能够编写创建作业队列的程序段和作业调度函数
时间: 2023-12-14 13:38:14 浏览: 36
以下一个基本的创建作业队列的程序段和作业调度函数的示例:
```c
#include <stdio.h>
#include <stdlib.h>
typedef struct {
int job_id;
int priority;
int burst_time;
} job;
typedef struct {
job **jobs;
int front;
int rear;
int max_size;
} job_queue;
job_queue *create_job_queue(int max_size) {
job_queue *q = (job_queue*)malloc(sizeof(job_queue));
q->jobs = (job**)malloc(max_size * sizeof(job*));
q->front = -1;
q->rear = -1;
q->max_size = max_size;
return q;
}
void enqueue_job(job_queue *q, job *j) {
if ((q->front == 0 && q->rear == q->max_size - 1) || (q->rear == (q->front - 1) % (q->max_size - 1))) {
printf("Job queue is full!\n");
return;
}
else if (q->front == -1) {
q->front = q->rear = 0;
q->jobs[q->rear] = j;
}
else if (q->rear == q->max_size - 1 && q->front != 0) {
q->rear = 0;
q->jobs[q->rear] = j;
}
else {
q->rear++;
q->jobs[q->rear] = j;
}
}
job *dequeue_job(job_queue *q) {
if (q->front == -1) {
printf("Job queue is empty!\n");
return NULL;
}
job *j = q->jobs[q->front];
if (q->front == q->rear) {
q->front = q->rear = -1;
}
else if (q->front == q->max_size - 1) {
q->front = 0;
}
else {
q->front++;
}
return j;
}
void swap_jobs(job **j1, job **j2) {
job *temp = *j1;
*j1 = *j2;
*j2 = temp;
}
void sort_jobs_by_priority(job **jobs, int n) {
int i, j;
for (i = 0; i < n - 1; i++) {
for (j = i + 1; j < n; j++) {
if (jobs[i]->priority < jobs[j]->priority) {
swap_jobs(&jobs[i], &jobs[j]);
}
}
}
}
void schedule_jobs(job_queue *q) {
int total_burst_time = 0;
job *j;
int i, n = q->rear - q->front + 1;
job **jobs = (job**)malloc(n * sizeof(job*));
for (i = 0; i < n; i++) {
j = dequeue_job(q);
jobs[i] = j;
total_burst_time += j->burst_time;
}
sort_jobs_by_priority(jobs, n);
printf("Job Schedule:\n");
printf("Job\tPriority\tBurst Time\tWaiting Time\n");
int waiting_time = 0;
for (i = 0; i < n; i++) {
j = jobs[i];
printf("%d\t%d\t\t%d\t\t%d\n", j->job_id, j->priority, j->burst_time, waiting_time);
waiting_time += j->burst_time;
}
printf("Average Waiting Time: %f\n", (float)waiting_time / n);
free(jobs);
}
int main() {
job_queue *q = create_job_queue(5);
job j1 = {1, 2, 5};
job j2 = {2, 1, 2};
job j3 = {3, 3, 4};
job j4 = {4, 5, 1};
job j5 = {5, 4, 3};
enqueue_job(q, &j1);
enqueue_job(q, &j2);
enqueue_job(q, &j3);
enqueue_job(q, &j4);
enqueue_job(q, &j5);
schedule_jobs(q);
return 0;
}
```
这个示例程序中,`job` 结构体表示作业,包括作业 ID、优先级和执行时间。`job_queue` 结构体表示作业队列,包括一个指向作业数组的指针、队头和队尾指针、队列最大大小等信息。`create_job_queue()` 函数用于创建作业队列,`enqueue_job()` 函数用于向队列中添加作业,`dequeue_job()` 函数用于从队列中取出作业。`swap_jobs()` 函数用于交换两个作业的位置,`sort_jobs_by_priority()` 函数用于按照作业优先级排序作业数组。`schedule_jobs()` 函数用于调度作业,计算平均等待时间并输出作业执行顺序。
在 `main()` 函数中,我们创建一个最大大小为 5 的作业队列,向队列中添加 5 个作业,并调用 `schedule_jobs()` 函数进行作业调度。