~bzr-pqm/bzr/bzr.dev

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
# Copyright (C) 2006-2010 Canonical Ltd
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""Test locks across all branch implemenations"""

from bzrlib import (
    branch as _mod_branch,
    errors,
    tests,
    )
from bzrlib.tests import (
    lock_helpers,
    per_branch,
    )


class TestBranchLocking(per_branch.TestCaseWithBranch):

    def setUp(self):
        super(TestBranchLocking, self).setUp()
        self.reduceLockdirTimeout()

    def get_instrumented_branch(self):
        """Get a Branch object which has been instrumented"""
        # TODO: jam 20060630 It may be that not all formats have a
        # 'control_files' member. So we should fail gracefully if
        # not there. But assuming it has them lets us test the exact
        # lock/unlock order.
        self.locks = []
        b = lock_helpers.LockWrapper(self.locks, self.get_branch(), 'b')
        b.repository = lock_helpers.LockWrapper(self.locks, b.repository, 'r')
        bcf = b.control_files
        rcf = getattr(b.repository, 'control_files', None)
        if rcf is None:
            self.combined_branch = False
        else:
            # Look out for branch types that reuse their control files
            self.combined_control = bcf is rcf
        try:
            b.control_files = lock_helpers.LockWrapper(
                self.locks, b.control_files, 'bc')
        except AttributeError:
            # RemoteBranch seems to trigger this.
            raise tests.TestSkipped(
                'Could not instrument branch control files.')
        if self.combined_control:
            # instrument the repository control files too to ensure its worked
            # with correctly. When they are not shared, we trust the repository
            # API and only instrument the repository itself.
            b.repository.control_files = lock_helpers.LockWrapper(
                self.locks, b.repository.control_files, 'rc')
        return b

    def test_01_lock_read(self):
        # Test that locking occurs in the correct order
        b = self.get_instrumented_branch()

        self.assertFalse(b.is_locked())
        self.assertFalse(b.repository.is_locked())
        b.lock_read()
        try:
            self.assertTrue(b.is_locked())
            self.assertTrue(b.repository.is_locked())
        finally:
            b.unlock()
        self.assertFalse(b.is_locked())
        self.assertFalse(b.repository.is_locked())

        if self.combined_control:
            self.assertEqual([('b', 'lr', True),
                              ('r', 'lr', True),
                              ('rc', 'lr', True),
                              ('bc', 'lr', True),
                              ('b', 'ul', True),
                              ('bc', 'ul', True),
                              ('r', 'ul', True),
                              ('rc', 'ul', True),
                             ], self.locks)
        else:
            self.assertEqual([('b', 'lr', True),
                              ('r', 'lr', True),
                              ('bc', 'lr', True),
                              ('b', 'ul', True),
                              ('bc', 'ul', True),
                              ('r', 'ul', True),
                             ], self.locks)

    def test_02_lock_write(self):
        # Test that locking occurs in the correct order
        b = self.get_instrumented_branch()

        self.assertFalse(b.is_locked())
        self.assertFalse(b.repository.is_locked())
        b.lock_write()
        try:
            self.assertTrue(b.is_locked())
            self.assertTrue(b.repository.is_locked())
        finally:
            b.unlock()
        self.assertFalse(b.is_locked())
        self.assertFalse(b.repository.is_locked())

        if self.combined_control:
            self.assertEqual([('b', 'lw', True),
                              ('r', 'lw', True),
                              ('rc', 'lw', True),
                              ('bc', 'lw', True),
                              ('b', 'ul', True),
                              ('bc', 'ul', True),
                              ('r', 'ul', True),
                              ('rc', 'ul', True),
                             ], self.locks)
        else:
            self.assertEqual([('b', 'lw', True),
                              ('r', 'lw', True),
                              ('bc', 'lw', True),
                              ('b', 'ul', True),
                              ('bc', 'ul', True),
                              ('r', 'ul', True),
                             ], self.locks)

    def test_03_lock_fail_unlock_repo(self):
        # Make sure branch.unlock() is called, even if there is a
        # failure while unlocking the repository.
        b = self.get_instrumented_branch()
        b.repository.disable_unlock()

        self.assertFalse(b.is_locked())
        self.assertFalse(b.repository.is_locked())
        b.lock_write()
        try:
            self.assertTrue(b.is_locked())
            self.assertTrue(b.repository.is_locked())
            self.assertLogsError(lock_helpers.TestPreventLocking, b.unlock)
            if self.combined_control:
                self.assertTrue(b.is_locked())
            else:
                self.assertFalse(b.is_locked())
            self.assertTrue(b.repository.is_locked())

