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86530b38 AT |
1 | import gc |
2 | import sys | |
3 | import unittest | |
4 | import UserList | |
5 | import weakref | |
6 | ||
7 | from test import test_support | |
8 | ||
9 | ||
10 | class C: | |
11 | def method(self): | |
12 | pass | |
13 | ||
14 | ||
15 | class Callable: | |
16 | bar = None | |
17 | ||
18 | def __call__(self, x): | |
19 | self.bar = x | |
20 | ||
21 | ||
22 | def create_function(): | |
23 | def f(): pass | |
24 | return f | |
25 | ||
26 | def create_bound_method(): | |
27 | return C().method | |
28 | ||
29 | def create_unbound_method(): | |
30 | return C.method | |
31 | ||
32 | ||
33 | class TestBase(unittest.TestCase): | |
34 | ||
35 | def setUp(self): | |
36 | self.cbcalled = 0 | |
37 | ||
38 | def callback(self, ref): | |
39 | self.cbcalled += 1 | |
40 | ||
41 | ||
42 | class ReferencesTestCase(TestBase): | |
43 | ||
44 | def test_basic_ref(self): | |
45 | self.check_basic_ref(C) | |
46 | self.check_basic_ref(create_function) | |
47 | self.check_basic_ref(create_bound_method) | |
48 | self.check_basic_ref(create_unbound_method) | |
49 | ||
50 | # Just make sure the tp_repr handler doesn't raise an exception. | |
51 | # Live reference: | |
52 | o = C() | |
53 | wr = weakref.ref(o) | |
54 | `wr` | |
55 | # Dead reference: | |
56 | del o | |
57 | `wr` | |
58 | ||
59 | def test_basic_callback(self): | |
60 | self.check_basic_callback(C) | |
61 | self.check_basic_callback(create_function) | |
62 | self.check_basic_callback(create_bound_method) | |
63 | self.check_basic_callback(create_unbound_method) | |
64 | ||
65 | def test_multiple_callbacks(self): | |
66 | o = C() | |
67 | ref1 = weakref.ref(o, self.callback) | |
68 | ref2 = weakref.ref(o, self.callback) | |
69 | del o | |
70 | self.assert_(ref1() is None, | |
71 | "expected reference to be invalidated") | |
72 | self.assert_(ref2() is None, | |
73 | "expected reference to be invalidated") | |
74 | self.assert_(self.cbcalled == 2, | |
75 | "callback not called the right number of times") | |
76 | ||
77 | def test_multiple_selfref_callbacks(self): | |
78 | # Make sure all references are invalidated before callbacks are called | |
79 | # | |
80 | # What's important here is that we're using the first | |
81 | # reference in the callback invoked on the second reference | |
82 | # (the most recently created ref is cleaned up first). This | |
83 | # tests that all references to the object are invalidated | |
84 | # before any of the callbacks are invoked, so that we only | |
85 | # have one invocation of _weakref.c:cleanup_helper() active | |
86 | # for a particular object at a time. | |
87 | # | |
88 | def callback(object, self=self): | |
89 | self.ref() | |
90 | c = C() | |
91 | self.ref = weakref.ref(c, callback) | |
92 | ref1 = weakref.ref(c, callback) | |
93 | del c | |
94 | ||
95 | def test_proxy_ref(self): | |
96 | o = C() | |
97 | o.bar = 1 | |
98 | ref1 = weakref.proxy(o, self.callback) | |
99 | ref2 = weakref.proxy(o, self.callback) | |
100 | del o | |
101 | ||
102 | def check(proxy): | |
103 | proxy.bar | |
104 | ||
105 | self.assertRaises(weakref.ReferenceError, check, ref1) | |
106 | self.assertRaises(weakref.ReferenceError, check, ref2) | |
107 | self.assertRaises(weakref.ReferenceError, bool, weakref.proxy(C())) | |
108 | self.assert_(self.cbcalled == 2) | |
109 | ||
110 | def check_basic_ref(self, factory): | |
111 | o = factory() | |
112 | ref = weakref.ref(o) | |
113 | self.assert_(ref() is not None, | |
114 | "weak reference to live object should be live") | |
115 | o2 = ref() | |
116 | self.assert_(o is o2, | |
117 | "<ref>() should return original object if live") | |
118 | ||
119 | def check_basic_callback(self, factory): | |
120 | self.cbcalled = 0 | |
121 | o = factory() | |
122 | ref = weakref.ref(o, self.callback) | |
123 | del o | |
124 | self.assert_(self.cbcalled == 1, | |
125 | "callback did not properly set 'cbcalled'") | |
126 | self.assert_(ref() is None, | |
127 | "ref2 should be dead after deleting object reference") | |
128 | ||
129 | def test_ref_reuse(self): | |
130 | o = C() | |
131 | ref1 = weakref.ref(o) | |
132 | # create a proxy to make sure that there's an intervening creation | |
133 | # between these two; it should make no difference | |
134 | proxy = weakref.proxy(o) | |
135 | ref2 = weakref.ref(o) | |
136 | self.assert_(ref1 is ref2, | |
137 | "reference object w/out callback should be re-used") | |
138 | ||
139 | o = C() | |
140 | proxy = weakref.proxy(o) | |
141 | ref1 = weakref.ref(o) | |
142 | ref2 = weakref.ref(o) | |
143 | self.assert_(ref1 is ref2, | |
144 | "reference object w/out callback should be re-used") | |
145 | self.assert_(weakref.getweakrefcount(o) == 2, | |
146 | "wrong weak ref count for object") | |
147 | del proxy | |
148 | self.assert_(weakref.getweakrefcount(o) == 1, | |
149 | "wrong weak ref count for object after deleting proxy") | |
150 | ||
151 | def test_proxy_reuse(self): | |
152 | o = C() | |
