cpython/Lib/test/test_asyncio/test_locks.py

994 lines
29 KiB
Python

"""Tests for lock.py"""
import unittest
from unittest import mock
import re
import asyncio
from asyncio import test_utils
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)
class LockTests(test_utils.TestCase):
def setUp(self):
super().setUp()
self.loop = self.new_test_loop()
def test_ctor_loop(self):
loop = mock.Mock()
lock = asyncio.Lock(loop=loop)
self.assertIs(lock._loop, loop)
lock = asyncio.Lock(loop=self.loop)
self.assertIs(lock._loop, self.loop)
def test_ctor_noloop(self):
asyncio.set_event_loop(self.loop)
lock = asyncio.Lock()
self.assertIs(lock._loop, self.loop)
def test_repr(self):
lock = asyncio.Lock(loop=self.loop)
self.assertTrue(repr(lock).endswith('[unlocked]>'))
self.assertTrue(RGX_REPR.match(repr(lock)))
@asyncio.coroutine
def acquire_lock():
yield from lock
self.loop.run_until_complete(acquire_lock())
self.assertTrue(repr(lock).endswith('[locked]>'))
self.assertTrue(RGX_REPR.match(repr(lock)))
def test_lock(self):
lock = asyncio.Lock(loop=self.loop)
@asyncio.coroutine
def acquire_lock():
return (yield from lock)
res = self.loop.run_until_complete(acquire_lock())
self.assertTrue(res)
self.assertTrue(lock.locked())
lock.release()
self.assertFalse(lock.locked())
def test_acquire(self):
lock = asyncio.Lock(loop=self.loop)
result = []
self.assertTrue(self.loop.run_until_complete(lock.acquire()))
@asyncio.coroutine
def c1(result):
if (yield from lock.acquire()):
result.append(1)
return True
@asyncio.coroutine
def c2(result):
if (yield from lock.acquire()):
result.append(2)
return True
@asyncio.coroutine
def c3(result):
if (yield from lock.acquire()):
result.append(3)
return True
t1 = asyncio.Task(c1(result), loop=self.loop)
t2 = asyncio.Task(c2(result), loop=self.loop)
test_utils.run_briefly(self.loop)
self.assertEqual([], result)
lock.release()
test_utils.run_briefly(self.loop)
self.assertEqual([1], result)
test_utils.run_briefly(self.loop)
self.assertEqual([1], result)
t3 = asyncio.Task(c3(result), loop=self.loop)
lock.release()
test_utils.run_briefly(self.loop)
self.assertEqual([1, 2], result)
lock.release()
test_utils.run_briefly(self.loop)
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())
def test_acquire_cancel(self):
lock = asyncio.Lock(loop=self.loop)
self.assertTrue(self.loop.run_until_complete(lock.acquire()))
task = asyncio.Task(lock.acquire(), loop=self.loop)
self.loop.call_soon(task.cancel)
self.assertRaises(
asyncio.CancelledError,
self.loop.run_until_complete, task)
self.assertFalse(lock._waiters)
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(loop=self.loop)
@asyncio.coroutine
def lockit(name, blocker):
yield from lock.acquire()
try:
if blocker is not None:
yield from blocker
finally:
lock.release()
fa = asyncio.Future(loop=self.loop)
ta = asyncio.Task(lockit('A', fa), loop=self.loop)
test_utils.run_briefly(self.loop)
self.assertTrue(lock.locked())
tb = asyncio.Task(lockit('B', None), loop=self.loop)
test_utils.run_briefly(self.loop)
self.assertEqual(len(lock._waiters), 1)
tc = asyncio.Task(lockit('C', None), loop=self.loop)
test_utils.run_briefly(self.loop)
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())
test_utils.run_briefly(self.loop)
self.assertFalse(lock.locked())
self.assertTrue(ta.done())
self.assertTrue(tb.cancelled())
self.assertTrue(tc.done())
def test_cancel_release_race(self):
