old_contents: #!/usr/bin/env python3
  """Example for aiohttp.web websocket server
  """
  
  import asyncio
  import os
  from aiohttp.web import (Application, Response,
                           WebSocketResponse, WebSocketDisconnectedError)
  
  WS_FILE = os.path.join(os.path.dirname(__file__), 'websocket.html')
  
  
  @asyncio.coroutine
  def handler(request):
      resp = WebSocketResponse()
      ok, protocol = resp.can_start(request)
      if not ok:
          with open(WS_FILE, 'rb') as fp:
              return Response(body=fp.read(), content_type='text/html')
  
      resp.start(request)
      print('{}: Someone joined.'.format(os.getpid()))
      for ws in request.app['sockets']:
          ws.send_str('Someone joined')
      request.app['sockets'].append(resp)
  
      try:
          while True:
              msg = yield from resp.receive_str()
              print(msg)
              for ws in request.app['sockets']:
                  if ws is not resp:
                      ws.send_str(msg)
      except WebSocketDisconnectedError:
          request.app['sockets'].remove(resp)
          print('Someone disconnected.')
          for ws in request.app['sockets']:
              ws.send_str('Someone disconnected.')
          raise
  
  
  @asyncio.coroutine
  def init(loop):
      app = Application(loop=loop)
      app['sockets'] = []
      app.router.add_route('GET', '/', handler)
  
      srv = yield from loop.create_server(app.make_handler(), '127.0.0.1', 8080)
      print("Server started at http://127.0.0.1:8080")
      return srv
  
  loop = asyncio.get_event_loop()
  loop.run_until_complete(init(loop))
  loop.run_forever()
  
new_contents: #!/usr/bin/env python3
  """Example for aiohttp.web websocket server
  """
  
  import asyncio
  import os
  from aiohttp.web import (Application, Response,
                           WebSocketResponse, WebSocketDisconnectedError)
  
  WS_FILE = os.path.join(os.path.dirname(__file__), 'websocket.html')
  
  
  @asyncio.coroutine
  def wshandler(request):
      resp = WebSocketResponse()
      ok, protocol = resp.can_start(request)
      if not ok:
          with open(WS_FILE, 'rb') as fp:
              return Response(body=fp.read(), content_type='text/html')
  
      resp.start(request)
      print('Someone joined.')
      for ws in request.app['sockets']:
          ws.send_str('Someone joined')
      request.app['sockets'].append(resp)
  
      try:
          while True:
              msg = yield from resp.receive_str()
              print(msg)
              for ws in request.app['sockets']:
                  if ws is not resp:
                      ws.send_str(msg)
      except WebSocketDisconnectedError:
          request.app['sockets'].remove(resp)
          print('Someone disconnected.')
          for ws in request.app['sockets']:
              ws.send_str('Someone disconnected.')
          raise
  
  
  @asyncio.coroutine
  def init(loop):
      app = Application(loop=loop)
      app['sockets'] = []
      app.router.add_route('GET', '/', wshandler)
  
      handler = app.make_handler()
      srv = yield from loop.create_server(handler, '127.0.0.1', 8080)
      print("Server started at http://127.0.0.1:8080")
      return srv, handler
  
  loop = asyncio.get_event_loop()
  srv, handler = loop.run_until_complete(init(loop))
  try:
      loop.run_forever()
  except KeyboardInterrupt:
      loop.run_until_complete(handler.finish_connections())
  
subject: Add finalizer