mercurial/lock.py
author mpm@selenic.com
Sat, 02 Jul 2005 15:21:22 -0800
changeset 576 da11baf5de7b
parent 515 03f27b1381f9
child 704 5ca319a641e1
child 705 574869103985
permissions -rw-r--r--
Handle unknown files better on update -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Handle unknown files better on update If we spot an unknown file that's identical to one that's in the update, we get the updated one so that it shows up in the dirstate properly. manifest hash: 988aca64f255df67c27d1c6f8694ea098e4ec159 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) iD8DBQFCxyFyywK+sNU5EO8RAjmiAKCTgINXMPB1CxHt0OgHYPucfjCS7QCcDpJJ VgKqZS54hTAWN3jL2yllUhI= =iPQD -----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
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:
            raise LockHeld(util.readlock(self.f))

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