mercurial/lock.py
author Yuya Nishihara <yuya@tcha.org>
Tue, 02 Jan 2018 17:00:48 +0900
changeset 35643 668c5a527eff
parent 35209 9153871d50e0
child 35897 4b1c04082cdc
permissions -rw-r--r--
log: simplify 'x or ancestors(x)' expression 'ancestors(x)' includes 'x'.
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
9309
cfdcb7a465af localrepo: document the locking scheme a little better
Greg Ward <greg-hg@gerg.ca>
parents: 8312
diff changeset
     1
# lock.py - simple advisory locking scheme for mercurial
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
     2
#
2859
345bac2bc4ec update copyrights.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 2579
diff changeset
     3
# Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
     4
#
8225
46293a0c7e9f updated license to be explicit about GPL version 2
Martin Geisler <mg@lazybytes.net>
parents: 8113
diff changeset
     5
# This software may be used and distributed according to the terms of the
10263
25e572394f5c Update license to GPLv2+
Matt Mackall <mpm@selenic.com>
parents: 9858
diff changeset
     6
# GNU General Public License version 2 or any later version.
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
     7
25956
8cd30e9277ae lock: use absolute_import
Gregory Szorc <gregory.szorc@gmail.com>
parents: 25660
diff changeset
     8
from __future__ import absolute_import
8cd30e9277ae lock: use absolute_import
Gregory Szorc <gregory.szorc@gmail.com>
parents: 25660
diff changeset
     9
26473
5f94e64f182c lock: turn prepinherit/reacquire into a single context manager
Siddharth Agarwal <sid0@fb.com>
parents: 26387
diff changeset
    10
import contextlib
25956
8cd30e9277ae lock: use absolute_import
Gregory Szorc <gregory.szorc@gmail.com>
parents: 25660
diff changeset
    11
import errno
30921
1f151a33af8e lock: include Linux pid namespace identifier in prefix
Jun Wu <quark@fb.com>
parents: 30920
diff changeset
    12
import os
25956
8cd30e9277ae lock: use absolute_import
Gregory Szorc <gregory.szorc@gmail.com>
parents: 25660
diff changeset
    13
import socket
8cd30e9277ae lock: use absolute_import
Gregory Szorc <gregory.szorc@gmail.com>
parents: 25660
diff changeset
    14
import time
8113
87a1605979e4 add a deprecation warning for gc based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 8108
diff changeset
    15
import warnings
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
    16
35208
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    17
from .i18n import _
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    18
25956
8cd30e9277ae lock: use absolute_import
Gregory Szorc <gregory.szorc@gmail.com>
parents: 25660
diff changeset
    19
from . import (
31375
d57aa655ce97 lock: encode result of gethostname into a bytestring
Augie Fackler <augie@google.com>
parents: 31354
diff changeset
    20
    encoding,
25956
8cd30e9277ae lock: use absolute_import
Gregory Szorc <gregory.szorc@gmail.com>
parents: 25660
diff changeset
    21
    error,
30921
1f151a33af8e lock: include Linux pid namespace identifier in prefix
Jun Wu <quark@fb.com>
parents: 30920
diff changeset
    22
    pycompat,
25956
8cd30e9277ae lock: use absolute_import
Gregory Szorc <gregory.szorc@gmail.com>
parents: 25660
diff changeset
    23
    util,
8cd30e9277ae lock: use absolute_import
Gregory Szorc <gregory.szorc@gmail.com>
parents: 25660
diff changeset
    24
)
8cd30e9277ae lock: use absolute_import
Gregory Szorc <gregory.szorc@gmail.com>
parents: 25660
diff changeset
    25
30920
dc9f086c7691 lock: move lock._host calculation to a function
Jun Wu <quark@fb.com>
parents: 28959
diff changeset
    26
def _getlockprefix():
dc9f086c7691 lock: move lock._host calculation to a function
Jun Wu <quark@fb.com>
parents: 28959
diff changeset
    27
    """Return a string which is used to differentiate pid namespaces
dc9f086c7691 lock: move lock._host calculation to a function
Jun Wu <quark@fb.com>
parents: 28959
diff changeset
    28
dc9f086c7691 lock: move lock._host calculation to a function
Jun Wu <quark@fb.com>
parents: 28959
diff changeset
    29
    It's useful to detect "dead" processes and remove stale locks with
30921
1f151a33af8e lock: include Linux pid namespace identifier in prefix
Jun Wu <quark@fb.com>
parents: 30920
diff changeset
    30
    confidence. Typically it's just hostname. On modern linux, we include an
1f151a33af8e lock: include Linux pid namespace identifier in prefix
Jun Wu <quark@fb.com>
parents: 30920
diff changeset
    31
    extra Linux-specific pid namespace identifier.
