FCFS CPU调度程序在C++

FCFS CPU Scheduling program in C++

本文关键字:C++ 调度程序 CPU FCFS      更新时间:2023-10-16

我正在尝试用c ++实现FCFS CPU调度。我有以下代码,它运行无错误,但在某些数字上给了我"垃圾数据",例如所有进程的等待时间、响应时间和周转时间的值,除了第一个计算出来的进程

#include "stdafx.h"
#include <iostream>
#include <string>
using namespace std;
class ProcessInfo
{
public:
    string ProcessID;
    int BurstTime;
    int Arrival;
    int WaitingTime;
    int ResponseTime;
    int TurnaroundTime;
};
int main()
{
    ProcessInfo P1, P2, P3 = ProcessInfo();
    ProcessInfo Array[3] = {P1, P2, P3};
    for(int i = 0; i < 3; i++)
    {
        cout<<"Please enter Process ID for process "<<i<<endl;
        cin>>Array[i].ProcessID;
        cout<<"Please enter Burst Time for process "<<i<<endl;
        cin>>Array[i].BurstTime;
        cout<<"Please enter Arrival Time for process "<<i<<endl;
        cin>>Array[i].Arrival;
    }
    if (Array[0].Arrival < Array[1].Arrival && Array[0].Arrival < Array[2].Arrival)
    {
        if (Array[1].Arrival < Array[2].Arrival)
        {
            P1.WaitingTime = 0;
            P1.ResponseTime = 0;
            P1.TurnaroundTime = P1.BurstTime;
            P2.WaitingTime = P1.TurnaroundTime - (P2.Arrival - P1.Arrival);
            P2.ResponseTime = 0;
            P2.TurnaroundTime = P2.WaitingTime + P2.BurstTime;
            P3.WaitingTime = P2.TurnaroundTime - (P3.Arrival - P2.Arrival);
            P3.ResponseTime = P2.TurnaroundTime - (P3.Arrival - P2.Arrival) ;
            P3.TurnaroundTime = P3.WaitingTime + P3.BurstTime;
            cout<<"Order of processes is: P1, P2, P3"<<endl;
            cout<<"The waiting time for P1: "<< P1.WaitingTime<<endl;
            cout<<"The response time for P1: "<<P1.ResponseTime<<endl;
            cout<<"The Turnaround time for P1: "<<P1.TurnaroundTime<<endl;
            cout<<"The waiting time for P2: "<< P2.WaitingTime<<endl;
            cout<<"The response time for P2: "<<P2.ResponseTime<<endl;
            cout<<"The Turnaround time for P2: "<<P2.TurnaroundTime<<endl;
            cout<<"The waiting time for P3: "<< P3.WaitingTime<<endl;
            cout<<"The response time for P3: "<<P3.ResponseTime<<endl;
            cout<<"The Turnaround time for P3: "<<P3.TurnaroundTime<<endl;
        }
        else
            if (Array[2].Arrival < Array[1].Arrival)
            {
                P1.WaitingTime = 0;
                P1.ResponseTime = 0;
                P1.TurnaroundTime = P1.BurstTime;
                P3.WaitingTime = P1.TurnaroundTime - (P3.Arrival - P1.Arrival);
                P3.ResponseTime = P3.WaitingTime;
                P3.TurnaroundTime = P3.WaitingTime + P3.BurstTime;
                P2.WaitingTime = P3.TurnaroundTime - (P2.Arrival - P3.Arrival);
                P2.ResponseTime = P2.WaitingTime;
                P2.TurnaroundTime = P2.WaitingTime + P2.BurstTime;
                cout<<"Order of processes is: P1, P3, P2"<<endl;
                cout<<"The waiting time for P1: "<< P1.WaitingTime<<endl;
                cout<<"The response time for P1: "<<P1.ResponseTime<<endl;
                cout<<"The Turnaround time for P1: "<<P1.TurnaroundTime<<endl;
                cout<<"The waiting time for P3: "<< P3.WaitingTime<<endl;
                cout<<"The response time for P3: "<<P3.ResponseTime<<endl;
                cout<<"The Turnaround time for P3: "<<P3.TurnaroundTime<<endl;
                cout<<"The waiting time for P2: "<< P2.WaitingTime<<endl;
                cout<<"The response time for P2: "<<P2.ResponseTime<<endl;
                cout<<"The Turnaround time for P2: "<<P2.TurnaroundTime<<endl;
            }
    }
    else
        if(Array[1].Arrival < Array[0].Arrival && Array[1].Arrival < Array[2].Arrival)
        {
            if (Array[2].Arrival < Array[0].Arrival)
            {
                P2.WaitingTime = 0;
                P2.ResponseTime = 0;
                P2.TurnaroundTime = P2.BurstTime;
                P3.WaitingTime = P2.TurnaroundTime - (P3.Arrival - P2.Arrival);
                P3.ResponseTime = P3.WaitingTime;
                P3.TurnaroundTime = P3.WaitingTime + P3.BurstTime;
                P1.WaitingTime = P3.TurnaroundTime - (P1.Arrival - P3.Arrival);
                P1.ResponseTime = P1.WaitingTime;
                P1.TurnaroundTime = P1.WaitingTime + P1.BurstTime;
                cout<<"Order of processes is: P2, P3, P1"<<endl;
                cout<<"The waiting time for P2: "<< P2.WaitingTime<<endl;
                cout<<"The response time for P2: "<<P2.ResponseTime<<endl;
                cout<<"The Turnaround time for P2: "<<P2.TurnaroundTime<<endl;
                cout<<"The waiting time for P3: "<< P3.WaitingTime<<endl;
                cout<<"The response time for P3: "<<P3.ResponseTime<<endl;
                cout<<"The Turnaround time for P3: "<<P3.TurnaroundTime<<endl;
