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Viewing changes to bzrlib/tests/test_lockdir.py

  • Committer: Andrew Bennetts
  • Date: 2010-10-13 00:26:41 UTC
  • mto: This revision was merged to the branch mainline in revision 5498.
  • Revision ID: andrew.bennetts@canonical.com-20101013002641-9tlh9k89mlj1666m
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bzrlib/tests/test_lockdir.py
1
 
# Copyright (C) 2006-2011 Canonical Ltd
 
1
# Copyright (C) 2006-2010 Canonical Ltd
2
2
#
3
3
# This program is free software; you can redistribute it and/or modify
4
4
# it under the terms of the GNU General Public License as published by
16
16
 
17
17
"""Tests for LockDir"""
18
18
 
 
19
from cStringIO import StringIO
19
20
import os
20
 
import sys
 
21
from threading import Thread, Lock
21
22
import time
22
23
 
23
24
import bzrlib
25
26
    config,
26
27
    errors,
27
28
    lock,
28
 
    lockdir,
29
29
    osutils,
30
30
    tests,
31
31
    transport,
34
34
    LockBreakMismatch,
35
35
    LockBroken,
36
36
    LockContention,
 
37
    LockError,
37
38
    LockFailed,
38
39
    LockNotHeld,
39
40
    )
40
 
from bzrlib.lockdir import (
41
 
    LockDir,
42
 
    LockHeldInfo,
43
 
    )
44
 
from bzrlib.tests import (
45
 
    features,
46
 
    TestCase,
47
 
    TestCaseWithTransport,
48
 
    )
 
41
from bzrlib.lockdir import LockDir
 
42
from bzrlib.tests import (features, TestCaseWithTransport)
49
43
from bzrlib.trace import note
50
44
 
 
45
# These tests sometimes use threads to test the behaviour of lock files with
 
46
# concurrent actors.  This is not a typical (or necessarily supported) use;
 
47
# they're really meant for guarding between processes.
 
48
 
51
49
# These tests are run on the default transport provided by the test framework
52
50
# (typically a local disk transport).  That can be changed by the --transport
53
51
# option to bzr selftest.  The required properties of the transport
54
52
# implementation are tested separately.  (The main requirement is just that
55
53
# they don't allow overwriting nonempty directories.)
56
54
 
57
 
 
58
55
class TestLockDir(TestCaseWithTransport):
59
56
    """Test LockDir operations"""
60
57
 
148
145
        self.addCleanup(lf1.unlock)
149
146
        # lock is held, should get some info on it
150
147
        info1 = lf1.peek()
151
 
        self.assertEqual(set(info1.info_dict.keys()),
152
 
            set(['user', 'nonce', 'hostname', 'pid', 'start_time']))
 
148
        self.assertEqual(set(info1.keys()),
 
149
                         set(['user', 'nonce', 'hostname', 'pid', 'start_time']))
153
150
        # should get the same info if we look at it through a different
154
151
        # instance
155
152
        info2 = LockDir(t, 'test_lock').peek()
168
165
        self.addCleanup(lf1.unlock)
169
166
        info2 = lf2.peek()
170
167
        self.assertTrue(info2)
171
 
        self.assertEqual(info2.get('nonce'), lf1.nonce)
 
168
        self.assertEqual(info2['nonce'], lf1.nonce)
172
169
 
173
170
    def test_30_lock_wait_fail(self):
174
171
        """Wait on a lock, then fail
191
188
            # it should only take about 0.4 seconds, but we allow more time in
192
189
            # case the machine is heavily loaded
193
190
            self.assertTrue(after - before <= 8.0,
194
 
                "took %f seconds to detect lock contention" % (after - before))
 
191
                    "took %f seconds to detect lock contention" % (after - before))
195
192
        finally:
196
193
            lf1.unlock()
197
194
        self.assertEqual(1, len(self._logged_reports))
198
 
        self.assertContainsRe(self._logged_reports[0][0],
199
 
            r'Unable to obtain lock .* held by jrandom@example\.com on .*'
200
 
            r' \(process #\d+\), acquired .* ago\.\n'
201
 
            r'Will continue to try until \d{2}:\d{2}:\d{2}, unless '
202
 
            r'you press Ctrl-C.\n'
203
 
            r'See "bzr help break-lock" for more.')
 