153 | proxy1 = weakref.proxy(o) | |
154 | ref = weakref.ref(o) | |
155 | proxy2 = weakref.proxy(o) | |
156 | self.assert_(proxy1 is proxy2, | |
157 | "proxy object w/out callback should have been re-used") | |
158 | ||
159 | def test_basic_proxy(self): | |
160 | o = C() | |
161 | self.check_proxy(o, weakref.proxy(o)) | |
162 | ||
163 | L = UserList.UserList() | |
164 | p = weakref.proxy(L) | |
165 | self.failIf(p, "proxy for empty UserList should be false") | |
166 | p.append(12) | |
167 | self.assertEqual(len(L), 1) | |
168 | self.failUnless(p, "proxy for non-empty UserList should be true") | |
169 | p[:] = [2, 3] | |
170 | self.assertEqual(len(L), 2) | |
171 | self.assertEqual(len(p), 2) | |
172 | self.failUnless(3 in p, | |
173 | "proxy didn't support __contains__() properly") | |
174 | p[1] = 5 | |
175 | self.assertEqual(L[1], 5) | |
176 | self.assertEqual(p[1], 5) | |
177 | L2 = UserList.UserList(L) | |
178 | p2 = weakref.proxy(L2) | |
179 | self.assertEqual(p, p2) | |
180 | ## self.assertEqual(repr(L2), repr(p2)) | |
181 | L3 = UserList.UserList(range(10)) | |
182 | p3 = weakref.proxy(L3) | |
183 | self.assertEqual(L3[:], p3[:]) | |
184 | self.assertEqual(L3[5:], p3[5:]) | |
185 | self.assertEqual(L3[:5], p3[:5]) | |
186 | self.assertEqual(L3[2:5], p3[2:5]) | |
187 | ||
188 | # The PyWeakref_* C API is documented as allowing either NULL or | |
189 | # None as the value for the callback, where either means "no | |
190 | # callback". The "no callback" ref and proxy objects are supposed | |
191 | # to be shared so long as they exist by all callers so long as | |
192 | # they are active. In Python 2.3.3 and earlier, this guaranttee | |
193 | # was not honored, and was broken in different ways for | |
194 | # PyWeakref_NewRef() and PyWeakref_NewProxy(). (Two tests.) | |
195 | ||
196 | def test_shared_ref_without_callback(self): | |
197 | self.check_shared_without_callback(weakref.ref) | |
198 | ||
199 | def test_shared_proxy_without_callback(self): | |
200 | self.check_shared_without_callback(weakref.proxy) | |
201 | ||
202 | def check_shared_without_callback(self, makeref): | |
203 | o = Object(1) | |
204 | p1 = makeref(o, None) | |
205 | p2 = makeref(o, None) | |
206 | self.assert_(p1 is p2, "both callbacks were None in the C API") | |
207 | del p1, p2 | |
208 | p1 = makeref(o) | |
209 | p2 = makeref(o, None) | |
210 | self.assert_(p1 is p2, "callbacks were NULL, None in the C API") | |
211 | del p1, p2 | |
212 | p1 = makeref(o) | |
213 | p2 = makeref(o) | |
214 | self.assert_(p1 is p2, "both callbacks were NULL in the C API") | |
215 | del p1, p2 | |
216 | p1 = makeref(o, None) | |
217 | p2 = makeref(o) | |
218 | self.assert_(p1 is p2, "callbacks were None, NULL in the C API") | |
219 | ||
220 | def test_callable_proxy(self): | |
221 | o = Callable() | |
222 | ref1 = weakref.proxy(o) | |
223 | ||
224 | self.check_proxy(o, ref1) | |
225 | ||
226 | self.assert_(type(ref1) is weakref.CallableProxyType, | |
227 | "proxy is not of callable type") | |
228 | ref1('twinkies!') | |
229 | self.assert_(o.bar == 'twinkies!', | |
230 | "call through proxy not passed through to original") | |
231 | ref1(x='Splat.') | |
232 | self.assert_(o.bar == 'Splat.', | |
233 | "call through proxy not passed through to original") | |
234 | ||
235 | # expect due to too few args | |
236 | self.assertRaises(TypeError, ref1) | |
237 | ||
238 | # expect due to too many args | |
239 | self.assertRaises(TypeError, ref1, 1, 2, 3) | |
240 | ||
241 | def check_proxy(self, o, proxy): | |
242 | o.foo = 1 | |
243 | self.assert_(proxy.foo == 1, | |
244 | "proxy does not reflect attribute addition") | |
245 | o.foo = 2 | |
246 | self.assert_(proxy.foo == 2, | |
247 | "proxy does not reflect attribute modification") | |
248 | del o.foo | |
249 | self.assert_(not hasattr(proxy, 'foo'), | |
250 | "proxy does not reflect attribute removal") | |
251 | ||
252 | proxy.foo = 1 | |
253 | self.assert_(o.foo == 1, | |
254 | "object does not reflect attribute addition via proxy") | |
255 | proxy.foo = 2 | |
256 | self.assert_( | |
257 | o.foo == 2, | |
258 | "object does not reflect attribute modification via proxy") | |
259 | del proxy.foo | |
260 | self.assert_(not hasattr(o, 'foo'), | |
261 | "object does not reflect attribute removal via proxy") | |
262 | ||
263 | def test_proxy_deletion(self): | |
264 | # Test clearing of SF bug #762891 | |
265 | class Foo: | |
266 | result = None | |
267 | def __delitem__(self, accessor): | |
268 | self.result = accessor | |
269 | g = Foo() | |
270 | f = weakref.proxy(g) | |
271 | del f[0] | |
272 | self.assertEqual(f.result, 0) | |
273 | ||
274 | def test_proxy_bool(self): | |
275 | # Test clearing of SF bug #1170766 | |
276 | class List(list): pass | |
277 | lyst = List() | |
278 | self.assertEqual(bool(weakref.proxy(lyst)), bool(lyst)) | |
279 | ||
280 | def test_getweakrefcount(self): | |
281 | o = C() | |
282 | ref1 = weakref.ref(o) | |
283 | ref2 = weakref.ref(o, self.callback) | |
284 | self.assert_(weakref.getweakrefcount(o) == 2, | |