                cout<<"The waiting time for P1: "<< P1.WaitingTime<<endl;
                cout<<"The response time for P1: "<<P1.ResponseTime<<endl;
                cout<<"The Turnaround time for P1: "<<P1.TurnaroundTime<<endl;
            }
            else
                if (Array[0].Arrival < Array[2].Arrival)
                {
                    P2.WaitingTime = 0;
                    P2.ResponseTime = 0;
                    P2.TurnaroundTime = P2.BurstTime;
                    P1.WaitingTime = P2.TurnaroundTime - (P1.Arrival - P2.Arrival);
                    P1.ResponseTime = P1.WaitingTime;
                    P1.TurnaroundTime = P1.WaitingTime + P1.BurstTime;
                    P3.WaitingTime = P1.TurnaroundTime - (P3.Arrival - P1.Arrival);
                    P3.ResponseTime = P3.WaitingTime;
                    P3.TurnaroundTime = P3.WaitingTime + P3.BurstTime;
                    cout<<"Order of processes is: P2, P1, P3"<<endl;
                    cout<<"The waiting time for P2: "<< P2.WaitingTime<<endl;
                    cout<<"The response time for P2: "<<P2.ResponseTime<<endl;
                    cout<<"The Turnaround time for P2: "<<P2.TurnaroundTime<<endl;
                    cout<<"The waiting time for P1: "<< P1.WaitingTime<<endl;
                    cout<<"The response time for P1: "<<P1.ResponseTime<<endl;
                    cout<<"The Turnaround time for P1: "<<P1.TurnaroundTime<<endl;
                    cout<<"The waiting time for P3: "<< P3.WaitingTime<<endl;
                    cout<<"The response time for P3: "<<P3.ResponseTime<<endl;
                    cout<<"The Turnaround time for P3: "<<P3.TurnaroundTime<<endl;
                }
        }
        else
            if(Array[2].Arrival < Array[1].Arrival && Array[2].Arrival < Array[0].Arrival)
            {
                if (Array[1].Arrival < Array[0].Arrival)
                {
                    P3.WaitingTime = 0;
                    P3.ResponseTime = 0;
                    P3.TurnaroundTime = P1.BurstTime;
                    P2.WaitingTime = P3.TurnaroundTime - (P2.Arrival - P3.Arrival);
                    P2.ResponseTime = P2.WaitingTime;
                    P2.TurnaroundTime = P2.WaitingTime + P2.BurstTime;
                    P1.WaitingTime = P2.TurnaroundTime - (P1.Arrival - P2.Arrival);
                    P1.ResponseTime = P1.WaitingTime;
                    P1.TurnaroundTime = P1.WaitingTime + P1.BurstTime;
                    cout<<"Order of processes is: P3, P2, P1"<<endl;
                    cout<<"The waiting time for P3: "<< P3.WaitingTime<<endl;
                    cout<<"The response time for P3: "<<P3.ResponseTime<<endl;
                    cout<<"The Turnaround time for P3: "<<P3.TurnaroundTime<<endl;
                    cout<<"The waiting time for P2: "<< P2.WaitingTime<<endl;
                    cout<<"The response time for P2: "<<P2.ResponseTime<<endl;
                    cout<<"The Turnaround time for P2: "<<P2.TurnaroundTime<<endl;
                    cout<<"The waiting time for P1: "<< P1.WaitingTime<<endl;
                    cout<<"The response time for P1: "<<P1.ResponseTime<<endl;
                    cout<<"The Turnaround time for P1: "<<P1.TurnaroundTime<<endl;
                }
                else
                    if (Array[0].Arrival < Array[1].Arrival)
                    {
                        P3.WaitingTime = 0;
                        P3.ResponseTime = 0;
                        P3.TurnaroundTime = P1.BurstTime;
                        P1.WaitingTime = P3.TurnaroundTime - (P1.Arrival - P3.Arrival);
                        P1.ResponseTime = P1.WaitingTime;
                        P1.TurnaroundTime = P1.WaitingTime + P1.BurstTime;
                        P2.WaitingTime = P1.TurnaroundTime - (P2.Arrival - P1.Arrival);
                        P2.ResponseTime = P2.WaitingTime;
                        P2.TurnaroundTime = P2.WaitingTime + P2.BurstTime;
                        cout<<"Order of processes is: P3, P1, P2"<<endl;
                        cout<<"The waiting time for P3: "<< P3.WaitingTime<<endl;
                        cout<<"The response time for P3: "<<P3.ResponseTime<<endl;
                        cout<<"The Turnaround time for P3: "<<P3.TurnaroundTime<<endl;
                        cout<<"The waiting time for P1: "<< P1.WaitingTime<<endl;
                        cout<<"The response time for P1: "<<P1.ResponseTime<<endl;
                        cout<<"The Turnaround time for P1: "<<P1.TurnaroundTime<<endl;
                        cout<<"The waiting time for P2: "<< P2.WaitingTime<<endl;
                        cout<<"The response time for P2: "<<P2.ResponseTime<<endl;
                        cout<<"The Turnaround time for P2: "<<P2.TurnaroundTime<<endl;
                    }
            }

