说明：   因为有多个缓冲区，所以生产者线程没有必要在生成新的数据之前等待最后一个数据被消费者线程处理完毕。同样，消费者线程并不一定每次只能处理一个数据。在多缓冲区机制下，线程之间不必互相等待形成死锁，因而提高了效率。
(Because there are a number of the buffer zone, so there is no need for the producer thread to generate new data on waiting until the last thread of data processed by consumers. Similarly, consumers do not necessarily each thread can only handle a data. In a multi-buffer mechanism, between the threads do not have to wait for the formation of deadlock with each other, thereby enhancing efficiency.)