c# - "A reference to a volatile field will not be treated as volatile" implications

Question

The following code

using System.Threading;

class Test
{
    volatile int counter = 0;
    public void Increment()
    {
        Interlocked.Increment(ref counter);
    }
}

Raises the following compiler warning:

"A reference to a volatile field will not be treated as volatile"

Am I doing something wrong here to raise this warning? Why does the compiler me warn about this?

Answer 1

You are not doing anything wrong. According to the documentation:

A volatile field should not normally be passed using a ref or out parameter, since it will not be treated as volatile within the scope of the function. There are exceptions to this, such as when calling an interlocked API.