static size_t sh_actual_size(char *ptr)
{
    int list;

    OPENSSL_assert(WITHIN_ARENA(ptr));
    if (!WITHIN_ARENA(ptr))
        return 0;
    list = sh_getlist(ptr);
    OPENSSL_assert(sh_testbit(ptr, list, sh.bittable));
    return sh.arena_size / (ONE << list);
}