利用Windows提供的MFC类编程实现读者/写者的同步互斥问题，保证：1）一个人在写时，其他人不允许写；2）一个人在写时，其他人不允许读；3）一个人在读时，其他人不允许写；4）一个人在读时，其他人允许读。-MFC classes provided by Windows programming reader/writer mutual exclusion synchronization to ensure that: 1) When a person writes, others are not allowed to write　2) When a person writes, others not allowed to read　3) When a person is reading, others are not allowed to write　4) a person reading, other people allowed to read.