import tornado.websocket
import tornado.ioloop

from time import sleep

line = 0 #the current message to be send
listeners = [] #for holding the connecting

class WebSocketHandler(tornado.websocket.WebSocketHandler):
    def open(self):
        listeners.append(self)#add to list of connections
    def on_close(self):
        listeners.remove(self)#remove from list of connections


application = tornado.web.Application([
    (r"/websocket", WebSocketHandler),
])

def main():
    global line
    #line=ser.readline() #get the message from the serial
    print(listeners) # <-- for debugging connections
    line = line + 1
    sleep(0.01)
    for i in range(0, len(listeners)): #go trough all connections and send the new message
        listeners[i].write_message(str(line))

if __name__ == "__main__":
    application.listen(8888)
    while(1):
        tornado.ioloop.IOLoop.instance().add_callback(main)