            # We unlock the branch control files, even if
            # we fail to unlock the repository
            if self.combined_control:
                self.assertEqual([('b', 'lw', True),
                                  ('r', 'lw', True),
                                  ('rc', 'lw', True),
                                  ('bc', 'lw', True),
                                  ('b', 'ul', True),
                                  ('bc', 'ul', True),
                                  ('r', 'ul', False),
                                 ], self.locks)
            else:
                self.assertEqual([('b', 'lw', True),
                                  ('r', 'lw', True),
                                  ('bc', 'lw', True),
                                  ('b', 'ul', True),
                                  ('bc', 'ul', True),
                                  ('r', 'ul', False),
                                 ], self.locks)

        finally:
            # For cleanup purposes, make sure we are unlocked
            b.repository._other.unlock()

    def test_04_lock_fail_unlock_control(self):
        # Make sure repository.unlock() is not called, if we fail to unlock
        # self leaving ourselves still locked, so that attempts to recover
        # don't encounter an unlocked repository.
        b = self.get_instrumented_branch()
        b.control_files.disable_unlock()

        self.assertFalse(b.is_locked())
        self.assertFalse(b.repository.is_locked())
        b.lock_write()
        try:
            self.assertTrue(b.is_locked())
            self.assertTrue(b.repository.is_locked())
            self.assertLogsError(lock_helpers.TestPreventLocking, b.unlock)
            self.assertTrue(b.is_locked())
            self.assertTrue(b.repository.is_locked())

            # We unlock the repository even if
            # we fail to unlock the control files
            if self.combined_control:
                self.assertEqual([('b', 'lw', True),
                                  ('r', 'lw', True),
                                  ('rc', 'lw', True),
                                  ('bc', 'lw', True),
                                  ('b', 'ul', True),
                                  ('bc', 'ul', False),
                                  ('r', 'ul', True),
                                  ('rc', 'ul', True),
                                 ], self.locks)
            else:
                self.assertEqual([('b', 'lw', True),
                                  ('r', 'lw', True),
                                  ('bc', 'lw', True),
                                  ('b', 'ul', True),
                                  ('bc', 'ul', False),
                                 ], self.locks)

        finally:
            # For cleanup purposes, make sure we are unlocked
            b.control_files._other.unlock()

    def test_05_lock_read_fail_repo(self):
        # Test that the branch is not locked if it cannot lock the repository
        b = self.get_instrumented_branch()
        b.repository.disable_lock_read()

        self.assertRaises(lock_helpers.TestPreventLocking, b.lock_read)
        self.assertFalse(b.is_locked())
        self.assertFalse(b.repository.is_locked())

        self.assertEqual([('b', 'lr', True),
                          ('r', 'lr', False),
                         ], self.locks)

    def test_06_lock_write_fail_repo(self):
        # Test that the branch is not locked if it cannot lock the repository
        b = self.get_instrumented_branch()
        b.repository.disable_lock_write()

        self.assertRaises(lock_helpers.TestPreventLocking, b.lock_write)
        self.assertFalse(b.is_locked())
        self.assertFalse(b.repository.is_locked())

        self.assertEqual([('b', 'lw', True),
                          ('r', 'lw', False),
                         ], self.locks)

    def test_07_lock_read_fail_control(self):
        # Test the repository is unlocked if we can't lock self
        b = self.get_instrumented_branch()
        b.control_files.disable_lock_read()

        self.assertRaises(lock_helpers.TestPreventLocking, b.lock_read)
        self.assertFalse(b.is_locked())
        self.assertFalse(b.repository.is_locked())

        if self.combined_control:
            self.assertEqual([('b', 'lr', True),
                              ('r', 'lr', True),
                              ('rc', 'lr', True),
                              ('bc', 'lr', False),
                              ('r', 'ul', True),
                              ('rc', 'ul', True),
                             ], self.locks)
        else:
            self.assertEqual([('b', 'lr', True),
                              ('r', 'lr', True),
                              ('bc', 'lr', False),
                              ('r', 'ul', True),
                             ], self.locks)

