1567 lines
52 KiB
Python
1567 lines
52 KiB
Python
import gc
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import sys
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import unittest
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import UserList
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import weakref
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import operator
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import contextlib
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import copy
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import time
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from test import test_support
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# Used in ReferencesTestCase.test_ref_created_during_del() .
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ref_from_del = None
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class C:
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def method(self):
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pass
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class Callable:
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bar = None
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def __call__(self, x):
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self.bar = x
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def create_function():
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def f(): pass
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return f
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def create_bound_method():
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return C().method
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def create_unbound_method():
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return C.method
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class Object:
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def __init__(self, arg):
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self.arg = arg
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def __repr__(self):
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return "<Object %r>" % self.arg
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def __eq__(self, other):
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if isinstance(other, Object):
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return self.arg == other.arg
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return NotImplemented
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def __ne__(self, other):
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if isinstance(other, Object):
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return self.arg != other.arg
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return NotImplemented
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def __hash__(self):
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return hash(self.arg)
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class RefCycle:
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def __init__(self):
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self.cycle = self
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@contextlib.contextmanager
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def collect_in_thread(period=0.0001):
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"""
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Ensure GC collections happen in a different thread, at a high frequency.
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"""
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threading = test_support.import_module('threading')
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please_stop = False
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def collect():
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while not please_stop:
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time.sleep(period)
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gc.collect()
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with test_support.disable_gc():
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old_interval = sys.getcheckinterval()
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sys.setcheckinterval(20)
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t = threading.Thread(target=collect)
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t.start()
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try:
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yield
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finally:
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please_stop = True
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t.join()
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sys.setcheckinterval(old_interval)
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class TestBase(unittest.TestCase):
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def setUp(self):
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self.cbcalled = 0
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def callback(self, ref):
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self.cbcalled += 1
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class ReferencesTestCase(TestBase):
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def test_basic_ref(self):
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self.check_basic_ref(C)
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self.check_basic_ref(create_function)
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self.check_basic_ref(create_bound_method)
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self.check_basic_ref(create_unbound_method)
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# Just make sure the tp_repr handler doesn't raise an exception.
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# Live reference:
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o = C()
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wr = weakref.ref(o)
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repr(wr)
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# Dead reference:
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del o
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repr(wr)
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def test_basic_callback(self):
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self.check_basic_callback(C)
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self.check_basic_callback(create_function)
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self.check_basic_callback(create_bound_method)
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self.check_basic_callback(create_unbound_method)
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def test_multiple_callbacks(self):
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o = C()
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ref1 = weakref.ref(o, self.callback)
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ref2 = weakref.ref(o, self.callback)
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del o
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self.assertIsNone(ref1(), "expected reference to be invalidated")
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self.assertIsNone(ref2(), "expected reference to be invalidated")
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self.assertEqual(self.cbcalled, 2,
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"callback not called the right number of times")
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def test_multiple_selfref_callbacks(self):
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# Make sure all references are invalidated before callbacks are called
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#
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# What's important here is that we're using the first
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# reference in the callback invoked on the second reference
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# (the most recently created ref is cleaned up first). This
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# tests that all references to the object are invalidated
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# before any of the callbacks are invoked, so that we only
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# have one invocation of _weakref.c:cleanup_helper() active
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# for a particular object at a time.
