__setitem__, 13, 13) | |
def test_weak_keyed_cascading_deletes(self): | |
# SF bug 742860. For some reason, before 2.3 __delitem__ iterated | |
# over the keys via self.data.iterkeys(). If things vanished from | |
# the dict during this (or got added), that caused a RuntimeError. | |
d = weakref.WeakKeyDictionary() | |
mutate = False | |
class C(object): | |
def __init__(self, i): | |
self.value = i | |
def __hash__(self): | |
return hash(self.value) | |
def __eq__(self, other): | |
if mutate: | |
# Side effect that mutates the dict, by removing the | |
# last strong reference to a key. | |
del objs[-1] | |
return self.value == other.value | |
objs = [C(i) for i in range(4)] | |
for o in objs: | |
d[o] = o.value | |
del o # now the only strong references to keys are in objs | |
# Find the order in which iterkeys sees the keys. | |
objs = d.keys() | |
# Reverse it, so that the iteration implementation of __delitem__ | |
# has to keep looping to find the first object we delete. | |
objs.reverse() | |
# Turn on mutation in C.__eq__. The first time thru the loop, | |
# under the iterkeys() business the first comparison will delete | |
# the last item iterkeys() would see, and that causes a | |
# RuntimeError: dictionary changed size during iteration | |
# when the iterkeys() loop goes around to try comparing the next | |
# key. After this was fixed, it just deletes the last object *our* | |
# "for o in obj" loop would have gotten to. | |
mutate = True | |
count = 0 | |
for o in objs: | |
count += 1 | |
del d[o] | |
self.assertEqual(len(d), 0) | |
self.assertEqual(count, 2) | |
from test import mapping_tests | |
class WeakValueDictionaryTestCase(mapping_tests.BasicTestMappingProtocol): | |
"""Check that WeakValueDictionary conforms to the mapping protocol""" | |
__ref = {"key1":Object(1), "key2":Object(2), "key3":Object(3)} | |
type2test = weakref.WeakValueDictionary | |
def _reference(self): | |
return self.__ref.copy() | |
class WeakKeyDictionaryTestCase(mapping_tests.BasicTestMappingProtocol): | |
"""Check that WeakKeyDictionary conforms to the mapping protocol""" | |
__ref = {Object("key1"):1, Object("key2"):2, Object("key3"):3} | |
type2test = weakref.WeakKeyDictionary | |
def _reference(self): | |
return self.__ref.copy() | |
libreftest = """ Doctest for examples in the library reference: weakref.rst | |
>>> import weakref | |
>>> class Dict(dict): | |
... pass | |
... | |
>>> obj = Dict(red=1, green=2, blue=3) # this object is weak referencable | |
>>> r = weakref.ref(obj) | |
>>> print r() is obj | |
True | |
>>> import weakref | |
>>> class Object: | |
... pass | |
... | |
>>> o = Object() | |
>>> r = weakref.ref(o) | |
>>> o2 = r() | |
>>> o is o2 | |
True | |
>>> del o, o2 | |
>>> print r() | |
None | |
>>> import weakref | |
>>> class ExtendedRef(weakref.ref): | |
... def __init__(self, ob, callback=None, **annotations): | |
... super(ExtendedRef, self).__init__(ob, callback) | |
... self.__counter = 0 | |
... for k, v in annotations.iteritems(): | |
... setattr(self, k, v) | |
... def __call__(self): | |
... '''Return a pair containing the referent and the number of | |
... times the reference has been called. | |
... ''' | |
... ob = super(ExtendedRef, self).__call__() | |
... if ob is not None: | |
... self.__counter += 1 | |
... ob = (ob, self.__counter) | |
... return ob | |
... | |
>>> class A: # not in docs from here, just testing the ExtendedRef | |
... pass | |
... | |
>>> a = A() | |
>>> r = ExtendedRef(a, foo=1, bar="baz") | |
>>> r.foo | |
1 | |
>>> r.bar | |
'baz' | |
>>> r()[1] | |
1 | |
>>> r()[1] | |
2 | |
>>> r()[0] is a | |
True | |
>>> import weakref | |
>>> _id2obj_dict = weakref.WeakValueDictionary() | |
>>> def remember(obj): | |
... oid = id(obj) | |
... _id2obj_dict[oid] = obj | |
... return oid | |
... | |
>>> def id2obj(oid): | |
... return _id2obj_dict[oid] | |
... | |
>>> a = A() # from here, just testing | |
>>> a_id = remember(a) | |
>>> id2obj(a_id) is a | |
True | |
>>> del a | |
>>> try: | |
... id2obj(a_id) | |
... except KeyError: | |
... print 'OK' | |
... else: | |
... print 'WeakValueDictionary error' | |
OK | |
""" | |
__test__ = {'libreftest' : libreftest} | |
def test_main(): | |
test_support.run_unittest( | |
ReferencesTestCase, | |
MappingTestCase, | |
WeakValueDictionaryTestCase, | |
WeakKeyDictionaryTestCase, | |
SubclassableWeakrefTestCase, | |
) | |
test_support.run_doctest(sys.modules[__name__]) | |
if __name__ == "__main__": | |
test_main() |