龙卷风在事件中发送消息 [英] Tornado send message on event

问题描述

我正在用 Python 创建一个程序，该程序以未知的时间间隔读取数据流.该程序还通过 websockets 发送这些数据.程序是服务器，它将接收到的数据发送给客户端.

Im creating a program in Python that reads a stream of data on an unknown interval. This program also sends this data through websockets. The program is the server and it sends the received data to the clients.

这是现在服务器的代码:

This is the code of the server now:

class WebSocketHandler(tornado.websocket.WebSocketHandler):
    def initialize(self):
        print 'Websocket opened'

    def open(self):
        print 'New connection'
        self.write_message('Test from server')

    def on_close(self):
        print 'Connection closed'

    def test(self):
        self.write_message("scheduled!")

def make_app():
    return tornado.web.Application([
    (r'/ws', WebSocketHandler),
    ])

if __name__ == '__main__':
    application = make_app()

    http_server = tornado.httpserver.HTTPServer(application)
    http_server.listen(8888)
    tornado.ioloop.IOLoop.instance().start()

但我希望能够在这个循环中使用 write_message :

But I want to be able to use write_message in this loop:

def read_function():
    while True:
        time.sleep(10) # a while loop to simulate the reading
        print 'read serial'
        str = 'string to send'
        # send message here to the clients

我该怎么做?

使用连接的两个线程都会有问题吗?它似乎适用于 1 个连接.

will there be a problem with both threads using connections? It seems like it works with 1 connection.

def read_function():
    while True:
        time.sleep(5) # a while loop to simulate the reading
        print 'read serial'
        str = 'string to send'
        [client.write_message(str) for client in connections]

if __name__ == '__main__':
    thread = Thread(target = read_function)
    application = make_app()
    http_server = tornado.httpserver.HTTPServer(application)
    http_server.listen(8888)
    thread.start()
    tornado.ioloop.IOLoop.instance().start()
    thread.join()

推荐答案

在 WebsocketHandler 之外使用 connections = set() 并在打开连接时使用 connections.add(self).不要忘记在关闭时使用 connections.remove(self) 删除它们.

Use connections = set() outside the WebsocketHandler and add every client on opening a connection with connections.add(self). Do not forget to remove them on closing with connections.remove(self).

现在，您可以通过以下方式从 websocket 线程中访问 write_message:[client.write_message('#your_message') for client in connections]

Now, you are able to access write_message out of the websocket thread through: [client.write_message('#your_message') for client in connections]

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