cpython/Lib/test/test_asyncio/test_locks.py

923 lines
26 KiB
Python

"""Tests for lock.py"""
import unittest
from unittest import mock
import re
import asyncio
STR_RGX_REPR = (
r'^<(?P<class>.*?) object at (?P<address>.*?)'
r'\[(?P<extras>'
r'(set|unset|locked|unlocked)(, value:\d)?(, waiters:\d+)?'
r')\]>\Z'
)
RGX_REPR = re.compile(STR_RGX_REPR)
def tearDownModule():
asyncio.set_event_loop_policy(None)
class LockTests(unittest.IsolatedAsyncioTestCase):
async def test_repr(self):
lock = asyncio.Lock()
self.assertTrue(repr(lock).endswith('[unlocked]>'))
self.assertTrue(RGX_REPR.match(repr(lock)))
await lock.acquire()
self.assertTrue(repr(lock).endswith('[locked]>'))
self.assertTrue(RGX_REPR.match(repr(lock)))
async def test_lock(self):
lock = asyncio.Lock()
with self.assertRaisesRegex(
TypeError,
"object Lock can't be used in 'await' expression"
):
await lock
self.assertFalse(lock.locked())
async def test_lock_doesnt_accept_loop_parameter(self):
primitives_cls = [
asyncio.Lock,
asyncio.Condition,
asyncio.Event,
asyncio.Semaphore,
asyncio.BoundedSemaphore,
]
loop = asyncio.get_running_loop()
for cls in primitives_cls:
with self.assertRaisesRegex(
TypeError,
rf'As of 3.10, the \*loop\* parameter was removed from '
rf'{cls.__name__}\(\) since it is no longer necessary'
):
cls(loop=loop)
async def test_lock_by_with_statement(self):
primitives = [
asyncio.Lock(),
asyncio.Condition(),
asyncio.Semaphore(),
asyncio.BoundedSemaphore(),
]
for lock in primitives:
await asyncio.sleep(0.01)
self.assertFalse(lock.locked())
with self.assertRaisesRegex(
TypeError,
r"object \w+ can't be used in 'await' expression"
):
with await lock:
pass
self.assertFalse(lock.locked())
async def test_acquire(self):
lock = asyncio.Lock()
result = []
self.assertTrue(await lock.acquire())
async def c1(result):
if await lock.acquire():
result.append(1)
return True
async def c2(result):
if await lock.acquire():
result.append(2)
return True
async def c3(result):
if await lock.acquire():
result.append(3)
return True
t1 = asyncio.create_task(c1(result))
t2 = asyncio.create_task(c2(result))
await asyncio.sleep(0)
self.assertEqual([], result)
lock.release()
await asyncio.sleep(0)
self.assertEqual([1], result)
await asyncio.sleep(0)
self.assertEqual([1], result)
t3 = asyncio.create_task(c3(result))
lock.release()
await asyncio.sleep(0)
self.assertEqual([1, 2], result)
lock.release()
await asyncio.sleep(0)
self.assertEqual([1, 2, 3], result)
self.assertTrue(t1.done())
self.assertTrue(t1.result())
self.assertTrue(t2.done())
self.assertTrue(t2.result())
self.assertTrue(t3.done())
self.assertTrue(t3.result())
async def test_acquire_cancel(self):
lock = asyncio.Lock()
self.assertTrue(await lock.acquire())
task = asyncio.create_task(lock.acquire())
asyncio.get_running_loop().call_soon(task.cancel)
with self.assertRaises(asyncio.CancelledError):
await task
self.assertFalse(lock._waiters)
async def test_cancel_race(self):