285 | "got wrong number of weak reference objects") | |
286 | ||
287 | proxy1 = weakref.proxy(o) | |
288 | proxy2 = weakref.proxy(o, self.callback) | |
289 | self.assert_(weakref.getweakrefcount(o) == 4, | |
290 | "got wrong number of weak reference objects") | |
291 | ||
292 | del ref1, ref2, proxy1, proxy2 | |
293 | self.assert_(weakref.getweakrefcount(o) == 0, | |
294 | "weak reference objects not unlinked from" | |
295 | " referent when discarded.") | |
296 | ||
297 | # assumes ints do not support weakrefs | |
298 | self.assert_(weakref.getweakrefcount(1) == 0, | |
299 | "got wrong number of weak reference objects for int") | |
300 | ||
301 | def test_getweakrefs(self): | |
302 | o = C() | |
303 | ref1 = weakref.ref(o, self.callback) | |
304 | ref2 = weakref.ref(o, self.callback) | |
305 | del ref1 | |
306 | self.assert_(weakref.getweakrefs(o) == [ref2], | |
307 | "list of refs does not match") | |
308 | ||
309 | o = C() | |
310 | ref1 = weakref.ref(o, self.callback) | |
311 | ref2 = weakref.ref(o, self.callback) | |
312 | del ref2 | |
313 | self.assert_(weakref.getweakrefs(o) == [ref1], | |
314 | "list of refs does not match") | |
315 | ||
316 | del ref1 | |
317 | self.assert_(weakref.getweakrefs(o) == [], | |
318 | "list of refs not cleared") | |
319 | ||
320 | # assumes ints do not support weakrefs | |
321 | self.assert_(weakref.getweakrefs(1) == [], | |
322 | "list of refs does not match for int") | |
323 | ||
324 | def test_newstyle_number_ops(self): | |
325 | class F(float): | |
326 | pass | |
327 | f = F(2.0) | |
328 | p = weakref.proxy(f) | |
329 | self.assert_(p + 1.0 == 3.0) | |
330 | self.assert_(1.0 + p == 3.0) # this used to SEGV | |
331 | ||
332 | def test_callbacks_protected(self): | |
333 | # Callbacks protected from already-set exceptions? | |
334 | # Regression test for SF bug #478534. | |
335 | class BogusError(Exception): | |
336 | pass | |
337 | data = {} | |
338 | def remove(k): | |
339 | del data[k] | |
340 | def encapsulate(): | |
341 | f = lambda : () | |
342 | data[weakref.ref(f, remove)] = None | |
343 | raise BogusError | |
344 | try: | |
345 | encapsulate() | |
346 | except BogusError: | |
347 | pass | |
348 | else: | |
349 | self.fail("exception not properly restored") | |
350 | try: | |
351 | encapsulate() | |
352 | except BogusError: | |
353 | pass | |
354 | else: | |
355 | self.fail("exception not properly restored") | |
356 | ||
357 | def test_sf_bug_840829(self): | |
358 | # "weakref callbacks and gc corrupt memory" | |
359 | # subtype_dealloc erroneously exposed a new-style instance | |
360 | # already in the process of getting deallocated to gc, | |
361 | # causing double-deallocation if the instance had a weakref | |
362 | # callback that triggered gc. | |
363 | # If the bug exists, there probably won't be an obvious symptom | |
364 | # in a release build. In a debug build, a segfault will occur | |
365 | # when the second attempt to remove the instance from the "list | |
366 | # of all objects" occurs. | |
367 | ||
368 | import gc | |
369 | ||
370 | class C(object): | |
371 | pass | |
372 | ||
373 | c = C() | |
374 | wr = weakref.ref(c, lambda ignore: gc.collect()) | |
375 | del c | |
376 | ||
377 | # There endeth the first part. It gets worse. | |
378 | del wr | |
379 | ||
380 | c1 = C() | |
381 | c1.i = C() | |
382 | wr = weakref.ref(c1.i, lambda ignore: gc.collect()) | |
383 | ||
384 | c2 = C() | |
385 | c2.c1 = c1 | |
386 | del c1 # still alive because c2 points to it | |
387 | ||
388 | # Now when subtype_dealloc gets called on c2, it's not enough just | |
389 | # that c2 is immune from gc while the weakref callbacks associated | |
390 | # with c2 execute (there are none in this 2nd half of the test, btw). | |
391 | # subtype_dealloc goes on to call the base classes' deallocs too, | |
392 | # so any gc triggered by weakref callbacks associated with anything | |
393 | # torn down by a base class dealloc can also trigger double | |
394 | # deallocation of c2. | |
395 | del c2 | |
396 | ||
397 | def test_callback_in_cycle_1(self): | |
398 | import gc | |
399 | ||
400 | class J(object): | |
401 | pass | |
402 | ||
403 | class II(object): | |
404 | def acallback(self, ignore): | |
405 | self.J | |
406 | ||
407 | I = II() | |
408 | I.J = J | |
409 | I.wr = weakref.ref(J, I.acallback) | |
410 | ||
411 | # Now J and II are each in a self-cycle (as all new-style class | |
412 | # objects are, since their __mro__ points back to them). I holds | |
413 | # both a weak reference (I.wr) and a strong reference (I.J) to class | |
414 | # J. I is also in a cycle (I.wr points to a weakref that references | |
415 | # I.acallback). When we del these three, they all become trash, but | |
416 | # the cycles prevent any of them from getting cleaned up immediately. | |
417 | # Instead they have to wait for cyclic gc to deduce that they're | |
418 | # trash. | |
419 | # | |
420 | # gc used to call tp_clear on all of them, and the order in which | |