# Issue 32734
# Acquire 4 locks, cancel second, release first
# and 2 locks are taken at once.
lock = asyncio.Lock(loop=self.loop)
lock_count = 0
call_count = 0
async def lockit():
nonlocal lock_count
nonlocal call_count
call_count += 1
await lock.acquire()
lock_count += 1
async def lockandtrigger():
await lock.acquire()
self.loop.call_soon(trigger)
def trigger():
t1.cancel()
lock.release()
t0 = self.loop.create_task(lockandtrigger())
t1 = self.loop.create_task(lockit())
t2 = self.loop.create_task(lockit())
t3 = self.loop.create_task(lockit())
# First loop acquires all
test_utils.run_briefly(self.loop)
self.assertTrue(t0.done())
# Second loop calls trigger
test_utils.run_briefly(self.loop)
# Third loop calls cancellation
test_utils.run_briefly(self.loop)
# 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()
test_utils.run_briefly(self.loop)
self.assertTrue(t3.cancelled())
def test_finished_waiter_cancelled(self):
lock = asyncio.Lock(loop=self.loop)
ta = asyncio.Task(lock.acquire(), loop=self.loop)
test_utils.run_briefly(self.loop)
self.assertTrue(lock.locked())
tb = asyncio.Task(lock.acquire(), loop=self.loop)
test_utils.run_briefly(self.loop)
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.Task(lock.acquire(), loop=self.loop)
lock.release()
tb.cancel()
test_utils.run_briefly(self.loop)
self.assertTrue(lock.locked())
self.assertTrue(ta.done())
self.assertTrue(tb.cancelled())
def test_release_not_acquired(self):
lock = asyncio.Lock(loop=self.loop)
self.assertRaises(RuntimeError, lock.release)
def test_release_no_waiters(self):
lock = asyncio.Lock(loop=self.loop)
self.loop.run_until_complete(lock.acquire())
self.assertTrue(lock.locked())
lock.release()
self.assertFalse(lock.locked())
def test_context_manager(self):
lock = asyncio.Lock(loop=self.loop)
@asyncio.coroutine
def acquire_lock():
return (yield from lock)
with self.loop.run_until_complete(acquire_lock()):
self.assertTrue(lock.locked())
self.assertFalse(lock.locked())
def test_context_manager_cant_reuse(self):
lock = asyncio.Lock(loop=self.loop)
@asyncio.coroutine
def acquire_lock():
return (yield from lock)
# This spells "yield from lock" outside a generator.
cm = self.loop.run_until_complete(acquire_lock())
with cm:
self.assertTrue(lock.locked())
self.assertFalse(lock.locked())
with self.assertRaises(AttributeError):
with cm:
pass
def test_context_manager_no_yield(self):
lock = asyncio.Lock(loop=self.loop)
try:
with lock:
self.fail('RuntimeError is not raised in with expression')
except RuntimeError as err:
self.assertEqual(
str(err),
'"yield from" should be used as context manager expression')
self.assertFalse(lock.locked())
class EventTests(test_utils.TestCase):
def setUp(self):
super().setUp()
self.loop = self.new_test_loop()
def test_ctor_loop(self):
loop = mock.Mock()
ev = asyncio.Event(loop=loop)
self.assertIs(ev._loop, loop)
ev = asyncio.Event(loop=self.loop)
self.assertIs(ev._loop, self.loop)
def test_ctor_noloop(self):
asyncio.set_event_loop(self.loop)
ev = asyncio.Event()
self.assertIs(ev._loop, self.loop)
def test_repr(self):
ev = asyncio.Event(loop=self.loop)
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)))
def test_wait(self):
ev = asyncio.Event(loop=self.loop)
self.assertFalse(ev.is_set())
result = []
@asyncio.coroutine
def c1(result):
