利用模拟用信号量机制实现读者和写者问题：通过用户控制读进程和写进程，反应读者和写者问题中所涉及的进程的同步与互斥。-Using simulated using semaphore mechanisms readers and writers problem: by the user to control the reading process and the writing process, the reaction synchronization and mutual exclusion problem readers and writers involved in the process.