oslo.concurrency/oslo_concurrency/tests/unit/test_lockutils.py

580 lines
20 KiB
Python

# Copyright 2011 Justin Santa Barbara
#
# 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 collections
import multiprocessing
import os
import shutil
import signal
import subprocess
import sys
import tempfile
import threading
import time
from oslo_config import cfg
from oslotest import base as test_base
import six
from oslo_concurrency.fixture import lockutils as fixtures
from oslo_concurrency import lockutils
from oslo_config import fixture as config
if sys.platform == 'win32':
import msvcrt
else:
import fcntl
def lock_file(handle):
if sys.platform == 'win32':
msvcrt.locking(handle.fileno(), msvcrt.LK_NBLCK, 1)
else:
fcntl.flock(handle, fcntl.LOCK_EX | fcntl.LOCK_NB)
def unlock_file(handle):
if sys.platform == 'win32':
msvcrt.locking(handle.fileno(), msvcrt.LK_UNLCK, 1)
else:
fcntl.flock(handle, fcntl.LOCK_UN)
def lock_files(handles_dir, out_queue):
with lockutils.lock('external', 'test-', external=True):
# Open some files we can use for locking
handles = []
for n in range(50):
path = os.path.join(handles_dir, ('file-%s' % n))
handles.append(open(path, 'w'))
# Loop over all the handles and try locking the file
# without blocking, keep a count of how many files we
# were able to lock and then unlock. If the lock fails
# we get an IOError and bail out with bad exit code
count = 0
for handle in handles:
try:
lock_file(handle)
count += 1
unlock_file(handle)
except IOError:
os._exit(2)
finally:
handle.close()
return out_queue.put(count)
class LockTestCase(test_base.BaseTestCase):
def setUp(self):
super(LockTestCase, self).setUp()
self.config = self.useFixture(config.Config(lockutils.CONF)).config
def test_synchronized_wrapped_function_metadata(self):
@lockutils.synchronized('whatever', 'test-')
def foo():
"""Bar."""
pass
self.assertEqual('Bar.', foo.__doc__, "Wrapped function's docstring "
"got lost")
self.assertEqual('foo', foo.__name__, "Wrapped function's name "
"got mangled")
def test_lock_internally_different_collections(self):
s1 = lockutils.Semaphores()
s2 = lockutils.Semaphores()
trigger = threading.Event()
who_ran = collections.deque()
def f(name, semaphores, pull_trigger):
with lockutils.internal_lock('testing', semaphores=semaphores):
if pull_trigger:
trigger.set()
else:
trigger.wait()
who_ran.append(name)
threads = [
threading.Thread(target=f, args=(1, s1, True)),
threading.Thread(target=f, args=(2, s2, False)),
]
for thread in threads:
thread.start()
for thread in threads:
thread.join()
self.assertEqual([1, 2], sorted(who_ran))
def test_lock_internally(self):
"""We can lock across multiple threads."""
saved_sem_num = len(lockutils._semaphores)
seen_threads = list()
def f(_id):
with lockutils.lock('testlock2', 'test-', external=False):
for x in range(10):
seen_threads.append(_id)
threads = []
for i in range(10):
thread = threading.Thread(target=f, args=(i,))
threads.append(thread)
thread.start()
for thread in threads:
thread.join()
self.assertEqual(100, len(seen_threads))
# Looking at the seen threads, split it into chunks of 10, and verify
# that the last 9 match the first in each chunk.
for i in range(10):
for j in range(9):
self.assertEqual(seen_threads[i * 10],
seen_threads[i * 10 + 1 + j])
self.assertEqual(saved_sem_num, len(lockutils._semaphores),
"Semaphore leak detected")
def test_lock_internal_fair(self):
"""Check that we're actually fair."""
