有大师帮我分析下这个类的作用吗？System.Runtime.Caching.SafeBitVector32

Question

有大师帮忙分析下这个类吗？我看出是一个索引，但是具体功能和作用还是没有完全吃透，有人能帮帮忙吗？

internal struct SafeBitVector32
{
    private volatile int _data;
    internal bool this[int bit]
    {
        get
        {
            int data = this._data;
            return (data & bit) == bit;
        }
        set
        {
            int data;
            int num;
            do
            {
                data = this._data;
                int value2;
                if (value)
                {
                    value2 = (data | bit);
                }
                else
                {
                    value2 = (data & ~bit);
                }
                num = Interlocked.CompareExchange(ref this._data, value2, data);
            }
            while (num != data);
        }
    }
    internal bool ChangeValue(int bit, bool value)
    {
        while (true)
        {
            int data = this._data;
            int num;
            if (value)
            {
                num = (data | bit);
            }
            else
            {
                num = (data & ~bit);
            }
            if (data == num)
            {
                break;
            }
            int num2 = Interlocked.CompareExchange(ref this._data, num, data);
            if (num2 == data)
            {
                return true;
            }
        }
        return false;
    }
}

}