graph TD
A[前台进程1] -->|P(mutex)：申请访问房态库| B{mutex=1?}
B -->|是，mutex=0| C[读写房态数据：查询/修改房间状态]
C -->|V(mutex)：释放房态库，mutex=1| D[进程结束]
E[前台进程2] -->|P(mutex)：申请访问房态库| F{mutex=0?}
F -->|否，进程2阻塞| G[进入阻塞队列]
C -->|V操作唤醒| H[进程2被唤醒，mutex=0]
H --> I[读写房态数据]
I --> J[V(mutex)，mutex=1]
J --> K[进程2结束]