30920
dc9f086c7691 lock: move lock._host calculation to a function
Jun Wu <quark@fb.com>
parents: 28959
diff changeset
    32
    """
31378
2e48c776a874 lock: do not encode result of gethostname on Python 2
Yuya Nishihara <yuya@tcha.org>
parents: 31375
diff changeset
    33
    result = socket.gethostname()
2e48c776a874 lock: do not encode result of gethostname on Python 2
Yuya Nishihara <yuya@tcha.org>
parents: 31375
diff changeset
    34
    if pycompat.ispy3:
2e48c776a874 lock: do not encode result of gethostname on Python 2
Yuya Nishihara <yuya@tcha.org>
parents: 31375
diff changeset
    35
        result = result.encode(pycompat.sysstr(encoding.encoding), 'replace')
30921
1f151a33af8e lock: include Linux pid namespace identifier in prefix
Jun Wu <quark@fb.com>
parents: 30920
diff changeset
    36
    if pycompat.sysplatform.startswith('linux'):
1f151a33af8e lock: include Linux pid namespace identifier in prefix
Jun Wu <quark@fb.com>
parents: 30920
diff changeset
    37
        try:
1f151a33af8e lock: include Linux pid namespace identifier in prefix
Jun Wu <quark@fb.com>
parents: 30920
diff changeset
    38
            result += '/%x' % os.stat('/proc/self/ns/pid').st_ino
1f151a33af8e lock: include Linux pid namespace identifier in prefix
Jun Wu <quark@fb.com>
parents: 30920
diff changeset
    39
        except OSError as ex:
1f151a33af8e lock: include Linux pid namespace identifier in prefix
Jun Wu <quark@fb.com>
parents: 30920
diff changeset
    40
            if ex.errno not in (errno.ENOENT, errno.EACCES, errno.ENOTDIR):
1f151a33af8e lock: include Linux pid namespace identifier in prefix
Jun Wu <quark@fb.com>
parents: 30920
diff changeset
    41
                raise
1f151a33af8e lock: include Linux pid namespace identifier in prefix
Jun Wu <quark@fb.com>
parents: 30920
diff changeset
    42
    return result
30920
dc9f086c7691 lock: move lock._host calculation to a function
Jun Wu <quark@fb.com>
parents: 28959
diff changeset
    43
35209
9153871d50e0 lock: allow to configure when the lock messages are displayed
Boris Feld <boris.feld@octobus.net>
parents: 35208
diff changeset
    44
def trylock(ui, vfs, lockname, timeout, warntimeout, *args, **kwargs):
35208
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    45
    """return an acquired lock or raise an a LockHeld exception
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    46
35209
9153871d50e0 lock: allow to configure when the lock messages are displayed
Boris Feld <boris.feld@octobus.net>
parents: 35208
diff changeset
    47
    This function is responsible to issue warnings and or debug messages about
9153871d50e0 lock: allow to configure when the lock messages are displayed
Boris Feld <boris.feld@octobus.net>
parents: 35208
diff changeset
    48
    the held lock while trying to acquires it."""
35208
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    49
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    50
    def printwarning(printer, locker):
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    51
        """issue the usual "waiting on lock" message through any channel"""
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    52
        # show more details for new-style locks
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    53
        if ':' in locker:
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    54
            host, pid = locker.split(":", 1)
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    55
            msg = _("waiting for lock on %s held by process %r "
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    56
                    "on host %r\n") % (l.desc, pid, host)
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    57
        else:
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    58
            msg = _("waiting for lock on %s held by %r\n") % (l.desc, locker)
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    59
        printer(msg)
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    60
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    61
    l = lock(vfs, lockname, 0, *args, dolock=False, **kwargs)
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    62
35209
9153871d50e0 lock: allow to configure when the lock messages are displayed
Boris Feld <boris.feld@octobus.net>
parents: 35208
diff changeset
    63
    debugidx = 0 if (warntimeout and timeout) else -1
35208
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    64
    warningidx = 0
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    65
    if not timeout:
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    66
        warningidx = -1
35209
9153871d50e0 lock: allow to configure when the lock messages are displayed
Boris Feld <boris.feld@octobus.net>
parents: 35208
diff changeset
    67
    elif warntimeout:
9153871d50e0 lock: allow to configure when the lock messages are displayed
Boris Feld <boris.feld@octobus.net>
parents: 35208
diff changeset
    68
        warningidx = warntimeout
35208
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    69
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    70
    delay = 0
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    71
    while True:
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    72
        try:
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    73
            l._trylock()
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    74
            break
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    75
        except error.LockHeld as inst:
35209
9153871d50e0 lock: allow to configure when the lock messages are displayed
Boris Feld <boris.feld@octobus.net>
parents: 35208
diff changeset
    76
            if delay == debugidx:
9153871d50e0 lock: allow to configure when the lock messages are displayed
Boris Feld <boris.feld@octobus.net>
parents: 35208
diff changeset
    77
                printwarning(ui.debug, inst.locker)
35208
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    78
            if delay == warningidx:
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    79
                printwarning(ui.warn, inst.locker)
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    80
            if timeout <= delay:
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    81
                raise error.LockHeld(errno.ETIMEDOUT, inst.filename,
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    82
                                     l.desc, inst.locker)
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    83
            time.sleep(1)
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    84
            delay += 1
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    85
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    86
    l.delay = delay
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    87
    if l.delay:
35209
9153871d50e0 lock: allow to configure when the lock messages are displayed
Boris Feld <boris.feld@octobus.net>
parents: 35208
diff changeset
    88
        if 0 <= warningidx <= l.delay:
9153871d50e0 lock: allow to configure when the lock messages are displayed
Boris Feld <boris.feld@octobus.net>
parents: 35208
diff changeset
    89
            ui.warn(_("got lock after %s seconds\n") % l.delay)
9153871d50e0 lock: allow to configure when the lock messages are displayed
Boris Feld <boris.feld@octobus.net>
parents: 35208
diff changeset
    90
        else:
9153871d50e0 lock: allow to configure when the lock messages are displayed
Boris Feld <boris.feld@octobus.net>
parents: 35208
diff changeset
    91
            ui.debug("got lock after %s seconds\n" % l.delay)
35208
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    92
    if l.acquirefn:
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    93
        l.acquirefn()
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    94
    return l
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
    95
1559
59b3639df0a9 Convert all classes to new-style classes by deriving them from object.
