为什么服务器每 1 秒而不是 100 毫秒更新客户端 - 提供完整的源代码答案

【问题标题】：Why server is updating clients every 1 second instead of 100ms - full sourcecode available为什么服务器每 1 秒而不是 100 毫秒更新客户端 - 提供完整的源代码
【发布时间】：2017-01-22 11:00:34
【问题描述】：

我的服务器设置为每 100 毫秒更新一次所有客户端 - 请参阅 self.TICKS_PER_SECOND = 10, 1000/10 = 100 毫秒。

但是，html 中的“时钟”仅每 1 秒更新一次。为什么？

如果我一直点击提交按钮，时钟会更新得更快。为什么？

app.py

import logging
import sys
from datetime import datetime
import time
current_milli_time = lambda: int(round(time.time() * 1000))

import json
import threading

from twisted.web.static import File
from twisted.python import log
from twisted.web.server import Site
from twisted.web.resource import Resource

from twisted.internet import pollreactor
pollreactor.install()

from twisted.internet import reactor

from autobahn.twisted.websocket import WebSocketServerFactory, \
    WebSocketServerProtocol

from autobahn.twisted.resource import WebSocketResource


class AppGameServerProtocol(WebSocketServerProtocol):

    def onOpen(self):
        """
        """
        self.factory.register(self)
        self.factory.onConnected(self)

    def onConnect(self, request):
        print("Client connecting: {}".format(request.peer))

    def connectionLost(self, reason):
        self.factory.unregister(self)

    def onMessage(self, payload, isBinary):
        self.factory.communicate(self, payload, isBinary)


class AppGameFactory(WebSocketServerFactory):

    def __init__(self, *args, **kwargs):
        super(AppGameFactory, self).__init__(*args, **kwargs)
        self.clients = {}

    def register(self, client):
        self.clients[client.peer] = {"object": client, "partner": None}

    def unregister(self, client):
        self.clients.pop(client.peer)


    def onConnected(self,client):
        client.sendMessage(json.dumps({"type": "connect"}))

    def communicate(self, client, payload, isBinary):
        print "msg received", payload

    def sendMessageAll(self, message):
        for i in self.clients:
            c = self.clients[i]
            c["object"].sendMessage(message)

class SummingThread(threading.Thread):
    def __init__(self, fac):
        super(SummingThread, self).__init__()
        self.fac = fac

        self.TICKS_PER_SECOND = 10
        self.SKIP_TICKS = 1000 / self.TICKS_PER_SECOND
        self.MAX_FRAMESKIP = 5
        self.loops = 0
        self.next_game_tick = current_milli_time()

    def run(self):
        while True:
            self.loops = 0
            while current_milli_time() > self.next_game_tick and self.loops < self.MAX_FRAMESKIP:

                self.fac.sendMessageAll("clock: " + datetime.utcnow().strftime('%Y-%m-%d %H:%M:%S.%f')[:-3])
                self.next_game_tick += self.SKIP_TICKS
                self.loops += 1



if __name__ == "__main__":
    log.startLogging(sys.stdout)

    factory = AppGameFactory(u"ws://127.0.0.1:8080")
    factory.protocol = AppGameServerProtocol
    resource = WebSocketResource(factory)

    root = Resource()
    root.putChild('', File('index.html'))

    root.putChild(u"ws", resource)

    thread1 = SummingThread(factory)
    thread1.start()

    try:
        site = Site(root)
        reactor.listenTCP(8080, site)
        reactor.run()
    except Exception as e:
        logging.exception("message")

index.html

<!DOCTYPE html>
<html>
<head>
    <script type="text/javascript">
        window.addEventListener("load", function() {

            var msgReceived = 0

            // create websocket instance
            var mySocket = new WebSocket("ws://localhost:8080/ws");

            // add event listener reacting when message is received
            mySocket.onmessage = function (event) {
                var output = document.getElementById("output");
                // put text into our output div
                msgReceived++;
                output.textContent = event.data + " msgReceived: " + msgReceived;
                //console.log(event.data);
            };

            var form = document.getElementsByClassName("foo");
            var input = document.getElementById("input");

            form[0].addEventListener("submit", function (e) {
                // on forms submission send input to our server
                input_text = input.value;
                mySocket.send(input_text);
                e.preventDefault()
            })
        });

    </script>
<style>
    /* just some super ugly css to make things bit more readable*/
    div {
        margin: 2em;
    }
    form {
        margin: 2em;
    }
</style>
</head>
<body>
    <form class="foo">
        <input id="input"></input>
        <input type="submit"></input>
    </form>
    <div id="output"></div>
</body>
</html>

【问题讨论】：

标签： javascript python websocket twisted

【解决方案1】：

您正在从多个线程调用 Twisted API。这是不允许的。您只能从反应器线程调用 Twisted API - 除了几个特定的线程安全 API。主要是reactor.callFromThread，它安排一个函数在反应器线程中运行。

考虑将SummingThread 替换为基于twisted.internet.task.LoopingCall 的构造。

例如：

from twisted.internet.task import LoopingCall

def game_tick(factory, skip_count):
    now = datetime.utcnow()
    factory.sendMessageAll(
        "clock: " + now.strftime('%Y-%m-%d %H:%M:%S.%f')[:-3]
    )


factory = # ...
task = LoopingCall.withCount(partial(game_tick, factory))
task.start(0.1)
# ...
reactor.run()

game_tick 每秒会被调用 10 次（或者，如果因为负载太高或其他问题而不太频繁，skip_count 将设置为大于 1 以指示错过了多少滴答声）。

【讨论】：