信号量（下）实验

#include 
#include 
#include 
#include 
sem_t d;
sem_t c;
void* Driver(void* arg)
{ sem wait(&d);
printf("开车\n");
printf("正常行车\n");
printf("到站停车\n");
sem_post(&c);
pthread_exit(0);
}
void* Conductor(void* arg)
{
printf("关车门\n");
sem_post(&d);
printf("售票\n");
sem wait(&c);
printf("开车门\n");
pthread_exit(0);
}
int main(int* argc, char const* argv[])
{
sem_init(&d, 0, 0);
sem_init(&c ,0, 0);
pthread_t Tid[2];
pthread_create(Tid, NULL, Conductor, NULL);
pthread_create(Tid+1 ，NULL, Driver, NULL);
pthread_join(Tid[0], NULL);
pthread_join(Tid[1], NULL);
sem_destroy(&d); 
sem_destroy(&c); 
return 0;
}