421 | # it does that is pretty accidental. The exact order in which we | |
422 | # built up these things manages to provoke gc into running tp_clear | |
423 | # in just the right order (I last). Calling tp_clear on II leaves | |
424 | # behind an insane class object (its __mro__ becomes NULL). Calling | |
425 | # tp_clear on J breaks its self-cycle, but J doesn't get deleted | |
426 | # just then because of the strong reference from I.J. Calling | |
427 | # tp_clear on I starts to clear I's __dict__, and just happens to | |
428 | # clear I.J first -- I.wr is still intact. That removes the last | |
429 | # reference to J, which triggers the weakref callback. The callback | |
430 | # tries to do "self.J", and instances of new-style classes look up | |
431 | # attributes ("J") in the class dict first. The class (II) wants to | |
432 | # search II.__mro__, but that's NULL. The result was a segfault in | |
433 | # a release build, and an assert failure in a debug build. | |
434 | del I, J, II | |
435 | gc.collect() | |
436 | ||
437 | def test_callback_in_cycle_2(self): | |
438 | import gc | |
439 | ||
440 | # This is just like test_callback_in_cycle_1, except that II is an | |
441 | # old-style class. The symptom is different then: an instance of an | |
442 | # old-style class looks in its own __dict__ first. 'J' happens to | |
443 | # get cleared from I.__dict__ before 'wr', and 'J' was never in II's | |
444 | # __dict__, so the attribute isn't found. The difference is that | |
445 | # the old-style II doesn't have a NULL __mro__ (it doesn't have any | |
446 | # __mro__), so no segfault occurs. Instead it got: | |
447 | # test_callback_in_cycle_2 (__main__.ReferencesTestCase) ... | |
448 | # Exception exceptions.AttributeError: | |
449 | # "II instance has no attribute 'J'" in <bound method II.acallback | |
450 | # of <?.II instance at 0x00B9B4B8>> ignored | |
451 | ||
452 | class J(object): | |
453 | pass | |
454 | ||
455 | class II: | |
456 | def acallback(self, ignore): | |
457 | self.J | |
458 | ||
459 | I = II() | |
460 | I.J = J | |
461 | I.wr = weakref.ref(J, I.acallback) | |
462 | ||
463 | del I, J, II | |
464 | gc.collect() | |
465 | ||
466 | def test_callback_in_cycle_3(self): | |
467 | import gc | |
468 | ||
469 | # This one broke the first patch that fixed the last two. In this | |
470 | # case, the objects reachable from the callback aren't also reachable | |
471 | # from the object (c1) *triggering* the callback: you can get to | |
472 | # c1 from c2, but not vice-versa. The result was that c2's __dict__ | |
473 | # got tp_clear'ed by the time the c2.cb callback got invoked. | |
474 | ||
475 | class C: | |
476 | def cb(self, ignore): | |
477 | self.me | |
478 | self.c1 | |
479 | self.wr | |
480 | ||
481 | c1, c2 = C(), C() | |
482 | ||
483 | c2.me = c2 | |
484 | c2.c1 = c1 | |
485 | c2.wr = weakref.ref(c1, c2.cb) | |
486 | ||
487 | del c1, c2 | |
488 | gc.collect() | |
489 | ||
490 | def test_callback_in_cycle_4(self): | |
491 | import gc | |
492 | ||
493 | # Like test_callback_in_cycle_3, except c2 and c1 have different | |
494 | # classes. c2's class (C) isn't reachable from c1 then, so protecting | |
495 | # objects reachable from the dying object (c1) isn't enough to stop | |
496 | # c2's class (C) from getting tp_clear'ed before c2.cb is invoked. | |
497 | # The result was a segfault (C.__mro__ was NULL when the callback | |
498 | # tried to look up self.me). | |
499 | ||
500 | class C(object): | |
501 | def cb(self, ignore): | |
502 | self.me | |
503 | self.c1 | |
504 | self.wr | |
505 | ||
506 | class D: | |
507 | pass | |
508 | ||
509 | c1, c2 = D(), C() | |
510 | ||
511 | c2.me = c2 | |
512 | c2.c1 = c1 | |
513 | c2.wr = weakref.ref(c1, c2.cb) | |
514 | ||
515 | del c1, c2, C, D | |
516 | gc.collect() | |
517 | ||
518 | def test_callback_in_cycle_resurrection(self): | |
519 | import gc | |
520 | ||
521 | # Do something nasty in a weakref callback: resurrect objects | |
522 | # from dead cycles. For this to be attempted, the weakref and | |
523 | # its callback must also be part of the cyclic trash (else the | |
524 | # objects reachable via the callback couldn't be in cyclic trash | |
525 | # to begin with -- the callback would act like an external root). | |
526 | # But gc clears trash weakrefs with callbacks early now, which | |
527 | # disables the callbacks, so the callbacks shouldn't get called | |
528 | # at all (and so nothing actually gets resurrected). | |
529 | ||
530 | alist = [] | |
531 | class C(object): | |
532 | def __init__(self, value): | |
533 | self.attribute = value | |
534 | ||
535 | def acallback(self, ignore): | |
536 | alist.append(self.c) | |
537 | ||
538 | c1, c2 = C(1), C(2) | |
539 | c1.c = c2 | |
540 | c2.c = c1 | |
541 | c1.wr = weakref.ref(c2, c1.acallback) | |
542 | c2.wr = weakref.ref(c1, c2.acallback) | |
543 | ||
544 | def C_went_away(ignore): | |
545 | alist.append("C went away") | |
546 | wr = weakref.ref(C, C_went_away) | |
547 | ||
548 | del c1, c2, C # make them all trash | |