def f(_id):
with lockutils.lock('testlock', 'test-',
external=False, fair=True):
lock_holder.append(_id)
lock_holder = []
threads = []
# While holding the fair lock, spawn a bunch of threads that all try
# to acquire the lock. They will all block. Then release the lock
# and see what happens.
with lockutils.lock('testlock', 'test-', external=False, fair=True):
for i in range(10):
thread = threading.Thread(target=f, args=(i,))
threads.append(thread)
thread.start()
# Allow some time for the new thread to get queued onto the
# list of pending writers before continuing. This is gross
# but there's no way around it without using knowledge of
# fasteners internals.
time.sleep(0.5)
# Wait for all threads.
for thread in threads:
thread.join()
self.assertEqual(10, len(lock_holder))
# Check that the threads each got the lock in fair order.
for i in range(10):
self.assertEqual(i, lock_holder[i])
def test_fair_lock_with_semaphore(self):
def do_test():
s = lockutils.Semaphores()
with lockutils.lock('testlock', 'test-', semaphores=s, fair=True):
pass
self.assertRaises(NotImplementedError, do_test)
def test_nested_synchronized_external_works(self):
"""We can nest external syncs."""
tempdir = tempfile.mkdtemp()
try:
self.config(lock_path=tempdir, group='oslo_concurrency')
sentinel = object()
@lockutils.synchronized('testlock1', 'test-', external=True)
def outer_lock():
@lockutils.synchronized('testlock2', 'test-', external=True)
def inner_lock():
return sentinel
return inner_lock()
self.assertEqual(sentinel, outer_lock())
finally:
if os.path.exists(tempdir):
shutil.rmtree(tempdir)
def _do_test_lock_externally(self):
"""We can lock across multiple processes."""
handles_dir = tempfile.mkdtemp()
try:
children = []
for n in range(50):
queue = multiprocessing.Queue()
proc = multiprocessing.Process(
target=lock_files,
args=(handles_dir, queue))
proc.start()
children.append((proc, queue))
for child, queue in children:
child.join()
count = queue.get(block=False)
self.assertEqual(50, count)
finally:
if os.path.exists(handles_dir):
shutil.rmtree(handles_dir, ignore_errors=True)
def test_lock_externally(self):
lock_dir = tempfile.mkdtemp()
self.config(lock_path=lock_dir, group='oslo_concurrency')
try:
self._do_test_lock_externally()
finally:
if os.path.exists(lock_dir):
shutil.rmtree(lock_dir, ignore_errors=True)
def test_lock_externally_lock_dir_not_exist(self):
lock_dir = tempfile.mkdtemp()
os.rmdir(lock_dir)
self.config(lock_path=lock_dir, group='oslo_concurrency')
try:
self._do_test_lock_externally()
finally:
if os.path.exists(lock_dir):
shutil.rmtree(lock_dir, ignore_errors=True)
def test_synchronized_with_prefix(self):
lock_name = 'mylock'
lock_pfix = 'mypfix-'
foo = lockutils.synchronized_with_prefix(lock_pfix)
@foo(lock_name, external=True)
def bar(dirpath, pfix, name):
return True
lock_dir = tempfile.mkdtemp()
self.config(lock_path=lock_dir, group='oslo_concurrency')
self.assertTrue(bar(lock_dir, lock_pfix, lock_name))
def test_synchronized_without_prefix(self):
lock_dir = tempfile.mkdtemp()
self.config(lock_path=lock_dir, group='oslo_concurrency')
@lockutils.synchronized('lock', external=True)
def test_without_prefix():
# We can't check much
pass
try:
test_without_prefix()
finally:
if os.path.exists(lock_dir):
shutil.rmtree(lock_dir, ignore_errors=True)
def test_synchronized_prefix_without_hypen(self):
lock_dir = tempfile.mkdtemp()
self.config(lock_path=lock_dir, group='oslo_concurrency')
@lockutils.synchronized('lock', 'hypen', True)
def test_without_hypen():
# We can't check much
pass
try:
test_without_hypen()
finally:
if os.path.exists(lock_dir):
shutil.rmtree(lock_dir, ignore_errors=True)
def test_contextlock(self):
lock_dir = tempfile.mkdtemp()
self.config(lock_path=lock_dir, group='oslo_concurrency')
try:
# Note(flaper87): Lock is not external, which means
# a semaphore will be yielded
with lockutils.lock("test") as sem:
if six.PY2:
self.assertIsInstance(sem, threading._Semaphore)
else:
self.assertIsInstance(sem, threading.Semaphore)
