Files
deb-python-taskflow/taskflow/tests/unit/test_utils_lock_utils.py
Joshua Harlow 7ca631356e Use and verify event and latch wait() return using timeouts
Instead of blocking up the whole test suite when a latch or
event was not decremented to its desired value (or not set for
an event) we should use a reasonably high value that we use
when waiting for those actions to occur and verify that when those
wait() functions return that we have reached the desired state and
if not either raise an exception or stop further testing.

Fixes bug 1363739

Change-Id: I8b40282ac2db9cabd48b0b65c8a2a49610d77c4f
2014-10-18 17:51:52 -07:00

528 lines
17 KiB
Python

# -*- coding: utf-8 -*-
# Copyright (C) 2014 Yahoo! Inc. 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 collections
import threading
import time
from concurrent import futures
import mock
from taskflow import test
from taskflow.tests import utils as test_utils
from taskflow.utils import lock_utils
from taskflow.utils import threading_utils
# NOTE(harlowja): Sleep a little so time.time() can not be the same (which will
# cause false positives when our overlap detection code runs). If there are
# real overlaps then they will still exist.
NAPPY_TIME = 0.05
# We will spend this amount of time doing some "fake" work.
WORK_TIMES = [(0.01 + x / 100.0) for x in range(0, 5)]
def _find_overlaps(times, start, end):
overlaps = 0
for (s, e) in times:
if s >= start and e <= end:
overlaps += 1
return overlaps
def _spawn_variation(readers, writers, max_workers=None):
start_stops = collections.deque()
lock = lock_utils.ReaderWriterLock()
def read_func(ident):
with lock.read_lock():
# TODO(harlowja): sometime in the future use a monotonic clock here
# to avoid problems that can be caused by ntpd resyncing the clock
# while we are actively running.
enter_time = time.time()
time.sleep(WORK_TIMES[ident % len(WORK_TIMES)])
exit_time = time.time()
start_stops.append((lock.READER, enter_time, exit_time))
time.sleep(NAPPY_TIME)
def write_func(ident):
with lock.write_lock():
enter_time = time.time()
time.sleep(WORK_TIMES[ident % len(WORK_TIMES)])
exit_time = time.time()
start_stops.append((lock.WRITER, enter_time, exit_time))
time.sleep(NAPPY_TIME)
if max_workers is None:
max_workers = max(0, readers) + max(0, writers)
if max_workers > 0:
with futures.ThreadPoolExecutor(max_workers=max_workers) as e:
count = 0
for _i in range(0, readers):
e.submit(read_func, count)
count += 1
for _i in range(0, writers):
e.submit(write_func, count)
count += 1
writer_times = []
reader_times = []
for (lock_type, start, stop) in list(start_stops):
if lock_type == lock.WRITER:
writer_times.append((start, stop))
else:
reader_times.append((start, stop))
return (writer_times, reader_times)
class MultilockTest(test.TestCase):
def test_empty_error(self):
self.assertRaises(ValueError,
lock_utils.MultiLock, [])
self.assertRaises(ValueError,
lock_utils.MultiLock, ())
self.assertRaises(ValueError,
lock_utils.MultiLock, iter([]))
def test_creation(self):
locks = []
for _i in range(0, 10):
locks.append(threading.Lock())
n_lock = lock_utils.MultiLock(locks)
self.assertEqual(0, n_lock.obtained)
self.assertEqual(len(locks), len(n_lock))
def test_acquired(self):
lock1 = threading.Lock()
lock2 = threading.Lock()
n_lock = lock_utils.MultiLock((lock1, lock2))
self.assertTrue(n_lock.acquire())
try:
self.assertTrue(lock1.locked())
self.assertTrue(lock2.locked())
