226
237
except (errors.TransportError, PathError), e:
227
238
self._trace("... failed to create pending dir, %s", e)
228
239
raise LockFailed(self, e)
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)
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)
240
258
# We must check we really got the lock, because Launchpad's sftp
241
259
# server at one time had a bug were the rename would successfully
242
260
# move the new directory into the existing directory, which was
262
280
(time.time() - start_time) * 1000)
263
281
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('locks.steal_dead'):
299
ui.ui_factory.show_user_warning(
301
lock_url=urlutils.join(self.transport.base, self.path),
302
other_holder_info=unicode(other_holder))
303
self.force_break(other_holder)
304
self._trace("stole lock from dead holder")
306
raise LockContention(self)
265
308
def _remove_pending_dir(self, tmpname):
266
309
"""Remove the pending directory
355
399
holder_info = self.peek()
356
400
except LockCorrupt, e:
357
401
# The lock info is corrupt.
358
if bzrlib.ui.ui_factory.get_boolean("Break (corrupt %r)" % (self,)):
402
if ui.ui_factory.get_boolean(u"Break (corrupt %r)" % (self,)):
359
403
self.force_break_corrupt(e.file_data)
361
405
if holder_info is not None:
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)):
406
if ui.ui_factory.confirm_action(
407
u"Break %(lock_info)s",
408
'bzrlib.lockdir.break',
409
dict(lock_info=unicode(holder_info))):
366
410
result = self.force_break(holder_info)
367
bzrlib.ui.ui_factory.show_message(
411
ui.ui_factory.show_message(
368
412
"Broke lock %s" % result.lock_url)
370
414
def force_break(self, dead_holder_info):
374
418
it still thinks it has the lock there will be two concurrent writers.
375
419
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.
382
421
After the lock is broken it will not be held by any process.
383
422
It is possible that another process may sneak in and take the
384
423
lock before the breaking process acquires it.
425
:param dead_holder_info:
426
Must be the result of a previous LockDir.peek() call; this is used
427
to check that it's still held by the same process that the user
428
decided was dead. If this is not the current holder,
429
LockBreakMismatch is raised.
386
431
:returns: LockResult for the broken lock.
388
if not isinstance(dead_holder_info, dict):
433
if not isinstance(dead_holder_info, LockHeldInfo):
389
434
raise ValueError("dead_holder_info: %r" % dead_holder_info)
390
435
self._check_not_locked()
391
436
current_info = self.peek()
489
535
def _prepare_info(self):
490
536
"""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()
522
539
def attempt_lock(self):
523
540
"""Take the lock; fail if it's already held.
587
616
start = 'Lock owner changed for'
588
617
last_info = new_info
589
formatted_info = self._format_lock_info(new_info)
618
msg = u'%s lock %s %s.' % (start, lock_url, new_info)
590
619
if deadline_str is None:
591
620
deadline_str = time.strftime('%H:%M:%S',
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]
621
time.localtime(deadline))
609
623
msg += ('\nWill continue to try until %s, unless '
611
msg_args.append(deadline_str)
612
626
msg += '\nSee "bzr help break-lock" for more.'
613
self._report_function(msg, *msg_args)
627
self._report_function(msg)
614
628
if (max_attempts is not None) and (attempt_count >= max_attempts):
615
629
self._trace("exceeded %d attempts")
616
630
raise LockContention(self)
705
702
if 'lock' not in debug.debug_flags:
707
704
mutter(str(self) + ": " + (format % args))
706
def get_config(self):
707
"""Get the configuration that governs this lockdir."""
708
# XXX: This really should also use the locationconfig at least, but
709
# that seems a bit hard to hook up at the moment. -- mbp 20110329
710
# FIXME: The above is still true ;) -- vila 20110811
711
return config.GlobalStack()
714
class LockHeldInfo(object):
715
"""The information recorded about a held lock.
717
This information is recorded into the lock when it's taken, and it can be
718
read back by any process with access to the lockdir. It can be used, for
719
example, to tell the user who holds the lock, or to try to detect whether
720
the lock holder is still alive.