195
        self.assertEqual(self._logged_reports[0][0],
 
196
            '%s lock %s held by %s\n'
 
197
            'at %s [process #%s], acquired %s.\n'
 
198
            'Will continue to try until %s, unless '
 
199
            'you press Ctrl-C.\n'
 
200
            'See "bzr help break-lock" for more.')
 
201
        start, lock_url, user, hostname, pid, time_ago, deadline_str = \
 
202
            self._logged_reports[0][1]
 
203
        self.assertEqual(start, u'Unable to obtain')
 
204
        self.assertEqual(user, u'jrandom@example.com')
 
205
        # skip hostname
 
206
        self.assertContainsRe(pid, r'\d+')
 
207
        self.assertContainsRe(time_ago, r'.* ago')
 
208
        self.assertContainsRe(deadline_str, r'\d{2}:\d{2}:\d{2}')
204
209
 
205
210
    def test_31_lock_wait_easy(self):
206
211
        """Succeed when waiting on a lock with no contention.
218
223
            lf1.unlock()
219
224
        self.assertEqual([], self._logged_reports)
220
225
 
 
226
    def test_32_lock_wait_succeed(self):
 
227
        """Succeed when trying to acquire a lock that gets released
 
228
 
 
229
        One thread holds on a lock and then releases it; another
 
230
        tries to lock it.
 
231
        """
 
232
        # This test sometimes fails like this:
 
233
        # Traceback (most recent call last):
 
234
 
 
235
        #   File "/home/pqm/bzr-pqm-workdir/home/+trunk/bzrlib/tests/
 
236
        # test_lockdir.py", line 247, in test_32_lock_wait_succeed
 
237
        #     self.assertEqual(1, len(self._logged_reports))
 
238
        # AssertionError: not equal:
 
239
        # a = 1
 
240
        # b = 0
 
241
        raise tests.TestSkipped("Test fails intermittently")
 
242
        t = self.get_transport()
 
243
        lf1 = LockDir(t, 'test_lock')
 
244
        lf1.create()
 
245
        lf1.attempt_lock()
 
246
 
 
247
        def wait_and_unlock():
 
248
            time.sleep(0.1)
 
249
            lf1.unlock()
 
250
        unlocker = Thread(target=wait_and_unlock)
 
251
        unlocker.start()
 
252
        try:
 
253
            lf2 = LockDir(t, 'test_lock')
 
254
            self.setup_log_reporter(lf2)
 
255
            before = time.time()
 
256
            # wait and then lock
 
257
            lf2.wait_lock(timeout=0.4, poll=0.1)
 
258
            after = time.time()
 
259
            self.assertTrue(after - before <= 1.0)
 
260
        finally:
 
261
            unlocker.join()
 
262
 
 
263
        # There should be only 1 report, even though it should have to
 
264
        # wait for a while
 
265
        lock_base = lf2.transport.abspath(lf2.path)
 
266
        self.assertEqual(1, len(self._logged_reports))
 
267
        self.assertEqual('%s %s\n'
 
268
                         '%s\n%s\n'
 
269
                         'Will continue to try until %s\n',
 
270
                         self._logged_reports[0][0])
 
271
        args = self._logged_reports[0][1]
 
272
        self.assertEqual('Unable to obtain', args[0])
 
273
        self.assertEqual('lock %s' % (lock_base,), args[1])
 
274
        self.assertStartsWith(args[2], 'held by ')
 
275
        self.assertStartsWith(args[3], 'locked ')
 
276
        self.assertEndsWith(args[3], ' ago')
 
277
        self.assertContainsRe(args[4], r'\d\d:\d\d:\d\d')
 
278
 
 
279
    def test_34_lock_write_waits(self):
 
280
        """LockDir.lock_write() will wait for the lock."""
 