finally:
n_lock.release()
self.assertFalse(lock1.locked())
self.assertFalse(lock2.locked())
def test_acquired_context_manager(self):
lock1 = threading.Lock()
n_lock = lock_utils.MultiLock([lock1])
with n_lock as gotten:
self.assertTrue(gotten)
self.assertTrue(lock1.locked())
self.assertFalse(lock1.locked())
self.assertEqual(0, n_lock.obtained)
def test_partial_acquired(self):
lock1 = threading.Lock()
lock2 = mock.create_autospec(threading.Lock())
lock2.acquire.return_value = False
n_lock = lock_utils.MultiLock((lock1, lock2))
with n_lock as gotten:
self.assertFalse(gotten)
self.assertTrue(lock1.locked())
self.assertEqual(1, n_lock.obtained)
self.assertEqual(2, len(n_lock))
self.assertEqual(0, n_lock.obtained)
def test_partial_acquired_failure(self):
lock1 = threading.Lock()
lock2 = mock.create_autospec(threading.Lock())
lock2.acquire.side_effect = RuntimeError("Broke")
n_lock = lock_utils.MultiLock((lock1, lock2))
self.assertRaises(threading.ThreadError, n_lock.acquire)
self.assertEqual(1, n_lock.obtained)
n_lock.release()
def test_release_failure(self):
lock1 = threading.Lock()
lock2 = mock.create_autospec(threading.Lock())
lock2.acquire.return_value = True
lock2.release.side_effect = RuntimeError("Broke")
n_lock = lock_utils.MultiLock((lock1, lock2))
self.assertTrue(n_lock.acquire())
self.assertEqual(2, n_lock.obtained)
self.assertRaises(threading.ThreadError, n_lock.release)
self.assertEqual(2, n_lock.obtained)
lock2.release.side_effect = None
n_lock.release()
self.assertEqual(0, n_lock.obtained)
def test_release_partial_failure(self):
lock1 = threading.Lock()
lock2 = mock.create_autospec(threading.Lock())
lock2.acquire.return_value = True
lock2.release.side_effect = RuntimeError("Broke")
lock3 = threading.Lock()
n_lock = lock_utils.MultiLock((lock1, lock2, lock3))
self.assertTrue(n_lock.acquire())
self.assertEqual(3, n_lock.obtained)
self.assertRaises(threading.ThreadError, n_lock.release)
self.assertEqual(2, n_lock.obtained)
lock2.release.side_effect = None
n_lock.release()
self.assertEqual(0, n_lock.obtained)
def test_acquired_pass(self):
activated = collections.deque()
lock1 = threading.Lock()
lock2 = threading.Lock()
n_lock = lock_utils.MultiLock((lock1, lock2))
def critical_section():
start = time.time()
time.sleep(0.05)
end = time.time()
activated.append((start, end))
def run():
with n_lock:
critical_section()
threads = []
for _i in range(0, 20):
t = threading.Thread(target=run)
t.daemon = True
threads.append(t)
t.start()
while threads:
t = threads.pop()
t.join()
for (start, end) in activated:
self.assertEqual(1, _find_overlaps(activated, start, end))
self.assertFalse(lock1.locked())
self.assertFalse(lock2.locked())
def test_acquired_fail(self):
activated = collections.deque()
lock1 = threading.Lock()
lock2 = threading.Lock()
n_lock = lock_utils.MultiLock((lock1, lock2))
def run():
with n_lock:
start = time.time()
time.sleep(0.05)
end = time.time()
activated.append((start, end))
def run_fail():
try:
with n_lock:
raise RuntimeError()
except RuntimeError:
pass
threads = []
for i in range(0, 20):
if i % 2 == 1:
target = run_fail
else:
target = run
t = threading.Thread(target=target)
threads.append(t)
t.daemon = True
t.start()
while threads:
t = threads.pop()
t.join()
for (start, end) in activated:
self.assertEqual(1, _find_overlaps(activated, start, end))
self.assertFalse(lock1.locked())
self.assertFalse(lock2.locked())