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#
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def callback(object, self=self):
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self.ref()
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c = C()
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self.ref = weakref.ref(c, callback)
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ref1 = weakref.ref(c, callback)
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del c
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def test_constructor_kwargs(self):
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c = C()
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self.assertRaises(TypeError, weakref.ref, c, callback=None)
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def test_proxy_ref(self):
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o = C()
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o.bar = 1
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ref1 = weakref.proxy(o, self.callback)
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ref2 = weakref.proxy(o, self.callback)
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del o
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def check(proxy):
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proxy.bar
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self.assertRaises(weakref.ReferenceError, check, ref1)
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self.assertRaises(weakref.ReferenceError, check, ref2)
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self.assertRaises(weakref.ReferenceError, bool, weakref.proxy(C()))
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self.assertEqual(self.cbcalled, 2)
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def check_basic_ref(self, factory):
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o = factory()
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ref = weakref.ref(o)
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self.assertIsNotNone(ref(),
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"weak reference to live object should be live")
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o2 = ref()
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self.assertIs(o, o2,
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"<ref>() should return original object if live")
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def check_basic_callback(self, factory):
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self.cbcalled = 0
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o = factory()
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ref = weakref.ref(o, self.callback)
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del o
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self.assertEqual(self.cbcalled, 1,
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"callback did not properly set 'cbcalled'")
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self.assertIsNone(ref(),
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"ref2 should be dead after deleting object reference")
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def test_ref_reuse(self):
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o = C()
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ref1 = weakref.ref(o)
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# create a proxy to make sure that there's an intervening creation
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# between these two; it should make no difference
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proxy = weakref.proxy(o)
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ref2 = weakref.ref(o)
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self.assertIs(ref1, ref2,
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"reference object w/out callback should be re-used")
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o = C()
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proxy = weakref.proxy(o)
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ref1 = weakref.ref(o)
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ref2 = weakref.ref(o)
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self.assertIs(ref1, ref2,
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"reference object w/out callback should be re-used")
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self.assertEqual(weakref.getweakrefcount(o), 2,
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"wrong weak ref count for object")
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del proxy
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self.assertEqual(weakref.getweakrefcount(o), 1,
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"wrong weak ref count for object after deleting proxy")
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def test_proxy_reuse(self):
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o = C()
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proxy1 = weakref.proxy(o)
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ref = weakref.ref(o)
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proxy2 = weakref.proxy(o)
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self.assertIs(proxy1, proxy2,
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"proxy object w/out callback should have been re-used")
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def test_basic_proxy(self):
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o = C()
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self.check_proxy(o, weakref.proxy(o))
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L = UserList.UserList()
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p = weakref.proxy(L)
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self.assertFalse(p, "proxy for empty UserList should be false")
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p.append(12)
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self.assertEqual(len(L), 1)
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self.assertTrue(p, "proxy for non-empty UserList should be true")
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with test_support.check_py3k_warnings():
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p[:] = [2, 3]
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self.assertEqual(len(L), 2)
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self.assertEqual(len(p), 2)
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self.assertIn(3, p, "proxy didn't support __contains__() properly")
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p[1] = 5
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self.assertEqual(L[1], 5)
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self.assertEqual(p[1], 5)
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L2 = UserList.UserList(L)
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p2 = weakref.proxy(L2)
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self.assertEqual(p, p2)
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## self.assertEqual(repr(L2), repr(p2))
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L3 = UserList.UserList(range(10))
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p3 = weakref.proxy(L3)
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with test_support.check_py3k_warnings():
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self.assertEqual(L3[:], p3[:])
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self.assertEqual(L3[5:], p3[5:])
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self.assertEqual(L3[:5], p3[:5])
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self.assertEqual(L3[2:5], p3[2:5])
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def test_proxy_unicode(self):
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# See bug 5037
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class C(object):
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def __str__(self):
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return "string"
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def __unicode__(self):
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return u"unicode"
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instance = C()
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self.assertIn("__unicode__", dir(weakref.proxy(instance)))
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self.assertEqual(unicode(weakref.proxy(instance)), u"unicode")
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def test_proxy_index(self):
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class C:
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def __index__(self):
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return 10
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o = C()
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p = weakref.proxy(o)
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self.assertEqual(operator.index(p), 10)
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def test_proxy_div(self):
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class C:
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def __floordiv__(self, other):
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return 42
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def __ifloordiv__(self, other):
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return 21
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o = C()
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p = weakref.proxy(o)
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self.assertEqual(p // 5, 42)
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p //= 5
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self.assertEqual(p, 21)
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# The PyWeakref_* C API is documented as allowing either NULL or
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# None as the value for the callback, where either means "no
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# callback". The "no callback" ref and proxy objects are supposed
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# to be shared so long as they exist by all callers so long as
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# they are active. In Python 2.3.3 and earlier, this guarantee
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# was not honored, and was broken in different ways for
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# PyWeakref_NewRef() and PyWeakref_NewProxy(). (Two tests.)