281
        # the test suite sets the default to 0 to make deadlocks fail fast.
 
282
        # change it for this test, as we want to try a manual deadlock.
 
283
        raise tests.TestSkipped('Timing-sensitive test')
 
284
        bzrlib.lockdir._DEFAULT_TIMEOUT_SECONDS = 300
 
285
        t = self.get_transport()
 
286
        lf1 = LockDir(t, 'test_lock')
 
287
        lf1.create()
 
288
        lf1.attempt_lock()
 
289
 
 
290
        def wait_and_unlock():
 
291
            time.sleep(0.1)
 
292
            lf1.unlock()
 
293
        unlocker = Thread(target=wait_and_unlock)
 
294
        unlocker.start()
 
295
        try:
 
296
            lf2 = LockDir(t, 'test_lock')
 
297
            self.setup_log_reporter(lf2)
 
298
            before = time.time()
 
299
            # wait and then lock
 
300
            lf2.lock_write()
 
301
            after = time.time()
 
302
        finally:
 
303
            unlocker.join()
 
304
 
 
305
        # There should be only 1 report, even though it should have to
 
306
        # wait for a while
 
307
        lock_base = lf2.transport.abspath(lf2.path)
 
308
        self.assertEqual(1, len(self._logged_reports))
 
309
        self.assertEqual('%s %s\n'
 
310
                         '%s\n%s\n'
 
311
                         'Will continue to try until %s\n',
 
312
                         self._logged_reports[0][0])
 
313
        args = self._logged_reports[0][1]
 
314
        self.assertEqual('Unable to obtain', args[0])
 
315
        self.assertEqual('lock %s' % (lock_base,), args[1])
 
316
        self.assertStartsWith(args[2], 'held by ')
 
317
        self.assertStartsWith(args[3], 'locked ')
 
318
        self.assertEndsWith(args[3], ' ago')
 
319
        self.assertContainsRe(args[4], r'\d\d:\d\d:\d\d')
 
320
 
 
321
    def test_35_wait_lock_changing(self):
 
322
        """LockDir.wait_lock() will report if the lock changes underneath.
 
323
 
 
324
        This is the stages we want to happen:
 
325
 
 
326
        0) Synchronization locks are created and locked.
 
327
        1) Lock1 obtains the lockdir, and releases the 'check' lock.
 
328
        2) Lock2 grabs the 'check' lock, and checks the lockdir.
 
329
           It sees the lockdir is already acquired, reports the fact,
 
330
           and unsets the 'checked' lock.
 
331
        3) Thread1 blocks on acquiring the 'checked' lock, and then tells
 
332
           Lock1 to release and acquire the lockdir. This resets the 'check'
 
333
           lock.
 
334
        4) Lock2 acquires the 'check' lock, and checks again. It notices
 
335
           that the holder of the lock has changed, and so reports a new
 
336
           lock holder.
 
337
        5) Thread1 blocks on the 'checked' lock, this time, it completely
 
338
           unlocks the lockdir, allowing Lock2 to acquire the lock.
 
339
        """
 
340
 
 
341
        raise tests.KnownFailure(
 
342
            "timing dependency in lock tests (#213182)")
 
343
 
 
344
        wait_to_check_lock = Lock()
 
345
        wait_until_checked_lock = Lock()
 
346
 
 
347
        wait_to_check_lock.acquire()
 
348
        wait_until_checked_lock.acquire()
 
349
        note('locked check and checked locks')
 
350
 
 
351
        class LockDir1(LockDir):
 
352
            """Use the synchronization points for the first lock."""
 
