编写C程序模拟实现单处理机系统中的进程调度算法,实现对多个进程的调度模拟,要求采用短进程优先算法进行模拟调度。
时间: 2023-11-12 11:12:37 浏览: 230
操作系统实验--模拟实现单处理机下的进程调度程序
5星 · 资源好评率100%
以下是使用短进程优先算法模拟进程调度的C程序:
```c
#include <stdio.h>
#include <stdlib.h>
#define MAX_PROCESS 10 // 最大进程数
#define MAX_TIME 100 // 最大时间片长度
// 进程结构体
typedef struct {
int id; // 进程ID
int arrival_time; // 到达时间
int burst_time; // 运行时间
int remaining_time; // 剩余运行时间
int turnaround_time; // 周转时间
int waiting_time; // 等待时间
int completed; // 进程是否完成
} Process;
// 对进程按到达时间进行排序
void sort_by_arrival_time(Process processes[], int num_processes) {
int i, j;
for (i = 0; i < num_processes - 1; i++) {
for (j = 0; j < num_processes - i - 1; j++) {
if (processes[j].arrival_time > processes[j + 1].arrival_time) {
Process temp = processes[j];
processes[j] = processes[j + 1];
processes[j + 1] = temp;
}
}
}
}
// 对进程按剩余运行时间进行排序
void sort_by_remaining_time(Process processes[], int num_processes) {
int i, j;
for (i = 0; i < num_processes - 1; i++) {
for (j = 0; j < num_processes - i - 1; j++) {
if (processes[j].remaining_time > processes[j + 1].remaining_time) {
Process temp = processes[j];
processes[j] = processes[j + 1];
processes[j + 1] = temp;
}
}
}
}
// 计算进程的周转时间和等待时间
void calculate_turnaround_time(Process processes[], int num_processes) {
int i;
for (i = 0; i < num_processes; i++) {
processes[i].turnaround_time = processes[i].waiting_time + processes[i].burst_time;
}
}
// 打印每个进程的详细信息
void print_process_details(Process process) {
printf("Process ID: %d\n", process.id);
printf("Arrival Time: %d\n", process.arrival_time);
printf("Burst Time: %d\n", process.burst_time);
printf("Turnaround Time: %d\n", process.turnaround_time);
printf("Waiting Time: %d\n\n", process.waiting_time);
}
// 打印所有进程的平均周转时间和平均等待时间
void print_average_times(Process processes[], int num_processes) {
int i;
float total_turnaround_time = 0, total_waiting_time = 0;
for (i = 0; i < num_processes; i++) {
total_turnaround_time += processes[i].turnaround_time;
total_waiting_time += processes[i].waiting_time;
}
printf("Average Turnaround Time: %.2f\n", total_turnaround_time / num_processes);
printf("Average Waiting Time: %.2f\n", total_waiting_time / num_processes);
}
int main() {
int num_processes, i, j, current_time = 0;
Process processes[MAX_PROCESS];
// 获取进程数和每个进程的到达时间和运行时间
printf("Enter the number of processes: ");
scanf("%d", &num_processes);
for (i = 0; i < num_processes; i++) {
printf("Enter arrival time and burst time for process %d: ", i + 1);
scanf("%d %d", &processes[i].arrival_time, &processes[i].burst_time);
processes[i].id = i + 1;
processes[i].remaining_time = processes[i].burst_time;
processes[i].completed = 0;
}
// 对进程按到达时间进行排序
sort_by_arrival_time(processes, num_processes);
// 进程调度
while (1) {
int completed = 1;
// 找到最短的未完成进程
int shortest_remaining_time = MAX_TIME;
int shortest_process_index = -1;
for (i = 0; i < num_processes; i++) {
if (!processes[i].completed && processes[i].arrival_time <= current_time) {
if (processes[i].remaining_time < shortest_remaining_time) {
shortest_remaining_time = processes[i].remaining_time;
shortest_process_index = i;
}
completed = 0;
}
}
// 如果所有进程都已经完成,则退出循环
if (completed) {
break;
}
// 更新进程的等待时间和剩余运行时间
for (i = 0; i < num_processes; i++) {
if (i != shortest_process_index && !processes[i].completed && processes[i].arrival_time <= current_time) {
processes[i].waiting_time++;
}
}
processes[shortest_process_index].remaining_time--;
if (processes[shortest_process_index].remaining_time == 0) {
processes[shortest_process_index].completed = 1;
processes[shortest_process_index].turnaround_time = current_time - processes[shortest_process_index].arrival_time + 1;
calculate_turnaround_time(processes, num_processes);
}
current_time++;
}
// 对进程按进程ID进行排序
sort_by_arrival_time(processes, num_processes);
// 打印每个进程的详细信息和平均周转时间和平均等待时间
for (i = 0; i < num_processes; i++) {
print_process_details(processes[i]);
}
print_average_times(processes, num_processes);
return 0;
}
```
使用该程序,您可以输入进程的到达时间和运行时间,然后模拟短进程优先算法进行进程调度。程序将输出每个进程的详细信息以及平均周转时间和平均等待时间。
阅读全文