lock.py
47 lines
| 1.0 KiB
| text/x-python
|
PythonLexer
/ mercurial / lock.py
|
r161 | # lock.py - simple locking scheme for mercurial | ||
# | ||||
# Copyright 2005 Matt Mackall <mpm@selenic.com> | ||||
# | ||||
# This software may be used and distributed according to the terms | ||||
# of the GNU General Public License, incorporated herein by reference. | ||||
import os, time | ||||
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r422 | import util | ||
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r161 | |||
class LockHeld(Exception): | ||||
pass | ||||
class lock: | ||||
def __init__(self, file, wait = 1): | ||||
self.f = file | ||||
self.held = 0 | ||||
self.wait = wait | ||||
self.lock() | ||||
def __del__(self): | ||||
self.release() | ||||
def lock(self): | ||||
while 1: | ||||
try: | ||||
self.trylock() | ||||
return 1 | ||||
except LockHeld, inst: | ||||
if self.wait: | ||||
time.sleep(1) | ||||
continue | ||||
raise inst | ||||
def trylock(self): | ||||
pid = os.getpid() | ||||
try: | ||||
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r422 | util.makelock(str(pid), self.f) | ||
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r161 | self.held = 1 | ||
except: | ||||
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r422 | raise LockHeld(util.readlock(self.f)) | ||
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r161 | |||
def release(self): | ||||
if self.held: | ||||
self.held = 0 | ||||
os.unlink(self.f) | ||||