353
 
 
354
            def attempt_lock(self):
 
355
                # Once we have acquired the lock, it is okay for
 
356
                # the other lock to check it
 
357
                try:
 
358
                    return super(LockDir1, self).attempt_lock()
 
359
                finally:
 
360
                    note('lock1: releasing check lock')
 
361
                    wait_to_check_lock.release()
 
362
 
 
363
        class LockDir2(LockDir):
 
364
            """Use the synchronization points for the second lock."""
 
365
 
 
366
            def attempt_lock(self):
 
367
                note('lock2: waiting for check lock')
 
368
                wait_to_check_lock.acquire()
 
369
                note('lock2: acquired check lock')
 
370
                try:
 
371
                    return super(LockDir2, self).attempt_lock()
 
372
                finally:
 
373
                    note('lock2: releasing checked lock')
 
374
                    wait_until_checked_lock.release()
 
375
 
 
376
        t = self.get_transport()
 
377
        lf1 = LockDir1(t, 'test_lock')
 
378
        lf1.create()
 
379
 
 
380
        lf2 = LockDir2(t, 'test_lock')
 
381
        self.setup_log_reporter(lf2)
 
382
 
 
383
        def wait_and_switch():
 
384
            lf1.attempt_lock()
 
385
            # Block until lock2 has had a chance to check
 
386
            note('lock1: waiting 1 for checked lock')
 
387
            wait_until_checked_lock.acquire()
 
388
            note('lock1: acquired for checked lock')
 
389
            note('lock1: released lockdir')
 
390
            lf1.unlock()
 
391
            note('lock1: acquiring lockdir')
 
392
            # Create a new nonce, so the lock looks different.
 
393
            lf1.nonce = osutils.rand_chars(20)
 
394
            lf1.lock_write()
 
395
            note('lock1: acquired lockdir')
 
396
 
 
397
            # Block until lock2 has peeked again
 
398
            note('lock1: waiting 2 for checked lock')
 
399
            wait_until_checked_lock.acquire()
 
400
            note('lock1: acquired for checked lock')
 
401
            # Now unlock, and let lock 2 grab the lock
 
402
            lf1.unlock()
 
403
            wait_to_check_lock.release()
 
404
 
 
405
        unlocker = Thread(target=wait_and_switch)
 
406
        unlocker.start()
 
407
        try:
 
408
            # Wait and play against the other thread
 
409
            lf2.wait_lock(timeout=20.0, poll=0.01)
 
410
        finally:
 
411
            unlocker.join()
 
412
        lf2.unlock()
 
413
 
 
414
        # There should be 2 reports, because the lock changed
 
415
        lock_base = lf2.transport.abspath(lf2.path)
 
416
        self.assertEqual(2, len(self._logged_reports))
 
417
        lock_url = lf2.transport.abspath(lf2.path)
 
418
        self.assertEqual('%s %s\n'
 
419
                         '%s\n%s\n'
 
420
                         'Will continue to try until %s, unless '
 
421
                         'you press Ctrl-C.\n'
 
422
                         'See "bzr help break-lock" for more.',
 
423
                         self._logged_reports[0][0])
 
424
        args = self._logged_reports[0][1]
 
425
        self.assertEqual('Unable to obtain', args[0])
 
426
        self.assertEqual('lock %s' % (lock_base,), args[1])
 
427
        self.assertStartsWith(args[2], 'held by ')
 
428
        self.assertStartsWith(args[3], 'locked ')
 
429
        self.assertEndsWith(args[3], ' ago')
 
430
        self.assertContainsRe(args[4], r'\d\d:\d\d:\d\d')
 
431
 
 
432
        self.assertEqual('%s %s\n'
 
433
                         '%s\n%s\n'
 
434
                         'Will continue to try until %s, unless '
 
435
                         'you press Ctrl-C.\n'
 
436
                         'See "bzr help break-lock" for more.',
 
437
                         self._logged_reports[1][0])
 
438
        args = self._logged_reports[1][1]
 
439
        self.assertEqual('Lock owner changed for', args[0])
 