Eric Hopper <hopper@omnifarious.org>
parents: 1530
diff changeset
    96
class lock(object):
9309
cfdcb7a465af localrepo: document the locking scheme a little better
Greg Ward <greg-hg@gerg.ca>
parents: 8312
diff changeset
    97
    '''An advisory lock held by one process to control access to a set
cfdcb7a465af localrepo: document the locking scheme a little better
Greg Ward <greg-hg@gerg.ca>
parents: 8312
diff changeset
    98
    of files.  Non-cooperating processes or incorrectly written scripts
cfdcb7a465af localrepo: document the locking scheme a little better
Greg Ward <greg-hg@gerg.ca>
parents: 8312
diff changeset
    99
    can ignore Mercurial's locking scheme and stomp all over the
cfdcb7a465af localrepo: document the locking scheme a little better
Greg Ward <greg-hg@gerg.ca>
parents: 8312
diff changeset
   100
    repository, so don't do that.
cfdcb7a465af localrepo: document the locking scheme a little better
Greg Ward <greg-hg@gerg.ca>
parents: 8312
diff changeset
   101
cfdcb7a465af localrepo: document the locking scheme a little better
Greg Ward <greg-hg@gerg.ca>
parents: 8312
diff changeset
   102
    Typically used via localrepository.lock() to lock the repository
cfdcb7a465af localrepo: document the locking scheme a little better
Greg Ward <greg-hg@gerg.ca>
parents: 8312
diff changeset
   103
    store (.hg/store/) or localrepository.wlock() to lock everything
cfdcb7a465af localrepo: document the locking scheme a little better
Greg Ward <greg-hg@gerg.ca>
parents: 8312
diff changeset
   104
    else under .hg/.'''
cfdcb7a465af localrepo: document the locking scheme a little better
Greg Ward <greg-hg@gerg.ca>
parents: 8312
diff changeset
   105
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   106
    # lock is symlink on platforms that support it, file on others.
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   107
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   108
    # symlink is used because create of directory entry and contents
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   109
    # are atomic even over nfs.
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   110
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   111
    # old-style lock: symlink to pid
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   112
    # new-style lock: symlink to hostname:pid
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   113
4947
3e25a6eb5c9a lock.py: cache hostname, but not pid, in case we fork
Bryan O'Sullivan <bos@serpentine.com>
parents: 3877
diff changeset
   114
    _host = None
3e25a6eb5c9a lock.py: cache hostname, but not pid, in case we fork
Bryan O'Sullivan <bos@serpentine.com>
parents: 3877
diff changeset
   115
26321
db4c192cb9b3 lock: move acquirefn call to inside the lock
Siddharth Agarwal <sid0@fb.com>
parents: 26291
diff changeset
   116
    def __init__(self, vfs, file, timeout=-1, releasefn=None, acquirefn=None,
35208
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
   117
                 desc=None, inheritchecker=None, parentlock=None,
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
   118
                 dolock=True):
20091
abfe6a8e619b lock: take both vfs and lock file path relative to vfs to access via vfs
FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
parents: 19927
diff changeset
   119
        self.vfs = vfs
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
   120
        self.f = file
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
   121
        self.held = 0
1787
e431344e604c add a timeout when a lock is held (default 1024 sec)
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 1753
diff changeset
   122
        self.timeout = timeout
1530
abfab59fce79 add a releasefn keyword to lock.lock
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 1062
diff changeset
   123
        self.releasefn = releasefn
26321
db4c192cb9b3 lock: move acquirefn call to inside the lock
Siddharth Agarwal <sid0@fb.com>
parents: 26291
diff changeset
   124
        self.acquirefn = acquirefn
2016
ff5c9a92f556 fix backtrace printed when cannot get lock.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1877
diff changeset
   125
        self.desc = desc
26498
e8564e04382d lock: add a way to prevent locks from being inherited
Siddharth Agarwal <sid0@fb.com>
parents: 26474
diff changeset
   126
        self._inheritchecker = inheritchecker
26356
927fa07a2ba4 lock: introduce state to keep track of inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26321
diff changeset
   127
        self.parentlock = parentlock
927fa07a2ba4 lock: introduce state to keep track of inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26321
diff changeset
   128
        self._parentheld = False
927fa07a2ba4 lock: introduce state to keep track of inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26321
diff changeset
   129
        self._inherited = False
15589
cc24e4ed3e0c lock: change name of release chain
Matt Mackall <mpm@selenic.com>
parents: 15583
diff changeset
   130
        self.postrelease  = []
26383
0fceb34806e1 lock: add a wrapper to os.getpid() to make testing easier
Siddharth Agarwal <sid0@fb.com>
parents: 26359
diff changeset
   131
        self.pid = self._getpid()
35208
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
   132
        if dolock:
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
   133
            self.delay = self.lock()
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
   134
            if self.acquirefn:
1b758105b5c7 lock: add a trylock method handling the timeout and messaging logic
Boris Feld <boris.feld@octobus.net>
parents: 32088
diff changeset
   135
                self.acquirefn()
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
   136
27797
054abf2377e8 lock: turn a lock into a Python context manager
Bryan O'Sullivan <bryano@fb.com>
parents: 26498
diff changeset
   137
    def __enter__(self):
054abf2377e8 lock: turn a lock into a Python context manager
Bryan O'Sullivan <bryano@fb.com>
parents: 26498
diff changeset
   138
        return self
054abf2377e8 lock: turn a lock into a Python context manager
Bryan O'Sullivan <bryano@fb.com>
parents: 26498
diff changeset
   139
054abf2377e8 lock: turn a lock into a Python context manager
Bryan O'Sullivan <bryano@fb.com>
parents: 26498
diff changeset
   140
    def __exit__(self, exc_type, exc_value, exc_tb):
054abf2377e8 lock: turn a lock into a Python context manager
Bryan O'Sullivan <bryano@fb.com>
parents: 26498
diff changeset
   141
        self.release()