# Several tasks:
# - A acquires the lock
# - B is blocked in acquire()
# - C is blocked in acquire()
#
# Now, concurrently:
# - B is cancelled
# - A releases the lock
#
# If B's waiter is marked cancelled but not yet removed from
# _waiters, A's release() call will crash when trying to set
# B's waiter; instead, it should move on to C's waiter.
# Setup: A has the lock, b and c are waiting.
lock = asyncio.Lock()
async def lockit(name, blocker):
await lock.acquire()
try:
if blocker is not None:
await blocker
finally:
lock.release()
fa = asyncio.get_running_loop().create_future()
ta = asyncio.create_task(lockit('A', fa))
await asyncio.sleep(0)
self.assertTrue(lock.locked())
tb = asyncio.create_task(lockit('B', None))
await asyncio.sleep(0)
self.assertEqual(len(lock._waiters), 1)
tc = asyncio.create_task(lockit('C', None))
await asyncio.sleep(0)
self.assertEqual(len(lock._waiters), 2)
# Create the race and check.
# Without the fix this failed at the last assert.
fa.set_result(None)
tb.cancel()
self.assertTrue(lock._waiters[0].cancelled())
await asyncio.sleep(0)
self.assertFalse(lock.locked())
self.assertTrue(ta.done())
self.assertTrue(tb.cancelled())
await tc
async def test_cancel_release_race(self):
# Issue 32734
# Acquire 4 locks, cancel second, release first
# and 2 locks are taken at once.
loop = asyncio.get_running_loop()
lock = asyncio.Lock()
lock_count = 0
call_count = 0
async def lockit():
nonlocal lock_count
nonlocal call_count
call_count += 1
await lock.acquire()
lock_count += 1
def trigger():
t1.cancel()
lock.release()
await lock.acquire()
t1 = asyncio.create_task(lockit())
t2 = asyncio.create_task(lockit())
t3 = asyncio.create_task(lockit())
# Start scheduled tasks
await asyncio.sleep(0)
loop.call_soon(trigger)
with self.assertRaises(asyncio.CancelledError):
# Wait for cancellation
await t1
# Make sure only one lock was taken
self.assertEqual(lock_count, 1)
# While 3 calls were made to lockit()
self.assertEqual(call_count, 3)
self.assertTrue(t1.cancelled() and t2.done())
# Cleanup the task that is stuck on acquire.
t3.cancel()
await asyncio.sleep(0)
self.assertTrue(t3.cancelled())
async def test_finished_waiter_cancelled(self):
lock = asyncio.Lock()
await lock.acquire()
self.assertTrue(lock.locked())
tb = asyncio.create_task(lock.acquire())
await asyncio.sleep(0)
self.assertEqual(len(lock._waiters), 1)
# Create a second waiter, wake up the first, and cancel it.
# Without the fix, the second was not woken up.
tc = asyncio.create_task(lock.acquire())
tb.cancel()
lock.release()
await asyncio.sleep(0)
self.assertTrue(lock.locked())
self.assertTrue(tb.cancelled())
# Cleanup
await tc
async def test_release_not_acquired(self):
lock = asyncio.Lock()
self.assertRaises(RuntimeError, lock.release)
async def test_release_no_waiters(self):
lock = asyncio.Lock()
await lock.acquire()
self.assertTrue(lock.locked())
lock.release()
self.assertFalse(lock.locked())
async def test_context_manager(self):
lock = asyncio.Lock()
self.assertFalse(lock.locked())
async with lock:
self.assertTrue(lock.locked())
self.assertFalse(lock.locked())
class EventTests(unittest.IsolatedAsyncioTestCase):
def test_repr(self):
ev = asyncio.Event()
self.assertTrue(repr(ev).endswith('[unset]>'))
match = RGX_REPR.match(repr(ev))
self.assertEqual(match.group('extras'), 'unset')
ev.set()
self.assertTrue(repr(ev).endswith('[set]>'))
self.assertTrue(RGX_REPR.match(repr(ev)))
