操作系统实验三：用PV操作实现司机售票员进程同步（C语言实现）

代码如下：
driver_spy.cpp

#include<stdio.h>
#include<stdlib.h>int S1 = 0, S2 = 1, sum = 0;  
char name[10] = "null";void driver(int s1, int s2, char name[]);
void busman(int s1, int s2, char name[]);
void p(int s, char name[]);
void v(int s, char name[]);
void addrecord();int main(){driver(S1, S2, "driver");busman(S1, S2, "busman");return 0;
}void driver(int s1, int s2, char name[])                              
{  		printf("离站开车\n");                      printf("正常行车\n");printf("到站停车\n"); v(s2, "driver");  //汽车到站，唤醒售票员开车门p(s1, "driver"); //初始S1=0，P(S1)后S1=-1,司机无法启动车辆，需等待售票员执行关门操作(V(S1))，需售票员关好门，唤醒司机，司机才能启动车辆 }
void busman(int s1, int s2, char name[])
{p(s2, "busman");	//售票员打开车门，需S2>0时。初始S2=0，售票员不能打开车门，需等司机执行V(S2)操作，唤醒售票员开门，售票员才能打开车门printf("开车门\n");printf("关车门\n");v(s1, "busman");	//售票员已关好车门，执行V(S1)，唤醒司机启动车辆printf("售票\n");		
}void p(int s, char name[]){s = s-1;while(1){if( s >= 0 ){if(name == "driver"){printf("P(S1)操作\n收到开车信号\n"); break;}if(name == "busman"){printf("P(S2)操作 - 收到开车门信号\n"); 				break;}break;}if(s < 0)if(name == "driver"){printf("P(S1)操作 - 司机进程阻塞，等待售票员进程发出开车信号\n"); busman(s, S2, "busman");}if(name == "busman"){printf("P(S2)操作 - 收到开车门信号\n");driver(S1, s, "driver");}}}
void v(int s, char name[]){s = s+1;while(1){if( s > 0 ){if(name = "driver")printf("V(S2)操作 - 发出开车门信号\n"); break;}if(s <= 0) if(name == "busman"){sum++;printf("V(S1)操作 - 发出开车信号\n售票\n");sum++;if(sum>2)   //执行两次循环 exit(-1);driver(s, S2, "driver");}	}		
}

运行结果如图：