File: test_object_marshaling.py

package info (click to toggle)
pygobject 3.22.0-2
  • links: PTS, VCS
  • area: main
  • in suites: stretch
  • size: 5,492 kB
  • ctags: 5,045
  • sloc: ansic: 20,987; python: 15,991; sh: 4,659; makefile: 569; xml: 31
file content (570 lines) | stat: -rw-r--r-- 22,360 bytes parent folder | download | duplicates (2)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
# -*- Mode: Python; py-indent-offset: 4 -*-
# vim: tabstop=4 shiftwidth=4 expandtab

import unittest
import weakref
import gc
import sys
import warnings

from gi.repository import GObject
from gi.repository import GIMarshallingTests

try:
    from gi.repository import Regress
except ImportError:
    Regress = None


class StrongRef(object):
    # A class that behaves like weakref.ref but holds a strong reference.
    # This allows re-use of the VFuncsBase by swapping out the ObjectRef
    # class var with either weakref.ref or StrongRef.

    def __init__(self, obj):
        self.obj = obj

    def __call__(self):
        return self.obj


class VFuncsBase(GIMarshallingTests.Object):
    # Class which generically implements the vfuncs used for reference counting tests
    # in a way that can be easily sub-classed and modified.

    #: Object type used by this class for testing
    #: This can be GObject.Object or GObject.InitiallyUnowned
    Object = GObject.Object

    #: Reference type used by this class for holding refs to in/out objects.
    #: This can be set to weakref.ref or StrongRef
    ObjectRef = weakref.ref

    def __init__(self):
        super(VFuncsBase, self).__init__()

        #: Hold ref of input or output python wrappers
        self.object_ref = None

        #: store grefcount of input object
        self.in_object_grefcount = None
        self.in_object_is_floating = None

    def do_vfunc_return_object_transfer_none(self):
        # Return an object but keep a python reference to it.
        obj = self.Object()
        self.object_ref = self.ObjectRef(obj)
        return obj

    def do_vfunc_return_object_transfer_full(self):
        # Return an object and hand off the reference to the caller.
        obj = self.Object()
        self.object_ref = self.ObjectRef(obj)
        return obj

    def do_vfunc_out_object_transfer_none(self):
        # Same as do_vfunc_return_object_transfer_none but the pygi
        # internals convert the return here into an out arg.
        obj = self.Object()
        self.object_ref = self.ObjectRef(obj)
        return obj

    def do_vfunc_out_object_transfer_full(self):
        # Same as do_vfunc_return_object_transfer_full but the pygi
        # internals convert the return here into an out arg.
        obj = self.Object()
        self.object_ref = self.ObjectRef(obj)
        return obj

    def do_vfunc_in_object_transfer_none(self, obj):
        # 'obj' will have a python wrapper as well as still held
        # by the caller.
        self.object_ref = self.ObjectRef(obj)
        self.in_object_grefcount = obj.__grefcount__
        self.in_object_is_floating = obj.is_floating()

    def do_vfunc_in_object_transfer_full(self, obj):
        # 'obj' will now be owned by the Python GObject wrapper.
        # When obj goes out of scope and is collected, the GObject
        # should also be fully released.
        self.object_ref = self.ObjectRef(obj)
        self.in_object_grefcount = obj.__grefcount__
        self.in_object_is_floating = obj.is_floating()


class TestVFuncsWithObjectArg(unittest.TestCase):
    # Basic set of tests which work on non-floating objects which python does
    # not keep an additional reference of.

    class VFuncs(VFuncsBase):
        # Object for testing non-floating objects without holding any refs.
        Object = GObject.Object
        ObjectRef = weakref.ref

    def test_vfunc_self_arg_ref_count(self):
        # Check to make sure vfunc "self" arguments don't leak.
        vfuncs = self.VFuncs()
        vfuncs_ref = weakref.ref(vfuncs)
        vfuncs.get_ref_info_for_vfunc_return_object_transfer_full()  # Use any vfunc to test this.

