C# volatile array items?

Question

Hi

I need an array with volatile items, and can't find a way to do that.

private volatile T[] _arr;

This means that the _arr reference is volatile, however it does not guarantee anything about the items inside the _arr object itself.

Is there any way to mark the _arr's Items as volatile?

Thanks.

EDIT:

The following code built according to binarycoder's answer. Is this code thread-safe to use?

public class VolatileArray<T>
{
    private T[] _arr;

    public VolatileArray(int length)
    {
        _arr = new T[length];
    }

    public VolatileArray(T[] arr)
    {
        _arr = arr;
    }

    public T this[int index]
    {
        get
        {
            T value = _arr[index];
            Thread.MemoryBarrier();
            return value;
        }

        set
        {
            Thread.MemoryBarrier();
            _arr[index] = value;
        }
    }

    public int Length
    {
        get { return _arr.Length; }
    }
}

Answer 1

Since it is possible to pass array elements by reference, you can use Thread.VolatileRead and Thread.VolatileWrite.

It is useful to understand that the volatile keyword works behind the scenes by using Thread.MemoryBarrier. You could write:

// Read
x = _arr[i];
Thread.MemoryBarrier();

// Write
Thread.MemoryBarrier();
_arr[i] = x;

Note that volatile and MemoryBarrier are advanced techniques that are both easy to get wrong. For example, see http://stackoverflow.com/questions/1787450/how-do-i-understand-read-memory-barriers-and-volatile. Usually you are better off with higher level constructs such as lock, Monitor, ReaderWriterLockSlim, and others.