Mercurial > hg
view mercurial/lock.py @ 1403:bc3e66edb04c
lazyindex fix, make load handle negative indexes properly.
author | Eric Hopper <hopper@omnifarious.org> |
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date | Tue, 18 Oct 2005 20:05:54 -0700 |
parents | 6d5a62a549fa |
children | abfab59fce79 |
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# 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 import util 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: util.makelock(str(pid), self.f) self.held = 1 except (OSError, IOError): raise LockHeld(util.readlock(self.f)) def release(self): if self.held: self.held = 0 try: os.unlink(self.f) except: pass