        gc.collect()
        self.assertEqual(sys.getrefcount(vfuncs), 2)
        self.assertEqual(vfuncs.__grefcount__, 1)

        del vfuncs
        gc.collect()
        self.assertTrue(vfuncs_ref() is None)

    def test_vfunc_return_object_transfer_none(self):
        # This tests a problem case where the vfunc returns a GObject owned solely by Python
        # but the argument is marked as transfer-none.
        # In this case pygobject marshaling adds an additional ref and gives a warning
        # of a potential leak. If this occures it is really a bug in the underlying library
        # but pygobject tries to react to this in a reasonable way.
        vfuncs = self.VFuncs()
        with warnings.catch_warnings(record=True) as warn:
            warnings.simplefilter('always')
            ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_out_object_transfer_none()
            self.assertTrue(issubclass(warn[0].category, RuntimeWarning))

        # The ref count of the GObject returned to the caller (get_ref_info_for_vfunc_return_object_transfer_none)
        # should be a single floating ref
        self.assertEqual(ref_count, 1)
        self.assertFalse(is_floating)

        gc.collect()
        self.assertTrue(vfuncs.object_ref() is None)

    def test_vfunc_out_object_transfer_none(self):
        # Same as above except uses out arg instead of return
        vfuncs = self.VFuncs()
        with warnings.catch_warnings(record=True) as warn:
            warnings.simplefilter('always')
            ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_out_object_transfer_none()
            self.assertTrue(issubclass(warn[0].category, RuntimeWarning))

        self.assertEqual(ref_count, 1)
        self.assertFalse(is_floating)

        gc.collect()
        self.assertTrue(vfuncs.object_ref() is None)

    def test_vfunc_return_object_transfer_full(self):
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_return_object_transfer_full()

        # The vfunc caller receives full ownership of a single ref which should not
        # be floating.
        self.assertEqual(ref_count, 1)
        self.assertFalse(is_floating)

        gc.collect()
        self.assertTrue(vfuncs.object_ref() is None)

    def test_vfunc_out_object_transfer_full(self):
        # Same as above except uses out arg instead of return
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_out_object_transfer_full()

        self.assertEqual(ref_count, 1)
        self.assertFalse(is_floating)

        gc.collect()
        self.assertTrue(vfuncs.object_ref() is None)

    def test_vfunc_in_object_transfer_none(self):
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_in_object_transfer_none(self.VFuncs.Object)

        gc.collect()
        self.assertEqual(vfuncs.in_object_grefcount, 2)  # initial + python wrapper
        self.assertFalse(vfuncs.in_object_is_floating)

        self.assertEqual(ref_count, 1)  # ensure python wrapper released
        self.assertFalse(is_floating)

        self.assertTrue(vfuncs.object_ref() is None)

    def test_vfunc_in_object_transfer_full(self):
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_in_object_transfer_full(self.VFuncs.Object)

        gc.collect()

        # python wrapper should take sole ownership of the gobject
        self.assertEqual(vfuncs.in_object_grefcount, 1)
        self.assertFalse(vfuncs.in_object_is_floating)

        # ensure python wrapper took ownership and released, after vfunc was complete
        self.assertEqual(ref_count, 0)
        self.assertFalse(is_floating)

        self.assertTrue(vfuncs.object_ref() is None)


class TestVFuncsWithFloatingArg(unittest.TestCase):
    # All tests here work with a floating object by using InitiallyUnowned as the argument

    class VFuncs(VFuncsBase):
        # Object for testing non-floating objects without holding any refs.
        Object = GObject.InitiallyUnowned
        ObjectRef = weakref.ref

    def test_vfunc_return_object_transfer_none_with_floating(self):
        # Python is expected to return a single floating reference without warning.
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_return_object_transfer_none()

        # The ref count of the GObject returned to the caller (get_ref_info_for_vfunc_return_object_transfer_none)
        # should be a single floating ref
        self.assertEqual(ref_count, 1)
        self.assertTrue(is_floating)

        gc.collect()
        self.assertTrue(vfuncs.object_ref() is None)

    def test_vfunc_out_object_transfer_none_with_floating(self):
        # Same as above except uses out arg instead of return
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_out_object_transfer_none()

        self.assertEqual(ref_count, 1)
        self.assertTrue(is_floating)

        gc.collect()
        self.assertTrue(vfuncs.object_ref() is None)

    def test_vfunc_return_object_transfer_full_with_floating(self):
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_return_object_transfer_full()