054abf2377e8 lock: turn a lock into a Python context manager
Bryan O'Sullivan <bryano@fb.com>
parents: 26498
diff changeset
   142
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
   143
    def __del__(self):
8108
a26d33749bd8 made repo locks recursive and deprecate refcounting based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 7640
diff changeset
   144
        if self.held:
8113
87a1605979e4 add a deprecation warning for gc based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 8108
diff changeset
   145
            warnings.warn("use lock.release instead of del lock",
87a1605979e4 add a deprecation warning for gc based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 8108
diff changeset
   146
                    category=DeprecationWarning,
87a1605979e4 add a deprecation warning for gc based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 8108
diff changeset
   147
                    stacklevel=2)
87a1605979e4 add a deprecation warning for gc based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 8108
diff changeset
   148
8108
a26d33749bd8 made repo locks recursive and deprecate refcounting based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 7640
diff changeset
   149
            # ensure the lock will be removed
a26d33749bd8 made repo locks recursive and deprecate refcounting based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 7640
diff changeset
   150
            # even if recursive locking did occur
a26d33749bd8 made repo locks recursive and deprecate refcounting based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 7640
diff changeset
   151
            self.held = 1
a26d33749bd8 made repo locks recursive and deprecate refcounting based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 7640
diff changeset
   152
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
   153
        self.release()
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
   154
26383
0fceb34806e1 lock: add a wrapper to os.getpid() to make testing easier
Siddharth Agarwal <sid0@fb.com>
parents: 26359
diff changeset
   155
    def _getpid(self):
28027
14033c5dd261 util: enable getpid to be replaced
timeless <timeless@mozdev.org>
parents: 27797
diff changeset
   156
        # wrapper around util.getpid() to make testing easier
14033c5dd261 util: enable getpid to be replaced
timeless <timeless@mozdev.org>
parents: 27797
diff changeset
   157
        return util.getpid()
26383
0fceb34806e1 lock: add a wrapper to os.getpid() to make testing easier
Siddharth Agarwal <sid0@fb.com>
parents: 26359
diff changeset
   158
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
   159
    def lock(self):
1787
e431344e604c add a timeout when a lock is held (default 1024 sec)
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 1753
diff changeset
   160
        timeout = self.timeout
14494
1ffeeb91c55d check-code: flag 0/1 used as constant Boolean expression
Martin Geisler <mg@lazybytes.net>
parents: 13281
diff changeset
   161
        while True:
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
   162
            try:
26082
b188f60bd955 lock: make trylock private
Matt Mackall <mpm@selenic.com>
parents: 26081
diff changeset
   163
                self._trylock()
20380
c697b70f295f localrepo: give a sigh of relief when getting lock after waiting for it
Mads Kiilerich <madski@unity3d.com>
parents: 20091
diff changeset
   164
                return self.timeout - timeout
25660
328739ea70c3 global: mass rewrite to use modern exception syntax
Gregory Szorc <gregory.szorc@gmail.com>
parents: 23032
diff changeset
   165
            except error.LockHeld as inst:
1787
e431344e604c add a timeout when a lock is held (default 1024 sec)
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 1753
diff changeset
   166
                if timeout != 0:
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
   167
                    time.sleep(1)
1787
e431344e604c add a timeout when a lock is held (default 1024 sec)
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 1753
diff changeset
   168
                    if timeout > 0:
e431344e604c add a timeout when a lock is held (default 1024 sec)
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 1753
diff changeset
   169
                        timeout -= 1
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
   170
                    continue
7640
7197812e8d44 error: move lock errors
Matt Mackall <mpm@selenic.com>
parents: 4959
diff changeset
   171
                raise error.LockHeld(errno.ETIMEDOUT, inst.filename, self.desc,
7197812e8d44 error: move lock errors
Matt Mackall <mpm@selenic.com>
parents: 4959
diff changeset
   172
                                     inst.locker)
515
03f27b1381f9 Whitespace cleanups
mpm@selenic.com
parents: 503
diff changeset
   173
26082
b188f60bd955 lock: make trylock private
Matt Mackall <mpm@selenic.com>
parents: 26081
diff changeset
   174
    def _trylock(self):
8108
a26d33749bd8 made repo locks recursive and deprecate refcounting based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 7640
diff changeset
   175
        if self.held:
a26d33749bd8 made repo locks recursive and deprecate refcounting based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 7640
diff changeset
   176
            self.held += 1
a26d33749bd8 made repo locks recursive and deprecate refcounting based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 7640
diff changeset
   177
            return
4947
3e25a6eb5c9a lock.py: cache hostname, but not pid, in case we fork
Bryan O'Sullivan <bos@serpentine.com>
parents: 3877
diff changeset
   178
        if lock._host is None:
30920
dc9f086c7691 lock: move lock._host calculation to a function
Jun Wu <quark@fb.com>
parents: 28959
diff changeset
   179
            lock._host = _getlockprefix()
31354
e6a2b625e0d9 lock: use %d to format integer into a bytestring
Augie Fackler <augie@google.com>
parents: 30921
diff changeset
   180
        lockname = '%s:%d' % (lock._host, self.pid)
26081
3b6e5914edd8 lock: loop a finite number of times in trylock (issue4787)
Matt Mackall <mpm@selenic.com>
parents: 25956
diff changeset
   181
        retry = 5
3b6e5914edd8 lock: loop a finite number of times in trylock (issue4787)
Matt Mackall <mpm@selenic.com>
parents: 25956
diff changeset
   182
        while not self.held and retry:
3b6e5914edd8 lock: loop a finite number of times in trylock (issue4787)
Matt Mackall <mpm@selenic.com>
parents: 25956
diff changeset
   183
            retry -= 1
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   184