if (yield from ev.wait()):
result.append(1)
@asyncio.coroutine
def c2(result):
if (yield from ev.wait()):
result.append(2)
@asyncio.coroutine
def c3(result):
if (yield from ev.wait()):
result.append(3)
t1 = asyncio.Task(c1(result), loop=self.loop)
t2 = asyncio.Task(c2(result), loop=self.loop)
test_utils.run_briefly(self.loop)
self.assertEqual([], result)
t3 = asyncio.Task(c3(result), loop=self.loop)
ev.set()
test_utils.run_briefly(self.loop)
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())
def test_wait_on_set(self):
ev = asyncio.Event(loop=self.loop)
ev.set()
res = self.loop.run_until_complete(ev.wait())
self.assertTrue(res)
def test_wait_cancel(self):
ev = asyncio.Event(loop=self.loop)
wait = asyncio.Task(ev.wait(), loop=self.loop)
self.loop.call_soon(wait.cancel)
self.assertRaises(
asyncio.CancelledError,
self.loop.run_until_complete, wait)
self.assertFalse(ev._waiters)
def test_clear(self):
ev = asyncio.Event(loop=self.loop)
self.assertFalse(ev.is_set())
ev.set()
self.assertTrue(ev.is_set())
ev.clear()
self.assertFalse(ev.is_set())
def test_clear_with_waiters(self):
ev = asyncio.Event(loop=self.loop)
result = []
@asyncio.coroutine
def c1(result):
if (yield from ev.wait()):
result.append(1)
return True
t = asyncio.Task(c1(result), loop=self.loop)
test_utils.run_briefly(self.loop)
self.assertEqual([], result)
ev.set()
ev.clear()
self.assertFalse(ev.is_set())
ev.set()
ev.set()
self.assertEqual(1, len(ev._waiters))
test_utils.run_briefly(self.loop)
self.assertEqual([1], result)
self.assertEqual(0, len(ev._waiters))
self.assertTrue(t.done())
self.assertTrue(t.result())
class ConditionTests(test_utils.TestCase):
def setUp(self):
super().setUp()
self.loop = self.new_test_loop()
def test_ctor_loop(self):
loop = mock.Mock()
cond = asyncio.Condition(loop=loop)
self.assertIs(cond._loop, loop)
cond = asyncio.Condition(loop=self.loop)
self.assertIs(cond._loop, self.loop)
def test_ctor_noloop(self):
asyncio.set_event_loop(self.loop)
cond = asyncio.Condition()
self.assertIs(cond._loop, self.loop)
def test_wait(self):
cond = asyncio.Condition(loop=self.loop)
result = []
@asyncio.coroutine
def c1(result):
yield from cond.acquire()
if (yield from cond.wait()):
result.append(1)
return True
@asyncio.coroutine
def c2(result):
yield from cond.acquire()
if (yield from cond.wait()):
result.append(2)
return True
@asyncio.coroutine
def c3(result):
yield from cond.acquire()
if (yield from cond.wait()):
result.append(3)
return True
t1 = asyncio.Task(c1(result), loop=self.loop)
t2 = asyncio.Task(c2(result), loop=self.loop)
t3 = asyncio.Task(c3(result), loop=self.loop)
test_utils.run_briefly(self.loop)
self.assertEqual([], result)
self.assertFalse(cond.locked())
self.assertTrue(self.loop.run_until_complete(cond.acquire()))
cond.notify()
test_utils.run_briefly(self.loop)
self.assertEqual([], result)
self.assertTrue(cond.locked())
cond.release()
test_utils.run_briefly(self.loop)
self.assertEqual([1], result)
self.assertTrue(cond.locked())
cond.notify(2)
test_utils.run_briefly(self.loop)
self.assertEqual([1], result)
self.assertTrue(cond.locked())
cond.release()
test_utils.run_briefly(self.loop)
self.assertEqual([1, 2], result)
self.assertTrue(cond.locked())
cond.release()
test_utils.run_briefly(self.loop)
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())