        # The vfunc caller receives full ownership of a single ref.
        self.assertEqual(ref_count, 1)
        self.assertFalse(is_floating)

        gc.collect()
        self.assertTrue(vfuncs.object_ref() is None)

    def test_vfunc_out_object_transfer_full_with_floating(self):
        # Same as above except uses out arg instead of return
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_out_object_transfer_full()

        self.assertEqual(ref_count, 1)
        self.assertFalse(is_floating)

        gc.collect()
        self.assertTrue(vfuncs.object_ref() is None)

    def test_vfunc_in_object_transfer_none_with_floating(self):
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_in_object_transfer_none(self.VFuncs.Object)

        gc.collect()

        # python wrapper should maintain the object as floating and add an additional ref
        self.assertEqual(vfuncs.in_object_grefcount, 2)
        self.assertTrue(vfuncs.in_object_is_floating)

        # vfunc caller should only have a single floating ref after the vfunc finishes
        self.assertEqual(ref_count, 1)
        self.assertTrue(is_floating)

        self.assertTrue(vfuncs.object_ref() is None)

    def test_vfunc_in_object_transfer_full_with_floating(self):
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_in_object_transfer_full(self.VFuncs.Object)

        gc.collect()

        # python wrapper sinks and owns the gobject
        self.assertEqual(vfuncs.in_object_grefcount, 1)
        self.assertFalse(vfuncs.in_object_is_floating)

        # ensure python wrapper took ownership and released
        self.assertEqual(ref_count, 0)
        self.assertFalse(is_floating)

        self.assertTrue(vfuncs.object_ref() is None)


class TestVFuncsWithHeldObjectArg(unittest.TestCase):
    # Same tests as TestVFuncsWithObjectArg except we hold
    # onto the python object reference in all cases.

    class VFuncs(VFuncsBase):
        # Object for testing non-floating objects with a held ref.
        Object = GObject.Object
        ObjectRef = StrongRef

    def test_vfunc_return_object_transfer_none_with_held_object(self):
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_return_object_transfer_none()

        # Python holds the single gobject ref in 'vfuncs.object_ref'
        # Because of this, we do not expect a floating ref or a ref increase.
        self.assertEqual(ref_count, 1)
        self.assertFalse(is_floating)

        # The actual grefcount should stay at 1 even after the vfunc return.
        self.assertEqual(vfuncs.object_ref().__grefcount__, 1)
        self.assertFalse(vfuncs.in_object_is_floating)

        held_object_ref = weakref.ref(vfuncs.object_ref)
        del vfuncs.object_ref
        gc.collect()
        self.assertTrue(held_object_ref() is None)

    def test_vfunc_out_object_transfer_none_with_held_object(self):
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_out_object_transfer_none()

        self.assertEqual(ref_count, 1)
        self.assertFalse(is_floating)

        self.assertEqual(vfuncs.object_ref().__grefcount__, 1)
        self.assertFalse(vfuncs.in_object_is_floating)

        held_object_ref = weakref.ref(vfuncs.object_ref)
        del vfuncs.object_ref
        gc.collect()
        self.assertTrue(held_object_ref() is None)

    def test_vfunc_return_object_transfer_full_with_held_object(self):
        # The vfunc caller receives full ownership which should not
        # be floating. However, the held python wrapper also has a ref.

