async def test_bad_release(self):
limiter = CapacityLimiter(1)
with pytest.raises(RuntimeError) as exc:
limiter.release()
exc.match(
"this borrower isn't holding any of this CapacityLimiter's tokens")
async def test_borrow_twice(self):
limiter = CapacityLimiter(1)
await limiter.acquire()
with pytest.raises(RuntimeError) as exc:
await limiter.acquire()
exc.match(
"this borrower is already holding one of this CapacityLimiter's tokens"
)
async def test_borrow(self):
limiter = CapacityLimiter(2)
assert limiter.total_tokens == 2
assert limiter.available_tokens == 2
assert limiter.borrowed_tokens == 0
async with limiter:
assert limiter.total_tokens == 2
assert limiter.available_tokens == 1
assert limiter.borrowed_tokens == 1
async def test_asyncio_deadlock(self) -> None:
"""Regression test for #398."""
limiter = CapacityLimiter(1)
async def acquire() -> None:
async with limiter:
await asyncio.sleep(0)
loop = asyncio.get_event_loop()
task1 = loop.create_task(acquire())
task2 = loop.create_task(acquire())
await asyncio.sleep(0)
task1.cancel()
await asyncio.wait_for(task2, 1)
async def test_increase_tokens(self):
async def setter():
# Wait until waiter() is inside the limiter block
await event1.wait()
async with limiter:
# This can only happen when total_tokens has been increased
event2.set()
async def waiter():
async with limiter:
event1.set()
await event2.wait()
limiter = CapacityLimiter(1)
event1, event2 = Event(), Event()
async with create_task_group() as tg:
tg.start_soon(setter)
tg.start_soon(waiter)
await wait_all_tasks_blocked()
assert event1.is_set()
assert not event2.is_set()
limiter.total_tokens = 2
assert event2.is_set()
async def test_limit(self):
async def taskfunc():
nonlocal value
for _ in range(5):
async with limiter:
assert value == 0
value = 1
await wait_all_tasks_blocked()
value = 0
value = 0
limiter = CapacityLimiter(1)
async with create_task_group() as tg:
for _ in range(3):
tg.start_soon(taskfunc)
async def test_statistics(self):
async def waiter():
async with limiter:
pass
limiter = CapacityLimiter(1)
assert limiter.statistics().total_tokens == 1
assert limiter.statistics().borrowed_tokens == 0
assert limiter.statistics().tasks_waiting == 0
async with create_task_group() as tg:
async with limiter:
assert limiter.statistics().borrowed_tokens == 1
assert limiter.statistics().tasks_waiting == 0
for i in range(1, 3):
tg.start_soon(waiter)
await wait_all_tasks_blocked()
assert limiter.statistics().tasks_waiting == i
assert limiter.statistics().tasks_waiting == 0
assert limiter.statistics().borrowed_tokens == 0