440
        self.assertEqual('lock %s' % (lock_base,), args[1])
 
441
        self.assertStartsWith(args[2], 'held by ')
 
442
        self.assertStartsWith(args[3], 'locked ')
 
443
        self.assertEndsWith(args[3], ' ago')
 
444
        self.assertContainsRe(args[4], r'\d\d:\d\d:\d\d')
 
445
 
221
446
    def test_40_confirm_easy(self):
222
447
        """Confirm a lock that's already held"""
223
448
        t = self.get_transport()
348
573
        ld.create()
349
574
        ld.lock_write()
350
575
        ld.transport.put_bytes_non_atomic('test_lock/held/info', '\0')
351
 
 
352
576
        class LoggingUIFactory(bzrlib.ui.SilentUIFactory):
353
577
            def __init__(self):
354
578
                self.prompts = []
355
 
 
356
579
            def get_boolean(self, prompt):
357
580
                self.prompts.append(('boolean', prompt))
358
581
                return True
359
 
 
360
582
        ui = LoggingUIFactory()
361
 
        self.overrideAttr(bzrlib.ui, 'ui_factory', ui)
362
 
        ld2.break_lock()
363
 
        self.assertLength(1, ui.prompts)
364
 
        self.assertEqual('boolean', ui.prompts[0][0])
365
 
        self.assertStartsWith(ui.prompts[0][1], 'Break (corrupt LockDir')
366
 
        self.assertRaises(LockBroken, ld.unlock)
 
583
        orig_factory = bzrlib.ui.ui_factory
 
584
        bzrlib.ui.ui_factory = ui
 
585
        try:
 
586
            ld2.break_lock()
 
587
            self.assertLength(1, ui.prompts)
 
588
            self.assertEqual('boolean', ui.prompts[0][0])
 
589
            self.assertStartsWith(ui.prompts[0][1], 'Break (corrupt LockDir')
 
590
            self.assertRaises(LockBroken, ld.unlock)
 
591
        finally:
 
592
            bzrlib.ui.ui_factory = orig_factory
367
593
 
368
594
    def test_break_lock_missing_info(self):
369
595
        """break_lock works even if the info file is missing (and tells the UI
374
600
        ld.create()
375
601
        ld.lock_write()
376
602
        ld.transport.delete('test_lock/held/info')
377
 
 
378
603
        class LoggingUIFactory(bzrlib.ui.SilentUIFactory):
379
604
            def __init__(self):
380
605
                self.prompts = []
381
 
 
382
606
            def get_boolean(self, prompt):
383
607
                self.prompts.append(('boolean', prompt))
384
608
                return True
385
 
 
386
609
        ui = LoggingUIFactory()
387
610
        orig_factory = bzrlib.ui.ui_factory
388
611
        bzrlib.ui.ui_factory = ui
408
631
        lf1 = LockDir(t, 'test_lock')
409
632
 
410
633
        lf1.create()
411
 
        self.assertTrue(t.has('test_lock'))
 
634
        self.failUnless(t.has('test_lock'))
412
635
 
413
636
        t.rmdir('test_lock')
414
 
        self.assertFalse(t.has('test_lock'))
 
637
        self.failIf(t.has('test_lock'))
415
638
 
416
639
        # This will create 'test_lock' if it needs to
417
640
        lf1.lock_write()
418
 
        self.assertTrue(t.has('test_lock'))
419
 
        self.assertTrue(t.has('test_lock/held/info'))
 
641
        self.failUnless(t.has('test_lock'))
 
642
        self.failUnless(t.has('test_lock/held/info'))
420
643
 
421
644
        lf1.unlock()
422
 
        self.assertFalse(t.has('test_lock/held/info'))
 
645
        self.failIf(t.has('test_lock/held/info'))
423
646
 
424
 
    def test_display_form(self):
 
