from flask import Flask, render_template

import socketio

# set async_mode to 'threading', 'eventlet' or 'gevent' to force a mode

# else, the best mode is selected automatically from what's installed

async_mode = None

sio = socketio.Server(async_mode=async_mode)

app = Flask(__name__)

app.wsgi_app = socketio.Middleware(sio, app.wsgi_app)

@app.route('/')

def index():

return render_template('latency.html')

@sio.on('ping_from_client')

def ping(sid):

sio.emit('pong_from_server', room=sid)

if __name__ == '__main__':

if sio.async_mode == 'threading':

# deploy with Werkzeug

app.run(threaded=True)

elif sio.async_mode == 'eventlet':

# deploy with eventlet

import eventlet

import eventlet.wsgi

eventlet.wsgi.server(eventlet.listen(('', 5000)), app)

elif sio.async_mode == 'gevent':

# deploy with gevent

from gevent import pywsgi

try:

from geventwebsocket.handler import WebSocketHandler

websocket = True

except ImportError:

websocket = False

if websocket:

pywsgi.WSGIServer(('', 5000), app,

handler_class=WebSocketHandler).serve_forever()

else:

pywsgi.WSGIServer(('', 5000), app).serve_forever()

else:

print('Unknown async_mode: ' + sio.async_mode)