分别使用FCFS、SJF（非抢占）、优先级调度（非抢占）、RR四种调度算法来模拟CPU调度的过程。（Linux、Windows下皆可）
输入：存储需要调度的作业信息的job.txt文档
输出：每个作业的编号、作业开始执行时间、作业结束时间以及该调度算法的平均等待时间
选作：SJF（抢占）、优先级调度（抢占）
#include<iostream>
#include<fstream>
using namespace std;
int h_start=0;
int m_start=0;
int mission;
int time_piece;
int wait_time;
char w;
class process
{
public:
int index;
int exe_time;
int h;
int m;
int priority;
char mark;
process()
{
mark='0';
}
};
void FCFS(process pro[])
{
process temp;
process pro1[5];
int i=0,j=0;
int key;
h_start=8;
m_start=0;
wait_time=0;
for(; i<5; i++)
pro1[i]=pro[i];
//按申请时间先后对5个进程进行排序
for(i=0; i<4; i++)
{
key=i;
for(j=i+1; j<5; j++)
if((pro1[j].h*60+pro1[j].m) < (pro1[key].h*60+pro1[key].m))
key=j;
temp=pro1[key];
pro1[key]=pro1[i];
pro1[i]=temp;
}
cout<<"FCFS:"<<endl;
for(i=0; i<5; i++)
{
wait_time+=h_start*60+m_start-pro1[i].h*60-pro1[i].m;
cout<<pro1[i].index<<' '<<h_start<<':'<<m_start<<' ';
m_start+=pro1[i].exe_time;
if(m_start>=60)
{
h_start++;
m_start-=60;
}
cout<<h_start<<':'<<m_start<<endl;
}
wait_time/=5;
cout<<"Average waiting time:"<<wait_time<<endl;
}
void SJF(process pro [])
{
process pro1[5];
process pro2[5];
process temp;
int n2=0;
int i=0,j=0;
int key=0;
int out=0;
h_start=8;
m_start=0;
wait_time=0;
for(i=0; i<5; i++)
pro1[i]=pro[i];
cout<<"SJF(非抢占):"<<endl;
while(out<5)
{
//将pro1中满足条件的进程加入到等待序列pro2中
for(i=0; i<5; i++)
{
if(pro1[i].mark=='0' && (pro1[i].h*60+pro1[i].m)<=(h_start*60+m_start))
{
pro2[n2++]=pro1[i];
pro1[i].mark='1';
}
}
//对等待序列pro2中的进程按照执行时间从小到大排序
for(i=0; i<n2-1; i++)
{
key=i;
for(j=i+1; j<n2; j++)
if(pro2[j].exe_time < pro2[key].exe_time)
key=j;
temp=pro2[key];
pro2[key]=pro2[i];
pro2[i]=temp;
}
//对排序后的序列进行执行
wait_time+=h_start*60+m_start-pro2[0].h*60-pro2[0].m;
cout<<pro2[0].index<<' '<<h_start<<':'<<m_start<<' ';
m_start+=pro2[0].exe_time;
if(m_start>60)
{
h_start++;
m_start-=60;
}
cout<<h_start<<':'<<m_start<<endl;
n2--;
out++;
//清除执行完成的进程
for(i=0; i<n2; i++)
pro2[i]=pro2[i+1];
}
wait_time/=5;
cout<<"Average waiting time:"<<wait_time<<endl;
}
void PRO(process pro[])
{
process pro1[5];
process pro2[5];
process temp;
int n2=0;
int i=0,j=0;
int key=0;
int out=0;
h_start=8;
m_start=0;
wait_time=0;
for(i=0; i<5; i++)
pro1[i]=pro[i];
cout<<"优先级调度(非抢占):"<<endl;
while(out<5)
{
//将pro1中满足条件的进程加入到等待序列pro2中
for(i=0; i<5; i++)
{