            try:
20091
abfe6a8e619b lock: take both vfs and lock file path relative to vfs to access via vfs
FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
parents: 19927
diff changeset
   185
                self.vfs.makelock(lockname, self.f)
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   186
                self.held = 1
25660
328739ea70c3 global: mass rewrite to use modern exception syntax
Gregory Szorc <gregory.szorc@gmail.com>
parents: 23032
diff changeset
   187
            except (OSError, IOError) as why:
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   188
                if why.errno == errno.EEXIST:
26387
e16f80f89a29 lock: recognize parent locks while acquiring
Siddharth Agarwal <sid0@fb.com>
parents: 26383
diff changeset
   189
                    locker = self._readlock()
32087
e1938d6051da lock: avoid unintentional lock acquisition at failure of readlock
FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
parents: 31378
diff changeset
   190
                    if locker is None:
e1938d6051da lock: avoid unintentional lock acquisition at failure of readlock
FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
parents: 31378
diff changeset
   191
                        continue
e1938d6051da lock: avoid unintentional lock acquisition at failure of readlock
FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
parents: 31378
diff changeset
   192
26387
e16f80f89a29 lock: recognize parent locks while acquiring
Siddharth Agarwal <sid0@fb.com>
parents: 26383
diff changeset
   193
                    # special case where a parent process holds the lock -- this
e16f80f89a29 lock: recognize parent locks while acquiring
Siddharth Agarwal <sid0@fb.com>
parents: 26383
diff changeset
   194
                    # is different from the pid being different because we do
e16f80f89a29 lock: recognize parent locks while acquiring
Siddharth Agarwal <sid0@fb.com>
parents: 26383
diff changeset
   195
                    # want the unlock and postrelease functions to be called,
e16f80f89a29 lock: recognize parent locks while acquiring
Siddharth Agarwal <sid0@fb.com>
parents: 26383
diff changeset
   196
                    # but the lockfile to not be removed.
e16f80f89a29 lock: recognize parent locks while acquiring
Siddharth Agarwal <sid0@fb.com>
parents: 26383
diff changeset
   197
                    if locker == self.parentlock:
e16f80f89a29 lock: recognize parent locks while acquiring
Siddharth Agarwal <sid0@fb.com>
parents: 26383
diff changeset
   198
                        self._parentheld = True
e16f80f89a29 lock: recognize parent locks while acquiring
Siddharth Agarwal <sid0@fb.com>
parents: 26383
diff changeset
   199
                        self.held = 1
e16f80f89a29 lock: recognize parent locks while acquiring
Siddharth Agarwal <sid0@fb.com>
parents: 26383
diff changeset
   200
                        return
e16f80f89a29 lock: recognize parent locks while acquiring
Siddharth Agarwal <sid0@fb.com>
parents: 26383
diff changeset
   201
                    locker = self._testlock(locker)
3686
4308f4cdc07b Don't step into an endless loop when lock file is empty.
Thomas Arendsen Hein <thomas@intevation.de>
parents: 2859
diff changeset
   202
                    if locker is not None:
20091
abfe6a8e619b lock: take both vfs and lock file path relative to vfs to access via vfs
FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
parents: 19927
diff changeset
   203
                        raise error.LockHeld(errno.EAGAIN,
abfe6a8e619b lock: take both vfs and lock file path relative to vfs to access via vfs
FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
parents: 19927
diff changeset
   204
                                             self.vfs.join(self.f), self.desc,
7640
7197812e8d44 error: move lock errors
Matt Mackall <mpm@selenic.com>
parents: 4959
diff changeset
   205
                                             locker)
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   206
                else:
7640
7197812e8d44 error: move lock errors
Matt Mackall <mpm@selenic.com>
parents: 4959
diff changeset
   207
                    raise error.LockUnavailable(why.errno, why.strerror,
7197812e8d44 error: move lock errors
Matt Mackall <mpm@selenic.com>
parents: 4959
diff changeset
   208
                                                why.filename, self.desc)
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   209
32088
0d892d820a51 lock: avoid unintentional lock acquisition at failure of readlock
FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
parents: 32087
diff changeset
   210
        if not self.held:
0d892d820a51 lock: avoid unintentional lock acquisition at failure of readlock
FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
parents: 32087
diff changeset
   211
            # use empty locker to mean "busy for frequent lock/unlock
0d892d820a51 lock: avoid unintentional lock acquisition at failure of readlock
FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
parents: 32087
diff changeset
   212
            # by many processes"
0d892d820a51 lock: avoid unintentional lock acquisition at failure of readlock
FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
parents: 32087
diff changeset
   213
            raise error.LockHeld(errno.EAGAIN,
0d892d820a51 lock: avoid unintentional lock acquisition at failure of readlock
FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
parents: 32087
diff changeset
   214
                                 self.vfs.join(self.f), self.desc, "")
0d892d820a51 lock: avoid unintentional lock acquisition at failure of readlock
FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
parents: 32087
diff changeset
   215
26290
9664d32bd6cb lock: factor code to read lock into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26082
diff changeset
   216
    def _readlock(self):
9664d32bd6cb lock: factor code to read lock into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26082
diff changeset
   217
        """read lock and return its value
9664d32bd6cb lock: factor code to read lock into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26082
diff changeset
   218
9664d32bd6cb lock: factor code to read lock into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26082
diff changeset
   219
        Returns None if no lock exists, pid for old-style locks, and host:pid
9664d32bd6cb lock: factor code to read lock into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26082
diff changeset
   220
        for new-style locks.