549 | self.assertEqual(alist, []) # del isn't enough to reclaim anything | |
550 | ||
551 | gc.collect() | |
552 | # c1.wr and c2.wr were part of the cyclic trash, so should have | |
553 | # been cleared without their callbacks executing. OTOH, the weakref | |
554 | # to C is bound to a function local (wr), and wasn't trash, so that | |
555 | # callback should have been invoked when C went away. | |
556 | self.assertEqual(alist, ["C went away"]) | |
557 | # The remaining weakref should be dead now (its callback ran). | |
558 | self.assertEqual(wr(), None) | |
559 | ||
560 | del alist[:] | |
561 | gc.collect() | |
562 | self.assertEqual(alist, []) | |
563 | ||
564 | def test_callbacks_on_callback(self): | |
565 | import gc | |
566 | ||
567 | # Set up weakref callbacks *on* weakref callbacks. | |
568 | alist = [] | |
569 | def safe_callback(ignore): | |
570 | alist.append("safe_callback called") | |
571 | ||
572 | class C(object): | |
573 | def cb(self, ignore): | |
574 | alist.append("cb called") | |
575 | ||
576 | c, d = C(), C() | |
577 | c.other = d | |
578 | d.other = c | |
579 | callback = c.cb | |
580 | c.wr = weakref.ref(d, callback) # this won't trigger | |
581 | d.wr = weakref.ref(callback, d.cb) # ditto | |
582 | external_wr = weakref.ref(callback, safe_callback) # but this will | |
583 | self.assert_(external_wr() is callback) | |
584 | ||
585 | # The weakrefs attached to c and d should get cleared, so that | |
586 | # C.cb is never called. But external_wr isn't part of the cyclic | |
587 | # trash, and no cyclic trash is reachable from it, so safe_callback | |
588 | # should get invoked when the bound method object callback (c.cb) | |
589 | # -- which is itself a callback, and also part of the cyclic trash -- | |
590 | # gets reclaimed at the end of gc. | |
591 | ||
592 | del callback, c, d, C | |
593 | self.assertEqual(alist, []) # del isn't enough to clean up cycles | |
594 | gc.collect() | |
595 | self.assertEqual(alist, ["safe_callback called"]) | |
596 | self.assertEqual(external_wr(), None) | |
597 | ||
598 | del alist[:] | |
599 | gc.collect() | |
600 | self.assertEqual(alist, []) | |
601 | ||
602 | def test_gc_during_ref_creation(self): | |
603 | self.check_gc_during_creation(weakref.ref) | |
604 | ||
605 | def test_gc_during_proxy_creation(self): | |
606 | self.check_gc_during_creation(weakref.proxy) | |
607 | ||
608 | def check_gc_during_creation(self, makeref): | |
609 | thresholds = gc.get_threshold() | |
610 | gc.set_threshold(1, 1, 1) | |
611 | gc.collect() | |
612 | class A: | |
613 | pass | |
614 | ||
615 | def callback(*args): | |
616 | pass | |
617 | ||
618 | referenced = A() | |
619 | ||
620 | a = A() | |
621 | a.a = a | |
622 | a.wr = makeref(referenced) | |
623 | ||
624 | try: | |
625 | # now make sure the object and the ref get labeled as | |
626 | # cyclic trash: | |
627 | a = A() | |
628 | weakref.ref(referenced, callback) | |
629 | ||
630 | finally: | |
631 | gc.set_threshold(*thresholds) | |
632 | ||
633 | ||
634 | class SubclassableWeakrefTestCase(unittest.TestCase): | |
635 | ||
636 | def test_subclass_refs(self): | |
637 | class MyRef(weakref.ref): | |
638 | def __init__(self, ob, callback=None, value=42): | |
639 | self.value = value | |
640 | super(MyRef, self).__init__(ob, callback) | |
641 | def __call__(self): | |
642 | self.called = True | |
643 | return super(MyRef, self).__call__() | |
644 | o = Object("foo") | |
645 | mr = MyRef(o, value=24) | |
646 | self.assert_(mr() is o) | |
647 | self.assert_(mr.called) | |
648 | self.assertEqual(mr.value, 24) | |
649 | del o | |
650 | self.assert_(mr() is None) | |
651 | self.assert_(mr.called) | |
652 | ||
653 | def test_subclass_refs_dont_replace_standard_refs(self): | |
654 | class MyRef(weakref.ref): | |
655 | pass | |
656 | o = Object(42) | |
657 | r1 = MyRef(o) | |
658 | r2 = weakref.ref(o) | |
659 | self.assert_(r1 is not r2) | |
660 | self.assertEqual(weakref.getweakrefs(o), [r2, r1]) | |
661 | self.assertEqual(weakref.getweakrefcount(o), 2) | |
662 | r3 = MyRef(o) | |
663 | self.assertEqual(weakref.getweakrefcount(o), 3) | |
664 | refs = weakref.getweakrefs(o) | |
665 | self.assertEqual(len(refs), 3) | |
666 | self.assert_(r2 is refs[0]) | |
667 | self.assert_(r1 in refs[1:]) | |
668 | self.assert_(r3 in refs[1:]) | |
669 | ||
670 | def test_subclass_refs_dont_conflate_callbacks(self): | |
671 | class MyRef(weakref.ref): | |
672 | pass | |
673 | o = Object(42) | |
674 | r1 = MyRef(o, id) | |
675 | r2 = MyRef(o, str) | |
676 | self.assert_(r1 is not r2) | |
677 | refs = weakref.getweakrefs(o) | |
678 | self.assert_(r1 in refs) | |
679 | self.assert_(r2 in refs) | |
680 | ||
681 | def test_subclass_refs_with_slots(self): | |
682 | class MyRef(weakref.ref): | |
683 | __slots__ = "slot1", "slot2" | |
684 | def __new__(type, ob, callback, slot1, slot2): | |
685 | return weakref.ref.__new__(type, ob, callback) | |
686 | def __init__(self, ob, callback, slot1, slot2): | |
687 | self.slot1 = slot1 | |