    }

你不初始化变量P1P2,所以这些结构的内容将是未定义的。

这将使以下操作:

P1.TurnaroundTime = P1.BurstTime;

也未定义。

如果需要良好的起始值,请添加默认构造函数。

不要使用 P1P2P3 进行计算。而是使用Array[0]Array[1]Array[2]

#include<iostream>
#include<cstdio>
#include<cstdlib>
int process,*q,i,slice,a=0,at2[10],to[10];
void takeprocess()
{
    printf("Enter the total number of processn");
    scanf("%d",&process);

}

void takecputime()
{
    q=(int*)calloc(process,(sizeof(int)));
for(i=1;i<=process;i++)
{
printf("Enter the CPU burst time for the process P%d : ",i);
   scanf("%d",q+i);
   to[i]=at2[i]=*(q+i);
}
}
void checkfcfs()
{
 int wt1[process];
    for(i=1;i<process;i++)
    {
        a=wt1[i]=*(q+i)+a;
    }
    a=0;
    printf("the waiting time for process P1 is : 0n");
    for(i=1;i<process;i++)
    {
   a=wt1[i]+a;
        printf("the waiting time for process P%d is : %dn",i+1,wt1[i]);
    }
    a=a/process;
    printf("the average waiting time for processes are :%dn",a);
    printf("the sequence of the processes are as followsn");
    for(i=1;i<=process;i++)
    {
        printf("P%dn",i);
    }

}
using namespace std;
int main()
{
             takeprocess();
             takecputime();
             checkfcfs();
             return 0;

}