author | Thomas Arendsen Hein <thomas@intevation.de> |
Fri, 10 Mar 2006 11:34:02 +0100 | |
changeset 1876 | 2e0fd78587bd |
parent 1836 | cd5c1db2132a |
child 1877 | d314a89fa4f1 |
permissions | -rw-r--r-- |
161 | 1 |
# lock.py - simple locking scheme for mercurial |
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# |
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# Copyright 2005 Matt Mackall <mpm@selenic.com> |
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# |
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# This software may be used and distributed according to the terms |
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# of the GNU General Public License, incorporated herein by reference. |
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1836
cd5c1db2132a
make lock module use demandload.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents:
1787
diff
changeset
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8 |
from demandload import * |
cd5c1db2132a
make lock module use demandload.
Vadim Gelfer <vadim.gelfer@gmail.com>
parents:
1787
diff
changeset
|
9 |
demandload(globals(), 'errno os time util') |
161 | 10 |
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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
|
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class LockUnavailable(LockException): |
161 | 16 |
pass |
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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): |
1787
e431344e604c
add a timeout when a lock is held (default 1024 sec)
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
1753
diff
changeset
|
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def __init__(self, file, timeout=-1, releasefn=None): |
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self.f = file |
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self.held = 0 |
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1787
e431344e604c
add a timeout when a lock is held (default 1024 sec)
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
1753
diff
changeset
|
22 |
self.timeout = timeout |
1530
abfab59fce79
add a releasefn keyword to lock.lock
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
1062
diff
changeset
|
23 |
self.releasefn = releasefn |
161 | 24 |
self.lock() |
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def __del__(self): |
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self.release() |
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def lock(self): |
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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 |
timeout = self.timeout |
161 | 31 |
while 1: |
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try: |
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self.trylock() |
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return 1 |
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except LockHeld, inst: |
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1787
e431344e604c
add a timeout when a lock is held (default 1024 sec)
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
1753
diff
changeset
|
36 |
if timeout != 0: |
161 | 37 |
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
|
38 |
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
|
39 |
timeout -= 1 |
161 | 40 |
continue |
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raise inst |
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def trylock(self): |
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pid = os.getpid() |
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try: |
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422
10c43444a38e
[PATCH] Enables lock work under the other 'OS'
mpm@selenic.com
parents:
161
diff
changeset
|
46 |
util.makelock(str(pid), self.f) |
161 | 47 |
self.held = 1 |
1753
e6e70450edb9
Raise a different exception when the lock is not available
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
1559
diff
changeset
|
48 |
except (OSError, IOError), why: |
e6e70450edb9
Raise a different exception when the lock is not available
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
1559
diff
changeset
|
49 |
if why.errno == errno.EEXIST: |
e6e70450edb9
Raise a different exception when the lock is not available
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
1559
diff
changeset
|
50 |
raise LockHeld(util.readlock(self.f)) |
e6e70450edb9
Raise a different exception when the lock is not available
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
1559
diff
changeset
|
51 |
else: |
e6e70450edb9
Raise a different exception when the lock is not available
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
1559
diff
changeset
|
52 |
raise LockUnavailable(why) |
161 | 53 |
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def release(self): |
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if self.held: |
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self.held = 0 |
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1530
abfab59fce79
add a releasefn keyword to lock.lock
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
1062
diff
changeset
|
57 |
if self.releasefn: |
abfab59fce79
add a releasefn keyword to lock.lock
Benoit Boissinot <benoit.boissinot@ens-lyon.org>
parents:
1062
diff
changeset
|
58 |
self.releasefn() |
503
c6a2e41c8c60
Fix troubles with clone and exception handling
mpm@selenic.com
parents:
429
diff
changeset
|
59 |
try: |
c6a2e41c8c60
Fix troubles with clone and exception handling
mpm@selenic.com
parents:
429
diff
changeset
|
60 |
os.unlink(self.f) |
c6a2e41c8c60
Fix troubles with clone and exception handling
mpm@selenic.com
parents:
429
diff
changeset
|
61 |
except: pass |
161 | 62 |