How does the ThreadStatic attribute work?

Question

How does [ThreadStatic] attribute work? I assumed that the compiler would emit some IL to stuff/retrieve the value in the TLS, but looking at a disassembly it d

Answer 1

The [ThreadStatic] creates isolated versions of the same variable in each thread.

Example:

[ThreadStatic] public static int i; // Declaration of the variable i with ThreadStatic Attribute.

public static void Main()
{
    new Thread(() =>
    {
        for (int x = 0; x < 10; x++)
        {
            i++;
            Console.WriteLine("Thread A: {0}", i); // Uses one instance of the i variable.
        }
    }).Start();

    new Thread(() =>
   {
       for (int x = 0; x < 10; x++)
       {
           i++;
           Console.WriteLine("Thread B: {0}", i); // Uses another instance of the i variable.
       }
   }).Start();
}