2015年10月22日 星期四

ConfigureAwait.aspx

ConfigureAwait.aspx 
  1. <%@ Page Language="C#" AutoEventWireup="true" Async="true" CodeBehind="ConfigureAwait.aspx.cs" Inherits="ConcurrencyWebForm.ConfigureAwait" %>
  2.  
  3. <!DOCTYPE html>
  4.  
  5. <html xmlns="http://www.w3.org/1999/xhtml">
  6. <head runat="server">
  7.     <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
  8.     <title></title>
  9. </head>
  10. <body>
  11.     <form id="form1" runat="server">
  12.         <div>
  13.             <asp:Button ID="btnSyncWithoutConfigureAwait" runat="server" Text="SyncWithoutConfigureAwait" OnClick="btnSyncWithoutConfigureAwait_Click" />
  14.             <br />
  15.             <asp:Button ID="btnSyncWithConfigureAwait" runat="server" Text="SyncWithConfigureAwait" OnClick="btnSyncWithConfigureAwait_Click" />
  16.             <br />
  17.             <asp:Button ID="btnAsyncWithConfigureAwait" runat="server" Text="AsyncWithConfigureAwait" OnClick="btnAsyncWithConfigureAwait_Click" />
  18.         </div>
  19.     </form>
  20. </body>
  21. </html>
  22.  
ConfigureAwait.aspx.cs 
  1. using System;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4. using System.Threading.Tasks;
  5. using System.Web;
  6. using System.Web.UI;
  7. using System.Web.UI.WebControls;
  8.  
  9. namespace ConcurrencyWebForm
  10. {
  11.     public partial class ConfigureAwait : System.Web.UI.Page
  12.     {
  13.         protected void Page_Load(object sender, EventArgs e)
  14.         {
  15.  
  16.         }
  17.  
  18.         
  19.         //此例會造成Deadlock        
  20.         //ps.以同步的方式執行非同步的function是非常不建議的
  21.         protected void btnSyncWithoutConfigureAwait_Click(object sender, EventArgs e)
  22.         {            
  23.             Task tVal = DoSomethingAsync();
  24.             string abc = "";
  25.             string cde = "";
  26.             Page.ClientScript.RegisterStartupScript(this.GetType(), "", "alert('" + tVal.Result.ToString() + "');", true);
  27.         }
  29.         private async Task DoSomethingAsync()
  30.         {
  31.             int val = 13;
  33.             // Asynchronously wait 3 second.
  34.             //只是為了讓此library function為非同步執行才用Task.Delay，實際尚無特別意義
  35.             await Task.Delay(TimeSpan.FromSeconds(3));
  37.             val *= 2;
  39.             // Asynchronously wait 3 second.
  40.             await Task.Delay(TimeSpan.FromSeconds(3));
  41.             
  42.             return val;
  43.         }
  47.         protected void btnSyncWithConfigureAwait_Click(object sender, EventArgs e)
  48.         {
  49.             Task tVal = DoSomethingAsyncWithConfigureAwait();
  50.             string abc = "";
  51.             string cde = "";
  52.             Page.ClientScript.RegisterStartupScript(this.GetType(), "", "alert('" + tVal.Result.ToString() + "');", true);
  53.         }
  55.         //.ConfigureAwait(false)另開了context以儲存library function的執行狀態        
  56.         private async Task DoSomethingAsyncWithConfigureAwait()
  57.         {
  58.             int val = 13;
  60.             // Asynchronously wait 3 second.     
  61.             //增加了.ConfigureAwait(false)另開了context
  62.             await Task.Delay(TimeSpan.FromSeconds(3)).ConfigureAwait(false);
  64.             val *= 2;
  66.             // Asynchronously wait 3 second.
  67.             //增加了.ConfigureAwait(false)另開了context
  68.             await Task.Delay(TimeSpan.FromSeconds(3)).ConfigureAwait(false);
  70.             return val;
  71.         }
  73.         protected async void btnAsyncWithConfigureAwait_Click(object sender, EventArgs e)
  74.         {
  75.             int intVal = await DoSomethingAsyncWithConfigureAwait();
  76.             string abc = "";
  77.             string cde = "";
  78.             Page.ClientScript.RegisterStartupScript(this.GetType(), "", "alert('" + intVal.ToString() + "');", true);
  79.         }
  81.       
  82.     }
  83. }
張貼者： 於

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