#include <iostream>
#include <cstdio>
#include <cmath>
#include <cstring>
using namespace std;
enum STATUS {RUN,READY,WAIT,FINISH};
struct PCBNode
{
int processID; //进程ID
STATUS status; //进程状态
int priorityNum; //优先数
int reqTime; //总的需要运行时间
int remainTime; //剩下需要运行时间
int arriveTime; //进入就绪队列时间
int startTime; //开始运行时间
int finishTime; //结束运行时间
int totalTime; //周转时间
float weightTotalTime; //带权周转时间
};
struct QueueNode
{
int ID; //进程ID
struct QueueNode * next; //队列中下一个进程指针
};
struct LinkQueue
{
QueueNode *head;//队首
};
void Fcfs(LinkQueue& Q, int& totalTimeSum, int& weightTotalTimeSum,PCBNode * ProcessTable);
bool RR_Run(LinkQueue& Q,QueueNode* q, QueueNode* p, const int Round,int& currentTime,PCBNode * ProcessTable);
//分配时间片给q所指进程,p为刚退出的进程
void RoundRobin(LinkQueue& Q,const int Round, int& totalTimeSum, int& weightTotalTimeSum,PCBNode * ProcessTable);
//时间片轮转调度,调用RR_Run(),时间片大小设为Round
void InitialQueue(LinkQueue& Q,PCBNode * ProcessTable,const int processnum);
//初始化就绪队列
void Input(PCBNode * ProcessTable, const int processnum);
//从input.txt文件输入数据
int main()
{
LinkQueue Q;//就绪队列
Q.head = NULL;
const int processnum = 16;//进程数
const int Round = 1; //时间片大小
int totalTimeSum = 0; //周转时间
int WeightTotalTimeSum = 0;//带权周转时间
PCBNode * ProcessTable=new PCBNode[processnum]; //进程表
Input(ProcessTable, processnum);
InitialQueue(Q, ProcessTable, processnum);
RoundRobin(Q, Round, totalTimeSum,WeightTotalTimeSum,ProcessTable);
cout < < "时间片轮调度的平均周转时间为: " < <totalTimeSum/processnum < <endl;
cout < < "时间片轮调度的平均带权周转时间为: " < <WeightTotalTimeSum/processnum < <endl;
Input(ProcessTable, processnum);
InitialQueue(Q, ProcessTable, processnum);
Fcfs(Q, totalTimeSum,WeightTotalTimeSum,ProcessTable);
cout < < "先来先服务的平均周转时间为: " < <totalTimeSum/processnum < <endl;
cout < < "先来先服务的平均带权周转时间为: " < <WeightTotalTimeSum/processnum < <endl;
delete [] ProcessTable;
return 0;
}
void RoundRobin(LinkQueue& Q,const int Round, int& totalTimeSum, int& weightTotalTimeSum,PCBNode * ProcessTable)
{
totalTimeSum = 0; //总的周转时间
weightTotalTimeSum = 0;//平均周转时间
int currentTime = 0; //当前时间
QueueNode* p;
QueueNode* q;
QueueNode* r;
bool finish = false;//调用RR_Run()后,该进程是否已经做完退出
p = Q.head;
q = p-> next;
while (q != NULL)//从队首开始依次分配时间片
{
do
{
cout < < "********************** " < <endl;
cout < < "在时间片 " < <(currentTime+1)/Round < < "内,活动进程为: " < <q-> ID < <endl;
cout < < "进程 " < <q-> ID < < " 现在需要的时间片为: " < <ProcessTable[q-> ID].remainTime < <endl;
finish = RR_Run(Q, q, p, Round, currentTime, ProcessTable);//分配时间片给q进程
cout < <endl;
if (!finish)//若是进程在本时间片内做完,则跳出do…while循环
{
if (q-> next == NULL)
{
r = Q.head-> next;
}
else
{
r = q-> next;
}
}
else //否则计算周转时间和带权周转时间
{
totalTimeSum += ProcessTable[q-> ID].totalTime;
weightTotalTimeSum += ProcessTable[q-> ID].weightTotalTime;
delete q; //从队列中删除q进程
q = p;
}
}while (!finish && (ProcessTable[r-> ID].arriveTime > currentTime + Round));
//下一个进程很晚才来,则继续给当前进程分配时间片
p = q;
q = q-> next;
if (q == NULL && Q.head-> next!=NULL)
{
p = Q.head;
q = p-> next;
}
}
delete Q.head;
Q.head = NULL;
}
bool RR_Run(LinkQueue& Q,QueueNode* q, QueueNode* p, const int Round,int& currentTime,PCBNode * ProcessTable)
{
if (ProcessTable[q-> ID].remainTime <= Round)//在此时间片内能够做完,之后退出进程调度
{
ProcessTable[q-> ID].finishTime = currentTime + ProcessTable[q-> ID].remainTime;
ProcessTable[q-> ID].totalTime += ProcessTable[q-> ID].remainTime;
ProcessTable[q-> ID].weightTotalTime = ProcessTable[q-> ID].totalTime/ProcessTable[q-> ID].reqTime;
currentTime = ProcessTable[q-> ID].finishTime;
p-> next = q-> next;
cout < <endl;
cout < < "进程 " < <q-> ID < < "完成! " < <endl;
return true;
}
else//此时间片内做不完
{
ProcessTable[q-> ID].remainTime = ProcessTable[q-> ID].remainTime - Round;
ProcessTable[q-> ID].totalTime += Round;
currentTime += Round;
return false;
}
}
void Fcfs(LinkQueue& Q, int& totalTimeSum, int& weightTotalTimeSum,PCBNode * ProcessTable)
{
totalTimeSum = 0;
weightTotalTimeSum = 0;//平均周转时间
QueueNode* p;
QueueNode* q;
p = Q.head-> next;
if (p !=NULL )
{
ProcessTable[p-> ID].startTime = ProcessTable[p-> ID].arriveTime;
ProcessTable[p-> ID].finishTime = ProcessTable[p-> ID].arriveTime + ProcessTable[p-> ID].reqTime;
}
for(q=p-> next; q!=NULL; q=q-> next)
{
if (ProcessTable[q-> ID].arriveTime < ProcessTable[p-> ID].finishTime)
{
ProcessTable[q-> ID].startTime = ProcessTable[p-> ID].finishTime;
ProcessTable[q-> ID].finishTime = ProcessTable[p-> ID].finishTime + ProcessTable[q-> ID].reqTime;
}
else//下个进程到达时间较晚
{
ProcessTable[q-> ID].startTime = ProcessTable[q-> ID].arriveTime;
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