RuntimeError: set_wakeup_fd only works in main thread

[eteamin]

Long story short

I'm trying to run an aiohttp Application in a deamon thread. I use asyncio.get_child_watcher() in the main thread so subprocesses will be allowed to run. but I get RuntimeError: set_wakeup_fd only works in main thread

Expected behaviour

Running aiohttp Application in a worker thread

Actual behaviour

RuntimeError is raised

Steps to reproduce

A little more of context:
I'm writing tests for an aiohttp application. This app calls an external rest-full API to get some data. Now I'm trying to create another aiohttp application in a daemon thread to mock that third-party application behaviour.
This is my MockServer class:

class MockingServer(object):
    def __init__(self, host, port):
    self.host = host
    self.port = port
    self.app = Application()
    r = Resource('/validate_get/{content_uid}/{user_uuid}', Route('GET', '/validate_get', self.mock_handler))
    resource = self.app.router.add_resource(r.path)
    resource.add_route(r.route.method, r.route.handler)

    async def mock_handler(self, request):
        return json_response({'ok': True})

    def start(self):
        asyncio.get_child_watcher()
        thread = Thread(target=self._start, daemon=True)
        thread.start()

    def _start(self, *args):
        loop = asyncio.new_event_loop()
        asyncio.set_event_loop(loop)
        run_app(self.app, port=self.port, loop=loop)` 

Your environment

Python 3.5.2
OSX
aiohttp

[asvetlov]

You don't need a separate thread for running mocking server.
Take a look on https://github.com/aio-libs/aiohttp/blob/master/examples/fake_server.py

[eteamin]

Thank you for the useful example!

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a [new issue] for related bugs.
If you feel like there's important points made in this discussion, please include those exceprts into that [new issue].
[new issue]: https://github.com/aio-libs/aiohttp/issues/new