        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_return_object_transfer_full()

        # Ref count from the perspective of C after the vfunc is called
        # The vfunc caller receives a new reference which should not
        # be floating. However, the held python wrapper also has a ref.
        self.assertEqual(ref_count, 2)
        self.assertFalse(is_floating)

        # Current ref count
        # The vfunc caller should have decremented its reference.
        self.assertEqual(vfuncs.object_ref().__grefcount__, 1)

        held_object_ref = weakref.ref(vfuncs.object_ref)
        del vfuncs.object_ref
        gc.collect()
        self.assertTrue(held_object_ref() is None)

    def test_vfunc_out_object_transfer_full_with_held_object(self):
        # Same test as above except uses out arg instead of return
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_out_object_transfer_full()

        # Ref count from the perspective of C after the vfunc is called
        # The vfunc caller receives a new reference which should not
        # be floating. However, the held python wrapper also has a ref.
        self.assertEqual(ref_count, 2)
        self.assertFalse(is_floating)

        # Current ref count
        # The vfunc caller should have decremented its reference.
        self.assertEqual(vfuncs.object_ref().__grefcount__, 1)

        held_object_ref = weakref.ref(vfuncs.object_ref())
        del vfuncs.object_ref
        gc.collect()
        self.assertTrue(held_object_ref() is None)

    def test_vfunc_in_object_transfer_none_with_held_object(self):
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_in_object_transfer_none(self.VFuncs.Object)

        gc.collect()

        # Ref count inside vfunc from the perspective of Python
        self.assertEqual(vfuncs.in_object_grefcount, 2)  # initial + python wrapper
        self.assertFalse(vfuncs.in_object_is_floating)

        # Ref count from the perspective of C after the vfunc is called
        self.assertEqual(ref_count, 2)  # kept after vfunc + held python wrapper
        self.assertFalse(is_floating)

        # Current ref count after C cleans up its reference
        self.assertEqual(vfuncs.object_ref().__grefcount__, 1)

        held_object_ref = weakref.ref(vfuncs.object_ref())
        del vfuncs.object_ref
        gc.collect()
        self.assertTrue(held_object_ref() is None)

    def test_vfunc_in_object_transfer_full_with_held_object(self):
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_in_object_transfer_full(self.VFuncs.Object)

        gc.collect()

        # Ref count inside vfunc from the perspective of Python
        self.assertEqual(vfuncs.in_object_grefcount, 1)  # python wrapper takes ownership of the gobject
        self.assertFalse(vfuncs.in_object_is_floating)

        # Ref count from the perspective of C after the vfunc is called
        self.assertEqual(ref_count, 1)
        self.assertFalse(is_floating)

        # Current ref count
        self.assertEqual(vfuncs.object_ref().__grefcount__, 1)

        held_object_ref = weakref.ref(vfuncs.object_ref())
        del vfuncs.object_ref
        gc.collect()
        self.assertTrue(held_object_ref() is None)


class TestVFuncsWithHeldFloatingArg(unittest.TestCase):
    # Tests for a floating object which we hold a reference to the python wrapper
    # on the VFuncs test class.

    class VFuncs(VFuncsBase):
        # Object for testing floating objects with a held ref.
        Object = GObject.InitiallyUnowned
        ObjectRef = StrongRef

    def test_vfunc_return_object_transfer_none_with_held_floating(self):
        # Python holds onto the wrapper which basically means the floating ref
        # should also be owned by python.

        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_return_object_transfer_none()

        # This is a borrowed ref from what is held in python.
        self.assertEqual(ref_count, 1)
        self.assertFalse(is_floating)

        # The actual grefcount should stay at 1 even after the vfunc return.
        self.assertEqual(vfuncs.object_ref().__grefcount__, 1)

        held_object_ref = weakref.ref(vfuncs.object_ref)
        del vfuncs.object_ref
        gc.collect()
        self.assertTrue(held_object_ref() is None)

    def test_vfunc_out_object_transfer_none_with_held_floating(self):
        # Same as above

        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_out_object_transfer_none()

        self.assertEqual(ref_count, 1)
        self.assertFalse(is_floating)

        self.assertEqual(vfuncs.object_ref().__grefcount__, 1)

        held_object_ref = weakref.ref(vfuncs.object_ref)
        del vfuncs.object_ref
        gc.collect()
        self.assertTrue(held_object_ref() is None)

    def test_vfunc_return_object_transfer_full_with_held_floating(self):
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_return_object_transfer_full()

        # Ref count from the perspective of C after the vfunc is called
        self.assertEqual(ref_count, 2)
        self.assertFalse(is_floating)

