C＃中同时执行2个线程 [英] c# execute 2 threads simultaneously

问题描述

我想一个HTTP处理程序中重现线程错误条件。

基本上，ASP.net工人procecss是创建2个线程同时它时调用HTTP处理程序在应用程序中的某一页的负荷。

在HTTP处理程序，是不是线程安全的资源。因此，当2个线程试图同时访问它发生异常。

我可能会，把一个锁声明周围的资源，但是我想确保它是逸岸的情况。所以，我想创建一个控制台应用程序第一次的情况。

但我不能得到2个线程在同一时间像asp.net WP确实执行的方法。所以，我的问题是你怎么可以创建2个线程，可以同时执行一个方法。

编辑：

底层的资源是用户表SQL数据库（只有一个名字列）。下面是一个示例code我试过了。

  [识别TestClass]
    公共类UnitTest1
    {
        [测试方法]
        公共无效Linq2SqlThreadSafetyTest（）
        {
            VAR threadOne =新主题（新ParameterizedThreadStart（InsertData））;
            VAR threadTwo =新主题（新ParameterizedThreadStart（InsertData））;            threadOne.Start（1）; //试图通过这个参数来同步。
            threadTwo.Start（0）;            threadOne.Join（）;
            threadTwo.Join（）;
        }
        私有静态无效InsertData（对象毫秒）
        {
            // LINQ的2 SQL数据上下文
            VAR数据库=新DataClassesDataContext（）;            //数据库实体
            VAR NEWUSER =新用户{名称=测试};            database.Users.InsertOnSubmit（NEWUSER）;            Thread.sleep代码（（int）的毫秒级）;            尝试
            {
                database.SubmitChanges（）; //这个语句引发的HTTP处理程序例外。
            }            赶上（例外的例外）
            {
                的Debug.WriteLine（exception.Message）;
            }
        }
    }
 

解决方案

您可以只设置一个静态的时间来启动这样你的工作。

  

私有静态的DateTime STARTTIME =
  DateTime.Now.AddSeconds（5）;
  //任意启动时间

 静态无效的主要（字串[] args）
    {
        的ThreadStart threadStart1 =新的ThreadStart（DoSomething的）;
        的ThreadStart threadStart2 =新的ThreadStart（DoSomething的）;
        螺纹TH1 =新主题（threadStart1）;
        螺纹TH2 =新主题（threadStart2）;        th1.Start（）;
        th2.Start（）;
 

  th1.Join（）;
 

  th2.Join（）;        到Console.ReadLine（）;
    }    私有静态无效DoSomething的（）
    {
        而（DateTime.Now＆LT;的startTime）
        {
            //没做什么
        }        //两个线程将在这里执行code并行
    }
 

I am trying to reproduce a threading error condition within an HTTP Handler.

Basically, the ASP.net worker procecss is creating 2 threads which invoke the HTTP handler in my application simultaneously when a certain page loads.

Inside the http handler, is a resource which is not thread safe. Hence, when the 2 threads try to access it simultaneously an exception occurs.

I could potentially, put a lock statement around the resource, however I want to make sure that it is infact the case. So I wanted to create the situation in a console application first.

But i cant get 2 threads to execute a method at the same time like asp.net wp does. So, my question is how can you can create 2 threads which can execute a method at the same time.

Edit:

The underlying resource is a sql database with a user table (has a name column only). Here is a sample code i tried.

[TestClass]
    public class UnitTest1
    {
        [TestMethod]
        public void Linq2SqlThreadSafetyTest()
        {
            var threadOne = new Thread(new ParameterizedThreadStart(InsertData));
            var threadTwo = new Thread(new ParameterizedThreadStart(InsertData));

            threadOne.Start(1); // Was trying to sync them via this parameter.
            threadTwo.Start(0);

            threadOne.Join();
            threadTwo.Join();
        }


        private static void InsertData( object milliseconds )
        {
            // Linq 2 sql data context
            var database = new DataClassesDataContext();

            // Database entity
            var newUser = new User {Name = "Test"};

            database.Users.InsertOnSubmit(newUser);

            Thread.Sleep( (int) milliseconds);

            try
            {
                database.SubmitChanges(); // This statement throws exception in the HTTP Handler.
            }

            catch (Exception exception)
            {
                Debug.WriteLine(exception.Message);
            }
        }
    }

解决方案

You could just set a static time to start your work like this.

private static DateTime startTime = DateTime.Now.AddSeconds(5); //arbitrary start time

    static void Main(string[] args)
    {
        ThreadStart threadStart1 = new ThreadStart(DoSomething);
        ThreadStart threadStart2 = new ThreadStart(DoSomething);
        Thread th1 = new Thread(threadStart1);
        Thread th2 = new Thread(threadStart2);

        th1.Start();             
        th2.Start();

          th1.Join();

        th2.Join();

        Console.ReadLine();
    }

    private static void DoSomething()
    {
        while (DateTime.Now < startTime)
        {
            //do nothing
        }

        //both threads will execute code here concurrently
    }

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