Question

Here is the culmination of a Skeet posting for a random provider:

public static class RandomProvider
{    
    private static int seed = Environment.TickCount;

    private static ThreadLocal<Random> randomWrapper = new ThreadLocal<Random>(() =>
        new Random(Interlocked.Increment(ref seed))
    );

    public static Random GetThreadRandom()
    {
        return randomWrapper.Value;
    }
}

I would like to use the same concept in a .NET 3.5 project, so ThreadLocal is not an option.

How would you modify the code to have a thread safe random provider without the help of ThreadLocal?

UPDATE

Ok, am going with Simon’s [ThreadStatic] for now since I understand it the best. Lots of good info here to review and rethink as time allows. Thanks all!

public static class RandomProvider
{
    private static int _seed = Environment.TickCount;

    [ThreadStatic]
    private static Random _random;

    /// <summary>
    /// Gets the thread safe random.
    /// </summary>
    /// <returns></returns>
    public static Random GetThreadRandom() { return _random ?? (_random = new Random(Interlocked.Increment(ref _seed))); }
}

Answer 1

You can use the ThreadStaticAttribute

[ThreadStatic]
private static Random _random;

private static Random Random
{
    get
    {
        int seed = Environment.TickCount;

        return _random ?? (_random = new Random(Interlocked.Increment(ref seed)))
    }
}