9664d32bd6cb lock: factor code to read lock into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26082
diff changeset
   221
        """
9664d32bd6cb lock: factor code to read lock into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26082
diff changeset
   222
        try:
9664d32bd6cb lock: factor code to read lock into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26082
diff changeset
   223
            return self.vfs.readlock(self.f)
9664d32bd6cb lock: factor code to read lock into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26082
diff changeset
   224
        except (OSError, IOError) as why:
9664d32bd6cb lock: factor code to read lock into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26082
diff changeset
   225
            if why.errno == errno.ENOENT:
9664d32bd6cb lock: factor code to read lock into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26082
diff changeset
   226
                return None
9664d32bd6cb lock: factor code to read lock into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26082
diff changeset
   227
            raise
9664d32bd6cb lock: factor code to read lock into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26082
diff changeset
   228
26291
1d33842c5b3e lock: factor out lock testing into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26290
diff changeset
   229
    def _testlock(self, locker):
26290
9664d32bd6cb lock: factor code to read lock into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26082
diff changeset
   230
        if locker is None:
9664d32bd6cb lock: factor code to read lock into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26082
diff changeset
   231
            return None
2579
0875cda033fd use __contains__, index or split instead of str.find
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 2016
diff changeset
   232
        try:
0875cda033fd use __contains__, index or split instead of str.find
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 2016
diff changeset
   233
            host, pid = locker.split(":", 1)
0875cda033fd use __contains__, index or split instead of str.find
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 2016
diff changeset
   234
        except ValueError:
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   235
            return locker
4947
3e25a6eb5c9a lock.py: cache hostname, but not pid, in case we fork
Bryan O'Sullivan <bos@serpentine.com>
parents: 3877
diff changeset
   236
        if host != lock._host:
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   237
            return locker
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
   238
        try:
2579
0875cda033fd use __contains__, index or split instead of str.find
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 2016
diff changeset
   239
            pid = int(pid)
9685
a820cd39d415 lock: catch specific exceptions
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 9680
diff changeset
   240
        except ValueError:
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   241
            return locker
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   242
        if util.testpid(pid):
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   243
            return locker
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   244
        # if locker dead, break lock.  must do this with another lock
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   245
        # held, or can race and break valid lock.
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   246
        try:
20091
abfe6a8e619b lock: take both vfs and lock file path relative to vfs to access via vfs
FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
parents: 19927
diff changeset
   247
            l = lock(self.vfs, self.f + '.break', timeout=0)
abfe6a8e619b lock: take both vfs and lock file path relative to vfs to access via vfs
FUJIWARA Katsunori <foozy@lares.dti.ne.jp>
parents: 19927
diff changeset
   248
            self.vfs.unlink(self.f)
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   249
            l.release()
7640
7197812e8d44 error: move lock errors
Matt Mackall <mpm@selenic.com>
parents: 4959
diff changeset
   250
        except error.LockError:
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
   251
            return locker
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
   252
26291
1d33842c5b3e lock: factor out lock testing into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26290
diff changeset
   253
    def testlock(self):
1d33842c5b3e lock: factor out lock testing into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26290
diff changeset
   254
        """return id of locker if lock is valid, else None.
1d33842c5b3e lock: factor out lock testing into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26290
diff changeset
   255
1d33842c5b3e lock: factor out lock testing into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26290
diff changeset
   256
        If old-style lock, we cannot tell what machine locker is on.
1d33842c5b3e lock: factor out lock testing into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26290
diff changeset
   257
        with new-style lock, if locker is on this machine, we can
1d33842c5b3e lock: factor out lock testing into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26290
diff changeset
   258
        see if locker is alive.  If locker is on this machine but
1d33842c5b3e lock: factor out lock testing into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26290
diff changeset
   259
        not alive, we can safely break lock.
1d33842c5b3e lock: factor out lock testing into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26290
diff changeset
   260
1d33842c5b3e lock: factor out lock testing into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26290
diff changeset
   261
        The lock file is only deleted when None is returned.