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def test_shared_ref_without_callback(self):
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self.check_shared_without_callback(weakref.ref)
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def test_shared_proxy_without_callback(self):
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self.check_shared_without_callback(weakref.proxy)
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def check_shared_without_callback(self, makeref):
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o = Object(1)
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p1 = makeref(o, None)
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p2 = makeref(o, None)
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self.assertIs(p1, p2, "both callbacks were None in the C API")
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del p1, p2
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p1 = makeref(o)
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p2 = makeref(o, None)
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self.assertIs(p1, p2, "callbacks were NULL, None in the C API")
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del p1, p2
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p1 = makeref(o)
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p2 = makeref(o)
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self.assertIs(p1, p2, "both callbacks were NULL in the C API")
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del p1, p2
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p1 = makeref(o, None)
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p2 = makeref(o)
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self.assertIs(p1, p2, "callbacks were None, NULL in the C API")
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def test_callable_proxy(self):
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o = Callable()
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ref1 = weakref.proxy(o)
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self.check_proxy(o, ref1)
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self.assertIs(type(ref1), weakref.CallableProxyType,
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"proxy is not of callable type")
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ref1('twinkies!')
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self.assertEqual(o.bar, 'twinkies!',
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"call through proxy not passed through to original")
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ref1(x='Splat.')
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self.assertEqual(o.bar, 'Splat.',
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"call through proxy not passed through to original")
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# expect due to too few args
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self.assertRaises(TypeError, ref1)
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# expect due to too many args
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self.assertRaises(TypeError, ref1, 1, 2, 3)
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def check_proxy(self, o, proxy):
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o.foo = 1
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self.assertEqual(proxy.foo, 1,
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"proxy does not reflect attribute addition")
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o.foo = 2
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self.assertEqual(proxy.foo, 2,
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"proxy does not reflect attribute modification")
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del o.foo
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self.assertFalse(hasattr(proxy, 'foo'),
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"proxy does not reflect attribute removal")
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proxy.foo = 1
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self.assertEqual(o.foo, 1,
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"object does not reflect attribute addition via proxy")
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proxy.foo = 2
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self.assertEqual(o.foo, 2,
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"object does not reflect attribute modification via proxy")
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del proxy.foo
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self.assertFalse(hasattr(o, 'foo'),
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"object does not reflect attribute removal via proxy")
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def test_proxy_deletion(self):
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# Test clearing of SF bug #762891
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class Foo:
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result = None
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def __delitem__(self, accessor):
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self.result = accessor
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g = Foo()
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f = weakref.proxy(g)
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del f[0]
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self.assertEqual(f.result, 0)
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def test_proxy_bool(self):
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# Test clearing of SF bug #1170766
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class List(list): pass
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lyst = List()
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self.assertEqual(bool(weakref.proxy(lyst)), bool(lyst))
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def test_getweakrefcount(self):
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o = C()
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ref1 = weakref.ref(o)
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ref2 = weakref.ref(o, self.callback)
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self.assertEqual(weakref.getweakrefcount(o), 2,
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"got wrong number of weak reference objects")
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proxy1 = weakref.proxy(o)
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proxy2 = weakref.proxy(o, self.callback)
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self.assertEqual(weakref.getweakrefcount(o), 4,
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"got wrong number of weak reference objects")
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del ref1, ref2, proxy1, proxy2
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self.assertEqual(weakref.getweakrefcount(o), 0,
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"weak reference objects not unlinked from"
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" referent when discarded.")