        # Current ref count
        # vfunc wrapper destroyes ref it was given
        self.assertEqual(vfuncs.object_ref().__grefcount__, 1)

        held_object_ref = weakref.ref(vfuncs.object_ref)
        del vfuncs.object_ref
        gc.collect()
        self.assertTrue(held_object_ref() is None)

    def test_vfunc_out_object_transfer_full_with_held_floating(self):
        # Same test as above except uses out arg instead of return
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_out_object_transfer_full()

        # Ref count from the perspective of C after the vfunc is called
        self.assertEqual(ref_count, 2)
        self.assertFalse(is_floating)

        # Current ref count
        # vfunc wrapper destroyes ref it was given
        self.assertEqual(vfuncs.object_ref().__grefcount__, 1)

        held_object_ref = weakref.ref(vfuncs.object_ref())
        del vfuncs.object_ref
        gc.collect()
        self.assertTrue(held_object_ref() is None)

    def test_vfunc_in_floating_transfer_none_with_held_floating(self):
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_in_object_transfer_none(self.VFuncs.Object)
        gc.collect()

        # Ref count inside vfunc from the perspective of Python
        self.assertTrue(vfuncs.in_object_is_floating)
        self.assertEqual(vfuncs.in_object_grefcount, 2)  # python wrapper sinks and owns the gobject

        # Ref count from the perspective of C after the vfunc is called
        self.assertTrue(is_floating)
        self.assertEqual(ref_count, 2)  # floating + held by wrapper

        # Current ref count after C cleans up its reference
        self.assertEqual(vfuncs.object_ref().__grefcount__, 1)

        held_object_ref = weakref.ref(vfuncs.object_ref())
        del vfuncs.object_ref
        gc.collect()
        self.assertTrue(held_object_ref() is None)

    def test_vfunc_in_floating_transfer_full_with_held_floating(self):
        vfuncs = self.VFuncs()
        ref_count, is_floating = vfuncs.get_ref_info_for_vfunc_in_object_transfer_full(self.VFuncs.Object)
        gc.collect()

        # Ref count from the perspective of C after the vfunc is called
        self.assertEqual(vfuncs.in_object_grefcount, 1)  # python wrapper sinks and owns the gobject
        self.assertFalse(vfuncs.in_object_is_floating)

        # Ref count from the perspective of C after the vfunc is called
        self.assertEqual(ref_count, 1)  # held by wrapper
        self.assertFalse(is_floating)

        # Current ref count
        self.assertEqual(vfuncs.object_ref().__grefcount__, 1)

        held_object_ref = weakref.ref(vfuncs.object_ref())
        del vfuncs.object_ref
        gc.collect()
        self.assertTrue(held_object_ref() is None)


@unittest.skipIf(Regress is None, 'Regress is required')
class TestArgumentTypeErrors(unittest.TestCase):
    def test_object_argument_type_error(self):
        # ensure TypeError is raised for things which are not GObjects
        obj = Regress.TestObj()
        obj.set_bare(GObject.Object())
        obj.set_bare(None)

        self.assertRaises(TypeError, obj.set_bare, object())
        self.assertRaises(TypeError, obj.set_bare, 42)
        self.assertRaises(TypeError, obj.set_bare, 'not an object')

    def test_instance_argument_error(self):
        # ensure TypeError is raised for non Regress.TestObj instances.
        obj = Regress.TestObj()
        self.assertEqual(Regress.TestObj.instance_method(obj), -1)
        self.assertRaises(TypeError, Regress.TestObj.instance_method, object())
        self.assertRaises(TypeError, Regress.TestObj.instance_method, GObject.Object())
        self.assertRaises(TypeError, Regress.TestObj.instance_method, 42)
        self.assertRaises(TypeError, Regress.TestObj.instance_method, 'not an object')

    def test_instance_argument_base_type_error(self):
        # ensure TypeError is raised when a base type is passed to something
        # expecting a derived type
        obj = Regress.TestSubObj()
        self.assertEqual(Regress.TestSubObj.instance_method(obj), 0)
        self.assertRaises(TypeError, Regress.TestSubObj.instance_method, GObject.Object())
        self.assertRaises(TypeError, Regress.TestSubObj.instance_method, Regress.TestObj())