if(pro1[i].mark=='0' && (pro1[i].h*60+pro1[i].m)<=(h_start*60+m_start))
{
pro2[n2++]=pro1[i];
pro1[i].mark='1';
}
}
//对等待序列pro2中的进程按照优先级排序
for(i=0; i<n2-1; i++)
{
key=i;
for(j=i+1; j<n2; j++)
if(pro2[j].priority < pro2[key].priority)
key=j;
temp=pro2[key];
pro2[key]=pro2[i];
pro2[i]=temp;
}
//对排序后的序列进行执行
wait_time+=h_start*60+m_start-pro2[0].h*60-pro2[0].m;
cout<<pro2[0].index<<' '<<h_start<<':'<<m_start<<' ';
m_start+=pro2[0].exe_time;
if(m_start>60)
{
h_start++;
m_start-=60;
}
cout<<h_start<<':'<<m_start<<endl;
n2--;
out++;
//清除执行完成的进程
for(i=0; i<n2; i++)
pro2[i]=pro2[i+1];
}
wait_time/=5;
cout<<"Average waiting time:"<<wait_time<<endl;
}
void RR(process pro[])
{
process temp;
process pro1[5];
int i=0,j=0;
int key=0,n1=5,n2=1;
int exet[5];
h_start=8;
m_start=0;
wait_time=0;
for(; i<5; i++)
pro1[i]=pro[i];
for(i=0; i<5; i++)
exet[i]=pro1[i].exe_time;
//按申请时间先后对5个进程进行排序
for(i=0; i<4; i++)
{
key=i;
for(j=i+1; j<5; j++)
if((pro1[j].h*60+pro1[j].m) < (pro1[key].h*60+pro1[key].m))
key=j;
temp=pro1[key];
pro1[key]=pro1[i];
pro1[i]=temp;
}
cout<<"RR:"<<endl;
//开始执行,mark=0：未等待 mark=1：等待 mark=2：执行结束
while(n1>0)
{
for(i=0; i<5; i++)
{
if(pro1[i].mark=='2')continue;
pro1[i].mark='1';
cout<<pro1[i].index<<' '<<h_start<<':'<<m_start<<' ';
//时间片不够用
if(pro1[i].exe_time>time_piece)
{
pro1[i].exe_time-=time_piece;
m_start+=time_piece;
if(m_start>=60)
{
h_start++;
m_start-=60;
}
cout<<h_start<<':'<<m_start<<endl;
//判断下一个进程是否处于等待状态
if(i+1==n1)i=-1;
else
{
if((h_start*60+m_start)<(pro1[i+1].h*60+pro1[i+1].m))
i=-1;
// else if(pro1[i+1].mark=='0')n2++;
}
}
//时间片够用
else
{
m_start+=pro1[i].exe_time;
if(m_start>=60)
{
h_start++;
m_start-=60;
}
cout<<h_start<<':'<<m_start<<endl;
n1--;
//n2--;
//清除执行结束的程序
//for(j=i;j<n1;j++)
//pro1[j]=pro1[j+1];
pro1[i].mark='2';
wait_time+=h_start*60+m_start-exet[i]-pro1[i].h*60-pro1[i].m;
//判断下一个进程是否处于等待状态
if(i+1==n1)i=-1;
else
{
if((h_start*60+m_start)<(pro1[i+1].h*60+pro1[i+1].m))
i=-1;
//else if(pro1[i+1].mark=='0'){n2++;i--;}
}
}
}
}
wait_time/=5;
cout<<"Average waiting time:"<<wait_time<<endl;
}
int main()
{
process p[5];
ifstream inFile("job.txt");
inFile>>mission;
inFile>>time_piece;
for(int i=0; i<5; i++)
{
inFile>>p[i].index;
inFile>>p[i].h;
inFile>>w;
inFile>>p[i].m;
inFile>>p[i].exe_time;
inFile>>p[i].priority;
}
FCFS(p);
SJF(p);
PRO(p);
RR(p);
inFile.close();
return 0;
}