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# assumes ints do not support weakrefs
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self.assertEqual(weakref.getweakrefcount(1), 0,
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"got wrong number of weak reference objects for int")
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def test_getweakrefs(self):
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o = C()
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ref1 = weakref.ref(o, self.callback)
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ref2 = weakref.ref(o, self.callback)
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del ref1
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self.assertEqual(weakref.getweakrefs(o), [ref2],
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"list of refs does not match")
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o = C()
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ref1 = weakref.ref(o, self.callback)
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ref2 = weakref.ref(o, self.callback)
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del ref2
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self.assertEqual(weakref.getweakrefs(o), [ref1],
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"list of refs does not match")
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del ref1
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self.assertEqual(weakref.getweakrefs(o), [],
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"list of refs not cleared")
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# assumes ints do not support weakrefs
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self.assertEqual(weakref.getweakrefs(1), [],
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"list of refs does not match for int")
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def test_newstyle_number_ops(self):
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class F(float):
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pass
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f = F(2.0)
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p = weakref.proxy(f)
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self.assertEqual(p + 1.0, 3.0)
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self.assertEqual(1.0 + p, 3.0) # this used to SEGV
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def test_callbacks_protected(self):
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# Callbacks protected from already-set exceptions?
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# Regression test for SF bug #478534.
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class BogusError(Exception):
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pass
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data = {}
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def remove(k):
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del data[k]
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def encapsulate():
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f = lambda : ()
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data[weakref.ref(f, remove)] = None
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raise BogusError
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try:
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encapsulate()
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except BogusError:
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pass
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else:
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self.fail("exception not properly restored")
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try:
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encapsulate()
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except BogusError:
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pass
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else:
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self.fail("exception not properly restored")
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def test_sf_bug_840829(self):
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# "weakref callbacks and gc corrupt memory"
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# subtype_dealloc erroneously exposed a new-style instance
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# already in the process of getting deallocated to gc,
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# causing double-deallocation if the instance had a weakref
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# callback that triggered gc.
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# If the bug exists, there probably won't be an obvious symptom
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# in a release build. In a debug build, a segfault will occur
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# when the second attempt to remove the instance from the "list
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# of all objects" occurs.
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import gc
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class C(object):
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pass
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c = C()
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wr = weakref.ref(c, lambda ignore: gc.collect())
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del c
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# There endeth the first part. It gets worse.
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del wr
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c1 = C()
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c1.i = C()
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wr = weakref.ref(c1.i, lambda ignore: gc.collect())
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c2 = C()
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c2.c1 = c1
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del c1 # still alive because c2 points to it
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# Now when subtype_dealloc gets called on c2, it's not enough just
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# that c2 is immune from gc while the weakref callbacks associated
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# with c2 execute (there are none in this 2nd half of the test, btw).
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# subtype_dealloc goes on to call the base classes' deallocs too,
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# so any gc triggered by weakref callbacks associated with anything
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# torn down by a base class dealloc can also trigger double
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# deallocation of c2.
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del c2
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|
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def test_callback_in_cycle_1(self):
|
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import gc
|
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|
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class J(object):
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pass
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|
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class II(object):
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def acallback(self, ignore):
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self.J
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I = II()
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I.J = J
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I.wr = weakref.ref(J, I.acallback)
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|
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# Now J and II are each in a self-cycle (as all new-style class
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# objects are, since their __mro__ points back to them). I holds
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# both a weak reference (I.wr) and a strong reference (I.J) to class
|
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# J. I is also in a cycle (I.wr points to a weakref that references
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# I.acallback). When we del these three, they all become trash, but
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# the cycles prevent any of them from getting cleaned up immediately.
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# Instead they have to wait for cyclic gc to deduce that they're
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# trash.
