Use lockutils from "oslo concurrency" lib

Module 'lockutils' was released within 'oslo concurrency' lib and removed
from oslo incubator. Use it from lib.

Changes:
- Removed local copy of 'lockutils' copied from incubator.
- Config opt 'lock path' moved to separate config group 'oslo_concurrency'.
Now it can be set for Devstack installation also by "OSLO_LOCK_PATH" env var.
- Removed explicit usage of 'lockutils.synchronized' within Manila and
reused it from manila.utils.

Change-Id: I21257bc8c0a41dc1bb342deadbcf279c9f3b670d
This commit is contained in:
Ponomaryov Valeriy 2014-12-25 14:41:05 +02:00 committed by Valeriy Ponomaryov
parent 67ccd12e42
commit 76f8d3b948
9 changed files with 17 additions and 347 deletions

View File

@ -56,6 +56,7 @@ MANILACLIENT_BRANCH=${MANILACLIENT_BRANCH:-master}
# set up default directories
MANILA_DIR=${MANILA_DIR:=$DEST/manila}
MANILA_LOCK_PATH=${MANILA_LOCK_PATH:=$OSLO_LOCK_PATH}
MANILA_LOCK_PATH=${MANILA_LOCK_PATH:=$MANILA_DIR/manila_locks}
MANILACLIENT_DIR=${MANILACLIENT_DIR:=$DEST/python-manilaclient}
MANILA_STATE_PATH=${MANILA_STATE_PATH:=$DATA_DIR/manila}
@ -247,7 +248,7 @@ function configure_manila {
iniset $MANILA_CONF DEFAULT cinder_admin_password $SERVICE_PASSWORD
iniset $MANILA_CONF DEFAULT neutron_admin_password $SERVICE_PASSWORD
iniset $MANILA_CONF DEFAULT lock_path $MANILA_LOCK_PATH
iniset $MANILA_CONF oslo_concurrency lock_path $MANILA_LOCK_PATH
# Note: set up config group does not mean that this backend will be enabled.
# To enable it, specify its name explicitly using "enabled_share_backends" opt.

