设计一段程序来模拟先来先服务,短作业优先、优先级调度算法和时间片轮转算法,要求可以根据不同调度算法,指定进程的数量、各进程的到达时间、各进程需要cpu的时间和各进程的优先级。
时间: 2023-05-03 12:01:26 浏览: 103
这段文字讲述了设计一个程序模拟服务的短作业优先、优先级调度算法和时间片轮转算法,要求可以根据不同调度算法,指定进程的数量、各进程的到达时间、各进程需要cpu的时间和各进程的优先级,并在各进程到达时间、需要cpu的时间和优先级不同的情况下,计算各进程的到达时间、各进程需要cpu的时 长和各进程的优先级,以及不同进程的优先级需要cpu的时间和各进程的优先级。同时还需要考虑各进程需要的cpu的时间和各进程的优先级的优先级。
相关问题
先来先服务调度算法(FCFS) 短作业优先调度算法(SJF) 时间片轮转调度算法(RR) 优先级调度算法
下面是对先来先服务调度算法(FCFS)、短作业优先调度算法(SJF)、时间片轮转调度算法(RR)和优先级调度算法的模拟实现的简要介绍:
1. 先来先服务调度算法(FCFS):
- 这是一种非抢占式调度算法,按照作业到达的顺序进行调度。
- 模拟实现时,可以根据作业到达的时间和执行时间,按照先后顺序进行调度,并计算平均等待时间和平均周转时间。
2. 短作业优先调度算法(SJF):
- 这是一种非抢占式调度算法,按照作业执行时间的长短进行调度。
- 模拟实现时,可以根据作业的执行时间,选择执行时间最短的作业进行调度,并计算平均等待时间和平均周转时间。
3. 时间片轮转调度算法(RR):
- 这是一种抢占式调度算法,将CPU时间分为固定长度的时间片,每个作业在一个时间片内执行。
- 模拟实现时,可以使用循环队列来维护就绪队列,每个作业在一个时间片内执行一定量的工作,并按照轮转的方式进行调度。
4. 优先级调度算法:
- 这是一种非抢占式或抢占式调度算法,根据作业的优先级进行调度,优先级高的作业先执行。
- 模拟实现时,可以为每个作业分配一个优先级,并根据优先级选择下一个要执行的作业,并计算平均等待时间和平均周转时间。
以上算法可以通过编写C程序来进行模拟实现,你可以根据具体的需求和输入数据进行算法的测试和比较。如果你需要更详细的实现代码或有其他问题,请告诉我。
一个c语言代码实现先来先服务调度算法、短作业优先算法、时间片轮转和优先级调度算法
先来先服务调度算法(FCFS):
```c
#include <stdio.h>
#define MAX 10
struct Process {
int pid;
int arrival_time;
int burst_time;
int waiting_time;
int turnaround_time;
};
int main() {
struct Process p[MAX];
int n, i;
float avg_waiting_time = 0, avg_turnaround_time = 0;
printf("Enter the number of processes: ");
scanf("%d", &n);
for(i=0; i<n; i++) {
printf("Enter arrival time and burst time for Process %d: ", i+1);
scanf("%d %d", &p[i].arrival_time, &p[i].burst_time);
p[i].pid = i+1;
}
// calculate waiting time and turnaround time
p[0].waiting_time = 0;
for(i=1; i<n; i++) {
p[i].waiting_time = p[i-1].waiting_time + p[i-1].burst_time;
}
for(i=0; i<n; i++) {
p[i].turnaround_time = p[i].waiting_time + p[i].burst_time;
avg_waiting_time += p[i].waiting_time;
avg_turnaround_time += p[i].turnaround_time;
}
// print result
printf("\nProcess\tArrival Time\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", p[i].pid, p[i].arrival_time, p[i].burst_time, p[i].waiting_time, p[i].turnaround_time);
}
avg_waiting_time /= n;
avg_turnaround_time /= n;
printf("Average Waiting Time: %f\n", avg_waiting_time);
printf("Average Turnaround Time: %f\n", avg_turnaround_time);
return 0;
}
```
短作业优先算法(SJF):
```c
#include <stdio.h>
#define MAX 10
struct Process {
int pid;
int arrival_time;
int burst_time;
int waiting_time;
int turnaround_time;
int is_completed;
};
int main() {
struct Process p[MAX];
int n, i, j;
float avg_waiting_time = 0, avg_turnaround_time = 0;
printf("Enter the number of processes: ");
scanf("%d", &n);
for(i=0; i<n; i++) {
printf("Enter arrival time and burst time for Process %d: ", i+1);
scanf("%d %d", &p[i].arrival_time, &p[i].burst_time);
p[i].pid = i+1;
p[i].is_completed = 0;
}
int time = 0, completed = 0;
while(completed != n) {
int shortest = -1;
for(i=0; i<n; i++) {
if(!p[i].is_completed && p[i].arrival_time <= time) {
if(shortest == -1 || p[i].burst_time < p[shortest].burst_time) {
shortest = i;
}
}
}
if(shortest != -1) {
p[shortest].waiting_time = time - p[shortest].arrival_time;
p[shortest].turnaround_time = p[shortest].waiting_time + p[shortest].burst_time;
avg_waiting_time += p[shortest].waiting_time;
avg_turnaround_time += p[shortest].turnaround_time;
p[shortest].is_completed = 1;
completed++;
time += p[shortest].burst_time;
} else {
time++;
}
}
// print result
printf("\nProcess\tArrival Time\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", p[i].pid, p[i].arrival_time, p[i].burst_time, p[i].waiting_time, p[i].turnaround_time);