722
Prior to bzr 2.4 a simple dict was used instead of an object.
725
def __init__(self, info_dict):
726
self.info_dict = info_dict
729
"""Return a debugging representation of this object."""
730
return "%s(%r)" % (self.__class__.__name__, self.info_dict)
732
def __unicode__(self):
733
"""Return a user-oriented description of this object."""
734
d = self.to_readable_dict()
736
u'held by %(user)s on %(hostname)s (process #%(pid)s), '
737
u'acquired %(time_ago)s' % d)
739
def to_readable_dict(self):
740
"""Turn the holder info into a dict of human-readable attributes.
742
For example, the start time is presented relative to the current time,
743
rather than as seconds since the epoch.
745
Returns a list of [user, hostname, pid, time_ago] all as readable
748
start_time = self.info_dict.get('start_time')
749
if start_time is None:
750
time_ago = '(unknown)'
752
time_ago = format_delta(
753
time.time() - int(self.info_dict['start_time']))
754
user = self.info_dict.get('user', '<unknown>')
755
hostname = self.info_dict.get('hostname', '<unknown>')
756
pid = self.info_dict.get('pid', '<unknown>')
763
def get(self, field_name):
764
"""Return the contents of a field from the lock info, or None."""
765
return self.info_dict.get(field_name)
768
def for_this_process(cls, extra_holder_info):
769
"""Return a new LockHeldInfo for a lock taken by this process.
772
hostname=get_host_name(),
773
pid=str(os.getpid()),
774
nonce=rand_chars(20),
775
start_time=str(int(time.time())),
776
user=get_username_for_lock_info(),
778
if extra_holder_info is not None:
779
info.update(extra_holder_info)
783
s = rio.Stanza(**self.info_dict)
787
def from_info_file_bytes(cls, info_file_bytes):
788
"""Construct from the contents of the held file."""
789
lines = osutils.split_lines(info_file_bytes)
791
stanza = rio.read_stanza(lines)
792
except ValueError, e:
793
mutter('Corrupt lock info file: %r', lines)
794
raise LockCorrupt("could not parse lock info file: " + str(e),
797
# see bug 185013; we fairly often end up with the info file being
798
# empty after an interruption; we could log a message here but
799
# there may not be much we can say
802
return cls(stanza.as_dict())
804
def __cmp__(self, other):
805
"""Value comparison of lock holders."""
807
cmp(type(self), type(other))
808
or cmp(self.info_dict, other.info_dict))
810
def is_locked_by_this_process(self):
811
"""True if this process seems to be the current lock holder."""
813
self.get('hostname') == get_host_name()
814
and self.get('pid') == str(os.getpid())
815
and self.get('user') == get_username_for_lock_info())
817
def is_lock_holder_known_dead(self):
818
"""True if the lock holder process is known to be dead.
820
False if it's either known to be still alive, or if we just can't tell.
822
We can be fairly sure the lock holder is dead if it declared the same
823
hostname and there is no process with the given pid alive. If people
824
have multiple machines with the same hostname this may cause trouble.
826
This doesn't check whether the lock holder is in fact the same process
827
calling this method. (In that case it will return true.)
829
if self.get('hostname') != get_host_name():
831
if self.get('hostname') == 'localhost':
834
if self.get('user') != get_username_for_lock_info():
835
# Could well be another local process by a different user, but
836
# just to be safe we won't conclude about this either.
838
pid_str = self.info_dict.get('pid', None)
840
mutter("no pid recorded in %r" % (self, ))
845
mutter("can't parse pid %r from %r"
848
return osutils.is_local_pid_dead(pid)
851
def get_username_for_lock_info():
852
"""Get a username suitable for putting into a lock.
854
It's ok if what's written here is not a proper email address as long
855
as it gives some clue who the user is.
858
return config.GlobalConfig().username()
859
except errors.NoWhoami:
860
return osutils.getuser_unicode()
added
removed
bzrlib/lockdir.py