688 | self.slot2 = slot2 | |
689 | def meth(self): | |
690 | return self.slot1 + self.slot2 | |
691 | o = Object(42) | |
692 | r = MyRef(o, None, "abc", "def") | |
693 | self.assertEqual(r.slot1, "abc") | |
694 | self.assertEqual(r.slot2, "def") | |
695 | self.assertEqual(r.meth(), "abcdef") | |
696 | self.failIf(hasattr(r, "__dict__")) | |
697 | ||
698 | ||
699 | class Object: | |
700 | def __init__(self, arg): | |
701 | self.arg = arg | |
702 | def __repr__(self): | |
703 | return "<Object %r>" % self.arg | |
704 | ||
705 | ||
706 | class MappingTestCase(TestBase): | |
707 | ||
708 | COUNT = 10 | |
709 | ||
710 | def test_weak_values(self): | |
711 | # | |
712 | # This exercises d.copy(), d.items(), d[], del d[], len(d). | |
713 | # | |
714 | dict, objects = self.make_weak_valued_dict() | |
715 | for o in objects: | |
716 | self.assert_(weakref.getweakrefcount(o) == 1, | |
717 | "wrong number of weak references to %r!" % o) | |
718 | self.assert_(o is dict[o.arg], | |
719 | "wrong object returned by weak dict!") | |
720 | items1 = dict.items() | |
721 | items2 = dict.copy().items() | |
722 | items1.sort() | |
723 | items2.sort() | |
724 | self.assert_(items1 == items2, | |
725 | "cloning of weak-valued dictionary did not work!") | |
726 | del items1, items2 | |
727 | self.assert_(len(dict) == self.COUNT) | |
728 | del objects[0] | |
729 | self.assert_(len(dict) == (self.COUNT - 1), | |
730 | "deleting object did not cause dictionary update") | |
731 | del objects, o | |
732 | self.assert_(len(dict) == 0, | |
733 | "deleting the values did not clear the dictionary") | |
734 | # regression on SF bug #447152: | |
735 | dict = weakref.WeakValueDictionary() | |
736 | self.assertRaises(KeyError, dict.__getitem__, 1) | |
737 | dict[2] = C() | |
738 | self.assertRaises(KeyError, dict.__getitem__, 2) | |
739 | ||
740 | def test_weak_keys(self): | |
741 | # | |
742 | # This exercises d.copy(), d.items(), d[] = v, d[], del d[], | |
743 | # len(d), d.has_key(). | |
744 | # | |
745 | dict, objects = self.make_weak_keyed_dict() | |
746 | for o in objects: | |
747 | self.assert_(weakref.getweakrefcount(o) == 1, | |
748 | "wrong number of weak references to %r!" % o) | |
749 | self.assert_(o.arg is dict[o], | |
750 | "wrong object returned by weak dict!") | |
751 | items1 = dict.items() | |
752 | items2 = dict.copy().items() | |
753 | self.assert_(set(items1) == set(items2), | |
754 | "cloning of weak-keyed dictionary did not work!") | |
755 | del items1, items2 | |
756 | self.assert_(len(dict) == self.COUNT) | |
757 | del objects[0] | |
758 | self.assert_(len(dict) == (self.COUNT - 1), | |
759 | "deleting object did not cause dictionary update") | |
760 | del objects, o | |
761 | self.assert_(len(dict) == 0, | |
762 | "deleting the keys did not clear the dictionary") | |
763 | o = Object(42) | |
764 | dict[o] = "What is the meaning of the universe?" | |
765 | self.assert_(dict.has_key(o)) | |
766 | self.assert_(not dict.has_key(34)) | |
767 | ||
768 | def test_weak_keyed_iters(self): | |
769 | dict, objects = self.make_weak_keyed_dict() | |
770 | self.check_iters(dict) | |
771 | ||
772 | def test_weak_valued_iters(self): | |
773 | dict, objects = self.make_weak_valued_dict() | |
774 | self.check_iters(dict) | |
775 | ||
776 | def check_iters(self, dict): | |
777 | # item iterator: | |
778 | items = dict.items() | |
779 | for item in dict.iteritems(): | |
780 | items.remove(item) | |
781 | self.assert_(len(items) == 0, "iteritems() did not touch all items") | |
782 | ||
783 | # key iterator, via __iter__(): | |
784 | keys = dict.keys() | |
785 | for k in dict: | |
786 | keys.remove(k) | |
787 | self.assert_(len(keys) == 0, "__iter__() did not touch all keys") | |
788 | ||
789 | # key iterator, via iterkeys(): | |
790 | keys = dict.keys() | |
791 | for k in dict.iterkeys(): | |
792 | keys.remove(k) | |
793 | self.assert_(len(keys) == 0, "iterkeys() did not touch all keys") | |
794 | ||
795 | # value iterator: | |
796 | values = dict.values() | |
797 | for v in dict.itervalues(): | |
798 | values.remove(v) | |
799 | self.assert_(len(values) == 0, | |
800 | "itervalues() did not touch all values") | |
801 | ||
802 | def test_make_weak_keyed_dict_from_dict(self): | |
803 | o = Object(3) | |
804 | dict = weakref.WeakKeyDictionary({o:364}) | |
805 | self.assert_(dict[o] == 364) | |
806 | ||
807 | def test_make_weak_keyed_dict_from_weak_keyed_dict(self): | |
808 | o = Object(3) | |
809 | dict = weakref.WeakKeyDictionary({o:364}) | |
810 | dict2 = weakref.WeakKeyDictionary(dict) | |
811 | self.assert_(dict[o] == 364) | |
812 | ||
813 | def make_weak_keyed_dict(self): | |
814 | dict = weakref.WeakKeyDictionary() | |
815 | objects = map(Object, range(self.COUNT)) | |
816 | for o in objects: | |
817 | dict[o] = o.arg | |
818 | return dict, objects | |
819 | ||
820 | def make_weak_valued_dict(self): | |
821 | dict = weakref.WeakValueDictionary() | |
822 | objects = map(Object, range(self.COUNT)) | |
823 | for o in objects: | |
824 | dict[o.arg] = o | |