}
avg_waiting_time /= n;
avg_turnaround_time /= n;
printf("Average Waiting Time: %f\n", avg_waiting_time);
printf("Average Turnaround Time: %f\n", avg_turnaround_time);
return 0;
}
```
时间片轮转算法(RR):
```c
#include <stdio.h>
#define MAX 10
struct Process {
int pid;
int arrival_time;
int burst_time;
int remaining_time;
int waiting_time;
int turnaround_time;
int is_completed;
};
int main() {
struct Process p[MAX];
int n, i, j, time_quantum;
float avg_waiting_time = 0, avg_turnaround_time = 0;
printf("Enter the number of processes: ");
scanf("%d", &n);
for(i=0; i<n; i++) {
printf("Enter arrival time and burst time for Process %d: ", i+1);
scanf("%d %d", &p[i].arrival_time, &p[i].burst_time);
p[i].pid = i+1;
p[i].remaining_time = p[i].burst_time;
p[i].is_completed = 0;
}
printf("Enter time quantum: ");
scanf("%d", &time_quantum);
int time = 0, completed = 0;
while(completed != n) {
for(i=0; i<n; i++) {
if(!p[i].is_completed && p[i].arrival_time <= time) {
int execute_time = time_quantum;
if(p[i].remaining_time < execute_time) {
execute_time = p[i].remaining_time;
}
p[i].remaining_time -= execute_time;
time += execute_time;
if(p[i].remaining_time == 0) {
p[i].waiting_time = time - p[i].arrival_time - p[i].burst_time;
if(p[i].waiting_time < 0) {
p[i].waiting_time = 0;
}
p[i].turnaround_time = p[i].waiting_time + p[i].burst_time;
avg_waiting_time += p[i].waiting_time;
avg_turnaround_time += p[i].turnaround_time;
p[i].is_completed = 1;
completed++;
}
}
}
}
// print result
printf("\nProcess\tArrival Time\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", p[i].pid, p[i].arrival_time, p[i].burst_time, p[i].waiting_time, p[i].turnaround_time);
}
avg_waiting_time /= n;
avg_turnaround_time /= n;
printf("Average Waiting Time: %f\n", avg_waiting_time);
printf("Average Turnaround Time: %f\n", avg_turnaround_time);
return 0;
}
```
优先级调度算法:
```c
#include <stdio.h>
#define MAX 10
struct Process {
int pid;
int arrival_time;
int burst_time;
int priority;
int waiting_time;
int turnaround_time;
int is_completed;
};
int main() {
struct Process p[MAX];
int n, i, j;
float avg_waiting_time = 0, avg_turnaround_time = 0;
printf("Enter the number of processes: ");
scanf("%d", &n);
for(i=0; i<n; i++) {
printf("Enter arrival time, burst time and priority for Process %d: ", i+1);
scanf("%d %d %d", &p[i].arrival_time, &p[i].burst_time, &p[i].priority);
p[i].pid = i+1;
p[i].is_completed = 0;
}
int time = 0, completed = 0;
while(completed != n) {
int highest_priority = -1, index = -1;
for(i=0; i<n; i++) {
if(!p[i].is_completed && p[i].arrival_time <= time) {
if(p[i].priority > highest_priority) {
highest_priority = p[i].priority;
index = i;
}
}
}
if(index != -1) {
p[index].waiting_time = time - p[index].arrival_time;
p[index].turnaround_time = p[index].waiting_time + p[index].burst_time;
avg_waiting_time += p[index].waiting_time;
avg_turnaround_time += p[index].turnaround_time;
p[index].is_completed = 1;
completed++;
time += p[index].burst_time;
} else {
time++;
}
}
// print result
printf("\nProcess\tArrival Time\tBurst Time\tPriority\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\t\t%d\n", p[i].pid, p[i].arrival_time, p[i].burst_time, p[i].priority, p[i].waiting_time, p[i].turnaround_time);
}
avg_waiting_time /= n;
avg_turnaround_time /= n;
printf("Average Waiting Time: %f\n", avg_waiting_time);
printf("Average Turnaround Time: %f\n", avg_turnaround_time);
return 0;
}
```