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#
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# gc used to call tp_clear on all of them, and the order in which
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# it does that is pretty accidental. The exact order in which we
|
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# built up these things manages to provoke gc into running tp_clear
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# in just the right order (I last). Calling tp_clear on II leaves
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# behind an insane class object (its __mro__ becomes NULL). Calling
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# tp_clear on J breaks its self-cycle, but J doesn't get deleted
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# just then because of the strong reference from I.J. Calling
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# tp_clear on I starts to clear I's __dict__, and just happens to
|
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# clear I.J first -- I.wr is still intact. That removes the last
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# reference to J, which triggers the weakref callback. The callback
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# tries to do "self.J", and instances of new-style classes look up
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# attributes ("J") in the class dict first. The class (II) wants to
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# search II.__mro__, but that's NULL. The result was a segfault in
|
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# a release build, and an assert failure in a debug build.
|
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del I, J, II
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gc.collect()
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|
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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.assertIs(external_wr(), 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])
|
|
|
|
def test_equality(self):
|
|
# Alive weakrefs defer equality testing to their underlying object.
|
|
x = Object(1)
|
|
y = Object(1)
|
|
z = Object(2)
|
|
a = weakref.ref(x)
|
|
b = weakref.ref(y)
|
|
c = weakref.ref(z)
|
|
d = weakref.ref(x)
|
|
# Note how we directly test the operators here, to stress both
|
|
# __eq__ and __ne__.
|
|
self.assertTrue(a == b)
|
|
self.assertFalse(a != b)
|
|
self.assertFalse(a == c)
|
|
self.assertTrue(a != c)
|
|
self.assertTrue(a == d)
|
|
self.assertFalse(a != d)
|
|
del x, y, z
|
|
gc.collect()
|
|
for r in a, b, c:
|
|
# Sanity check
|
|
self.assertIs(r(), None)
|
|
# Dead weakrefs compare by identity: whether `a` and `d` are the
|
|
# same weakref object is an implementation detail, since they pointed
|
|
# to the same original object and didn't have a callback.
|
|
# (see issue #16453).
|
|
self.assertFalse(a == b)
|
|
self.assertTrue(a != b)
|
|
self.assertFalse(a == c)
|
|
self.assertTrue(a != c)
|
|
self.assertEqual(a == d, a is d)
|
|
self.assertEqual(a != d, a is not d)
|
|
|
|
def test_hashing(self):
|
|
# Alive weakrefs hash the same as the underlying object
|
|
x = Object(42)
|
|
y = Object(42)
|
|
a = weakref.ref(x)
|
|
b = weakref.ref(y)
|
|
self.assertEqual(hash(a), hash(42))
|
|
del x, y
|
|
gc.collect()
|
|
# Dead weakrefs:
|
|
# - retain their hash is they were hashed when alive;
|
|
# - otherwise, cannot be hashed.
|
|
self.assertEqual(hash(a), hash(42))
|
|
self.assertRaises(TypeError, hash, b)
|
|
|
|
def test_trashcan_16602(self):
|
|
# Issue #16602: when a weakref's target was part of a long
|
|
# deallocation chain, the trashcan mechanism could delay clearing
|
|
# of the weakref and make the target object visible from outside
|
|
# code even though its refcount had dropped to 0. A crash ensued.
|
|
class C(object):
|
|
def __init__(self, parent):
|
|
if not parent:
|
|
return
|
|
wself = weakref.ref(self)
|
|
def cb(wparent):
|
|
o = wself()
|
|
self.wparent = weakref.ref(parent, cb)
|
|
|
|
d = weakref.WeakKeyDictionary()
|
|
root = c = C(None)
|
|
for n in range(100):
|
|
d[c] = c = C(c)
|
|
del root
|
|
gc.collect()
|
|
|
|
|
|
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.assertIs(mr(), o)
|
|
self.assertTrue(mr.called)
|
|
self.assertEqual(mr.value, 24)
|
|
del o
|
|
self.assertIsNone(mr())
|
|
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.assertIsNot(r1, 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.assertIs(r2, 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.assertIsNot(r1, 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 MappingTestCase(TestBase):
|
|
|
|
COUNT = 10
|
|
|
|
def check_len_cycles(self, dict_type, cons):
|
|
N = 20
|
|
items = [RefCycle() for i in range(N)]
|
|
dct = dict_type(cons(i, o) for i, o in enumerate(items))
|
|
# Keep an iterator alive
|
|
it = dct.iteritems()
|
|
try:
|
|
next(it)
|
|
except StopIteration:
|
|
pass
|
|
del items
|
|
gc.collect()
|
|
n1 = len(dct)
|
|
list(it)
|
|
del it
|
|
gc.collect()
|
|
n2 = len(dct)