def test_double_acquire_single(self):
activated = collections.deque()
def run():
start = time.time()
time.sleep(0.05)
end = time.time()
activated.append((start, end))
lock1 = threading.RLock()
lock2 = threading.RLock()
n_lock = lock_utils.MultiLock((lock1, lock2))
with n_lock:
run()
with n_lock:
run()
run()
for (start, end) in activated:
self.assertEqual(1, _find_overlaps(activated, start, end))
def test_double_acquire_many(self):
activated = collections.deque()
n_lock = lock_utils.MultiLock((threading.RLock(), threading.RLock()))
def critical_section():
start = time.time()
time.sleep(0.05)
end = time.time()
activated.append((start, end))
def run():
with n_lock:
critical_section()
with n_lock:
critical_section()
critical_section()
threads = []
for i in range(0, 20):
t = threading.Thread(target=run)
threads.append(t)
t.daemon = True
t.start()
while threads:
t = threads.pop()
t.join()
for (start, end) in activated:
self.assertEqual(1, _find_overlaps(activated, start, end))
def test_no_acquire_release(self):
lock1 = threading.Lock()
lock2 = threading.Lock()
n_lock = lock_utils.MultiLock((lock1, lock2))
self.assertRaises(threading.ThreadError, n_lock.release)
class ReadWriteLockTest(test.TestCase):
def test_writer_abort(self):
lock = lock_utils.ReaderWriterLock()
self.assertFalse(lock.owner)
def blow_up():
with lock.write_lock():
self.assertEqual(lock.WRITER, lock.owner)
raise RuntimeError("Broken")
self.assertRaises(RuntimeError, blow_up)
self.assertFalse(lock.owner)
def test_reader_abort(self):
lock = lock_utils.ReaderWriterLock()
self.assertFalse(lock.owner)
def blow_up():
with lock.read_lock():
self.assertEqual(lock.READER, lock.owner)
raise RuntimeError("Broken")
self.assertRaises(RuntimeError, blow_up)
self.assertFalse(lock.owner)
def test_double_reader_abort(self):
lock = lock_utils.ReaderWriterLock()
activated = collections.deque()
def double_bad_reader():
with lock.read_lock():
with lock.read_lock():
raise RuntimeError("Broken")
def happy_writer():
with lock.write_lock():
activated.append(lock.owner)
with futures.ThreadPoolExecutor(max_workers=20) as e:
for i in range(0, 20):
if i % 2 == 0:
e.submit(double_bad_reader)
else:
e.submit(happy_writer)
self.assertEqual(10, len([a for a in activated if a == 'w']))
def test_double_reader_writer(self):
lock = lock_utils.ReaderWriterLock()
activated = collections.deque()
active = threading_utils.Event()
def double_reader():
with lock.read_lock():
active.set()
while not lock.has_pending_writers:
time.sleep(0.001)
with lock.read_lock():
activated.append(lock.owner)
def happy_writer():
with lock.write_lock():
activated.append(lock.owner)
reader = threading.Thread(target=double_reader)
reader.start()
self.assertTrue(active.wait(test_utils.WAIT_TIMEOUT))
writer = threading.Thread(target=happy_writer)
writer.start()
reader.join()
writer.join()
self.assertEqual(2, len(activated))
self.assertEqual(['r', 'w'], list(activated))
def test_reader_chaotic(self):
lock = lock_utils.ReaderWriterLock()
activated = collections.deque()
def chaotic_reader(blow_up):
with lock.read_lock():
if blow_up:
raise RuntimeError("Broken")
else:
activated.append(lock.owner)
def happy_writer():
with lock.write_lock():
activated.append(lock.owner)
with futures.ThreadPoolExecutor(max_workers=20) as e:
for i in range(0, 20):
if i % 2 == 0:
e.submit(chaotic_reader, blow_up=bool(i % 4 == 0))
else:
e.submit(happy_writer)