ev._waiters.append(mock.Mock())
self.assertTrue('waiters:1' in repr(ev))
self.assertTrue(RGX_REPR.match(repr(ev)))
async def test_wait(self):
ev = asyncio.Event()
self.assertFalse(ev.is_set())
result = []
async def c1(result):
if await ev.wait():
result.append(1)
async def c2(result):
if await ev.wait():
result.append(2)
async def c3(result):
if await ev.wait():
result.append(3)
t1 = asyncio.create_task(c1(result))
t2 = asyncio.create_task(c2(result))
await asyncio.sleep(0)
self.assertEqual([], result)
t3 = asyncio.create_task(c3(result))
ev.set()
await asyncio.sleep(0)
self.assertEqual([3, 1, 2], result)
self.assertTrue(t1.done())
self.assertIsNone(t1.result())
self.assertTrue(t2.done())
self.assertIsNone(t2.result())
self.assertTrue(t3.done())
self.assertIsNone(t3.result())
async def test_wait_on_set(self):
ev = asyncio.Event()
ev.set()
res = await ev.wait()
self.assertTrue(res)
async def test_wait_cancel(self):
ev = asyncio.Event()
wait = asyncio.create_task(ev.wait())
asyncio.get_running_loop().call_soon(wait.cancel)
with self.assertRaises(asyncio.CancelledError):
await wait
self.assertFalse(ev._waiters)
async def test_clear(self):
ev = asyncio.Event()
self.assertFalse(ev.is_set())
ev.set()
self.assertTrue(ev.is_set())
ev.clear()
self.assertFalse(ev.is_set())
async def test_clear_with_waiters(self):
ev = asyncio.Event()
result = []
async def c1(result):
if await ev.wait():
result.append(1)
return True
t = asyncio.create_task(c1(result))
await asyncio.sleep(0)
self.assertEqual([], result)
ev.set()
ev.clear()
self.assertFalse(ev.is_set())
ev.set()
ev.set()
self.assertEqual(1, len(ev._waiters))
await asyncio.sleep(0)
self.assertEqual([1], result)
self.assertEqual(0, len(ev._waiters))
self.assertTrue(t.done())
self.assertTrue(t.result())
class ConditionTests(unittest.IsolatedAsyncioTestCase):
async def test_wait(self):
cond = asyncio.Condition()
result = []
async def c1(result):
await cond.acquire()
if await cond.wait():
result.append(1)
return True
async def c2(result):
await cond.acquire()
if await cond.wait():
result.append(2)
return True
async def c3(result):
await cond.acquire()
if await cond.wait():
result.append(3)
return True
t1 = asyncio.create_task(c1(result))
t2 = asyncio.create_task(c2(result))
t3 = asyncio.create_task(c3(result))
await asyncio.sleep(0)
self.assertEqual([], result)
self.assertFalse(cond.locked())
self.assertTrue(await cond.acquire())
cond.notify()
await asyncio.sleep(0)
self.assertEqual([], result)
self.assertTrue(cond.locked())
cond.release()
await asyncio.sleep(0)
self.assertEqual([1], result)
self.assertTrue(cond.locked())
cond.notify(2)
await asyncio.sleep(0)
self.assertEqual([1], result)
self.assertTrue(cond.locked())
cond.release()
await asyncio.sleep(0)
self.assertEqual([1, 2], result)
self.assertTrue(cond.locked())
cond.release()
await asyncio.sleep(0)
self.assertEqual([1, 2, 3], result)
self.assertTrue(cond.locked())
self.assertTrue(t1.done())
self.assertTrue(t1.result())
self.assertTrue(t2.done())
self.assertTrue(t2.result())
self.assertTrue(t3.done())
self.assertTrue(t3.result())
async def test_wait_cancel(self):
cond = asyncio.Condition()
await cond.acquire()
wait = asyncio.create_task(cond.wait())
asyncio.get_running_loop().call_soon(wait.cancel)
with self.assertRaises(asyncio.CancelledError):
await wait
self.assertFalse(cond._waiters)
self.assertTrue(cond.locked())
