typedef struct _VF_AVL_TREE
{
    volatile long Lock;
    void *NodeToFree;
    unsigned __int64 NodeRangeSize;
    unsigned __int64 NodeCount;
    VF_AVL_TABLE *Tables;
    unsigned long TablesNo;
    union
    {
        unsigned long NodeSize;
        unsigned long UseLookaside;
    } u1;
} VF_AVL_TREE, *PVF_AVL_TREE;