private static final long BUSY_OFFSET;

  static {
    try {
      UNSAFE = getUnsafe();
      Class<?> sk = Striped64.class;
      BASE_OFFSET = UNSAFE.objectFieldOffset(sk.getDeclaredField("base"));
      BUSY_OFFSET = UNSAFE.objectFieldOffset(sk.getDeclaredField("busy"));
    } catch (Exception e) {
      throw new Error(e);
    }
  }

  /**