mercurial/lock.py
author mpm@selenic.com
Tue, 21 Jun 2005 19:33:13 -0800
changeset 420 dbe86d465e09
parent 161 0b4c5cb953d9
child 422 10c43444a38e
child 429 688d03d6997a
permissions -rw-r--r--
[PATCH] Repo locator fix for the other `OS' -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 [PATCH] Repo locator fix for the other `OS' From: K Thananchayan <thananck@yahoo.com> The following patch modifies repo locator to behave properly under windows. manifest hash: 481252f9667ab5408dc1985a72a1916f903f4f2b -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) iD8DBQFCuNv5ywK+sNU5EO8RAvD9AJ9mYSzmn99sc2vNtw68sPaKKWe2UQCgoiLd 1q1t+JMs57+I0LUdwrwsEDw= =dlmm -----END PGP SIGNATURE-----

# 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

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:
            os.symlink(str(pid), self.f)
            self.held = 1
        except:
            raise LockHeld(os.readlink(self.f))

    def release(self):
        if self.held:
            self.held = 0
            os.unlink(self.f)