扩展 Microsoft 的 ASP.NET 反向 AJAX“长轮询”代码复合体示例

发布于 2024-11-02 07:01:34 字数 1541 浏览 5 评论 0 原文

我正在调查 Microsoft 的反向 AJAX 示例，其中他们在 ScriptManager 中使用较长的超时

<asp:ScriptManager ID="ScriptManager1" runat="server" AsyncPostBackTimeout="2147483647">

，并且用于控制等待的 ManualResetEvent：

    private ManualResetEvent messageEvent = new ManualResetEvent(false);
    public Message DequeueMessage()
    {
        // Wait until a new message.
        messageEvent.WaitOne();
    }


    public void EnqueueMessage(Message message)
    {
        lock (messageQueue)
        {
            messageQueue.Enqueue(message);

            // Set a new message event.
            messageEvent.Set();
        }
    }

我注意到将

AsyncPostBackTimeout 设置为较低值 (5) 不会导致脚本超时或失败
在 web 中.config 似乎没有效果

当执行时间太长时，以下 javascript 似乎不会运行

 Sys.WebForms.PageRequestManager.getInstance() .add_endRequest(function (sender, args) {
   if (args.get_error() && args.get_error().name === 'Sys.WebForms.PageRequestManagerTimeoutException') {
       alert('超时了！');
       // 记住设置 errorHandled = true 以避免从 AJAX 库本身获取弹出窗口 
       args.set_errorHandled(true);
      }
     });

这让我问这些问题

影响此代码执行的正确 IIS 设置和 .js 回调是什么？< /p>
当此应用程序扩展时，IIS 基础结构的哪些部分会受到压力？
如果这成为基于 WAS 的 WCF 服务，#2 中的任何内容是否会发生变化？

原文

I'm investigating Microsoft's reverse-AJAX sample wherein they use a long timeout in the ScriptManager

<asp:ScriptManager ID="ScriptManager1" runat="server" AsyncPostBackTimeout="2147483647">

And a ManualResetEvent to control the wait:

    private ManualResetEvent messageEvent = new ManualResetEvent(false);
    public Message DequeueMessage()
    {
        // Wait until a new message.
        messageEvent.WaitOne();
    }


    public void EnqueueMessage(Message message)
    {
        lock (messageQueue)
        {
            messageQueue.Enqueue(message);

            // Set a new message event.
            messageEvent.Set();
        }
    }

I've noticed that

Setting AsyncPostBackTimeout to a low value (5) does not cause the script to timeout or fail
<httpRuntime executionTimeout="5"/> in web.config does not seem to have an effect

The following javascript doesn't appear to run when execution takes too long

   Sys.WebForms.PageRequestManager.getInstance() .add_endRequest(function (sender, args) {
   if (args.get_error() && args.get_error().name === 'Sys.WebForms.PageRequestManagerTimeoutException') {
       alert('Caught a timeout!');
       // remember to set errorHandled = true to keep from getting a popup from the AJAX library itself 
       args.set_errorHandled(true);
      }
     });

Which makes me ask these questions

What are the correct IIS settings and .js callbacks that affect the execution of this code?
What portions of the IIS infrastructure are stressed when this application scales?
Does anything in #2 change if this becomes a WAS-based WCF service?