|
|
# iteration should prevent garbage collection here
|
|
# Note that this is a test on an implementation detail. The requirement
|
|
# is only to provide stable iteration, not that the size of the container
|
|
# stay fixed.
|
|
self.assertEqual(n1, 20)
|
|
#self.assertIn(n1, (0, 1))
|
|
self.assertEqual(n2, 0)
|
|
|
|
def test_weak_keyed_len_cycles(self):
|
|
self.check_len_cycles(weakref.WeakKeyDictionary, lambda n, k: (k, n))
|
|
|
|
def test_weak_valued_len_cycles(self):
|
|
self.check_len_cycles(weakref.WeakValueDictionary, lambda n, k: (n, k))
|
|
|
|
def check_len_race(self, dict_type, cons):
|
|
# Extended sanity checks for len() in the face of cyclic collection
|
|
self.addCleanup(gc.set_threshold, *gc.get_threshold())
|
|
for th in range(1, 100):
|
|
N = 20
|
|
gc.collect(0)
|
|
gc.set_threshold(th, th, th)
|
|
items = [RefCycle() for i in range(N)]
|
|
dct = dict_type(cons(o) for o in items)
|
|
del items
|
|
# All items will be collected at next garbage collection pass
|
|
it = dct.iteritems()
|
|
try:
|
|
next(it)
|
|
except StopIteration:
|
|
pass
|
|
n1 = len(dct)
|
|
del it
|
|
n2 = len(dct)
|
|
self.assertGreaterEqual(n1, 0)
|
|
self.assertLessEqual(n1, N)
|
|
self.assertGreaterEqual(n2, 0)
|
|
self.assertLessEqual(n2, n1)
|
|
|
|
def test_weak_keyed_len_race(self):
|
|
self.check_len_race(weakref.WeakKeyDictionary, lambda k: (k, 1))
|
|
|
|
def test_weak_valued_len_race(self):
|
|
self.check_len_race(weakref.WeakValueDictionary, lambda k: (1, k))
|
|
|
|
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.assertEqual(weakref.getweakrefcount(o), 1,
|
|
"wrong number of weak references to %r!" % o)
|
|
self.assertIs(o, dict[o.arg],
|
|
"wrong object returned by weak dict!")
|
|
items1 = dict.items()
|
|
items2 = dict.copy().items()
|
|
items1.sort()
|
|
items2.sort()
|
|
self.assertEqual(items1, items2,
|
|
"cloning of weak-valued dictionary did not work!")
|
|
del items1, items2
|
|
self.assertEqual(len(dict), self.COUNT)
|
|
del objects[0]
|
|
self.assertEqual(len(dict), (self.COUNT - 1),
|
|
"deleting object did not cause dictionary update")
|
|
del objects, o
|
|
self.assertEqual(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.assertEqual(weakref.getweakrefcount(o), 1,
|
|
"wrong number of weak references to %r!" % o)
|
|
self.assertIs(o.arg, dict[o],
|
|
"wrong object returned by weak dict!")
|
|
items1 = dict.items()
|
|
items2 = dict.copy().items()
|
|
self.assertEqual(set(items1), set(items2),
|
|
"cloning of weak-keyed dictionary did not work!")
