使用EOS的信号量，编程解决生产者—消费者问题，理解进程同步的意义。

调试跟踪EOS信号量的工作过程，理解进程同步的原理。

修改EOS的信号量算法，使之支持等待超时唤醒功能（有限等待），加深理解进程同步的原理。

-Semaphore using EOS programming to solve the producer- consumer issues, understand the significance of the process of synchronization. The to debug tracking EOS semaphore process, understand the principle of the process of synchronization. Modify EOS semaphore algorithm support wait timeout wake-up function (limited waiting), a better understanding of the process synchronization principle.