mercurial/lock.py
author mpm@selenic.com
Wed, 22 Jun 2005 12:14:44 -0800
changeset 436 6aeb4fee51f6
parent 429 688d03d6997a
child 503 c6a2e41c8c60
permissions -rw-r--r--
Optimize annotate a bit -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Optimize annotate a bit Keep the original text around so we don't need to rejoin it Use slice insert-in-place rather than += to construct new lists Construct the decorated list with list multiply rather than comprehension manifest hash: 8c0effb9777750d524d71ad3a2eade3c6ddd579e -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (GNU/Linux) iD8DBQFCuca0ywK+sNU5EO8RAtvQAJwOViomGCtlZx/R76i8/CZGvGPqUwCfdybd nRUv1854GjzCbfygzXfeIes= =6Q+E -----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
            os.unlink(self.f)