ubuntu短作业优先调度算法c

下面是一个简单的 Ubuntu 短作业优先调度算法的 C 代码示例：

#include <stdio.h>

struct Process {
    int pid;            // 进程 ID
    int arrival_time;   // 进程到达时间
    int burst_time;     // 进程执行时间
    int waiting_time;   // 进程等待时间
    int turnaround_time;// 进程周转时间
    int completion_time;// 进程完成时间
};

void sjf(struct Process processes[], int n) {
    int i, j, time = 0;
    float avg_waiting_time = 0, avg_turnaround_time = 0;
    struct Process temp;

    for (i = 0; i < n; i++) {
        for (j = i + 1; j < n; j++) {
            if (processes[i].burst_time > processes[j].burst_time) {
                temp = processes[i];
                processes[i] = processes[j];
                processes[j] = temp;
            }
        }
    }

    for (i = 0; i < n; i++) {
        processes[i].completion_time = time + processes[i].burst_time;
        processes[i].turnaround_time = processes[i].completion_time - processes[i].arrival_time;
        processes[i].waiting_time = processes[i].turnaround_time - processes[i].burst_time;
        avg_waiting_time += processes[i].waiting_time;
        avg_turnaround_time += processes[i].turnaround_time;
        time = processes[i].completion_time;
    }

    avg_waiting_time /= n;
    avg_turnaround_time /= n;

    printf("PID\tArrival Time\tBurst Time\tCompletion Time\tTurnaround Time\tWaiting Time\n");
    for (i = 0; i < n; i++) {
        printf("%d\t%d\t\t%d\t\t%d\t\t%d\t\t\t%d\n", processes[i].pid, processes[i].arrival_time,
               processes[i].burst_time, processes[i].completion_time, processes[i].turnaround_time,
               processes[i].waiting_time);
    }
    printf("Average Waiting Time: %.2f\n", avg_waiting_time);
    printf("Average Turnaround Time: %.2f\n", avg_turnaround_time);
}

int main() {
    int n, i;
    struct Process processes[10];

    printf("Enter the number of processes: ");
    scanf("%d", &n);

    printf("Enter process details:\n");
    for (i = 0; i < n; i++) {
        printf("Process %d:\n", i + 1);
        printf("\tPID: ");
        scanf("%d", &processes[i].pid);
        printf("\tArrival Time: ");
        scanf("%d", &processes[i].arrival_time);
        printf("\tBurst Time: ");
        scanf("%d", &processes[i].burst_time);
    }

    sjf(processes, n);

    return 0;
}

这个代码实现了一个简单的 Ubuntu 短作业优先调度算法。在这个算法中，进程按照它们的执行时间进行排序，并且短的进程先执行。当一个进程执行完毕后，就会执行下一个最短的进程，直到所有的进程都执行完毕。