View File

@ -1,326 +0,0 @@
# Copyright 2011 OpenStack Foundation.
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import contextlib
import errno
import functools
import logging
import os
import shutil
import subprocess
import sys
import tempfile
import threading
import time
import weakref
from oslo.config import cfg
from manila.openstack.common import fileutils
from manila.openstack.common._i18n import _, _LE, _LI
LOG = logging.getLogger(__name__)
util_opts = [
cfg.BoolOpt('disable_process_locking', default=False,
help='Enables or disables inter-process locks.'),
cfg.StrOpt('lock_path',
default=os.environ.get("MANILA_LOCK_PATH"),
help='Directory to use for lock files.')
]
CONF = cfg.CONF
CONF.register_opts(util_opts)
def set_defaults(lock_path):
cfg.set_defaults(util_opts, lock_path=lock_path)
class _FileLock(object):
"""Lock implementation which allows multiple locks, working around
issues like bugs.debian.org/cgi-bin/bugreport.cgi?bug=632857 and does
not require any cleanup. Since the lock is always held on a file
descriptor rather than outside of the process, the lock gets dropped
automatically if the process crashes, even if __exit__ is not executed.
There are no guarantees regarding usage by multiple green threads in a
single process here. This lock works only between processes. Exclusive
access between local threads should be achieved using the semaphores
in the @synchronized decorator.
Note these locks are released when the descriptor is closed, so it's not
safe to close the file descriptor while another green thread holds the
lock. Just opening and closing the lock file can break synchronisation,
so lock files must be accessed only using this abstraction.
"""
def __init__(self, name):
self.lockfile = None
self.fname = name
def acquire(self):
basedir = os.path.dirname(self.fname)
if not os.path.exists(basedir):
fileutils.ensure_tree(basedir)
LOG.info(_LI('Created lock path: %s'), basedir)
self.lockfile = open(self.fname, 'w')
while True:
try:
# Using non-blocking locks since green threads are not
# patched to deal with blocking locking calls.
# Also upon reading the MSDN docs for locking(), it seems
# to have a laughable 10 attempts "blocking" mechanism.
self.trylock()
LOG.debug('Got file lock "%s"', self.fname)
return True
except IOError as e:
if e.errno in (errno.EACCES, errno.EAGAIN):
# external locks synchronise things like iptables
# updates - give it some time to prevent busy spinning
time.sleep(0.01)
else:
raise threading.ThreadError(_("Unable to acquire lock on"
" `%(filename)s` due to"
" %(exception)s") %
{'filename': self.fname,
'exception': e})
def __enter__(self):
self.acquire()
return self
def release(self):
try:
self.unlock()
self.lockfile.close()
LOG.debug('Released file lock "%s"', self.fname)
except IOError:
LOG.exception(_LE("Could not release the acquired lock `%s`"),
self.fname)
def __exit__(self, exc_type, exc_val, exc_tb):
self.release()
def exists(self):
return os.path.exists(self.fname)
def trylock(self):
raise NotImplementedError()
def unlock(self):
raise NotImplementedError()
class _WindowsLock(_FileLock):
def trylock(self):
msvcrt.locking(self.lockfile.fileno(), msvcrt.LK_NBLCK, 1)
def unlock(self):
msvcrt.locking(self.lockfile.fileno(), msvcrt.LK_UNLCK, 1)
class _FcntlLock(_FileLock):
def trylock(self):
fcntl.lockf(self.lockfile, fcntl.LOCK_EX | fcntl.LOCK_NB)
def unlock(self):
fcntl.lockf(self.lockfile, fcntl.LOCK_UN)
if os.name == 'nt':
import msvcrt
InterProcessLock = _WindowsLock
else:
import fcntl
InterProcessLock = _FcntlLock
_semaphores = weakref.WeakValueDictionary()
_semaphores_lock = threading.Lock()
def _get_lock_path(name, lock_file_prefix, lock_path=None):
# NOTE(mikal): the lock name cannot contain directory
# separators
name = name.replace(os.sep, '_')
if lock_file_prefix:
sep = '' if lock_file_prefix.endswith('-') else '-'
name = '%s%s%s' % (lock_file_prefix, sep, name)
local_lock_path = lock_path or CONF.lock_path
if not local_lock_path:
raise cfg.RequiredOptError('lock_path')
return os.path.join(local_lock_path, name)
def external_lock(name, lock_file_prefix=None, lock_path=None):
LOG.debug('Attempting to grab external lock "%(lock)s"',
{'lock': name})
lock_file_path = _get_lock_path(name, lock_file_prefix, lock_path)
return InterProcessLock(lock_file_path)
def remove_external_lock_file(name, lock_file_prefix=None):
"""Remove an external lock file when it's not used anymore
This will be helpful when we have a lot of lock files
"""
with internal_lock(name):
lock_file_path = _get_lock_path(name, lock_file_prefix)
try:
os.remove(lock_file_path)
except OSError:
LOG.info(_LI('Failed to remove file %(file)s'),
{'file': lock_file_path})
def internal_lock(name):
with _semaphores_lock:
try:
sem = _semaphores[name]
LOG.debug('Using existing semaphore "%s"', name)
except KeyError:
sem = threading.Semaphore()
_semaphores[name] = sem
LOG.debug('Created new semaphore "%s"', name)
return sem
@contextlib.contextmanager
def lock(name, lock_file_prefix=None, external=False, lock_path=None):
"""Context based lock
This function yields a `threading.Semaphore` instance (if we don't use
eventlet.monkey_patch(), else `semaphore.Semaphore`) unless external is
True, in which case, it'll yield an InterProcessLock instance.
:param lock_file_prefix: The lock_file_prefix argument is used to provide
lock files on disk with a meaningful prefix.
:param external: The external keyword argument denotes whether this lock
should work across multiple processes. This means that if two different
workers both run a method decorated with @synchronized('mylock',
external=True), only one of them will execute at a time.
"""
int_lock = internal_lock(name)
with int_lock:
LOG.debug('Acquired semaphore "%(lock)s"', {'lock': name})
try:
if external and not CONF.disable_process_locking:
ext_lock = external_lock(name, lock_file_prefix, lock_path)
with ext_lock:
yield ext_lock
else:
yield int_lock
finally:
LOG.debug('Releasing semaphore "%(lock)s"', {'lock': name})
def synchronized(name, lock_file_prefix=None, external=False, lock_path=None):
"""Synchronization decorator.
Decorating a method like so::
@synchronized('mylock')
def foo(self, *args):
...
ensures that only one thread will execute the foo method at a time.
Different methods can share the same lock::
@synchronized('mylock')
def foo(self, *args):
...
@synchronized('mylock')
def bar(self, *args):
...
This way only one of either foo or bar can be executing at a time.
"""
def wrap(f):
@functools.wraps(f)
def inner(*args, **kwargs):
try:
with lock(name, lock_file_prefix, external, lock_path):
LOG.debug('Got semaphore / lock "%(function)s"',
{'function': f.__name__})
return f(*args, **kwargs)
finally:
LOG.debug('Semaphore / lock released "%(function)s"',
{'function': f.__name__})
return inner
return wrap
def synchronized_with_prefix(lock_file_prefix):
"""Partial object generator for the synchronization decorator.
Redefine @synchronized in each project like so::
(in nova/utils.py)
from nova.openstack.common import lockutils
synchronized = lockutils.synchronized_with_prefix('nova-')
(in nova/foo.py)
from nova import utils
@utils.synchronized('mylock')
def bar(self, *args):
...
The lock_file_prefix argument is used to provide lock files on disk with a
meaningful prefix.
"""
return functools.partial(synchronized, lock_file_prefix=lock_file_prefix)
def main(argv):
"""Create a dir for locks and pass it to command from arguments
If you run this:
python -m openstack.common.lockutils python setup.py testr <etc>
a temporary directory will be created for all your locks and passed to all
your tests in an environment variable. The temporary dir will be deleted
afterwards and the return value will be preserved.
"""
lock_dir = tempfile.mkdtemp()
os.environ["MANILA_LOCK_PATH"] = lock_dir
try:
ret_val = subprocess.call(argv[1:])
finally:
shutil.rmtree(lock_dir, ignore_errors=True)
return ret_val
if __name__ == '__main__':
sys.exit(main(sys.argv))