def test_wait_cancel(self):
cond = asyncio.Condition(loop=self.loop)
self.loop.run_until_complete(cond.acquire())
wait = asyncio.Task(cond.wait(), loop=self.loop)
self.loop.call_soon(wait.cancel)
self.assertRaises(
asyncio.CancelledError,
self.loop.run_until_complete, wait)
self.assertFalse(cond._waiters)
self.assertTrue(cond.locked())
def test_wait_cancel_contested(self):
cond = asyncio.Condition(loop=self.loop)
self.loop.run_until_complete(cond.acquire())
self.assertTrue(cond.locked())
wait_task = asyncio.Task(cond.wait(), loop=self.loop)
test_utils.run_briefly(self.loop)
self.assertFalse(cond.locked())
# Notify, but contest the lock before cancelling
self.loop.run_until_complete(cond.acquire())
self.assertTrue(cond.locked())
cond.notify()
self.loop.call_soon(wait_task.cancel)
self.loop.call_soon(cond.release)
try:
self.loop.run_until_complete(wait_task)
except asyncio.CancelledError:
# Should not happen, since no cancellation points
pass
self.assertTrue(cond.locked())
def test_wait_unacquired(self):
cond = asyncio.Condition(loop=self.loop)
self.assertRaises(
RuntimeError,
self.loop.run_until_complete, cond.wait())
def test_wait_for(self):
cond = asyncio.Condition(loop=self.loop)
presult = False
def predicate():
return presult
result = []
@asyncio.coroutine
def c1(result):
yield from cond.acquire()
if (yield from cond.wait_for(predicate)):
result.append(1)
cond.release()
return True
t = asyncio.Task(c1(result), loop=self.loop)
test_utils.run_briefly(self.loop)
self.assertEqual([], result)
self.loop.run_until_complete(cond.acquire())
cond.notify()
cond.release()
test_utils.run_briefly(self.loop)
self.assertEqual([], result)
presult = True
self.loop.run_until_complete(cond.acquire())
cond.notify()
cond.release()
test_utils.run_briefly(self.loop)
self.assertEqual([1], result)
self.assertTrue(t.done())
self.assertTrue(t.result())
def test_wait_for_unacquired(self):
cond = asyncio.Condition(loop=self.loop)
# predicate can return true immediately
res = self.loop.run_until_complete(cond.wait_for(lambda: [1, 2, 3]))
self.assertEqual([1, 2, 3], res)
self.assertRaises(
RuntimeError,
self.loop.run_until_complete,
cond.wait_for(lambda: False))
def test_notify(self):
cond = asyncio.Condition(loop=self.loop)
result = []
@asyncio.coroutine
def c1(result):
yield from cond.acquire()
if (yield from cond.wait()):
result.append(1)
cond.release()
return True
@asyncio.coroutine
def c2(result):
yield from cond.acquire()
if (yield from cond.wait()):
result.append(2)
cond.release()
return True
@asyncio.coroutine
def c3(result):
yield from cond.acquire()
if (yield from cond.wait()):
result.append(3)
cond.release()
return True
t1 = asyncio.Task(c1(result), loop=self.loop)
t2 = asyncio.Task(c2(result), loop=self.loop)
t3 = asyncio.Task(c3(result), loop=self.loop)
test_utils.run_briefly(self.loop)
self.assertEqual([], result)
self.loop.run_until_complete(cond.acquire())
cond.notify(1)
cond.release()
test_utils.run_briefly(self.loop)
self.assertEqual([1], result)
self.loop.run_until_complete(cond.acquire())
cond.notify(1)
cond.notify(2048)
cond.release()
test_utils.run_briefly(self.loop)
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())
def test_notify_all(self):
cond = asyncio.Condition(loop=self.loop)
result = []
