237
226
except (errors.TransportError, PathError), e:
238
227
self._trace("... failed to create pending dir, %s", e)
239
228
raise LockFailed(self, e)
242
self.transport.rename(tmpname, self._held_dir)
244
except (errors.TransportError, PathError, DirectoryNotEmpty,
245
FileExists, ResourceBusy), e:
246
self._trace("... contention, %s", e)
247
other_holder = self.peek()
248
self._trace("other holder is %r" % other_holder)
250
self._handle_lock_contention(other_holder)
252
self._remove_pending_dir(tmpname)
255
self._trace("... lock failed, %s", e)
256
self._remove_pending_dir(tmpname)
230
self.transport.rename(tmpname, self._held_dir)
231
except (errors.TransportError, PathError, DirectoryNotEmpty,
232
FileExists, ResourceBusy), e:
233
self._trace("... contention, %s", e)
234
self._remove_pending_dir(tmpname)
235
raise LockContention(self)
237
self._trace("... lock failed, %s", e)
238
self._remove_pending_dir(tmpname)
258
240
# We must check we really got the lock, because Launchpad's sftp
259
241
# server at one time had a bug were the rename would successfully
260
242
# move the new directory into the existing directory, which was
280
262
(time.time() - start_time) * 1000)
281
263
return self.nonce
283
def _handle_lock_contention(self, other_holder):
284
"""A lock we want to take is held by someone else.
286
This function can: tell the user about it; possibly detect that it's
287
safe or appropriate to steal the lock, or just raise an exception.
289
If this function returns (without raising an exception) the lock will
292
:param other_holder: A LockHeldInfo for the current holder; note that
293
it might be None if the lock can be seen to be held but the info
296
if (other_holder is not None):
297
if other_holder.is_lock_holder_known_dead():
298
if self.get_config().get_user_option_as_bool(
301
ui.ui_factory.show_user_warning(
303
lock_url=urlutils.join(self.transport.base, self.path),
304
other_holder_info=unicode(other_holder))
305
self.force_break(other_holder)
306
self._trace("stole lock from dead holder")
308
raise LockContention(self)
310
265
def _remove_pending_dir(self, tmpname):
311
266
"""Remove the pending directory
401
355
holder_info = self.peek()
402
356
except LockCorrupt, e:
403
357
# The lock info is corrupt.
404
if ui.ui_factory.get_boolean(u"Break (corrupt %r)" % (self,)):
358
if bzrlib.ui.ui_factory.get_boolean("Break (corrupt %r)" % (self,)):
405
359
self.force_break_corrupt(e.file_data)
407
361
if holder_info is not None:
408
if ui.ui_factory.confirm_action(
409
u"Break %(lock_info)s",
410
'bzrlib.lockdir.break',
411
dict(lock_info=unicode(holder_info))):
362
lock_info = '\n'.join(self._format_lock_info(holder_info))
363
if bzrlib.ui.ui_factory.confirm_action(
364
"Break %(lock_info)s", 'bzrlib.lockdir.break',
365
dict(lock_info=lock_info)):
412
366
result = self.force_break(holder_info)
413
ui.ui_factory.show_message(
367
bzrlib.ui.ui_factory.show_message(
414
368
"Broke lock %s" % result.lock_url)
416
370
def force_break(self, dead_holder_info):
420
374
it still thinks it has the lock there will be two concurrent writers.
421
375
In general the user's approval should be sought for lock breaks.
377
dead_holder_info must be the result of a previous LockDir.peek() call;
378
this is used to check that it's still held by the same process that
379
the user decided was dead. If this is not the current holder,
380
LockBreakMismatch is raised.
423
382
After the lock is broken it will not be held by any process.
424
383
It is possible that another process may sneak in and take the
425
384
lock before the breaking process acquires it.
427
:param dead_holder_info:
428
Must be the result of a previous LockDir.peek() call; this is used
429
to check that it's still held by the same process that the user
430
decided was dead. If this is not the current holder,
431
LockBreakMismatch is raised.
433
386
:returns: LockResult for the broken lock.
435
if not isinstance(dead_holder_info, LockHeldInfo):
388
if not isinstance(dead_holder_info, dict):
436
389
raise ValueError("dead_holder_info: %r" % dead_holder_info)
437
390
self._check_not_locked()
438
391
current_info = self.peek()
537
489
def _prepare_info(self):
538
490
"""Write information about a pending lock to a temporary file.
492
# XXX: is creating this here inefficient?
493
config = bzrlib.config.GlobalConfig()
495
user = config.username()
496
except errors.NoWhoami:
497
user = osutils.getuser_unicode()
498
s = rio.Stanza(hostname=get_host_name(),
499
pid=str(os.getpid()),
500
start_time=str(int(time.time())),
506
def _parse_info(self, info_bytes):
507
lines = osutils.split_lines(info_bytes)
509
stanza = rio.read_stanza(lines)
510
except ValueError, e:
511
mutter('Corrupt lock info file: %r', lines)
512
raise LockCorrupt("could not parse lock info file: " + str(e),
515
# see bug 185013; we fairly often end up with the info file being
516
# empty after an interruption; we could log a message here but
517
# there may not be much we can say
520
return stanza.as_dict()
541
522
def attempt_lock(self):
542
523
"""Take the lock; fail if it's already held.