View File

@ -20,6 +20,7 @@ __all__ = [
import copy
import itertools
import oslo_concurrency.opts
import manila.api.middleware.auth
import manila.api.middleware.sizelimit
@ -33,7 +34,6 @@ import manila.network
import manila.network.linux.interface
import manila.network.neutron.api
import manila.openstack.common.eventlet_backdoor
import manila.openstack.common.lockutils
import manila.openstack.common.log
import manila.openstack.common.policy
import manila.openstack.common.sslutils
@ -79,7 +79,6 @@ _global_opt_lists = [
manila.network.network_opts,
manila.network.neutron.api.neutron_opts,
manila.openstack.common.eventlet_backdoor.eventlet_backdoor_opts,
manila.openstack.common.lockutils.util_opts,
manila.openstack.common.log.common_cli_opts,
manila.openstack.common.log.generic_log_opts,
manila.openstack.common.log.log_opts,
@ -121,6 +120,8 @@ _opts = [
("ssl", manila.openstack.common.sslutils.ssl_opts)
]
_opts.extend(oslo_concurrency.opts.list_opts())
def list_opts():
"""Return a list of oslo.config options available in Manila."""

View File

@ -26,7 +26,6 @@ from manila.i18n import _
from manila.i18n import _LE
from manila.i18n import _LI
from manila.i18n import _LW
from manila.openstack.common import lockutils
from manila.openstack.common import log as logging
from manila.share.drivers.emc.plugins.vnx import constants
from manila.share.drivers.emc.plugins.vnx import utils as vnx_utils
@ -1410,7 +1409,7 @@ class NASCommandHelper(object):
def allow_nfs_share_access(self, path, host_ip, mover_name):
sharename = path.strip('/')
@lockutils.synchronized('emc-shareaccess-' + sharename)
@utils.synchronized('emc-shareaccess-' + sharename)
def do_allow_access(path, host_ip, mover_name):
ok = (constants.STATUS_OK, '')
status, share = self.get_nfs_share_by_path(path, mover_name)
@ -1450,7 +1449,7 @@ class NASCommandHelper(object):
def deny_nfs_share_access(self, path, host_ip, mover_name):
sharename = path.strip('/')
@lockutils.synchronized('emc-shareaccess-' + sharename)
@utils.synchronized('emc-shareaccess-' + sharename)
def do_deny_access(path, host_ip, mover_name):
ok = (constants.STATUS_OK, '')
status, share = self.get_nfs_share_by_path(path, mover_name)

View File

@ -23,14 +23,15 @@ inline callbacks.
import os
import shutil
import tempfile
import uuid
import fixtures
import mock
from oslo.config import cfg
from oslo.config import fixture as config_fixture
from oslo.messaging import conffixture as messaging_conffixture
from oslo.utils import timeutils
from oslo_concurrency import lockutils
import six
import testtools
@ -146,9 +147,13 @@ class TestCase(testtools.TestCase):
self.stubs = StubOutForTesting(self)
self.injected = []
self._services = []
CONF.set_override('fatal_exception_format_errors', True)
self.flags(fatal_exception_format_errors=True)
# This will be cleaned up by the NestedTempfile fixture
CONF.set_override('lock_path', tempfile.mkdtemp())
lock_path = self.useFixture(fixtures.TempDir()).path
self.fixture = self.useFixture(config_fixture.Config(lockutils.CONF))
self.fixture.config(lock_path=lock_path, group='oslo_concurrency')
self.fixture.config(
disable_process_locking=True, group='oslo_concurrency')
rpc.add_extra_exmods('manila.tests')
self.addCleanup(rpc.clear_extra_exmods)

View File

@ -13,9 +13,6 @@
# License for the specific language governing permissions and limitations
# under the License.
import shutil
import tempfile
from oslo.config import cfg
from oslo.serialization import jsonutils
import webob
@ -43,17 +40,11 @@ class AdminActionsTest(test.TestCase):
def setUp(self):
super(AdminActionsTest, self).setUp()
self.tempdir = tempfile.mkdtemp()
self.flags(rpc_backend='manila.openstack.common.rpc.impl_fake')
self.flags(lock_path=self.tempdir)
self.share_api = share_api.API()
self.admin_context = context.RequestContext('admin', 'fake', True)
self.member_context = context.RequestContext('fake', 'fake')
def tearDown(self):
shutil.rmtree(self.tempdir)
super(AdminActionsTest, self).tearDown()
def test_reset_status_as_admin(self):
# current status is available
share = db.share_create(self.admin_context, {'status': 'available'})

View File

@ -36,13 +36,13 @@ import netaddr
from oslo.config import cfg
from oslo.utils import importutils
from oslo.utils import timeutils
from oslo_concurrency import lockutils
from oslo_concurrency import processutils
import paramiko
import six
from manila import exception
from manila.i18n import _
from manila.openstack.common import lockutils
from manila.openstack.common import log as logging

View File

@ -4,7 +4,6 @@
module=eventlet_backdoor
module=fileutils
module=local
module=lockutils
module=log
module=loopingcall
module=policy

View File

@ -180,7 +180,7 @@ function run_pep8 {
bash -c "${wrapper} flake8"
}
TESTRTESTS="python -m manila.openstack.common.lockutils python setup.py testr"
TESTRTESTS="python setup.py testr"
if [ $never_venv -eq 0 ]
then