# NOTE(flaper87): Lock is external so an InterProcessLock
# will be yielded.
with lockutils.lock("test2", external=True) as lock:
self.assertTrue(lock.exists())
with lockutils.lock("test1",
external=True) as lock1:
self.assertIsInstance(lock1,
lockutils.InterProcessLock)
finally:
if os.path.exists(lock_dir):
shutil.rmtree(lock_dir, ignore_errors=True)
def test_contextlock_unlocks(self):
lock_dir = tempfile.mkdtemp()
self.config(lock_path=lock_dir, group='oslo_concurrency')
sem = None
try:
with lockutils.lock("test") as sem:
if six.PY2:
self.assertIsInstance(sem, threading._Semaphore)
else:
self.assertIsInstance(sem, threading.Semaphore)
with lockutils.lock("test2", external=True) as lock:
self.assertTrue(lock.exists())
# NOTE(flaper87): Lock should be free
with lockutils.lock("test2", external=True) as lock:
self.assertTrue(lock.exists())
# NOTE(flaper87): Lock should be free
# but semaphore should already exist.
with lockutils.lock("test") as sem2:
self.assertEqual(sem, sem2)
finally:
if os.path.exists(lock_dir):
shutil.rmtree(lock_dir, ignore_errors=True)
def _test_remove_lock_external_file(self, lock_dir, use_external=False):
lock_name = 'mylock'
lock_pfix = 'mypfix-remove-lock-test-'
if use_external:
lock_path = lock_dir
else:
lock_path = None
lockutils.remove_external_lock_file(lock_name, lock_pfix, lock_path)
for ent in os.listdir(lock_dir):
self.assertRaises(OSError, ent.startswith, lock_pfix)
if os.path.exists(lock_dir):
shutil.rmtree(lock_dir, ignore_errors=True)
def test_remove_lock_external_file(self):
lock_dir = tempfile.mkdtemp()
self.config(lock_path=lock_dir, group='oslo_concurrency')
self._test_remove_lock_external_file(lock_dir)
def test_remove_lock_external_file_lock_path(self):
lock_dir = tempfile.mkdtemp()
self._test_remove_lock_external_file(lock_dir,
use_external=True)
def test_no_slash_in_b64(self):
# base64(sha1(foobar)) has a slash in it
with lockutils.lock("foobar"):
pass
def test_deprecated_names(self):
paths = self.create_tempfiles([['fake.conf', '\n'.join([
'[DEFAULT]',
'lock_path=foo',
'disable_process_locking=True'])
]])
conf = cfg.ConfigOpts()
conf(['--config-file', paths[0]])
conf.register_opts(lockutils._opts, 'oslo_concurrency')
self.assertEqual('foo', conf.oslo_concurrency.lock_path)
self.assertTrue(conf.oslo_concurrency.disable_process_locking)
class FileBasedLockingTestCase(test_base.BaseTestCase):
def setUp(self):
super(FileBasedLockingTestCase, self).setUp()
self.lock_dir = tempfile.mkdtemp()
def test_lock_file_exists(self):
lock_file = os.path.join(self.lock_dir, 'lock-file')
@lockutils.synchronized('lock-file', external=True,
lock_path=self.lock_dir)
def foo():
self.assertTrue(os.path.exists(lock_file))
foo()
def test_interprocess_lock(self):
lock_file = os.path.join(self.lock_dir, 'processlock')
pid = os.fork()
if pid:
# Make sure the child grabs the lock first
start = time.time()
while not os.path.exists(lock_file):
if time.time() - start > 5:
self.fail('Timed out waiting for child to grab lock')
time.sleep(0)
lock1 = lockutils.InterProcessLock('foo')
lock1.lockfile = open(lock_file, 'w')
# NOTE(bnemec): There is a brief window between when the lock file
# is created and when it actually becomes locked. If we happen to
# context switch in that window we may succeed in locking the
# file. Keep retrying until we either get the expected exception
# or timeout waiting.
while time.time() - start < 5:
try:
lock1.trylock()
lock1.unlock()
time.sleep(0)
except IOError:
# This is what we expect to happen
break
else:
self.fail('Never caught expected lock exception')
# We don't need to wait for the full sleep in the child here
os.kill(pid, signal.SIGKILL)
else:
try:
lock2 = lockutils.InterProcessLock('foo')
lock2.lockfile = open(lock_file, 'w')
have_lock = False
while not have_lock:
try:
lock2.trylock()
have_lock = True
except IOError:
pass
finally:
# NOTE(bnemec): This is racy, but I don't want to add any
# synchronization primitives that might mask a problem
# with the one we're trying to test here.
time.sleep(.5)
os._exit(0)
def test_interthread_external_lock(self):
call_list = []
@lockutils.synchronized('foo', external=True, lock_path=self.lock_dir)
def foo(param):
"""Simulate a long-running threaded operation."""
