操作系统实验一_ cpu scheduling 1、设计一个按优先权调度算法实现处理机调度的程序 2、设计一个按时间片轮转实现处理机调度的程序
时间: 2023-05-04 12:01:19 浏览: 111
1. CPU调度算法是操作系统中用于实现处理机调度的重要算法,它的设计直接影响着系统的性能和响应速度。一个按优先权限调度算法的程序可以实现处理机调度的操作。
2. 在操作系统中,实时系统常常需要进行时间片轮转的处理机调度,这就需要设计一个按时钟时间片轮转的调度算法的程序。
相关问题
通过ava语言实现以下要求:选择一个调度算法,实现处理机调度。 1、设计一个按下面三种调度算法实现处理机调度的程序。 1)先来先服务 2)短进程优先或优先权高优先 3)按时间片轮转
以下是使用 Java 语言实现三种调度算法的示例代码:
1. 先来先服务(FCFS)调度算法:
```
import java.util.*;
public class FCFS {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter the number of processes: ");
int n = input.nextInt();
int[] bt = new int[n];
int[] wt = new int[n];
int[] tat = new int[n];
int[] ct = new int[n];
int sum = 0;
float avgwt = 0, avgtat = 0;
System.out.println("Enter the Burst Time for each process: ");
for (int i = 0; i < n; i++) {
System.out.print("Process " + (i + 1) + ": ");
bt[i] = input.nextInt();
}
ct[0] = bt[0];
for (int i = 1; i < n; i++) {
ct[i] = ct[i - 1] + bt[i];
}
for (int i = 0; i < n; i++) {
tat[i] = ct[i];
wt[i] = tat[i] - bt[i];
avgwt += wt[i];
avgtat += tat[i];
}
System.out.println("\nFCFS Scheduling Algorithm:");
System.out.println("Process\tBT\tCT\tTAT\tWT");
for (int i = 0; i < n; i++) {
System.out.println((i + 1) + "\t" + bt[i] + "\t" + ct[i] + "\t" + tat[i] + "\t" + wt[i]);
}
avgwt /= n;
avgtat /= n;
System.out.println("Average Waiting Time: " + avgwt);
System.out.println("Average Turnaround Time: " + avgtat);
}
}
```
2. 短进程优先或优先权高优先调度算法:
```
import java.util.*;
public class SJF {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter the number of processes: ");
int n = input.nextInt();
int[] bt = new int[n];
int[] wt = new int[n];
int[] tat = new int[n];
int[] ct = new int[n];
int sum = 0;
float avgwt = 0, avgtat = 0;
System.out.println("Enter the Burst Time for each process: ");
for (int i = 0; i < n; i++) {
System.out.print("Process " + (i + 1) + ": ");
bt[i] = input.nextInt();
}
int[] p = new int[n];
for (int i = 0; i < n; i++) {
p[i] = i + 1;
}
for (int i = 0; i < n; i++) {
for (int j = i + 1; j < n; j++) {
if (bt[i] > bt[j]) {
int temp = bt[i];
bt[i] = bt[j];
bt[j] = temp;
temp = p[i];
p[i] = p[j];
p[j] = temp;
}
}
}
ct[0] = bt[0];
for (int i = 1; i < n; i++) {
ct[i] = ct[i - 1] + bt[i];
}
for (int i = 0; i < n; i++) {
tat[i] = ct[i];
wt[i] = tat[i] - bt[i];
avgwt += wt[i];
avgtat += tat[i];
}
System.out.println("\nSJF Scheduling Algorithm:");
System.out.println("Process\tBT\tCT\tTAT\tWT");
for (int i = 0; i < n; i++) {
System.out.println(p[i] + "\t" + bt[i] + "\t" + ct[i] + "\t" + tat[i] + "\t" + wt[i]);
}
avgwt /= n;
avgtat /= n;
System.out.println("Average Waiting Time: " + avgwt);
System.out.println("Average Turnaround Time: " + avgtat);
}
}
```
3. 按时间片轮转调度算法:
```
import java.util.*;
public class RoundRobin {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter the number of processes: ");
int n = input.nextInt();
int[] bt = new int[n];
int[] wt = new int[n];
int[] tat = new int[n];
int[] ct = new int[n];
int[] rem_bt = new int[n];
int sum = 0, t = 0, tq;
float avgwt = 0, avgtat = 0;
System.out.println("Enter the Burst Time for each process: ");
for (int i = 0; i < n; i++) {
System.out.print("Process " + (i + 1) + ": ");
bt[i] = input.nextInt();
rem_bt[i] = bt[i];
}
System.out.print("Enter the time quantum: ");
tq = input.nextInt();
while (true) {
boolean done = true;
for (int i = 0; i < n; i++) {
if (rem_bt[i] > 0) {
done = false;
if (rem_bt[i] > tq) {
t += tq;
rem_bt[i] -= tq;
} else {
t += rem_bt[i];
ct[i] = t;
tat[i] = ct[i];
wt[i] = tat[i] - bt[i];
avgwt += wt[i];
avgtat += tat[i];
rem_bt[i] = 0;
}
}
}
if (done) {
break;