    def test_08_lock_write_fail_control(self):
        # Test the repository is unlocked if we can't lock self
        b = self.get_instrumented_branch()
        b.control_files.disable_lock_write()

        self.assertRaises(lock_helpers.TestPreventLocking, b.lock_write)
        self.assertFalse(b.is_locked())
        self.assertFalse(b.repository.is_locked())
        if self.combined_control:
            self.assertEqual([('b', 'lw', True),
                              ('r', 'lw', True),
                              ('rc', 'lw', True),
                              ('bc', 'lw', False),
                              ('r', 'ul', True),
                              ('rc', 'ul', True),
                             ], self.locks)
        else:
            self.assertEqual([('b', 'lw', True),
                              ('r', 'lw', True),
                              ('bc', 'lw', False),
                              ('r', 'ul', True),
                             ], self.locks)

    def test_lock_write_returns_None_refuses_token(self):
        branch = self.make_branch('b')
        token = branch.lock_write()
        try:
            if token is not None:
                # This test does not apply, because this lockable supports
                # tokens.
                return
            self.assertRaises(errors.TokenLockingNotSupported,
                              branch.lock_write, token='token')
        finally:
            branch.unlock()

    def test_reentering_lock_write_raises_on_token_mismatch(self):
        branch = self.make_branch('b')
        token = branch.lock_write()
        try:
            if token is None:
                # This test does not apply, because this lockable refuses
                # tokens.
                return
            different_branch_token = token + 'xxx'
            # Re-using the same lockable instance with a different branch token
            # will raise TokenMismatch.
            self.assertRaises(errors.TokenMismatch,
                              branch.lock_write,
                              token=different_branch_token)
        finally:
            branch.unlock()

    def test_lock_write_with_nonmatching_token(self):
        branch = self.make_branch('b')
        token = branch.lock_write()
        try:
            if token is None:
                # This test does not apply, because this branch refuses
                # tokens.
                return
            different_branch_token = token + 'xxx'

            new_branch = branch.bzrdir.open_branch()
            # We only want to test the relocking abilities of branch, so use the
            # existing repository object which is already locked.
            new_branch.repository = branch.repository
            self.assertRaises(errors.TokenMismatch,
                              new_branch.lock_write,
                              token=different_branch_token)
        finally:
            branch.unlock()


    def test_lock_write_with_matching_token(self):
        """Test that a branch can be locked with a token, if it is already
        locked by that token."""
        branch = self.make_branch('b')
        token = branch.lock_write()
        try:
            if token is None:
                # This test does not apply, because this branch refuses tokens.
                return
            # The same instance will accept a second lock_write if the specified
            # token matches.
            branch.lock_write(token=token)
            branch.unlock()
            # Calling lock_write on a new instance for the same lockable will
            # also succeed.
            new_branch = branch.bzrdir.open_branch()
            # We only want to test the relocking abilities of branch, so use the
            # existing repository object which is already locked.
            new_branch.repository = branch.repository
            new_branch.lock_write(token=token)
            new_branch.unlock()
        finally:
            branch.unlock()

    def test_unlock_after_lock_write_with_token(self):
        # If lock_write did not physically acquire the lock (because it was
        # passed some tokens), then unlock should not physically release it.
        branch = self.make_branch('b')
        token = branch.lock_write()
        try:
            if token is None:
                # This test does not apply, because this lockable refuses
                # tokens.
                return
            new_branch = branch.bzrdir.open_branch()
            # We only want to test the relocking abilities of branch, so use the
            # existing repository object which is already locked.
            new_branch.repository = branch.repository
            new_branch.lock_write(token=token)
            new_branch.unlock()
            self.assertTrue(branch.get_physical_lock_status()) #XXX
        finally:
            branch.unlock()

    def test_lock_write_with_token_fails_when_unlocked(self):
        # First, lock and then unlock to get superficially valid tokens.  This
        # mimics a likely programming error, where a caller accidentally tries
        # to lock with a token that is no longer valid (because the original
        # lock was released).
        branch = self.make_branch('b')
        token = branch.lock_write()
        branch.unlock()
        if token is None:
            # This test does not apply, because this lockable refuses
            # tokens.
            return

        self.assertRaises(errors.TokenMismatch,
                          branch.lock_write, token=token)

