说明：  循环缓冲区好处是：使共享资源的线程的等待时间减到最小，并使他们的平均操作速度相同。 注意：循环缓冲区不适合于生产者和消费者持续以不同的速度进行操作的情况。 缓冲区太小，这样会使线程等待更多的时间。 缓冲区太大，这样会浪费内存。
(Circular buffer benefits are: to make a thread of shared resources to minimize the waiting time, make them the same as the average operating speed. Note: The circular buffer is not suitable for producers and consumers continues to operate at different speeds situation. The buffer is too small, this would allow a thread to wait for more time. Buffer too large, this will waste memory.)