C# Threading, My static variable not getting locked - asp.net

Question

I have many static variables in my application and methods which modify those variables. Please find an example code below. Can somebody tell me how to lock my static variable in the following example. It's not getting locked
using System.Threading;
using System;
namespace ThreadTest
{
public class Program
{
public static void Main(string[] args)
{
MyTest.TestVar = 0;
Thread th = new Thread(ThreadB);
Thread th1 = new Thread(ThreadC);
th1.Start();
Console.WriteLine("Thread B started:");
th.Start();
Console.WriteLine("Thread C started :");
for (int i = 0; i < 10; i++)
{
MyTest.TestVar = Convert.ToInt32(MyTest.TestVar) + 1;
Console.WriteLine("A " + MyTest.TestVar);
Thread.Sleep(100);
}
Console.WriteLine("Threads completed");
}
public static void ThreadB()
{
lock (MyTest.TestVar)
{
for (int i = 0; i < 10; i++)
{
MyTest.TestVar = Convert.ToInt32(MyTest.TestVar) + 1;
Console.WriteLine("B " + MyTest.TestVar);
Thread.Sleep(10);
}
}
}
public static void ThreadC()
{
for (int i = 0; i < 10; i++)
{
MyTest.TestVar = Convert.ToInt32(MyTest.TestVar) + 1;
Console.WriteLine("C " + MyTest.TestVar);
//Thread.Sleep(100);
}
}
}
public class MyTest
{
public static Object TestVar;
}
}
Fiddle here https://dotnetfiddle.net/dBJpo2

Answer 1

Use lock statement for your issue. Use sample code like below.
Declare and instantiate a private object variable in your console app that will be used to lock access to TestVar.
//declare a private variable for locking
private Object obj = new Object() ;
Then, enclose the statement where TestVar is being incremeted by 1 within a lock statement.
//use lock to synchronize access to
//property TestVar
lock (obj)
{
MyTest.TestVar = Convert.ToInt32(MyTest.TestVar) + 1;
}
After above steps, C# runtime will only allow one thread at a time to execute the line of code that changes the value of TestVar.