用流程图简要描述c语言的时间片轮转调度算法实现单处理机系统的进程调度
时间: 2024-05-27 20:12:39 浏览: 91
抱歉,我不是一个能够展示流程图和代码的AI,但是我可以简单地向您解释C语言的时间片轮转调度算法的工作原理。这个算法是一种简单而有效的进程调度算法,它将处理器时间分成等长的时间片,并逐个轮流为每个进程分配处理器时间,直到进程执行完毕或者时间片用尽。如果进程没有执行完毕,它将被重新放入就绪队列并等待下一次轮转。这样可以避免进程长时间占用处理器导致其它进程无法获得CPU资源。
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用c++的时间片轮转调度算法实现单处理机系统的进程调度
以下是用 C 语言实现时间片轮转调度算法的单处理机系统进程调度的示例代码:
```
#include <stdio.h>
#include <stdlib.h>
#define MAX_PROCESSES 10
#define TIME_QUANTUM 2
struct process {
int pid;
int arrival_time;
int burst_time;
int remaining_time;
int completion_time;
int turnaround_time;
int waiting_time;
};
int main() {
struct process processes[MAX_PROCESSES];
int num_processes, i, j, time = 0, completed = 0, quantum_remaining = 0;
printf("Enter the number of processes: ");
scanf("%d", &num_processes);
// Input the details of each process
for (i = 0; i < num_processes; i++) {
printf("\nEnter details of process %d:\n", i + 1);
printf("Arrival time: ");
scanf("%d", &processes[i].arrival_time);
printf("Burst time: ");
scanf("%d", &processes[i].burst_time);
processes[i].remaining_time = processes[i].burst_time;
processes[i].pid = i + 1;
}
// Perform time slice based scheduling
printf("\nTime Slice based Scheduling using Round Robin Algorithm\n\n");
printf("Time\tProcess ID\tRemaining Time\n");
while (completed < num_processes) {
// Check for new arrivals
for (i = 0; i < num_processes; i++) {
if (processes[i].arrival_time == time) {
printf("\nProcess %d has arrived.", processes[i].pid);
}
}
// Execute the current process for the time quantum or until it completes
for (i = 0; i < num_processes; i++) {
if (processes[i].remaining_time > 0) {
if (quantum_remaining == 0) {
printf("\nTime quantum expired. Switching to process %d.", processes[i].pid);
quantum_remaining = TIME_QUANTUM;
}
if (quantum_remaining >= processes[i].remaining_time) {
quantum_remaining -= processes[i].remaining_time;
time += processes[i].remaining_time;
processes[i].remaining_time = 0;
processes[i].completion_time = 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;
completed++;
printf("\n%d\t%d\t\t%d (Completed)", time, processes[i].pid, processes[i].remaining_time);
} else {
processes[i].remaining_time -= quantum_remaining;
time += quantum_remaining;
quantum_remaining = 0;
printf("\n%d\t%d\t\t%d (Remaining)", time, processes[i].pid, processes[i].remaining_time);
}
}
}
}
// Print the final statistics
printf("\n\nProcess\tArrival Time\tBurst Time\tCompletion Time\tTurnaround Time\tWaiting Time");
for (i = 0; i < num_processes; i++) {
printf("\n%d\t\t%d\t\t%d\t\t%d\t\t%d\t\t\t%d", processes[i].pid, processes[i].arrival_time, processes[i].burst_time, processes[i].completion_time, processes[i].turnaround_time, processes[i].waiting_time);
}
return 0;
}
```
该代码使用 `struct process` 结构体来存储每个进程的详细信息,包括进程 ID、到达时间、执行时间、剩余时间、完成时间、周转时间和等待时间。它使用了时间片轮转调度算法,时间片大小为 2 个时间单位。在每个时间单位,它检查是否有新的进程到达,然后执行当前进程直到时间片结束或进程完成。完成的进程将计算其完成时间、周转时间和等待时间,并增加已完成进程的数量。在所有进程完成后,它将打印每个进程的统计信息。
需要注意的是,这只是一个示例代码,可能需要根据实际应用对其进行修改。
用c语言的时间片转轮调度算法实现单处理机系统的进程调度
以下是使用C语言实现时间片转轮调度算法的单处理机系统进程调度的示例代码:
```c
#include<stdio.h>
#include<stdlib.h>
// 定义进程结构体
typedef struct {
int pid; // 进程ID
int burst; // 进程的执行时间
int remaining; // 进程的剩余执行时间
int priority; // 进程的优先级
int waiting; // 进程的等待时间
int turnaround; // 进程的周转时间
} Process;
// 定义时间片转轮调度算法函数
void roundRobin(Process processes[], int n, int quantum) {
int i, time, remain = n;
int flag = 0, total_waiting = 0, total_turnaround = 0;
// 初始化进程的剩余时间
for (i = 0; i < n; i++) {
processes[i].remaining = processes[i].burst;
}
// 模拟进程执行
for (time = 0, i = 0; remain != 0; ) {
// 如果当前进程未执行完,继续执行
if (processes[i].remaining <= quantum && processes[i].remaining > 0) {
time += processes[i].remaining;
processes[i].remaining = 0;
flag = 1;
}
// 如果当前进程已经执行完毕,计算等待时间和周转时间,并将进程数减1
else if (processes[i].remaining > 0) {
processes[i].remaining -= quantum;
time += quantum;
}
if (processes[i].remaining == 0 && flag == 1) {
remain--;
processes[i].waiting = time - processes[i].burst;
processes[i].turnaround = time;
total_waiting += processes[i].waiting;
total_turnaround += processes[i].turnaround;
flag = 0;
}
// 转到下一个进程
if (i == n - 1) {
i = 0;
}
else if (processes[i + 1].arrival <= time) {
i++;
}
else {
i = 0;
}
}
// 输出每个进程的等待时间和周转时间
printf("\nProcess\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", processes[i].pid, processes[i].burst, processes[i].waiting, processes[i].turnaround);
}
// 输出平均等待时间和平均周转时间
printf("Average waiting time = %f\n", (float)total_waiting / (float)n);
printf("Average turnaround time = %f\n", (float)total_turnaround / (float)n);
}
int main() {
int i, n, quantum;
// 输入进程数和时间片大小
printf("Enter the number of processes: ");
scanf("%d", &n);
printf("Enter time quantum: ");
scanf("%d", &quantum);
// 动态分配进程数组空间
Process* processes = (Process*)malloc(n * sizeof(Process));
// 输入每个进程的信息
for (i = 0; i < n; i++) {
printf("Enter the burst time and priority of process %d: ", i + 1);
scanf("%d %d", &processes[i].burst, &processes[i].priority);
processes[i].pid = i + 1;
}
// 调用时间片转轮调度算法函数
roundRobin(processes, n, quantum);
return 0;
}
```
这段代码中,我们先定义了一个进程结构体,包含进程ID、执行时间、剩余执行时间、优先级、等待时间和周转时间等信息。接着定义了一个时间片转轮调度算法函数,其中使用一个循环模拟进程的执行过程,直到所有进程都执行完毕,计算每个进程的等待时间和周转时间,并输出每个进程的信息和平均等待时间和平均周转时间。在主函数中,我们先输入进程数和时间片大小,然后动态分配进程数组的空间,再输入每个进程的信息,并调用时间片转轮调度算法函数进行进程调度。
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