.NET rocks

Sometimes it must be singleton and sometimes it must be generic, but what if it must be a generic singleton?

Within the last days I thought about a good solution for a generic singleton class. I use this class to build a usefull and small datastore solution.

Here is my idea for a generic singleton using a mutex to lock the object for the data access.

public class DataStore<T> where T : new()
{
    static Mutex mutex = new Mutex();
    static DataStore<T> instance;
    private List<T> cache;
    
    private DataStore()
    {
        cache = new List<T>();
    }

    public static T Instance
    {
        get
        {
            mutex.WaitOne();
            if (instance == null)
            {
                instance = (DataStore<T>)Activator.CreateInstance(typeof(DataStore<T>));
            }
            mutex.ReleaseMutex();
            return instance;
        }
    }    
}