647
    def test__format_lock_info(self):
425
648
        ld1 = self.get_lock()
426
649
        ld1.create()
427
650
        ld1.lock_write()
428
651
        try:
429
 
            info_list = ld1.peek().to_readable_dict()
 
652
            info_list = ld1._format_lock_info(ld1.peek())
430
653
        finally:
431
654
            ld1.unlock()
432
 
        self.assertEqual(info_list['user'], u'jrandom@example.com')
433
 
        self.assertContainsRe(info_list['pid'], '^\d+$')
434
 
        self.assertContainsRe(info_list['time_ago'], r'^\d+ seconds? ago$')
 
655
        self.assertEqual(info_list[0], u'jrandom@example.com')
 
656
        # info_list[1] is hostname. we skip this.
 
657
        self.assertContainsRe(info_list[2], '^\d+$') # pid
 
658
        self.assertContainsRe(info_list[3], r'^\d+ seconds? ago$') # time_ago
435
659
 
436
660
    def test_lock_without_email(self):
437
661
        global_config = config.GlobalConfig()
485
709
        # should be nothing before we start
486
710
        ld1.create()
487
711
        t = self.get_transport().clone('test_lock')
488
 
 
489
712
        def check_dir(a):
490
713
            self.assertEquals(a, t.list_dir('.'))
491
 
 
492
714
        check_dir([])
493
715
        # when held, that's all we see
494
716
        ld1.attempt_lock()
511
733
        t.put_bytes('test_lock/held/info', '')
512
734
        lf = LockDir(t, 'test_lock')
513
735
        info = lf.peek()
514
 
        formatted_info = info.to_readable_dict()
 
736
        formatted_info = lf._format_lock_info(info)
515
737
        self.assertEquals(
516
 
            dict(user='<unknown>', hostname='<unknown>', pid='<unknown>',
517
 
                time_ago='(unknown)'),
 
738
            ['<unknown>', '<unknown>', '<unknown>', '(unknown)'],
518
739
            formatted_info)
519
740
 
520
741
    def test_corrupt_lockdir_info(self):
521
742
        """We can cope with corrupt (and thus unparseable) info files."""
522
743
        # This seems like a fairly common failure case too - see
523
 
        # <https://bugs.launchpad.net/bzr/+bug/619872> for instance.
 
744
        # <https://bugs.edge.launchpad.net/bzr/+bug/619872> for instance.
524
745
        # In particular some systems tend to fill recently created files with
525
746
        # nul bytes after recovering from a system crash.
526
747
        t = self.get_transport()
653
874
        ld2.force_break(holder_info)
654
875
        lock_path = ld.transport.abspath(ld.path)
655
876
        self.assertEqual([], self._calls)
656
 