|
|
del items1, items2
|
|
self.assertEqual(len(dict), self.COUNT)
|
|
del objects[0]
|
|
self.assertEqual(len(dict), (self.COUNT - 1),
|
|
"deleting object did not cause dictionary update")
|
|
del objects, o
|
|
self.assertEqual(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.assertEqual(len(items), 0, "iteritems() did not touch all items")
|
|
|
|
# key iterator, via __iter__():
|
|
keys = dict.keys()
|
|
for k in dict:
|
|
keys.remove(k)
|
|
self.assertEqual(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.assertEqual(len(keys), 0, "iterkeys() did not touch all keys")
|
|
|
|
# value iterator:
|
|
values = dict.values()
|
|
for v in dict.itervalues():
|
|
values.remove(v)
|
|
self.assertEqual(len(values), 0,
|
|
"itervalues() did not touch all values")
|
|
|
|
def check_weak_destroy_while_iterating(self, dict, objects, iter_name):
|
|
n = len(dict)
|
|
it = iter(getattr(dict, iter_name)())
|
|
next(it) # Trigger internal iteration
|
|
# Destroy an object
|
|
del objects[-1]
|
|
gc.collect() # just in case
|
|
# We have removed either the first consumed object, or another one
|
|
self.assertIn(len(list(it)), [len(objects), len(objects) - 1])
|
|
del it
|
|
# The removal has been committed
|
|
self.assertEqual(len(dict), n - 1)
|
|
|
|
def check_weak_destroy_and_mutate_while_iterating(self, dict, testcontext):
|
|
# Check that we can explicitly mutate the weak dict without
|
|
# interfering with delayed removal.
|
|
# `testcontext` should create an iterator, destroy one of the
|
|
# weakref'ed objects and then return a new key/value pair corresponding
|
|
# to the destroyed object.
|
|
with testcontext() as (k, v):
|
|
self.assertFalse(k in dict)
|
|
with testcontext() as (k, v):
|
|
self.assertRaises(KeyError, dict.__delitem__, k)
|
|
self.assertFalse(k in dict)
|
|
with testcontext() as (k, v):
|
|
self.assertRaises(KeyError, dict.pop, k)
|
|
self.assertFalse(k in dict)
|
|
with testcontext() as (k, v):
|
|
dict[k] = v
|
|
self.assertEqual(dict[k], v)
|
|
ddict = copy.copy(dict)
|
|
with testcontext() as (k, v):
|
|
dict.update(ddict)
|
|
self.assertEqual(dict, ddict)
|
|
with testcontext() as (k, v):
|
|
dict.clear()
|
|
self.assertEqual(len(dict), 0)
|
|
|
|
def test_weak_keys_destroy_while_iterating(self):
|
|
# Issue #7105: iterators shouldn't crash when a key is implicitly removed
|
|
dict, objects = self.make_weak_keyed_dict()
|
|
self.check_weak_destroy_while_iterating(dict, objects, 'iterkeys')
|
|
self.check_weak_destroy_while_iterating(dict, objects, 'iteritems')
|
|
self.check_weak_destroy_while_iterating(dict, objects, 'itervalues')
|
|
self.check_weak_destroy_while_iterating(dict, objects, 'iterkeyrefs')
|
|
dict, objects = self.make_weak_keyed_dict()
|
|
@contextlib.contextmanager
|
|
def testcontext():
|
|
try:
|
|
it = iter(dict.iteritems())
|
|
next(it)
|
|
# Schedule a key/value for removal and recreate it
|
|
v = objects.pop().arg
|
|
gc.collect() # just in case
|
|
yield Object(v), v
|
|
finally:
|
|
it = None # should commit all removals
|
|
gc.collect()
|
|
self.check_weak_destroy_and_mutate_while_iterating(dict, testcontext)
|
|
|
|
def test_weak_values_destroy_while_iterating(self):
|
|
# Issue #7105: iterators shouldn't crash when a key is implicitly removed
|
|
dict, objects = self.make_weak_valued_dict()
|
|
self.check_weak_destroy_while_iterating(dict, objects, 'iterkeys')
|
|
self.check_weak_destroy_while_iterating(dict, objects, 'iteritems')
|
|
self.check_weak_destroy_while_iterating(dict, objects, 'itervalues')
|
|
self.check_weak_destroy_while_iterating(dict, objects, 'itervaluerefs')