1d33842c5b3e lock: factor out lock testing into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26290
diff changeset
   262
1d33842c5b3e lock: factor out lock testing into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26290
diff changeset
   263
        """
1d33842c5b3e lock: factor out lock testing into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26290
diff changeset
   264
        locker = self._readlock()
1d33842c5b3e lock: factor out lock testing into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26290
diff changeset
   265
        return self._testlock(locker)
1d33842c5b3e lock: factor out lock testing into a separate function
Siddharth Agarwal <sid0@fb.com>
parents: 26290
diff changeset
   266
26473
5f94e64f182c lock: turn prepinherit/reacquire into a single context manager
Siddharth Agarwal <sid0@fb.com>
parents: 26387
diff changeset
   267
    @contextlib.contextmanager
5f94e64f182c lock: turn prepinherit/reacquire into a single context manager
Siddharth Agarwal <sid0@fb.com>
parents: 26387
diff changeset
   268
    def inherit(self):
5f94e64f182c lock: turn prepinherit/reacquire into a single context manager
Siddharth Agarwal <sid0@fb.com>
parents: 26387
diff changeset
   269
        """context for the lock to be inherited by a Mercurial subprocess.
26357
6979a1369185 lock: add a method to prepare the lock for inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26356
diff changeset
   270
26473
5f94e64f182c lock: turn prepinherit/reacquire into a single context manager
Siddharth Agarwal <sid0@fb.com>
parents: 26387
diff changeset
   271
        Yields a string that will be recognized by the lock in the subprocess.
5f94e64f182c lock: turn prepinherit/reacquire into a single context manager
Siddharth Agarwal <sid0@fb.com>
parents: 26387
diff changeset
   272
        Communicating this string to the subprocess needs to be done separately
5f94e64f182c lock: turn prepinherit/reacquire into a single context manager
Siddharth Agarwal <sid0@fb.com>
parents: 26387
diff changeset
   273
        -- typically by an environment variable.
26357
6979a1369185 lock: add a method to prepare the lock for inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26356
diff changeset
   274
        """
6979a1369185 lock: add a method to prepare the lock for inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26356
diff changeset
   275
        if not self.held:
6979a1369185 lock: add a method to prepare the lock for inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26356
diff changeset
   276
            raise error.LockInheritanceContractViolation(
26473
5f94e64f182c lock: turn prepinherit/reacquire into a single context manager
Siddharth Agarwal <sid0@fb.com>
parents: 26387
diff changeset
   277
                'inherit can only be called while lock is held')
26357
6979a1369185 lock: add a method to prepare the lock for inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26356
diff changeset
   278
        if self._inherited:
6979a1369185 lock: add a method to prepare the lock for inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26356
diff changeset
   279
            raise error.LockInheritanceContractViolation(
26473
5f94e64f182c lock: turn prepinherit/reacquire into a single context manager
Siddharth Agarwal <sid0@fb.com>
parents: 26387
diff changeset
   280
                'inherit cannot be called while lock is already inherited')
26498
e8564e04382d lock: add a way to prevent locks from being inherited
Siddharth Agarwal <sid0@fb.com>
parents: 26474
diff changeset
   281
        if self._inheritchecker is not None:
e8564e04382d lock: add a way to prevent locks from being inherited
Siddharth Agarwal <sid0@fb.com>
parents: 26474
diff changeset
   282
            self._inheritchecker()
26357
6979a1369185 lock: add a method to prepare the lock for inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26356
diff changeset
   283
        if self.releasefn:
6979a1369185 lock: add a method to prepare the lock for inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26356
diff changeset
   284
            self.releasefn()
6979a1369185 lock: add a method to prepare the lock for inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26356
diff changeset
   285
        if self._parentheld:
6979a1369185 lock: add a method to prepare the lock for inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26356
diff changeset
   286
            lockname = self.parentlock
6979a1369185 lock: add a method to prepare the lock for inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26356
diff changeset
   287
        else:
6979a1369185 lock: add a method to prepare the lock for inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26356
diff changeset
   288
            lockname = '%s:%s' % (lock._host, self.pid)
6979a1369185 lock: add a method to prepare the lock for inheritance
Siddharth Agarwal <sid0@fb.com>
parents: 26356
diff changeset
   289
        self._inherited = True
26473
5f94e64f182c lock: turn prepinherit/reacquire into a single context manager
Siddharth Agarwal <sid0@fb.com>
parents: 26387
diff changeset
   290
        try:
5f94e64f182c lock: turn prepinherit/reacquire into a single context manager
Siddharth Agarwal <sid0@fb.com>
parents: 26387
diff changeset
   291
            yield lockname
5f94e64f182c lock: turn prepinherit/reacquire into a single context manager
Siddharth Agarwal <sid0@fb.com>
parents: 26387
diff changeset
   292
        finally:
5f94e64f182c lock: turn prepinherit/reacquire into a single context manager
Siddharth Agarwal <sid0@fb.com>
parents: 26387
diff changeset
   293
            if self.acquirefn:
5f94e64f182c lock: turn prepinherit/reacquire into a single context manager
Siddharth Agarwal <sid0@fb.com>
parents: 26387
diff changeset
   294
                self.acquirefn()
5f94e64f182c lock: turn prepinherit/reacquire into a single context manager
Siddharth Agarwal <sid0@fb.com>
parents: 26387
diff changeset
   295
            self._inherited = False
26358
de5a52e5eb9e lock: add a method to reacquire the lock after subprocesses exit
Siddharth Agarwal <sid0@fb.com>
parents: 26357
diff changeset
   296
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
   297
    def release(self):
15583
926a06f7a353 lock: add mechanism to register post release callback
Pierre-Yves David <pierre-yves.david@ens-lyon.org>
parents: 14494
diff changeset
   298
        """release the lock and execute callback function if any
926a06f7a353 lock: add mechanism to register post release callback
Pierre-Yves David <pierre-yves.david@ens-lyon.org>
parents: 14494
diff changeset
   299
17537
31f32a96e1e3 Merge spelling fixes
Bryan O'Sullivan <bryano@fb.com>
parents: 17427 17510
diff changeset
   300
        If the lock has been acquired multiple times, the actual release is
17510
7c44b703657b spelling: release
timeless@mozdev.org
parents: 15589
diff changeset
   301
        delayed to the last release call."""
