old_contents: from aiohttp import web
  
  import socketio
  
  sio = socketio.AsyncServer(async_mode='aiohttp')
  app = web.Application()
  sio.attach(app)
  
  
  async def background_task():
      """Example of how to send server generated events to clients."""
      count = 0
      while True:
          await sio.sleep(10)
          count += 1
          await sio.emit('my_response', {'data': 'Server generated event'})
  
  
  async def index(request):
      with open('app.html') as f:
          return web.Response(text=f.read(), content_type='text/html')
  
  
  @sio.event
  async def my_event(sid, message):
      await sio.emit('my_response', {'data': message['data']}, room=sid)
  
  
  @sio.event
  async def my_broadcast_event(sid, message):
      await sio.emit('my_response', {'data': message['data']})
  
  
  @sio.event
  async def join(sid, message):
      sio.enter_room(sid, message['room'])
      await sio.emit('my_response', {'data': 'Entered room: ' + message['room']},
                     room=sid)
  
  
  @sio.event
  async def leave(sid, message):
      sio.leave_room(sid, message['room'])
      await sio.emit('my_response', {'data': 'Left room: ' + message['room']},
                     room=sid)
  
  
  @sio.event
  async def close_room(sid, message):
      await sio.emit('my_response',
                     {'data': 'Room ' + message['room'] + ' is closing.'},
                     room=message['room'])
      await sio.close_room(message['room'])
  
  
  @sio.event
  async def my_room_event(sid, message):
      await sio.emit('my_response', {'data': message['data']},
                     room=message['room'])
  
  
  @sio.event
  async def disconnect_request(sid):
      await sio.disconnect(sid)
  
  
  @sio.event
  async def connect(sid, environ):
      await sio.emit('my_response', {'data': 'Connected', 'count': 0}, room=sid)
  
  
  @sio.event
  def disconnect(sid):
      print('Client disconnected')
  
  
  app.router.add_static('/static', 'static')
  app.router.add_get('/', index)
  
  
  if __name__ == '__main__':
      sio.start_background_task(background_task)
      web.run_app(app)
  
new_contents: from aiohttp import web
  
  import socketio
  
  sio = socketio.AsyncServer(async_mode='aiohttp')
  app = web.Application()
  sio.attach(app)
  
  
  async def background_task():
      """Example of how to send server generated events to clients."""
      count = 0
      while True:
          await sio.sleep(10)
          count += 1
          await sio.emit('my_response', {'data': 'Server generated event'})
  
  
  async def index(request):
      with open('app.html') as f:
          return web.Response(text=f.read(), content_type='text/html')
  
  
  @sio.event
  async def my_event(sid, message):
      await sio.emit('my_response', {'data': message['data']}, room=sid)
  
  
  @sio.event
  async def my_broadcast_event(sid, message):
      await sio.emit('my_response', {'data': message['data']})
  
  
  @sio.event
  async def join(sid, message):
      sio.enter_room(sid, message['room'])
      await sio.emit('my_response', {'data': 'Entered room: ' + message['room']},
                     room=sid)
  
  
  @sio.event
  async def leave(sid, message):
      sio.leave_room(sid, message['room'])
      await sio.emit('my_response', {'data': 'Left room: ' + message['room']},
                     room=sid)
  
  
  @sio.event
  async def close_room(sid, message):
      await sio.emit('my_response',
                     {'data': 'Room ' + message['room'] + ' is closing.'},
                     room=message['room'])
      await sio.close_room(message['room'])
  
  
  @sio.event
  async def my_room_event(sid, message):
      await sio.emit('my_response', {'data': message['data']},
                     room=message['room'])
  
  
  @sio.event
  async def disconnect_request(sid):
      await sio.disconnect(sid)
  
  
  @sio.event
  async def connect(sid, environ):
      await sio.emit('my_response', {'data': 'Connected', 'count': 0}, room=sid)
  
  
  @sio.event
  def disconnect(sid):
      print('Client disconnected')
  
  
  app.router.add_static('/static', 'static')
  app.router.add_get('/', index)
  
  
  async def init_app():
      sio.start_background_task(background_task)
      return app
  
  
  if __name__ == '__main__':
      web.run_app(init_app())
  
subject: Fix aiohttp example's background task (Fixes #881)