|
|
dict, objects = self.make_weak_valued_dict()
|
|
@contextlib.contextmanager
|
|
def testcontext():
|
|
try:
|
|
it = iter(dict.iteritems())
|
|
next(it)
|
|
# Schedule a key/value for removal and recreate it
|
|
k = objects.pop().arg
|
|
gc.collect() # just in case
|
|
yield k, Object(k)
|
|
finally:
|
|
it = None # should commit all removals
|
|
gc.collect()
|
|
self.check_weak_destroy_and_mutate_while_iterating(dict, testcontext)
|
|
|
|
def test_make_weak_keyed_dict_from_dict(self):
|
|
o = Object(3)
|
|
dict = weakref.WeakKeyDictionary({o:364})
|
|
self.assertEqual(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.assertEqual(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 test_make_weak_valued_dict_misc(self):
|
|
# errors
|
|
self.assertRaises(TypeError, weakref.WeakValueDictionary.__init__)
|
|
self.assertRaises(TypeError, weakref.WeakValueDictionary, {}, {})
|
|
self.assertRaises(TypeError, weakref.WeakValueDictionary, (), ())
|
|
# special keyword arguments
|
|
o = Object(3)
|
|
for kw in 'self', 'other', 'iterable':
|
|
d = weakref.WeakValueDictionary(**{kw: o})
|
|
self.assertEqual(list(d.keys()), [kw])
|
|
self.assertEqual(d[kw], o)
|
|
|
|
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.assertEqual(len(weakdict), 2)
|
|
k, v = weakdict.popitem()
|
|
self.assertEqual(len(weakdict), 1)
|
|
if k is key1:
|
|
self.assertIs(v, value1)
|
|
else:
|
|
self.assertIs(v, value2)
|
|
k, v = weakdict.popitem()
|
|
self.assertEqual(len(weakdict), 0)
|
|
if k is key1:
|
|
self.assertIs(v, value1)
|
|
else:
|
|
self.assertIs(v, 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.assertIsNot(value1, 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()})
|
|
# errors
|
|
self.assertRaises(TypeError, weakref.WeakValueDictionary.update)
|
|
d = weakref.WeakValueDictionary()
|
|
self.assertRaises(TypeError, d.update, {}, {})
|
|
self.assertRaises(TypeError, d.update, (), ())
|
|
self.assertEqual(list(d.keys()), [])
|
|
# special keyword arguments
|
|
o = Object(3)
|
|
for kw in 'self', 'dict', 'other', 'iterable':
|
|
d = weakref.WeakValueDictionary()
|
|
d.update(**{kw: o})
|
|
self.assertEqual(list(d.keys()), [kw])
|
|
self.assertEqual(d[kw], o)
|
|
|
|
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.assertEqual(len(d), 2)
|
|
del d[o1]
|
|
self.assertEqual(len(d), 1)
|
|
self.assertEqual(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.assertEqual(len(d), 2)
|
|
del d['something']
|
|
self.assertEqual(len(d), 1)
|
|
self.assertEqual(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)
|
|
|
|
def test_threaded_weak_valued_setdefault(self):
|
|
d = weakref.WeakValueDictionary()
|
|
with collect_in_thread():
|
|
for i in range(50000):
|
|
x = d.setdefault(10, RefCycle())
|
|
self.assertIsNot(x, None) # we never put None in there!
|
|
del x
|
|
|
|
def test_threaded_weak_valued_pop(self):
|
|
d = weakref.WeakValueDictionary()
|
|
with collect_in_thread():
|
|
for i in range(50000):
|
|
d[10] = RefCycle()
|
|
x = d.pop(10, 10)
|
|
self.assertIsNot(x, None) # we never put None in there!
|
|
|
|
def test_threaded_weak_valued_consistency(self):
|
|
# Issue #28427: old keys should not remove new values from
|
|
# WeakValueDictionary when collecting from another thread.
|
|
d = weakref.WeakValueDictionary()
|
|
with collect_in_thread():
|
|
for i in range(200000):
|
|
o = RefCycle()
|
|
d[10] = o
|
|
# o is still alive, so the dict can't be empty
|
|
self.assertEqual(len(d), 1)
|
|
o = None # lose ref
|
|
|
|
|
|
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()
|