    def test_lock_write_reenter_with_token(self):
        branch = self.make_branch('b')
        token = branch.lock_write()
        try:
            if token is None:
                # This test does not apply, because this lockable refuses
                # tokens.
                return
            # Relock with a token.
            branch.lock_write(token=token)
            branch.unlock()
        finally:
            branch.unlock()
        # The lock should be unlocked on disk.  Verify that with a new lock
        # instance.
        new_branch = branch.bzrdir.open_branch()
        # Calling lock_write now should work, rather than raise LockContention.
        new_branch.lock_write()
        new_branch.unlock()

    def test_leave_lock_in_place(self):
        branch = self.make_branch('b')
        # Lock the branch, then use leave_lock_in_place so that when we
        # unlock the branch the lock is still held on disk.
        token = branch.lock_write()
        try:
            if token is None:
                # This test does not apply, because this repository refuses lock
                # tokens.
                self.assertRaises(NotImplementedError,
                                  branch.leave_lock_in_place)
                return
            branch.leave_lock_in_place()
        finally:
            branch.unlock()
        # We should be unable to relock the repo.
        self.assertRaises(errors.LockContention, branch.lock_write)
        # Cleanup
        branch.lock_write(token)
        branch.dont_leave_lock_in_place()
        branch.unlock()

    def test_dont_leave_lock_in_place(self):
        branch = self.make_branch('b')
        # Create a lock on disk.
        token = branch.lock_write()
        try:
            if token is None:
                # This test does not apply, because this branch refuses lock
                # tokens.
                self.assertRaises(NotImplementedError,
                                  branch.dont_leave_lock_in_place)
                return
            try:
                branch.leave_lock_in_place()
            except NotImplementedError:
                # This branch doesn't support this API.
                return
            try:
                branch.repository.leave_lock_in_place()
            except NotImplementedError:
                # This repo doesn't support leaving locks around,
                # assume it is essentially lock-free.
                repo_token = None
            else:
                repo_token = branch.repository.lock_write()
                branch.repository.unlock()
        finally:
            branch.unlock()
        # Reacquire the lock (with a different branch object) by using the
        # tokens.
        new_branch = branch.bzrdir.open_branch()
        if repo_token is not None:
            # We have to explicitly lock the repository first.
            new_branch.repository.lock_write(token=repo_token)
        new_branch.lock_write(token=token)
        if repo_token is not None:
            # Now we don't need our own repository lock anymore (the branch is
            # holding it for us).
            new_branch.repository.unlock()
        # Call dont_leave_lock_in_place, so that the lock will be released by
        # this instance, even though the lock wasn't originally acquired by it.
        new_branch.dont_leave_lock_in_place()
        if repo_token is not None:
            new_branch.repository.dont_leave_lock_in_place()
        new_branch.unlock()
        # Now the branch (and repository) is unlocked.  Test this by locking it
        # without tokens.
        branch.lock_write()
        branch.unlock()

    def test_lock_read_then_unlock(self):
        # Calling lock_read then unlocking should work without errors.
        branch = self.make_branch('b')
        branch.lock_read()
        branch.unlock()

    def test_lock_write_locks_repo_too(self):
        if isinstance(self.branch_format, _mod_branch.BzrBranchFormat4):
            # Branch format 4 is combined with the repository, so this test
            # doesn't apply.
            return
        branch = self.make_branch('b')
        branch = branch.bzrdir.open_branch()
        branch.lock_write()
        try:
            # The branch should have asked the repository to lock.
            self.assertTrue(branch.repository.is_write_locked())
            # Does the repository type actually lock?
            if not branch.repository.get_physical_lock_status():
                # The test was successfully applied, so it was applicable.
                return
            # Now the branch.repository is physically locked, so we can't lock
            # it with a new repository instance.
            new_repo = branch.bzrdir.open_repository()
            self.assertRaises(errors.LockContention, new_repo.lock_write)
            # We can call lock_write on the original repository object though,
            # because it is already locked.
            branch.repository.lock_write()
            branch.repository.unlock()
        finally:
            branch.unlock()

    def test_lock_and_unlock_leaves_repo_unlocked(self):
        branch = self.make_branch('b')
        branch.lock_write()
        branch.unlock()
        self.assertRaises(errors.LockNotHeld, branch.repository.unlock)