618
587
start = 'Lock owner changed for'
619
588
last_info = new_info
620
msg = u'%s lock %s %s.' % (start, lock_url, new_info)
589
formatted_info = self._format_lock_info(new_info)
621
590
if deadline_str is None:
622
591
deadline_str = time.strftime('%H:%M:%S',
623
time.localtime(deadline))
592
time.localtime(deadline))
593
# As local lock urls are correct we display them.
594
# We avoid displaying remote lock urls.
595
lock_url = self.transport.abspath(self.path)
596
if lock_url.startswith('file://'):
597
lock_url = lock_url.split('.bzr/')[0]
600
user, hostname, pid, time_ago = formatted_info
601
msg = ('%s lock %s ' # lock_url
605
'[process #%s], ' # pid
606
'acquired %s.') # time ago
607
msg_args = [start, lock_url, user, hostname, pid, time_ago]
625
609
msg += ('\nWill continue to try until %s, unless '
611
msg_args.append(deadline_str)
628
612
msg += '\nSee "bzr help break-lock" for more.'
629
self._report_function(msg)
613
self._report_function(msg, *msg_args)
630
614
if (max_attempts is not None) and (attempt_count >= max_attempts):
631
615
self._trace("exceeded %d attempts")
632
616
raise LockContention(self)
704
705
if 'lock' not in debug.debug_flags:
706
707
mutter(str(self) + ": " + (format % args))
708
def get_config(self):
709
"""Get the configuration that governs this lockdir."""
710
# XXX: This really should also use the locationconfig at least, but
711
# that seems a bit hard to hook up at the moment. -- mbp 20110329
712
return config.GlobalConfig()
715
class LockHeldInfo(object):
716
"""The information recorded about a held lock.
718
This information is recorded into the lock when it's taken, and it can be
719
read back by any process with access to the lockdir. It can be used, for
720
example, to tell the user who holds the lock, or to try to detect whether
721
the lock holder is still alive.
723
Prior to bzr 2.4 a simple dict was used instead of an object.
726
def __init__(self, info_dict):
727
self.info_dict = info_dict
730
"""Return a debugging representation of this object."""
731
return "%s(%r)" % (self.__class__.__name__, self.info_dict)
733
def __unicode__(self):
734
"""Return a user-oriented description of this object."""
735
d = self.to_readable_dict()
737
u'held by %(user)s on %(hostname)s (process #%(pid)s), '
738
u'acquired %(time_ago)s' % d)
740
def to_readable_dict(self):
741
"""Turn the holder info into a dict of human-readable attributes.
743
For example, the start time is presented relative to the current time,
744
rather than as seconds since the epoch.
746
Returns a list of [user, hostname, pid, time_ago] all as readable
749
start_time = self.info_dict.get('start_time')
750
if start_time is None:
751
time_ago = '(unknown)'
753
time_ago = format_delta(
754
time.time() - int(self.info_dict['start_time']))
755
user = self.info_dict.get('user', '<unknown>')
756
hostname = self.info_dict.get('hostname', '<unknown>')
757
pid = self.info_dict.get('pid', '<unknown>')
764
def get(self, field_name):
765
"""Return the contents of a field from the lock info, or None."""
766
return self.info_dict.get(field_name)
769
def for_this_process(cls, extra_holder_info):
770
"""Return a new LockHeldInfo for a lock taken by this process.
773
hostname=get_host_name(),
774
pid=str(os.getpid()),
775
nonce=rand_chars(20),
776
start_time=str(int(time.time())),
777
user=get_username_for_lock_info(),
779
if extra_holder_info is not None:
780
info.update(extra_holder_info)
784
s = rio.Stanza(**self.info_dict)
788
def from_info_file_bytes(cls, info_file_bytes):
789
"""Construct from the contents of the held file."""
790
lines = osutils.split_lines(info_file_bytes)
792
stanza = rio.read_stanza(lines)
793
except ValueError, e:
794
mutter('Corrupt lock info file: %r', lines)
795
raise LockCorrupt("could not parse lock info file: " + str(e),
798
# see bug 185013; we fairly often end up with the info file being
799
# empty after an interruption; we could log a message here but
800
# there may not be much we can say
803
return cls(stanza.as_dict())
805
def __cmp__(self, other):
806
"""Value comparison of lock holders."""
808
cmp(type(self), type(other))
809
or cmp(self.info_dict, other.info_dict))
811
def is_locked_by_this_process(self):
812
"""True if this process seems to be the current lock holder."""
814
self.get('hostname') == get_host_name()
815
and self.get('pid') == str(os.getpid())
816
and self.get('user') == get_username_for_lock_info())
818
def is_lock_holder_known_dead(self):
819
"""True if the lock holder process is known to be dead.
821
False if it's either known to be still alive, or if we just can't tell.
823
We can be fairly sure the lock holder is dead if it declared the same
824
hostname and there is no process with the given pid alive. If people
825
have multiple machines with the same hostname this may cause trouble.
827
This doesn't check whether the lock holder is in fact the same process
828
calling this method. (In that case it will return true.)
830
if self.get('hostname') != get_host_name():
832
if self.get('hostname') == 'localhost':
835
if self.get('user') != get_username_for_lock_info():
836
# Could well be another local process by a different user, but
837
# just to be safe we won't conclude about this either.
839
pid_str = self.info_dict.get('pid', None)
841
mutter("no pid recorded in %r" % (self, ))
846
mutter("can't parse pid %r from %r"
849
return osutils.is_local_pid_dead(pid)
852
def get_username_for_lock_info():
853
"""Get a username suitable for putting into a lock.
855
It's ok if what's written here is not a proper email address as long
856
as it gives some clue who the user is.
859
return config.GlobalConfig().username()
860
except errors.NoWhoami:
861
return osutils.getuser_unicode()
added
removed
bzrlib/lockdir.py
