Application hanging after KeyboardInterrupt

Nadie ha tomado este issue todavía.

* **uvloop version**: 0.14.0
* **Python version**: 3.7.4
* **Platform**: Manjaro
* **Can you reproduce the bug with `PYTHONASYNCIODEBUG` in env?**: Yes
* **Does uvloop behave differently from vanilla asyncio? How?**: With vanilla, the application terminates gracefully upon reception of a keyboard interrupt. If I use `uvloop`, I get a runtime warning and the application hangs until I run a `kill -9` on the process id.

Snippet: `issue.py`
```
import asyncio
from asyncio import AbstractEventLoop
import os
from typing import Union, Type

import uvloop # type: ignore
from aiohttp import web
import signal

import aiologger

logger = aiologger.Logger.with_default_handlers()

async def handle_exception(loop: AbstractEventLoop, context):
# context["message"] will always be there; but context["exception"] may not
msg = context.get("exception", context["message"])
await logger.error(f"Caught exception: {msg}")
await logger.info("Shutting down...")
asyncio.create_task(shutdown(loop))

async def shutdown(loop: AbstractEventLoop, signal=None):
"""Cleanup tasks tied to the service's shutdown."""
if signal:
await logger.info(f"Received exit signal {signal.name}...")

tasks = [t for t in asyncio.all_tasks() if t is not asyncio.current_task()]

[task.cancel() for task in tasks]

await logger.info(f"Cancelling {len(tasks)} outstanding tasks")
await asyncio.gather(*tasks, return_exceptions=True)
loop.stop()

async def start(
app: web.Application, host: str, port: Union[str, int]
) -> web.AppRunner:
"""Start the server"""
runner = web.AppRunner(app)
await runner.setup()
server = web.TCPSite(runner, host, int(port))
await server.start()
return runner

def main() -> None:
"""Entrypoint"""
host = os.environ.get("HOST", "localhost")
port = os.environ.get("PORT", 8000)
app = web.Application()
loop = asyncio.get_event_loop()
signals = (signal.SIGHUP, signal.SIGTERM, signal.SIGINT)
for s in signals:
loop.add_signal_handler(
s, lambda s=s: asyncio.create_task(shutdown(loop, signal=s))
)
loop.set_exception_handler(handle_exception)
print(
f"======== Running on http://{host}:{port} ========\n" "(Press CTRL+C to quit)"
)
try:
runner = loop.run_until_complete(start(app, host, port))
loop.run_forever()
finally:
loop.run_until_complete(runner.cleanup())
loop.close()

if __name__ == "__main__":
uvloop.install()
main()

```

Run the file:
`python issue.py`

Then hit Ctrl+c on keyboard, output:
```
======== Running on http://0.0.0.0:8000 ========
(Press CTRL+C to quit)
^Cissue.py:70: RuntimeWarning: coroutine 'handle_exception' was never awaited
Coroutine created at (most recent call last)
File "issue.py", line 78, in
main()
File "issue.py", line 70, in main
loop.run_forever()
loop.run_forever()
RuntimeWarning: Enable tracemalloc to get the object allocation traceback
```
Which hangs until running `kill -9 `

If you comment out `uvloop.install()` and follow the same steps, the program terminates as expected. Output:
```
======== Running on http://0.0.0.0:8000 ========
(Press CTRL+C to quit)
^CReceived exit signal SIGINT...
Cancelling 0 outstanding tasks

```

Empieza ejecutando issue.py con uvloop 0.14.0, Python 3.7.4 y PYTHONASYNCIODEBUG habilitado; después, compara su comportamiento con Ctrl+C con el de vanilla asyncio. Investiga el manejo de excepciones del bucle de eventos y la ruta de apagado por señal que se muestran en el fragmento. Se considera terminado cuando KeyboardInterrupt activa una limpieza ordenada sin la advertencia de una coroutine no esperada ni un proceso bloqueado.

Escrito por el modelo de indexación a partir del texto del issue.