remotefilelog: remove dead code for using flock() for locking
Differential Revision: https://phab.mercurial-scm.org/D6860
--- a/hgext/remotefilelog/extutil.py Thu Sep 12 21:55:45 2019 -0700
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,66 +0,0 @@
-# extutil.py - useful utility methods for extensions
-#
-# Copyright 2016 Facebook
-#
-# This software may be used and distributed according to the terms of the
-# GNU General Public License version 2 or any later version.
-
-from __future__ import absolute_import
-
-import contextlib
-import errno
-import os
-import time
-
-from mercurial import (
- error,
- lock as lockmod,
- util,
- vfs as vfsmod,
-)
-
-@contextlib.contextmanager
-def flock(lockpath, description, timeout=-1):
- """A flock based lock object. Currently it is always non-blocking.
-
- Note that since it is flock based, you can accidentally take it multiple
- times within one process and the first one to be released will release all
- of them. So the caller needs to be careful to not create more than one
- instance per lock.
- """
-
- # best effort lightweight lock
- try:
- import fcntl
- fcntl.flock
- except ImportError:
- # fallback to Mercurial lock
- vfs = vfsmod.vfs(os.path.dirname(lockpath))
- with lockmod.lock(vfs, os.path.basename(lockpath), timeout=timeout):
- yield
- return
- # make sure lock file exists
- util.makedirs(os.path.dirname(lockpath))
- with open(lockpath, 'a'):
- pass
- lockfd = os.open(lockpath, os.O_RDONLY, 0o664)
- start = time.time()
- while True:
- try:
- fcntl.flock(lockfd, fcntl.LOCK_EX | fcntl.LOCK_NB)
- break
- except IOError as ex:
- if ex.errno == errno.EAGAIN:
- if timeout != -1 and time.time() - start > timeout:
- raise error.LockHeld(errno.EAGAIN, lockpath, description,
- '')
- else:
- time.sleep(0.05)
- continue
- raise
-
- try:
- yield
- finally:
- fcntl.flock(lockfd, fcntl.LOCK_UN)
- os.close(lockfd)