block descriptor

基本解释

Each file descriptor in the set is described by a pollcache control block -- pccb.
其中的每个文件描述符由一个 poll 缓存控制块（pccb）表示。
On returning to the tcp_usrreq function, the socket descriptor is made to point to the socket's TCP control block.
在返回到 tcp_usrreq 函数时，创建套接字描述符，以指向套接字的 TCP 控制块。
Experiments demonstrated that the color block co-occurrence matrix descriptor considerably improves the retrieval performance and can combine the feature of color and texture effectively.
实验结果表明，彩色子块共生矩阵描述子能够有效地结合颜色和纹理特征，具有良好的检索性能。