def test_asyncio_adapter(self):
# This test demonstrates that when using the asyncio coroutine
# runner (i.e. run_until_complete), the to_asyncio_future
# adapter is needed. No adapter is needed in the other direction,
# as demonstrated by other tests in the package.
@gen.coroutine
def tornado_coroutine():
yield gen.Task(self.io_loop.add_callback)
raise gen.Return(42)
native_coroutine_without_adapter = exec_test(globals(), locals(), """
async def native_coroutine_without_adapter():
return await tornado_coroutine()
""")["native_coroutine_without_adapter"]
native_coroutine_with_adapter = exec_test(globals(), locals(), """
async def native_coroutine_with_adapter():
return await to_asyncio_future(tornado_coroutine())
""")["native_coroutine_with_adapter"]
# Use the adapter, but two degrees from the tornado coroutine.
native_coroutine_with_adapter2 = exec_test(globals(), locals(), """
async def native_coroutine_with_adapter2():
return await to_asyncio_future(native_coroutine_without_adapter())
""")["native_coroutine_with_adapter2"]
# Tornado supports native coroutines both with and without adapters
self.assertEqual(
self.io_loop.run_sync(native_coroutine_without_adapter),
42)
self.assertEqual(
self.io_loop.run_sync(native_coroutine_with_adapter),
42)
self.assertEqual(
self.io_loop.run_sync(native_coroutine_with_adapter2),
42)
# Asyncio only supports coroutines that yield asyncio-compatible
# Futures.
with self.assertRaises(RuntimeError):
asyncio.get_event_loop().run_until_complete(
native_coroutine_without_adapter())
self.assertEqual(
asyncio.get_event_loop().run_until_complete(
native_coroutine_with_adapter()),
42)
self.assertEqual(
asyncio.get_event_loop().run_until_complete(
native_coroutine_with_adapter2()),
42)
def test_asyncio_future(self):
# Test that we can yield an asyncio future from a tornado coroutine.
# Without 'yield from', we must wrap coroutines in ensure_future,
# which was introduced during Python 3.4, deprecating the prior "async".
if hasattr(asyncio, 'ensure_future'):
ensure_future = asyncio.ensure_future
else:
ensure_future = asyncio. async
x = yield ensure_future(asyncio.get_event_loop().run_in_executor(
None, lambda: 42))
self.assertEqual(x, 42)
def test_asyncio_callback(self):
# Basic test that the asyncio loop is set up correctly.
asyncio.get_event_loop().call_soon(self.stop)
self.wait()