async def test_wait_cancel_contested(self):
cond = asyncio.Condition()
await cond.acquire()
self.assertTrue(cond.locked())
wait_task = asyncio.create_task(cond.wait())
await asyncio.sleep(0)
self.assertFalse(cond.locked())
# Notify, but contest the lock before cancelling
await cond.acquire()
self.assertTrue(cond.locked())
cond.notify()
asyncio.get_running_loop().call_soon(wait_task.cancel)
asyncio.get_running_loop().call_soon(cond.release)
try:
await wait_task
except asyncio.CancelledError:
# Should not happen, since no cancellation points
pass
self.assertTrue(cond.locked())
async def test_wait_cancel_after_notify(self):
# See bpo-32841
waited = False
cond = asyncio.Condition()
async def wait_on_cond():
nonlocal waited
async with cond:
waited = True # Make sure this area was reached
await cond.wait()
waiter = asyncio.create_task(wait_on_cond())
await asyncio.sleep(0) # Start waiting
await cond.acquire()
cond.notify()
await asyncio.sleep(0) # Get to acquire()
waiter.cancel()
await asyncio.sleep(0) # Activate cancellation
cond.release()
await asyncio.sleep(0) # Cancellation should occur
self.assertTrue(waiter.cancelled())
self.assertTrue(waited)
async def test_wait_unacquired(self):
cond = asyncio.Condition()
with self.assertRaises(RuntimeError):
await cond.wait()
async def test_wait_for(self):
cond = asyncio.Condition()
presult = False
def predicate():
return presult
result = []
async def c1(result):
await cond.acquire()
if await cond.wait_for(predicate):
result.append(1)
cond.release()
return True
t = asyncio.create_task(c1(result))
await asyncio.sleep(0)
self.assertEqual([], result)
await cond.acquire()
cond.notify()
cond.release()
await asyncio.sleep(0)
self.assertEqual([], result)
presult = True
await cond.acquire()
cond.notify()
cond.release()
await asyncio.sleep(0)
self.assertEqual([1], result)
self.assertTrue(t.done())
self.assertTrue(t.result())
async def test_wait_for_unacquired(self):
cond = asyncio.Condition()
# predicate can return true immediately
res = await cond.wait_for(lambda: [1, 2, 3])
self.assertEqual([1, 2, 3], res)
with self.assertRaises(RuntimeError):
await cond.wait_for(lambda: False)
async def test_notify(self):
cond = asyncio.Condition()
result = []
async def c1(result):
await cond.acquire()
if await cond.wait():
result.append(1)
cond.release()
return True
async def c2(result):
await cond.acquire()
if await cond.wait():
result.append(2)
cond.release()
return True
async def c3(result):
await cond.acquire()
if await cond.wait():
result.append(3)
cond.release()
return True
t1 = asyncio.create_task(c1(result))
t2 = asyncio.create_task(c2(result))
t3 = asyncio.create_task(c3(result))
await asyncio.sleep(0)
self.assertEqual([], result)
await cond.acquire()
cond.notify(1)
cond.release()
await asyncio.sleep(0)
self.assertEqual([1], result)
await cond.acquire()
cond.notify(1)
cond.notify(2048)
cond.release()
await asyncio.sleep(0)
self.assertEqual([1, 2, 3], result)
self.assertTrue(t1.done())
self.assertTrue(t1.result())
self.assertTrue(t2.done())
self.assertTrue(t2.result())
self.assertTrue(t3.done())
self.assertTrue(t3.result())
async def test_notify_all(self):
cond = asyncio.Condition()
result = []
async def c1(result):
await cond.acquire()
if await cond.wait():
result.append(1)
cond.release()
return True
async def c2(result):
await cond.acquire()
if await cond.wait():
result.append(2)
cond.release()
return True
t1 = asyncio.create_task(c1(result))