@asyncio.coroutine
def c1(result):
yield from cond.acquire()
if (yield from cond.wait()):
result.append(1)
cond.release()
return True
@asyncio.coroutine
def c2(result):
yield from cond.acquire()
if (yield from cond.wait()):
result.append(2)
cond.release()
return True
t1 = asyncio.Task(c1(result), loop=self.loop)
t2 = asyncio.Task(c2(result), loop=self.loop)
test_utils.run_briefly(self.loop)
self.assertEqual([], result)
self.loop.run_until_complete(cond.acquire())
cond.notify_all()
cond.release()
test_utils.run_briefly(self.loop)
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(loop=self.loop)
self.assertRaises(RuntimeError, cond.notify)
def test_notify_all_unacquired(self):
cond = asyncio.Condition(loop=self.loop)
self.assertRaises(RuntimeError, cond.notify_all)
def test_repr(self):
cond = asyncio.Condition(loop=self.loop)
self.assertTrue('unlocked' in repr(cond))
self.assertTrue(RGX_REPR.match(repr(cond)))
self.loop.run_until_complete(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)))
def test_context_manager(self):
cond = asyncio.Condition(loop=self.loop)
@asyncio.coroutine
def acquire_cond():
return (yield from cond)
with self.loop.run_until_complete(acquire_cond()):
self.assertTrue(cond.locked())
self.assertFalse(cond.locked())
def test_context_manager_no_yield(self):
cond = asyncio.Condition(loop=self.loop)
try:
with cond:
self.fail('RuntimeError is not raised in with expression')
except RuntimeError as err:
self.assertEqual(
str(err),
'"yield from" should be used as context manager expression')
self.assertFalse(cond.locked())
def test_explicit_lock(self):
lock = asyncio.Lock(loop=self.loop)
cond = asyncio.Condition(lock, loop=self.loop)
self.assertIs(cond._lock, lock)
self.assertIs(cond._loop, lock._loop)
def test_ambiguous_loops(self):
loop = self.new_test_loop()
self.addCleanup(loop.close)
lock = asyncio.Lock(loop=self.loop)
with self.assertRaises(ValueError):
asyncio.Condition(lock, loop=loop)
class SemaphoreTests(test_utils.TestCase):
def setUp(self):
super().setUp()
self.loop = self.new_test_loop()
def test_ctor_loop(self):
loop = mock.Mock()
sem = asyncio.Semaphore(loop=loop)
self.assertIs(sem._loop, loop)
sem = asyncio.Semaphore(loop=self.loop)
self.assertIs(sem._loop, self.loop)
def test_ctor_noloop(self):
asyncio.set_event_loop(self.loop)
sem = asyncio.Semaphore()
self.assertIs(sem._loop, self.loop)
def test_initial_value_zero(self):
sem = asyncio.Semaphore(0, loop=self.loop)
self.assertTrue(sem.locked())
def test_repr(self):
sem = asyncio.Semaphore(loop=self.loop)
self.assertTrue(repr(sem).endswith('[unlocked,value:1]>'))
self.assertTrue(RGX_REPR.match(repr(sem)))
self.loop.run_until_complete(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)))
def test_semaphore(self):
sem = asyncio.Semaphore(loop=self.loop)
self.assertEqual(1, sem._value)
@asyncio.coroutine
def acquire_lock():
return (yield from sem)
res = self.loop.run_until_complete(acquire_lock())
self.assertTrue(res)
self.assertTrue(sem.locked())
self.assertEqual(0, sem._value)
sem.release()
self.assertFalse(sem.locked())
self.assertEqual(1, sem._value)
def test_semaphore_value(self):
self.assertRaises(ValueError, asyncio.Semaphore, -1)
def test_acquire(self):
sem = asyncio.Semaphore(3, loop=self.loop)
result = []
