title: asyncio doesn't work on listening to the http request
body: <p>I am running <code>aiohttp</code> as my server. When a request comes in, I try to spawn a process to handle it. But I get the below error:</p>
  
  <blockquote>
    <p>Traceback (most recent call last):   File "asyncppx.py", line 33, in
    
        app.add_routes([web.get('/', asyncio.ensure_future(runMcows(n)))])   File
    "/Users/i3ye/Programming/vsc/async/env/lib/python3.6/site-packages/aiohttp/web_app.py",
    line 231, in add_routes
        self.router.add_routes(routes)   File "/Users/i3ye/Programming/vsc/async/env/lib/python3.6/site-packages/aiohttp/web_urldispatcher.py",
    line 966, in add_routes
        route_obj.register(self)   File "/Users/i3ye/Programming/vsc/async/env/lib/python3.6/site-packages/aiohttp/web_routedef.py",
    line 38, in register
        reg(self.path, self.handler, **self.kwargs)   File "/Users/i3ye/Programming/vsc/async/env/lib/python3.6/site-packages/aiohttp/web_urldispatcher.py",
    line 922, in add_get
        resource.add_route(hdrs.METH_HEAD, handler, **kwargs)   File "/Users/i3ye/Programming/vsc/async/env/lib/python3.6/site-packages/aiohttp/web_urldispatcher.py",
    line 269, in add_route
        expect_handler=expect_handler)   File "/Users/i3ye/Programming/vsc/async/env/lib/python3.6/site-packages/aiohttp/web_urldispatcher.py",
    line 682, in <strong>init</strong>
        resource=resource)   File "/Users/i3ye/Programming/vsc/async/env/lib/python3.6/site-packages/aiohttp/web_urldispatcher.py",
    line 103, in <strong>init</strong>
        assert callable(handler), handler AssertionError: > Task was destroyed but it
    is pending! task: > sys:1: RuntimeWarning: coroutine 'runMcows' was never
    awaited</p>
  </blockquote>
  
  <p>The code is below, any suggestions?</p>
  
  <pre><code>from aiohttp import web
  import aiohttp
  import asyncio
  
  loop = asyncio.get_event_loop()
  
  #tasks = []
  n = 0
  
  def mcowA(n):
     print (n, " : A") 
     return
  
  async def fetch(session, url):
      async with session.get(url) as response:
          return await response.text()
  
  def mcowB(n):
     print (n, " : B") 
     return
  
  async def runMcows(n):
      mcowA(n)
      async with aiohttp.ClientSession() as session:
          html = await fetch(session, 'http://localhost:8081')
      mcowB(n)
      return html
  
  
  try:
      app = web.Application()
      app.add_routes([web.get('/', asyncio.ensure_future(runMcows(n)))])
      loop.run_forever()
      web.run_app(app)
  finally:
      loop.close()
  </code></pre>