 
657
 
 
658
 
class TestLockHeldInfo(TestCase):
659
 
    """Can get information about the lock holder, and detect whether they're
660
 
    still alive."""
661
 
 
662
 
    def test_repr(self):
663
 
        info = LockHeldInfo.for_this_process(None)
664
 
        self.assertContainsRe(repr(info), r"LockHeldInfo\(.*\)")
665
 
 
666
 
    def test_unicode(self):
667
 
        info = LockHeldInfo.for_this_process(None)
668
 
        self.assertContainsRe(unicode(info),
669
 
            r'held by .* on .* \(process #\d+\), acquired .* ago')
670
 
 
671
 
    def test_is_locked_by_this_process(self):
672
 
        info = LockHeldInfo.for_this_process(None)
673
 
        self.assertTrue(info.is_locked_by_this_process())
674
 
 
675
 
    def test_is_not_locked_by_this_process(self):
676
 
        info = LockHeldInfo.for_this_process(None)
677
 
        info.info_dict['pid'] = '123123123123123'
678
 
        self.assertFalse(info.is_locked_by_this_process())
679
 
 
680
 
    def test_lock_holder_live_process(self):
681
 
        """Detect that the holder (this process) is still running."""
682
 
        info = LockHeldInfo.for_this_process(None)
683
 
        self.assertFalse(info.is_lock_holder_known_dead())
684
 
 
685
 
    def test_lock_holder_dead_process(self):
686
 
        """Detect that the holder (this process) is still running."""
687
 
        info = LockHeldInfo.for_this_process(None)
688
 
        info.info_dict['pid'] = '123123123'
689
 
        if sys.platform == 'win32':
690
 
            self.knownFailure(
691
 
                'live lock holder detection not implemented yet on win32')
692
 
        self.assertTrue(info.is_lock_holder_known_dead())
693
 
 
694
 
    def test_lock_holder_other_machine(self):
695
 
        """The lock holder isn't here so we don't know if they're alive."""
696
 
        info = LockHeldInfo.for_this_process(None)
697
 
        info.info_dict['hostname'] = 'egg.example.com'
698
 
        info.info_dict['pid'] = '123123123'
699
 
        self.assertFalse(info.is_lock_holder_known_dead())
700
 
 
701
 
    def test_lock_holder_other_user(self):
702
 
        """Only auto-break locks held by this user."""
703
 
        info = LockHeldInfo.for_this_process(None)
704
 
        info.info_dict['user'] = 'notme@example.com'
705
 
        info.info_dict['pid'] = '123123123'
706
 
        self.assertFalse(info.is_lock_holder_known_dead())
707
 
 
708
 
    def test_no_good_hostname(self):
709
 
        """Correctly handle ambiguous hostnames.
710
 
 
711
 
        If the lock's recorded with just 'localhost' we can't really trust
712
 
        it's the same 'localhost'.  (There are quite a few of them. :-)
713
 
        So even if the process is known not to be alive, we can't say that's
714
 
        known for sure.
715
 
        """
716
 
        self.overrideAttr(lockdir, 'get_host_name',
717
 
            lambda: 'localhost')
718
 
        info = LockHeldInfo.for_this_process(None)
719
 
        info.info_dict['pid'] = '123123123'
720
 
        self.assertFalse(info.is_lock_holder_known_dead())
721
 
 
722
 
 
723
 
class TestStaleLockDir(TestCaseWithTransport):
724
 
    """Can automatically break stale locks.
725
 
 
726
 
    :see: https://bugs.launchpad.net/bzr/+bug/220464
727
 
    """
728
 
 
729
 
    def test_auto_break_stale_lock(self):
730
 
        """Locks safely known to be stale are just cleaned up.
731
 
 
732
 
        This generates a warning but no other user interaction.
733
 
        """
734
 
        # This is off by default at present; see the discussion in the bug.
735
 
        # If you change the default, don't forget to update the docs.
736
 
        config.GlobalConfig().set_user_option('locks.steal_dead', True)
737
 
        # Create a lock pretending to come from a different nonexistent
738
 
        # process on the same machine.
739
 
        l1 = LockDir(self.get_transport(), 'a',
740
 
            extra_holder_info={'pid': '12312313'})
741
 
        token_1 = l1.attempt_lock()
742
 
        l2 = LockDir(self.get_transport(), 'a')
743
 
        token_2 = l2.attempt_lock()
744
 
        # l1 will notice its lock was stolen.
745
 
        self.assertRaises(errors.LockBroken,
746
 
            l1.unlock)
747
 
        l2.unlock()
748
 
 
749
 
    def test_auto_break_stale_lock_configured_off(self):
750
 
        """Automatic breaking can be turned off"""
751
 
        l1 = LockDir(self.get_transport(), 'a',
752
 
            extra_holder_info={'pid': '12312313'})
753
 
        token_1 = l1.attempt_lock()
754
 
        self.addCleanup(l1.unlock)
755
 
        l2 = LockDir(self.get_transport(), 'a')
756
 
        # This fails now, because dead lock breaking is off by default.
757
 
        self.assertRaises(LockContention,
758
 
            l2.attempt_lock)
759
 
        # and it's in fact not broken
760
 
        l1.confirm()