writers = [a for a in activated if a == 'w']
readers = [a for a in activated if a == 'r']
self.assertEqual(10, len(writers))
self.assertEqual(5, len(readers))
def test_writer_chaotic(self):
lock = lock_utils.ReaderWriterLock()
activated = collections.deque()
def chaotic_writer(blow_up):
with lock.write_lock():
if blow_up:
raise RuntimeError("Broken")
else:
activated.append(lock.owner)
def happy_reader():
with lock.read_lock():
activated.append(lock.owner)
with futures.ThreadPoolExecutor(max_workers=20) as e:
for i in range(0, 20):
if i % 2 == 0:
e.submit(chaotic_writer, blow_up=bool(i % 4 == 0))
else:
e.submit(happy_reader)
writers = [a for a in activated if a == 'w']
readers = [a for a in activated if a == 'r']
self.assertEqual(5, len(writers))
self.assertEqual(10, len(readers))
def test_single_reader_writer(self):
results = []
lock = lock_utils.ReaderWriterLock()
with lock.read_lock():
self.assertTrue(lock.is_reader())
self.assertEqual(0, len(results))
with lock.write_lock():
results.append(1)
self.assertTrue(lock.is_writer())
with lock.read_lock():
self.assertTrue(lock.is_reader())
self.assertEqual(1, len(results))
self.assertFalse(lock.is_reader())
self.assertFalse(lock.is_writer())
def test_reader_to_writer(self):
lock = lock_utils.ReaderWriterLock()
def writer_func():
with lock.write_lock():
pass
with lock.read_lock():
self.assertRaises(RuntimeError, writer_func)
self.assertFalse(lock.is_writer())
self.assertFalse(lock.is_reader())
self.assertFalse(lock.is_writer())
def test_writer_to_reader(self):
lock = lock_utils.ReaderWriterLock()
def reader_func():
with lock.read_lock():
pass
with lock.write_lock():
self.assertRaises(RuntimeError, reader_func)
self.assertFalse(lock.is_reader())
self.assertFalse(lock.is_reader())
self.assertFalse(lock.is_writer())
def test_double_writer(self):
lock = lock_utils.ReaderWriterLock()
with lock.write_lock():
self.assertFalse(lock.is_reader())
self.assertTrue(lock.is_writer())
with lock.write_lock():
self.assertTrue(lock.is_writer())
self.assertTrue(lock.is_writer())
self.assertFalse(lock.is_reader())
self.assertFalse(lock.is_writer())
def test_double_reader(self):
lock = lock_utils.ReaderWriterLock()
with lock.read_lock():
self.assertTrue(lock.is_reader())
self.assertFalse(lock.is_writer())
with lock.read_lock():
self.assertTrue(lock.is_reader())
self.assertTrue(lock.is_reader())
self.assertFalse(lock.is_reader())
self.assertFalse(lock.is_writer())
def test_multi_reader_multi_writer(self):
writer_times, reader_times = _spawn_variation(10, 10)
self.assertEqual(10, len(writer_times))
self.assertEqual(10, len(reader_times))
for (start, stop) in writer_times:
self.assertEqual(0, _find_overlaps(reader_times, start, stop))
self.assertEqual(1, _find_overlaps(writer_times, start, stop))
for (start, stop) in reader_times:
self.assertEqual(0, _find_overlaps(writer_times, start, stop))
def test_multi_reader_single_writer(self):
writer_times, reader_times = _spawn_variation(9, 1)
self.assertEqual(1, len(writer_times))
self.assertEqual(9, len(reader_times))
start, stop = writer_times[0]
self.assertEqual(0, _find_overlaps(reader_times, start, stop))
def test_multi_writer(self):
writer_times, reader_times = _spawn_variation(0, 10)
self.assertEqual(10, len(writer_times))
self.assertEqual(0, len(reader_times))
for (start, stop) in writer_times:
self.assertEqual(1, _find_overlaps(writer_times, start, stop))