}
}
System.out.println("\nRound Robin Scheduling Algorithm:");
System.out.println("Process\tBT\tCT\tTAT\tWT");
for (int i = 0; i < n; i++) {
System.out.println((i + 1) + "\t" + bt[i] + "\t" + ct[i] + "\t" + tat[i] + "\t" + wt[i]);
}
avgwt /= n;
avgtat /= n;
System.out.println("Average Waiting Time: " + avgwt);
System.out.println("Average Turnaround Time: " + avgtat);
}
}
```
编写和调试一个进程调度程序,实现基于优先权的进程调度算法和基于时间片轮转调度算法。
这里是一个基于C语言的进程调度程序,实现了基于优先权的进程调度算法和基于时间片轮转调度算法。本程序中,优先级值越小,优先级越高。时间片长度为2个时间单位。
```
#include<stdio.h>
#include<stdlib.h>
#define MAX 10
#define TIME_QUANTUM 2
struct process {
int pid; // 进程ID
int priority; // 优先级
int burst_time; // 执行时间
int waiting_time; // 等待时间
int turnaround_time; // 周转时间
};
void execute_priority(struct process *proc, int n) {
int i, j;
struct process temp;
float total_waiting_time = 0, total_turnaround_time = 0;
// 按照优先级排序
for (i = 0; i < n-1; i++) {
for (j = i+1; j < n; j++) {
if (proc[i].priority > proc[j].priority) {
temp = proc[i];
proc[i] = proc[j];
proc[j] = temp;
}
}
}
// 计算等待时间和周转时间
for (i = 0; i < n; i++) {
if (i == 0) {
proc[i].waiting_time = 0;
proc[i].turnaround_time = proc[i].burst_time;
} else {
proc[i].waiting_time = proc[i-1].waiting_time + proc[i-1].burst_time;
proc[i].turnaround_time = proc[i].waiting_time + proc[i].burst_time;
}
total_waiting_time += proc[i].waiting_time;
total_turnaround_time += proc[i].turnaround_time;
}
// 输出结果
printf("\nProcess ID\tPriority\tBurst Time\tWaiting Time\tTurnaround Time\n");
for (i = 0; i < n; i++) {
printf("%d\t\t%d\t\t%d\t\t%d\t\t%d\n", proc[i].pid, proc[i].priority, proc[i].burst_time, proc[i].waiting_time, proc[i].turnaround_time);
}
printf("Average Waiting Time: %f\n", total_waiting_time/n);
printf("Average Turnaround Time: %f\n", total_turnaround_time/n);
}
void execute_round_robin(struct process *proc, int n) {
int i, j, time = 0, remain = n, flag = 0;
float total_waiting_time = 0, total_turnaround_time = 0;
// 执行进程
while (remain != 0) {
if (proc[flag].burst_time <= TIME_QUANTUM && proc[flag].burst_time > 0) {
time += proc[flag].burst_time;
proc[flag].burst_time = 0;
flag++;
remain--;
} else if (proc[flag].burst_time > 0) {
proc[flag].burst_time -= TIME_QUANTUM;
time += TIME_QUANTUM;
flag++;
}
if (flag == n) flag = 0;
}
// 计算等待时间和周转时间
for (i = 0; i < n; i++) {
proc[i].turnaround_time = time;
proc[i].waiting_time = proc[i].turnaround_time - proc[i].burst_time;
total_waiting_time += proc[i].waiting_time;
total_turnaround_time += proc[i].turnaround_time;
}
// 输出结果
printf("\nProcess ID\tBurst Time\tWaiting Time\tTurnaround Time\n");
for (i = 0; i < n; i++) {
printf("%d\t\t%d\t\t%d\t\t%d\n", proc[i].pid, proc[i].burst_time, proc[i].waiting_time, proc[i].turnaround_time);
}
printf("Average Waiting Time: %f\n", total_waiting_time/n);
printf("Average Turnaround Time: %f\n", total_turnaround_time/n);
}
int main() {
int i, n, algorithm;
struct process proc[MAX];
// 输入进程信息
printf("Enter the number of processes: ");
scanf("%d", &n);
for (i = 0; i < n; i++) {
printf("\nEnter the process ID: ");
scanf("%d", &proc[i].pid);
printf("Enter the burst time: ");
scanf("%d", &proc[i].burst_time);
printf("Enter the priority: ");
scanf("%d", &proc[i].priority);
}
// 选择调度算法
printf("\nChoose a scheduling algorithm:\n");
printf("1. Priority scheduling\n");
printf("2. Round-robin scheduling\n");
printf("Enter your choice: ");
scanf("%d", &algorithm);
// 执行调度算法
switch (algorithm) {
case 1: execute_priority(proc, n); break;
case 2: execute_round_robin(proc, n); break;
default: printf("\nInvalid choice!\n");
}
return 0;
}
```