825 | return dict, objects | |
826 | ||
827 | def check_popitem(self, klass, key1, value1, key2, value2): | |
828 | weakdict = klass() | |
829 | weakdict[key1] = value1 | |
830 | weakdict[key2] = value2 | |
831 | self.assert_(len(weakdict) == 2) | |
832 | k, v = weakdict.popitem() | |
833 | self.assert_(len(weakdict) == 1) | |
834 | if k is key1: | |
835 | self.assert_(v is value1) | |
836 | else: | |
837 | self.assert_(v is value2) | |
838 | k, v = weakdict.popitem() | |
839 | self.assert_(len(weakdict) == 0) | |
840 | if k is key1: | |
841 | self.assert_(v is value1) | |
842 | else: | |
843 | self.assert_(v is value2) | |
844 | ||
845 | def test_weak_valued_dict_popitem(self): | |
846 | self.check_popitem(weakref.WeakValueDictionary, | |
847 | "key1", C(), "key2", C()) | |
848 | ||
849 | def test_weak_keyed_dict_popitem(self): | |
850 | self.check_popitem(weakref.WeakKeyDictionary, | |
851 | C(), "value 1", C(), "value 2") | |
852 | ||
853 | def check_setdefault(self, klass, key, value1, value2): | |
854 | self.assert_(value1 is not value2, | |
855 | "invalid test" | |
856 | " -- value parameters must be distinct objects") | |
857 | weakdict = klass() | |
858 | o = weakdict.setdefault(key, value1) | |
859 | self.assert_(o is value1) | |
860 | self.assert_(weakdict.has_key(key)) | |
861 | self.assert_(weakdict.get(key) is value1) | |
862 | self.assert_(weakdict[key] is value1) | |
863 | ||
864 | o = weakdict.setdefault(key, value2) | |
865 | self.assert_(o is value1) | |
866 | self.assert_(weakdict.has_key(key)) | |
867 | self.assert_(weakdict.get(key) is value1) | |
868 | self.assert_(weakdict[key] is value1) | |
869 | ||
870 | def test_weak_valued_dict_setdefault(self): | |
871 | self.check_setdefault(weakref.WeakValueDictionary, | |
872 | "key", C(), C()) | |
873 | ||
874 | def test_weak_keyed_dict_setdefault(self): | |
875 | self.check_setdefault(weakref.WeakKeyDictionary, | |
876 | C(), "value 1", "value 2") | |
877 | ||
878 | def check_update(self, klass, dict): | |
879 | # | |
880 | # This exercises d.update(), len(d), d.keys(), d.has_key(), | |
881 | # d.get(), d[]. | |
882 | # | |
883 | weakdict = klass() | |
884 | weakdict.update(dict) | |
885 | self.assert_(len(weakdict) == len(dict)) | |
886 | for k in weakdict.keys(): | |
887 | self.assert_(dict.has_key(k), | |
888 | "mysterious new key appeared in weak dict") | |
889 | v = dict.get(k) | |
890 | self.assert_(v is weakdict[k]) | |
891 | self.assert_(v is weakdict.get(k)) | |
892 | for k in dict.keys(): | |
893 | self.assert_(weakdict.has_key(k), | |
894 | "original key disappeared in weak dict") | |
895 | v = dict[k] | |
896 | self.assert_(v is weakdict[k]) | |
897 | self.assert_(v is weakdict.get(k)) | |
898 | ||
899 | def test_weak_valued_dict_update(self): | |
900 | self.check_update(weakref.WeakValueDictionary, | |
901 | {1: C(), 'a': C(), C(): C()}) | |
902 | ||
903 | def test_weak_keyed_dict_update(self): | |
904 | self.check_update(weakref.WeakKeyDictionary, | |
905 | {C(): 1, C(): 2, C(): 3}) | |
906 | ||
907 | def test_weak_keyed_delitem(self): | |
908 | d = weakref.WeakKeyDictionary() | |
909 | o1 = Object('1') | |
910 | o2 = Object('2') | |
911 | d[o1] = 'something' | |
912 | d[o2] = 'something' | |
913 | self.assert_(len(d) == 2) | |
914 | del d[o1] | |
915 | self.assert_(len(d) == 1) | |
916 | self.assert_(d.keys() == [o2]) | |
917 | ||
918 | def test_weak_valued_delitem(self): | |
919 | d = weakref.WeakValueDictionary() | |
920 | o1 = Object('1') | |
921 | o2 = Object('2') | |
922 | d['something'] = o1 | |
923 | d['something else'] = o2 | |
924 | self.assert_(len(d) == 2) | |
925 | del d['something'] | |
926 | self.assert_(len(d) == 1) | |
927 | self.assert_(d.items() == [('something else', o2)]) | |
928 | ||
929 | def test_weak_keyed_bad_delitem(self): | |
930 | d = weakref.WeakKeyDictionary() | |
931 | o = Object('1') | |
932 | # An attempt to delete an object that isn't there should raise | |
933 | # KeyError. It didn't before 2.3. | |
934 | self.assertRaises(KeyError, d.__delitem__, o) | |
935 | self.assertRaises(KeyError, d.__getitem__, o) | |
936 | ||
937 | # If a key isn't of a weakly referencable type, __getitem__ and | |
938 | # __setitem__ raise TypeError. __delitem__ should too. | |
939 | self.assertRaises(TypeError, d.__delitem__, 13) | |
940 | self.assertRaises(TypeError, d.__getitem__, 13) | |
941 | self.assertRaises(TypeError, d.__setitem__, 13, 13) | |
942 | ||
943 | def test_weak_keyed_cascading_deletes(self): | |
944 | # SF bug 742860. For some reason, before 2.3 __delitem__ iterated | |
945 | # over the keys via self.data.iterkeys(). If things vanished from | |
946 | # the dict during this (or got added), that caused a RuntimeError. | |
947 | ||
948 | d = weakref.WeakKeyDictionary() | |
949 | mutate = False | |
950 | ||
951 | class C(object): | |
952 | def __init__(self, i): | |
953 | self.value = i | |
954 | def __hash__(self): | |
955 | return hash(self.value) | |
956 | def __eq__(self, other): | |