t2 = asyncio.create_task(c2(result))
await asyncio.sleep(0)
self.assertEqual([], result)
await cond.acquire()
cond.notify_all()
cond.release()
await asyncio.sleep(0)
self.assertEqual([1, 2], result)
self.assertTrue(t1.done())
self.assertTrue(t1.result())
self.assertTrue(t2.done())
self.assertTrue(t2.result())
def test_notify_unacquired(self):
cond = asyncio.Condition()
self.assertRaises(RuntimeError, cond.notify)
def test_notify_all_unacquired(self):
cond = asyncio.Condition()
self.assertRaises(RuntimeError, cond.notify_all)
async def test_repr(self):
cond = asyncio.Condition()
self.assertTrue('unlocked' in repr(cond))
self.assertTrue(RGX_REPR.match(repr(cond)))
await cond.acquire()
self.assertTrue('locked' in repr(cond))
cond._waiters.append(mock.Mock())
self.assertTrue('waiters:1' in repr(cond))
self.assertTrue(RGX_REPR.match(repr(cond)))
cond._waiters.append(mock.Mock())
self.assertTrue('waiters:2' in repr(cond))
self.assertTrue(RGX_REPR.match(repr(cond)))
async def test_context_manager(self):
cond = asyncio.Condition()
self.assertFalse(cond.locked())
async with cond:
self.assertTrue(cond.locked())
self.assertFalse(cond.locked())
async def test_explicit_lock(self):
async def f(lock=None, cond=None):
if lock is None:
lock = asyncio.Lock()
if cond is None:
cond = asyncio.Condition(lock)
self.assertIs(cond._lock, lock)
self.assertFalse(lock.locked())
self.assertFalse(cond.locked())
async with cond:
self.assertTrue(lock.locked())
self.assertTrue(cond.locked())
self.assertFalse(lock.locked())
self.assertFalse(cond.locked())
async with lock:
self.assertTrue(lock.locked())
self.assertTrue(cond.locked())
self.assertFalse(lock.locked())
self.assertFalse(cond.locked())
# All should work in the same way.
await f()
await f(asyncio.Lock())
lock = asyncio.Lock()
await f(lock, asyncio.Condition(lock))
async def test_ambiguous_loops(self):
loop = asyncio.new_event_loop()
self.addCleanup(loop.close)
async def wrong_loop_in_lock():
with self.assertRaises(TypeError):
asyncio.Lock(loop=loop) # actively disallowed since 3.10
lock = asyncio.Lock()
lock._loop = loop # use private API for testing
async with lock:
# acquired immediately via the fast-path
# without interaction with any event loop.
cond = asyncio.Condition(lock)
# cond.acquire() will trigger waiting on the lock
# and it will discover the event loop mismatch.
with self.assertRaisesRegex(
RuntimeError,
"is bound to a different event loop",
):
await cond.acquire()
async def wrong_loop_in_cond():
# Same analogy here with the condition's loop.
lock = asyncio.Lock()
async with lock:
with self.assertRaises(TypeError):
asyncio.Condition(lock, loop=loop)
cond = asyncio.Condition(lock)
cond._loop = loop
with self.assertRaisesRegex(
RuntimeError,
"is bound to a different event loop",
):
await cond.wait()
await wrong_loop_in_lock()
await wrong_loop_in_cond()
async def test_timeout_in_block(self):
condition = asyncio.Condition()
async with condition:
with self.assertRaises(asyncio.TimeoutError):
await asyncio.wait_for(condition.wait(), timeout=0.5)
class SemaphoreTests(unittest.IsolatedAsyncioTestCase):
def test_initial_value_zero(self):
sem = asyncio.Semaphore(0)
self.assertTrue(sem.locked())
async def test_repr(self):
sem = asyncio.Semaphore()
self.assertTrue(repr(sem).endswith('[unlocked, value:1]>'))
self.assertTrue(RGX_REPR.match(repr(sem)))
await sem.acquire()
