dotnetcore5.0 session redis 使用 是否有阻塞

今天来尝试一下dotnetcore5.0 的session redis的用法， 顺便看看你是否有阻塞，在我以前的文章 你的项目真的需要Session吗？redis保存session性能怎么样？ 和 asp.net mvc Session RedisSessionStateProvider锁的实现 有提到asp.net mvc session 锁的问题【默认内存保存是不存在】，前几天 发现beego session redis 是没有锁的 ，大家可以参考beego Session redis存储以及是否阻塞 和 beego Session redis源码解读， 这次我打算用VScode来创建项目，VScode的搭建可以参考 使用Visual Studio Code开发.NET Core看这篇就够了​​​​​​​

1.创建项目SessionDemo，把launchSettings.json 的https部分移除

运行界面 如下， 表示项目okay

2添加必要的包

dotnet add package Microsoft.AspNetCore.DataProtection.StackExchangeRedis
dotnet add package Microsoft.Extensions.Caching.StackExchangeRedis
dotnet add package Microsoft.AspNetCore.Http  //使用Session时有扩展方法
dotnet add package Microsoft.AspNetCore.Session 

修改Startup.cs文件如下

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpsPolicy;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.AspNetCore.DataProtection;
using StackExchange.Redis;
namespace SessionDemo
{
    public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddRazorPages();
            // add by gavin for session redis
            var redisConn = "127.0.0.1:6379";
                   
            services.AddDataProtection()
                .SetApplicationName("vextus")
                .PersistKeysToStackExchangeRedis(ConnectionMultiplexer.Connect(redisConn),"DataProtection-Keys");

            services.AddStackExchangeRedisCache(o =>
            {
                o.Configuration = redisConn;
            });
            services.AddSession();
            services.AddMvc(x=> { x.EnableEndpointRouting = false; }); //写controller 路由需要
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            else
            {
                app.UseExceptionHandler("/Error");
                // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
                app.UseHsts();
            }

            app.UseHttpsRedirection();
            app.UseStaticFiles();

            app.UseRouting();

            app.UseAuthorization();

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapRazorPages();
            });
             // add by gavin for session redis
            app.UseSession();
            app.UseMvc(x => { x.MapRoute( name: "default",template: "{controller=Home}/{action=Index}/{id?}"); });
        }
    }
}

创建一个HomeController.cs 如下：

using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Mvc;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
namespace SessionDemo
{
     public class HomeController : Controller
    {
        public IActionResult Index()
        {
            this.HttpContext.Session.SetString("name", "test");
            return Content("Home");
        }
        public IActionResult V1()
        {
            var txt = this.HttpContext.Session.GetString("name");
            Thread.Sleep(1000 * 4);
            this.HttpContext.Session.SetString("name", "V1");
            return Content("Get Session:"+txt+" set session:V1");
        }
        public IActionResult V2()
        {
            var txt = this.HttpContext.Session.GetString("name");
            Thread.Sleep(1000 * 1);
            this.HttpContext.Session.SetString("name", "V2");
            return Content("Get Session:" + txt + " set session:V2");
        }
        public IActionResult V3()
        {
            var txt = this.HttpContext.Session.GetString("name");

            return Content("Get Session:" + txt);
        }
    }
}

修改Index.cshtml 如下：

@page
@model IndexModel
@{
    ViewData["Title"] = "Home page";
}

<div class="text-center">
<div>test</div>
        <script src="https://cdn.staticfile.org/jquery/1.10.2/jquery.min.js"></script>
        <input type="button" value="set session" id="setsession" /><br />
        V1: <p id="txt1"></p><br />
        V2:  <p id="txt2"></p><br />
        <input type="button" value="get session" id="getsession" /><br />
        V3:  <p id="txt3"></p><br />
        <script>
        $("#setsession").click(function(){
            $.get("http://localhost:5000/home/v1",function(data){$("#txt1").html(data) ;});
            $.get("http://localhost:5000/home/v2",function(data){$("#txt2").html(data) ;});

        });
        $("#getsession").click(function(){
            $.get("http://localhost:5000/home/v3",function(data){$("#txt3").html(data) ;});

        });
        </script>
</div>

运行项目， 首先访问http://localhost:5000/home/index 设置session， 然后在进入http://localhost:5000/ ，页面首先点击 setsession， 完全返回后 ，再次点击get session。

 结论setsession同时发起V1和V2的请求，V1和V2获取的session 是先前index 设置的test，V2 把session设置为V2保存，由于V1等待时间长一些， 所以V1在V2后面设置session值V1， 后面V3 获取的session是V1。同时V1和V2的响应时间就说明V1和V2之间没有阻塞。看看redis里面的数据