call_list.append(param)
# NOTE(bnemec): This is racy, but I don't want to add any
# synchronization primitives that might mask a problem
# with the one we're trying to test here.
time.sleep(.5)
call_list.append(param)
def other(param):
foo(param)
thread = threading.Thread(target=other, args=('other',))
thread.start()
# Make sure the other thread grabs the lock
# NOTE(bnemec): File locks do not actually work between threads, so
# this test is verifying that the local semaphore is still enforcing
# external locks in that case. This means this test does not have
# the same race problem as the process test above because when the
# file is created the semaphore has already been grabbed.
start = time.time()
while not os.path.exists(os.path.join(self.lock_dir, 'foo')):
if time.time() - start > 5:
self.fail('Timed out waiting for thread to grab lock')
time.sleep(0)
thread1 = threading.Thread(target=other, args=('main',))
thread1.start()
thread1.join()
thread.join()
self.assertEqual(['other', 'other', 'main', 'main'], call_list)
def test_non_destructive(self):
lock_file = os.path.join(self.lock_dir, 'not-destroyed')
with open(lock_file, 'w') as f:
f.write('test')
with lockutils.lock('not-destroyed', external=True,
lock_path=self.lock_dir):
with open(lock_file) as f:
self.assertEqual('test', f.read())
class LockutilsModuleTestCase(test_base.BaseTestCase):
def setUp(self):
super(LockutilsModuleTestCase, self).setUp()
self.old_env = os.environ.get('OSLO_LOCK_PATH')
if self.old_env is not None:
del os.environ['OSLO_LOCK_PATH']
def tearDown(self):
if self.old_env is not None:
os.environ['OSLO_LOCK_PATH'] = self.old_env
super(LockutilsModuleTestCase, self).tearDown()
def test_main(self):
script = '\n'.join([
'import os',
'lock_path = os.environ.get("OSLO_LOCK_PATH")',
'assert lock_path is not None',
'assert os.path.isdir(lock_path)',
])
argv = ['', sys.executable, '-c', script]
retval = lockutils._lock_wrapper(argv)
self.assertEqual(0, retval, "Bad OSLO_LOCK_PATH has been set")
def test_return_value_maintained(self):
script = '\n'.join([
'import sys',
'sys.exit(1)',
])
argv = ['', sys.executable, '-c', script]
retval = lockutils._lock_wrapper(argv)
self.assertEqual(1, retval)
def test_direct_call_explodes(self):
cmd = [sys.executable, '-m', 'oslo_concurrency.lockutils']
with open(os.devnull, 'w') as devnull:
retval = subprocess.call(cmd, stderr=devnull)
self.assertEqual(1, retval)
class TestLockFixture(test_base.BaseTestCase):
def setUp(self):
super(TestLockFixture, self).setUp()
self.config = self.useFixture(config.Config(lockutils.CONF)).config
self.tempdir = tempfile.mkdtemp()
def _check_in_lock(self):
self.assertTrue(self.lock.exists())
def tearDown(self):
self._check_in_lock()
super(TestLockFixture, self).tearDown()
def test_lock_fixture(self):
# Setup lock fixture to test that teardown is inside the lock
self.config(lock_path=self.tempdir, group='oslo_concurrency')
fixture = fixtures.LockFixture('test-lock')
self.useFixture(fixture)
self.lock = fixture.lock
class TestGetLockPath(test_base.BaseTestCase):
def setUp(self):
super(TestGetLockPath, self).setUp()
self.conf = self.useFixture(config.Config(lockutils.CONF)).conf
def test_get_default(self):
lockutils.set_defaults(lock_path='/the/path')
self.assertEqual('/the/path', lockutils.get_lock_path(self.conf))
def test_get_override(self):
lockutils._register_opts(self.conf)
self.conf.set_override('lock_path', '/alternate/path',
group='oslo_concurrency')
self.assertEqual('/alternate/path', lockutils.get_lock_path(self.conf))