我正在写一个模拟一个男女皆宜的浴室的程序(用于作业)。一次只允许4人入住,如果另一个人已经在使用浴室,男人和女人不能入住。我的问题是允许最多4人在浴室。从输出中可以看到,一次只有1人进入洗手间。这里是我的代码:相互排斥和信号量
const int Delayx = 60;
int i;
int restroom = 0;
int Menwaiting = 0;
int Womenwaiting = 0;
semaphore max_capacity;
semaphore woman;
semaphore man;
semaphore mutex;
semaphore restroomcount;
void Delay(void)
{
int DelayTime;
DelayTime = random(Delayx);
for (i = 0; i<DelayTime; i++);
}
void Woman(void)
{
// for(;;){
Womenwaiting++;
//wait(mutex);
wait(woman);
wait(max_capacity);
//wait(woman);
wait(mutex);
wait(restroomcount);
cout << "A Woman has entered Restroom"<<endl;
cout << "People in the Restroom:" << restroom++ <<endl <<endl;
signal(restroomcount);
Womenwaiting--;
Delay();
wait(restroomcount);
cout << "A woman has exited Restroom"<<endl;
cout << "People in the Restroom:" << restroom-- <<endl<<endl;
signal(restroomcount);
signal(mutex);
signal(max_capacity);
if(Menwaiting > Womenwaiting){
signal(man);
}
else{
signal(woman);
}
//signal(max_capacity);
//signal(man);
// }
}
void Man(void)
{
// for(;;){
Menwaiting++;
//wait(mutex);
wait(man);
wait(max_capacity);
//wait(man);
wait(mutex);
wait(restroomcount);
cout <<"A Man has entered the Restroom"<<endl;
cout <<"People in the Restroom:" << restroom++ <<endl<<endl;
signal(restroomcount);
Menwaiting--;
//signal(mutex);
Delay();
//wait(mutex);
wait(restroomcount);
cout << "A man has exited the Restroom"<<endl;
cout <<"People in the Restroom:" << restroom-- <<endl<<endl;
signal(restroomcount);
signal(mutex);
signal(max_capacity);
if(Womenwaiting > Menwaiting){
signal(woman);
}
else{
signal(man);
}
//signal(max_capacity);
//signal(woman);
//}
}
void main()
{
initialsem(woman,1);
initialsem(man,1);
initialsem(max_capacity,4);
initialsem(mutex,1);
initialsem(restroomcount,1);
cobegin
{
Woman(); Woman(); Woman(); Woman(); Woman(); Man(); Man(); Man(); Man(); Man();
}
}
这将生成以下的输出:
一名男子进入洗手间
人们在厕所:1的人已经退出了厕所
洗手间里的人:0一个男人已经进入洗手间
人们在厕所:1的人已经退出了厕所
人们在厕所:0一个女人进入厕所
人们在厕所:1一个女人已退出厕所
人们在厕所:0一个女人进入厕所 在洗手间
人:1一个女人已经离开厕所
人们在厕所:0
依此类推,直到永远。
这段代码的一部分,被认为是负责预防男人进入洗手间,如果那里已经有女人了,反之亦然? – 2010-10-03 16:03:43
这个任务应该是单线程的吗?使用线程?协同程序? – dgnorton 2010-10-03 16:17:35
我不明白:如果男女不能同时进入同一个房间,他们应该怎么做爱? – ereOn 2010-10-03 16:20:09