设有父子2个进程共享一个临界资源，每个进程循环进入该临界区3次：父进程每次进入临界区后显示“prnt in”，出临界区则显示“prnt out”；子进程每次进入临界区后显示“chld in”出临界区则显示“chld out”。观察运行结果，应该是一个进程出来后另一个才能进去。

-Father and son with two processes share a critical resource in each process cycle to enter the critical section 3 times: each time the parent process into the critical region revealed　prnt in , a critical region showed　prnt out　 each sub-process times to enter the critical region revealed　chld in　a critical region showed　chld out . Observation of the results, it should be a process in order to go after another.