Mercurial > hg > mercurial-crew-with-dirclash
view mercurial/lock.py @ 1636:7da32bb3d1d3
contrib: add Chris Mason's stand-alone diff tool
This uses Mercurial's diff algorithm to generate unidiffs like the traditional diff tool.
author | Matt Mackall <mpm@selenic.com> |
---|---|
date | Tue, 24 Jan 2006 14:49:19 +1300 |
parents | 59b3639df0a9 |
children | e6e70450edb9 |
line wrap: on
line source
# 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(object): def __init__(self, file, wait=1, releasefn=None): self.f = file self.held = 0 self.wait = wait self.releasefn = releasefn 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 if self.releasefn: self.releasefn() try: os.unlink(self.f) except: pass