async def test_capacity_next_reblocks():
"""
GIVEN
Channel is open and full, and two coroutines are awaiting
capacity.
WHEN
Capacity becomes available, and first unblocked coroutine
puts an item.
EXPECT
Second coroutine remains blocked.
"""
q = asyncio.Queue(1)
ch = Channel(q)
assert ch.offer('a')
b = 'b'
async def put_item():
await ch.capacity()
ch.offer(b)
asyncio.get_running_loop().call_later(0.05, ch.poll)
with pytest.raises(asyncio.TimeoutError):
await asyncio.wait_for(asyncio.gather(put_item(), ch.capacity()),
timeout=0.1)
# Verify that new item was put and unblock the second coroutine.
assert await ch.take() == b
async def test_capacity_unblock_next():
"""
GIVEN
Channel is open and full, and two coroutines are awaiting
capacity.
WHEN
Capacity becomes available, and first unblocked coroutine does
not put item.
EXPECT
Second coroutine unblocks.
"""
q = asyncio.Queue(1)
ch = Channel(q)
assert ch.offer('a')
asyncio.get_running_loop().call_later(0.05, ch.poll)
await asyncio.wait_for(asyncio.gather(ch.capacity(), ch.capacity()),
timeout=0.1)
async def test_capacity():
"""
GIVEN
Channel is open and full.
WHEN
Wait for capacity.
EXPECT
Blocks.
"""
q = asyncio.Queue(1)
ch = Channel(q)
x = 'x'
ch.offer(x)
with pytest.raises(asyncio.TimeoutError):
await asyncio.wait_for(ch.capacity(), timeout=0.05)