957 | if mutate: | |
958 | # Side effect that mutates the dict, by removing the | |
959 | # last strong reference to a key. | |
960 | del objs[-1] | |
961 | return self.value == other.value | |
962 | ||
963 | objs = [C(i) for i in range(4)] | |
964 | for o in objs: | |
965 | d[o] = o.value | |
966 | del o # now the only strong references to keys are in objs | |
967 | # Find the order in which iterkeys sees the keys. | |
968 | objs = d.keys() | |
969 | # Reverse it, so that the iteration implementation of __delitem__ | |
970 | # has to keep looping to find the first object we delete. | |
971 | objs.reverse() | |
972 | ||
973 | # Turn on mutation in C.__eq__. The first time thru the loop, | |
974 | # under the iterkeys() business the first comparison will delete | |
975 | # the last item iterkeys() would see, and that causes a | |
976 | # RuntimeError: dictionary changed size during iteration | |
977 | # when the iterkeys() loop goes around to try comparing the next | |
978 | # key. After this was fixed, it just deletes the last object *our* | |
979 | # "for o in obj" loop would have gotten to. | |
980 | mutate = True | |
981 | count = 0 | |
982 | for o in objs: | |
983 | count += 1 | |
984 | del d[o] | |
985 | self.assertEqual(len(d), 0) | |
986 | self.assertEqual(count, 2) | |
987 | ||
988 | from test import mapping_tests | |
989 | ||
990 | class WeakValueDictionaryTestCase(mapping_tests.BasicTestMappingProtocol): | |
991 | """Check that WeakValueDictionary conforms to the mapping protocol""" | |
992 | __ref = {"key1":Object(1), "key2":Object(2), "key3":Object(3)} | |
993 | type2test = weakref.WeakValueDictionary | |
994 | def _reference(self): | |
995 | return self.__ref.copy() | |
996 | ||
997 | class WeakKeyDictionaryTestCase(mapping_tests.BasicTestMappingProtocol): | |
998 | """Check that WeakKeyDictionary conforms to the mapping protocol""" | |
999 | __ref = {Object("key1"):1, Object("key2"):2, Object("key3"):3} | |
1000 | type2test = weakref.WeakKeyDictionary | |
1001 | def _reference(self): | |
1002 | return self.__ref.copy() | |
1003 | ||
1004 | libreftest = """ Doctest for examples in the library reference: libweakref.tex | |
1005 | ||
1006 | >>> import weakref | |
1007 | >>> class Dict(dict): | |
1008 | ... pass | |
1009 | ... | |
1010 | >>> obj = Dict(red=1, green=2, blue=3) # this object is weak referencable | |
1011 | >>> r = weakref.ref(obj) | |
1012 | >>> print r() | |
1013 | {'blue': 3, 'green': 2, 'red': 1} | |
1014 | ||
1015 | >>> import weakref | |
1016 | >>> class Object: | |
1017 | ... pass | |
1018 | ... | |
1019 | >>> o = Object() | |
1020 | >>> r = weakref.ref(o) | |
1021 | >>> o2 = r() | |
1022 | >>> o is o2 | |
1023 | True | |
1024 | >>> del o, o2 | |
1025 | >>> print r() | |
1026 | None | |
1027 | ||
1028 | >>> import weakref | |
1029 | >>> class ExtendedRef(weakref.ref): | |
1030 | ... def __init__(self, ob, callback=None, **annotations): | |
1031 | ... super(ExtendedRef, self).__init__(ob, callback) | |
1032 | ... self.__counter = 0 | |
1033 | ... for k, v in annotations.iteritems(): | |
1034 | ... setattr(self, k, v) | |
1035 | ... def __call__(self): | |
1036 | ... '''Return a pair containing the referent and the number of | |
1037 | ... times the reference has been called. | |
1038 | ... ''' | |
1039 | ... ob = super(ExtendedRef, self).__call__() | |
1040 | ... if ob is not None: | |
1041 | ... self.__counter += 1 | |
1042 | ... ob = (ob, self.__counter) | |
1043 | ... return ob | |
1044 | ... | |
1045 | >>> class A: # not in docs from here, just testing the ExtendedRef | |
1046 | ... pass | |
1047 | ... | |
1048 | >>> a = A() | |
1049 | >>> r = ExtendedRef(a, foo=1, bar="baz") | |
1050 | >>> r.foo | |
1051 | 1 | |
1052 | >>> r.bar | |
1053 | 'baz' | |
1054 | >>> r()[1] | |
1055 | 1 | |
1056 | >>> r()[1] | |
1057 | 2 | |
1058 | >>> r()[0] is a | |
1059 | True | |
1060 | ||
1061 | ||
1062 | >>> import weakref | |
1063 | >>> _id2obj_dict = weakref.WeakValueDictionary() | |
1064 | >>> def remember(obj): | |
1065 | ... oid = id(obj) | |
1066 | ... _id2obj_dict[oid] = obj | |
1067 | ... return oid | |
1068 | ... | |
1069 | >>> def id2obj(oid): | |
1070 | ... return _id2obj_dict[oid] | |
1071 | ... | |
1072 | >>> a = A() # from here, just testing | |
1073 | >>> a_id = remember(a) | |
1074 | >>> id2obj(a_id) is a | |
1075 | True | |
1076 | >>> del a | |
1077 | >>> try: | |
1078 | ... id2obj(a_id) | |
1079 | ... except KeyError: | |
1080 | ... print 'OK' | |
1081 | ... else: | |
1082 | ... print 'WeakValueDictionary error' | |
1083 | OK | |
1084 | ||
1085 | """ | |
1086 | ||
1087 | __test__ = {'libreftest' : libreftest} | |
1088 | ||
1089 | def test_main(): | |
1090 | test_support.run_unittest( | |
1091 | ReferencesTestCase, | |
1092 | MappingTestCase, | |
1093 | WeakValueDictionaryTestCase, | |
1094 | WeakKeyDictionaryTestCase, | |
1095 | ) | |
1096 | test_support.run_doctest(sys.modules[__name__]) | |
1097 | ||
1098 | ||
1099 | if __name__ == "__main__": | |
1100 | test_main() |