self.assertTrue(repr(sem).endswith('[locked]>'))
self.assertTrue('waiters' not in repr(sem))
self.assertTrue(RGX_REPR.match(repr(sem)))
sem._waiters.append(mock.Mock())
self.assertTrue('waiters:1' in repr(sem))
self.assertTrue(RGX_REPR.match(repr(sem)))
sem._waiters.append(mock.Mock())
self.assertTrue('waiters:2' in repr(sem))
self.assertTrue(RGX_REPR.match(repr(sem)))
async def test_semaphore(self):
sem = asyncio.Semaphore()
self.assertEqual(1, sem._value)
with self.assertRaisesRegex(
TypeError,
"object Semaphore can't be used in 'await' expression",
):
await sem
self.assertFalse(sem.locked())
self.assertEqual(1, sem._value)
def test_semaphore_value(self):
self.assertRaises(ValueError, asyncio.Semaphore, -1)
async def test_acquire(self):
sem = asyncio.Semaphore(3)
result = []
self.assertTrue(await sem.acquire())
self.assertTrue(await sem.acquire())
self.assertFalse(sem.locked())
async def c1(result):
await sem.acquire()
result.append(1)
return True
async def c2(result):
await sem.acquire()
result.append(2)
return True
async def c3(result):
await sem.acquire()
result.append(3)
return True
async def c4(result):
await sem.acquire()
result.append(4)
return True
t1 = asyncio.create_task(c1(result))
t2 = asyncio.create_task(c2(result))
t3 = asyncio.create_task(c3(result))
await asyncio.sleep(0)
self.assertEqual([1], result)
self.assertTrue(sem.locked())
self.assertEqual(2, len(sem._waiters))
self.assertEqual(0, sem._value)
t4 = asyncio.create_task(c4(result))
sem.release()
sem.release()
self.assertEqual(2, sem._value)
await asyncio.sleep(0)
self.assertEqual(0, sem._value)
self.assertEqual(3, len(result))
self.assertTrue(sem.locked())
self.assertEqual(1, len(sem._waiters))
self.assertEqual(0, sem._value)
self.assertTrue(t1.done())
self.assertTrue(t1.result())
race_tasks = [t2, t3, t4]
done_tasks = [t for t in race_tasks if t.done() and t.result()]
self.assertTrue(2, len(done_tasks))
# cleanup locked semaphore
sem.release()
await asyncio.gather(*race_tasks)
async def test_acquire_cancel(self):
sem = asyncio.Semaphore()
await sem.acquire()
acquire = asyncio.create_task(sem.acquire())
asyncio.get_running_loop().call_soon(acquire.cancel)
with self.assertRaises(asyncio.CancelledError):
await acquire
self.assertTrue((not sem._waiters) or
all(waiter.done() for waiter in sem._waiters))
async def test_acquire_cancel_before_awoken(self):
sem = asyncio.Semaphore(value=0)
t1 = asyncio.create_task(sem.acquire())
t2 = asyncio.create_task(sem.acquire())
t3 = asyncio.create_task(sem.acquire())
t4 = asyncio.create_task(sem.acquire())
await asyncio.sleep(0)
t1.cancel()
t2.cancel()
sem.release()
await asyncio.sleep(0)
num_done = sum(t.done() for t in [t3, t4])
self.assertEqual(num_done, 1)
self.assertTrue(t3.done())
self.assertFalse(t4.done())
t3.cancel()
t4.cancel()
await asyncio.sleep(0)
async def test_acquire_hang(self):
sem = asyncio.Semaphore(value=0)
t1 = asyncio.create_task(sem.acquire())
t2 = asyncio.create_task(sem.acquire())
await asyncio.sleep(0)
t1.cancel()
sem.release()
await asyncio.sleep(0)
self.assertTrue(sem.locked())
self.assertTrue(t2.done())
def test_release_not_acquired(self):
sem = asyncio.BoundedSemaphore()
self.assertRaises(ValueError, sem.release)
async def test_release_no_waiters(self):
sem = asyncio.Semaphore()
await sem.acquire()
self.assertTrue(sem.locked())
sem.release()
self.assertFalse(sem.locked())
if __name__ == '__main__':
unittest.main()