Mercurial > hg > gitweb

annotate mercurial/lock.py @ 1960:dac4bd67f6c5

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
update test for unrelated repo.
author Vadim Gelfer <vadim.gelfer@gmail.com>
date Tue, 14 Mar 2006 23:00:45 -0800
parents d314a89fa4f1
children ff5c9a92f556
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
1 # lock.py - simple locking scheme for mercurial
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
2 #
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
3 # Copyright 2005 Matt Mackall <mpm@selenic.com>
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
4 #
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
5 # This software may be used and distributed according to the terms
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
6 # of the GNU General Public License, incorporated herein by reference.
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
7
1836
cd5c1db2132a make lock module use demandload.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1787
diff changeset
8 from demandload import *
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
9 demandload(globals(), 'errno os socket time util')
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
10
1753
e6e70450edb9 Raise a different exception when the lock is not available
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 1559
diff changeset
11 class LockException(Exception):
e6e70450edb9 Raise a different exception when the lock is not available
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 1559
diff changeset
12 pass
e6e70450edb9 Raise a different exception when the lock is not available
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 1559
diff changeset
13 class LockHeld(LockException):
e6e70450edb9 Raise a different exception when the lock is not available
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 1559
diff changeset
14 pass
e6e70450edb9 Raise a different exception when the lock is not available
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 1559
diff changeset
15 class LockUnavailable(LockException):
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
16 pass
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
17
1559
59b3639df0a9 Convert all classes to new-style classes by deriving them from object.
Eric Hopper <hopper@omnifarious.org>
parents: 1530
diff changeset
18 class lock(object):
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
19 # 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
20
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
21 # 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
22 # 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
23
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
24 # 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
25 # 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
26
1787
e431344e604c add a timeout when a lock is held (default 1024 sec)
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 1753
diff changeset
27 def __init__(self, file, timeout=-1, releasefn=None):
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
28 self.f = file
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
29 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
30 self.timeout = timeout
1530
abfab59fce79 add a releasefn keyword to lock.lock
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 1062
diff changeset
31 self.releasefn = releasefn
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
32 self.id = None
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
33 self.host = None
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
34 self.pid = None
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
35 self.lock()
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
36
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
37 def __del__(self):
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
38 self.release()
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
39
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
40 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
41 timeout = self.timeout
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
42 while 1:
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
43 try:
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
44 self.trylock()
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
45 return 1
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
46 except LockHeld, 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
47 if timeout != 0:
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
48 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
49 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
50 timeout -= 1
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
51 continue
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
52 raise inst
515
03f27b1381f9 Whitespace cleanups
mpm@selenic.com
parents: 503
diff changeset
53
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
54 def trylock(self):
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
55 if self.id is None:
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
56 self.host = socket.gethostname()
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
57 self.pid = os.getpid()
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
58 self.id = '%s:%s' % (self.host, self.pid)
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
59 while not self.held:
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
60 try:
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
61 util.makelock(self.id, self.f)
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
62 self.held = 1
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
63 except (OSError, IOError), why:
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
64 if why.errno == errno.EEXIST:
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
65 locker = self.testlock()
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
66 if locker:
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
67 raise LockHeld(locker)
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
68 else:
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
69 raise LockUnavailable(why)
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
70
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
71 def testlock(self):
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
72 '''return id of locker if lock is valid, else None.'''
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
73 # if old-style lock, we cannot tell what machine locker is on.
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
74 # with new-style lock, if locker is on this machine, we can
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
75 # see if locker is alive. if locker is on this machine but
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
76 # not alive, we can safely break lock.
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
77 locker = util.readlock(self.f)
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
78 c = locker.find(':')
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
79 if c == -1:
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
80 return locker
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
81 host = locker[:c]
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
82 if host != self.host:
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
83 return locker
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
84 try:
1877
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
85 pid = int(locker[c+1:])
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
86 except:
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
87 return locker
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
88 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
89 return locker
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
90 # 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
91 # 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
92 try:
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
93 l = lock(self.f + '.break')
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
94 l.trylock()
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
95 os.unlink(self.f)
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
96 l.release()
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
97 except (LockHeld, LockUnavailable):
d314a89fa4f1 change lock format to let us detect and break stale locks.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents: 1836
diff changeset
98 return locker
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
99
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
100 def release(self):
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
101 if self.held:
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
102 self.held = 0
1530
abfab59fce79 add a releasefn keyword to lock.lock
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 1062
diff changeset
103 if self.releasefn:
abfab59fce79 add a releasefn keyword to lock.lock
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents: 1062
diff changeset
104 self.releasefn()
503
c6a2e41c8c60 Fix troubles with clone and exception handling
mpm@selenic.com
parents: 429
diff changeset
105 try:
c6a2e41c8c60 Fix troubles with clone and exception handling
mpm@selenic.com
parents: 429
diff changeset
106 os.unlink(self.f)
c6a2e41c8c60 Fix troubles with clone and exception handling
mpm@selenic.com
parents: 429
diff changeset
107 except: pass
161
0b4c5cb953d9 Simply repository locking
mpm@selenic.com
parents:
diff changeset
108