os.cpp

管程经典题目

#define NULL 0
#include<iostream>
#include<time.h>
#include <unistd.h>
#include<stdio.h>
using namespace std;
const int TimeOfSmoking=2;
int SmokerSqueue[3]={0,0,0};int value=0,ssin=0,ssout=0;

void P(int i)
{
	value--;
	if(value<0)
	{
		SmokerSqueue[ssin]=i;
		ssin--;
		if(ssin==-1)ssin=2;
	}
}

int V()
{
	int temp;
	value++;
	if(value<=0)
	{
		temp=SmokerSqueue[ssout];
		SmokerSqueue[ssout]=0;
		ssout--;
		if(ssout==-1)ssout=2;
	}
	return (temp);
}

void seller(int &thing1,int &thing2)
{
	srand((unsigned)time(NULL));
	int i;
	i=rand()%3+1;
	thing1=(i+1)%3+1;
	thing2=(i-1)%3+1;
}

void PrintQueue()
{
	cout<<"The waiting queue is(head--tail):";
	for(int i=ssout;;i--)
	{
		if(i==-1)i=2;
		if(SmokerSqueue[i]!=0)cout<<SmokerSqueue[i]<<" ";
		if(i==ssin)break;
	}
	cout<<endl;
}

bool smoker(int i,int thing1,int thing2)
{
	cout<<"The "<<i<<"th smoker is matching the things"<<endl;
	if(i!=thing1&&i!=thing2)
	{
		PrintQueue();
		cout<<"The "<<i<<"th smoker is smoking..."<<endl;
		cout<<endl;
		sleep(TimeOfSmoking);
		P(i);
		return(true);
	}
	else
	{
		PrintQueue();
		P(i);
		return(false);
	}
}

int main()
{
	int thing1,thing2;
	P(1);P(2);P(3);seller(thing1,thing2);
	cout<<"The things are:"<<thing1<<" "<<thing2<<endl;
	while(true)
	{
	if(smoker(V(),thing1,thing2)){seller(thing1,thing2);cout<<"Now the things are:"<<thing1<<" "<<thing2<<endl;}
	else continue;
	}
	return 0;
}