self.assertTrue(self.loop.run_until_complete(sem.acquire()))
self.assertTrue(self.loop.run_until_complete(sem.acquire()))
self.assertFalse(sem.locked())
@asyncio.coroutine
def c1(result):
yield from sem.acquire()
result.append(1)
return True
@asyncio.coroutine
def c2(result):
yield from sem.acquire()
result.append(2)
return True
@asyncio.coroutine
def c3(result):
yield from sem.acquire()
result.append(3)
return True
@asyncio.coroutine
def c4(result):
yield from sem.acquire()
result.append(4)
return True
t1 = asyncio.Task(c1(result), loop=self.loop)
t2 = asyncio.Task(c2(result), loop=self.loop)
t3 = asyncio.Task(c3(result), loop=self.loop)
test_utils.run_briefly(self.loop)
self.assertEqual([1], result)
self.assertTrue(sem.locked())
self.assertEqual(2, len(sem._waiters))
self.assertEqual(0, sem._value)
t4 = asyncio.Task(c4(result), loop=self.loop)
sem.release()
sem.release()
self.assertEqual(2, sem._value)
test_utils.run_briefly(self.loop)
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()
self.loop.run_until_complete(asyncio.gather(*race_tasks))
def test_acquire_cancel(self):
sem = asyncio.Semaphore(loop=self.loop)
self.loop.run_until_complete(sem.acquire())
acquire = asyncio.Task(sem.acquire(), loop=self.loop)
self.loop.call_soon(acquire.cancel)
self.assertRaises(
asyncio.CancelledError,
self.loop.run_until_complete, acquire)
self.assertTrue((not sem._waiters) or
all(waiter.done() for waiter in sem._waiters))
def test_acquire_cancel_before_awoken(self):
sem = asyncio.Semaphore(value=0, loop=self.loop)
t1 = asyncio.Task(sem.acquire(), loop=self.loop)
t2 = asyncio.Task(sem.acquire(), loop=self.loop)
t3 = asyncio.Task(sem.acquire(), loop=self.loop)
t4 = asyncio.Task(sem.acquire(), loop=self.loop)
test_utils.run_briefly(self.loop)
sem.release()
t1.cancel()
t2.cancel()
test_utils.run_briefly(self.loop)
num_done = sum(t.done() for t in [t3, t4])
self.assertEqual(num_done, 1)
t3.cancel()
t4.cancel()
test_utils.run_briefly(self.loop)
def test_acquire_hang(self):
sem = asyncio.Semaphore(value=0, loop=self.loop)
t1 = asyncio.Task(sem.acquire(), loop=self.loop)
t2 = asyncio.Task(sem.acquire(), loop=self.loop)
test_utils.run_briefly(self.loop)
sem.release()
t1.cancel()
test_utils.run_briefly(self.loop)
self.assertTrue(sem.locked())
def test_release_not_acquired(self):
sem = asyncio.BoundedSemaphore(loop=self.loop)
self.assertRaises(ValueError, sem.release)
def test_release_no_waiters(self):
sem = asyncio.Semaphore(loop=self.loop)
self.loop.run_until_complete(sem.acquire())
self.assertTrue(sem.locked())
sem.release()
self.assertFalse(sem.locked())
def test_context_manager(self):
sem = asyncio.Semaphore(2, loop=self.loop)
@asyncio.coroutine
def acquire_lock():
return (yield from sem)
with self.loop.run_until_complete(acquire_lock()):
self.assertFalse(sem.locked())
self.assertEqual(1, sem._value)
with self.loop.run_until_complete(acquire_lock()):
self.assertTrue(sem.locked())
self.assertEqual(2, sem._value)
def test_context_manager_no_yield(self):
sem = asyncio.Semaphore(2, loop=self.loop)
try:
with sem:
self.fail('RuntimeError is not raised in with expression')
except RuntimeError as err:
self.assertEqual(
str(err),
'"yield from" should be used as context manager expression')
self.assertEqual(2, sem._value)
if __name__ == '__main__':
unittest.main()