8108
a26d33749bd8 made repo locks recursive and deprecate refcounting based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 7640
diff changeset
   302
        if self.held > 1:
a26d33749bd8 made repo locks recursive and deprecate refcounting based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 7640
diff changeset
   303
            self.held -= 1
9680
8cea86d73887 lock: use '==' instead of 'is' for integer equality ('is' may not work)
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 9309
diff changeset
   304
        elif self.held == 1:
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
   305
            self.held = 0
26383
0fceb34806e1 lock: add a wrapper to os.getpid() to make testing easier
Siddharth Agarwal <sid0@fb.com>
parents: 26359
diff changeset
   306
            if self._getpid() != self.pid:
18907
af9fa8d4c939 lock: if we fork, ensure that only the parent releases
Bryan O'Sullivan <bryano@fb.com>
parents: 17683
diff changeset
   307
                # we forked, and are not the parent
af9fa8d4c939 lock: if we fork, ensure that only the parent releases
Bryan O'Sullivan <bryano@fb.com>
parents: 17683
diff changeset
   308
                return
503
c6a2e41c8c60 Fix troubles with clone and exception handling
mpm@selenic.com
parents: 429
diff changeset
   309
            try:
23032
f484be02bd35 lock: while releasing, unlink lockfile even if the release function throws
Siddharth Agarwal <sid0@fb.com>
parents: 20380
diff changeset
   310
                if self.releasefn:
f484be02bd35 lock: while releasing, unlink lockfile even if the release function throws
Siddharth Agarwal <sid0@fb.com>
parents: 20380
diff changeset
   311
                    self.releasefn()
f484be02bd35 lock: while releasing, unlink lockfile even if the release function throws
Siddharth Agarwal <sid0@fb.com>
parents: 20380
diff changeset
   312
            finally:
26359
c545d51c901e lock.release: do not unlink inherited locks
Siddharth Agarwal <sid0@fb.com>
parents: 26358
diff changeset
   313
                if not self._parentheld:
c545d51c901e lock.release: do not unlink inherited locks
Siddharth Agarwal <sid0@fb.com>
parents: 26358
diff changeset
   314
                    try:
c545d51c901e lock.release: do not unlink inherited locks
Siddharth Agarwal <sid0@fb.com>
parents: 26358
diff changeset
   315
                        self.vfs.unlink(self.f)
c545d51c901e lock.release: do not unlink inherited locks
Siddharth Agarwal <sid0@fb.com>
parents: 26358
diff changeset
   316
                    except OSError:
c545d51c901e lock.release: do not unlink inherited locks
Siddharth Agarwal <sid0@fb.com>
parents: 26358
diff changeset
   317
                        pass
26474
431094a3b21f lock.release: don't call postrelease functions for inherited locks
Siddharth Agarwal <sid0@fb.com>
parents: 26473
diff changeset
   318
            # The postrelease functions typically assume the lock is not held
431094a3b21f lock.release: don't call postrelease functions for inherited locks
Siddharth Agarwal <sid0@fb.com>
parents: 26473
diff changeset
   319
            # at all.
431094a3b21f lock.release: don't call postrelease functions for inherited locks
Siddharth Agarwal <sid0@fb.com>
parents: 26473
diff changeset
   320
            if not self._parentheld:
431094a3b21f lock.release: don't call postrelease functions for inherited locks
Siddharth Agarwal <sid0@fb.com>
parents: 26473
diff changeset
   321
                for callback in self.postrelease:
431094a3b21f lock.release: don't call postrelease functions for inherited locks
Siddharth Agarwal <sid0@fb.com>
parents: 26473
diff changeset
   322
                    callback()
28959
518c3e392f75 lock: clear postrelease hooks list after usage
Gregory Szorc <gregory.szorc@gmail.com>
parents: 28027
diff changeset
   323
                # Prevent double usage and help clear cycles.
518c3e392f75 lock: clear postrelease hooks list after usage
Gregory Szorc <gregory.szorc@gmail.com>
parents: 28027
diff changeset
   324
                self.postrelease = None
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
   325
8108
a26d33749bd8 made repo locks recursive and deprecate refcounting based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 7640
diff changeset
   326
def release(*locks):
a26d33749bd8 made repo locks recursive and deprecate refcounting based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 7640
diff changeset
   327
    for lock in locks:
a26d33749bd8 made repo locks recursive and deprecate refcounting based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 7640
diff changeset
   328
        if lock is not None:
a26d33749bd8 made repo locks recursive and deprecate refcounting based lock releasing
Ronny Pfannschmidt <Ronny.Pfannschmidt@gmx.de>
parents: 7640
diff changeset
   329
            lock.release()