java编写和调试一个进程调度程序,实现基于优先权的进程调度算法和基于时间片轮转调度算法。
时间: 2024-05-07 12:17:50 浏览: 100
基于优先数和轮转时间片的进程调度算法
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首先,我来解释一下什么是进程调度。进程调度是指操作系统决定哪些进程占用CPU,从而实现多个进程同时运行的过程。而基于优先权的进程调度算法和基于时间片轮转调度算法是两种常见的进程调度算法。
基于优先权的进程调度算法是根据进程的优先级来选择下一个要执行的进程。每个进程都有一个优先级,优先级越高的进程越先被执行。如果有多个进程的优先级相同,则可以采用先来先服务(FCFS)的方式进行调度。
基于时间片轮转调度算法是将所有进程按照到达时间的先后顺序排列,并将它们放入一个就绪队列中。操作系统按照一定的时间片轮转,每个进程被分配一个时间片来运行。当一个进程用完了它的时间片,操作系统将它放回就绪队列的末尾,并将下一个进程从队列的头部开始运行。
下面是 Java 实现基于优先权的进程调度算法和基于时间片轮转调度算法的代码示例:
基于优先权的进程调度算法:
```java
import java.util.*;
public class PriorityScheduling {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int n, bt[], wt[], tat[], p[], pr[];
System.out.print("Enter the number of processes: ");
n = scanner.nextInt();
bt = new int[n];
wt = new int[n];
tat = new int[n];
p = new int[n];
pr = new int[n];
System.out.println("Enter burst time and priority for each process: ");
for (int i = 0; i < n; i++) {
System.out.print("Process " + (i + 1) + ": ");
bt[i] = scanner.nextInt();
pr[i] = scanner.nextInt();
p[i] = i + 1;
}
for (int i = 0; i < n - 1; i++) {
for (int j = i + 1; j < n; j++) {
if (pr[i] < pr[j]) {
int temp = pr[i];
pr[i] = pr[j];
pr[j] = temp;
temp = bt[i];
bt[i] = bt[j];
bt[j] = temp;
temp = p[i];
p[i] = p[j];
p[j] = temp;
}
}
}
wt[0] = 0;
tat[0] = bt[0];
for (int i = 1; i < n; i++) {
wt[i] = wt[i - 1] + bt[i - 1];
tat[i] = tat[i - 1] + bt[i];
}
float avg_wt = 0, avg_tat = 0;
System.out.println("Process\tBurst Time\tPriority\tWaiting Time\tTurnaround Time");
for (int i = 0; i < n; i++) {
avg_wt += wt[i];
avg_tat += tat[i];
System.out.println(p[i] + "\t\t" + bt[i] + "\t\t" + pr[i] + "\t\t" + wt[i] + "\t\t" + tat[i]);
}
avg_wt /= n;
avg_tat /= n;
System.out.println("Average Waiting Time: " + avg_wt);
System.out.println("Average Turnaround Time: " + avg_tat);
}
}
```
基于时间片轮转调度算法:
```java
import java.util.*;
public class RoundRobinScheduling {
public static void main(String[] args) {
Scanner scanner = new Scanner(System.in);
int n, bt[], wt[], tat[], p[], ts;
System.out.print("Enter the number of processes: ");
n = scanner.nextInt();
bt = new int[n];
wt = new int[n];
tat = new int[n];
p = new int[n];
System.out.print("Enter time slice: ");
ts = scanner.nextInt();
System.out.println("Enter burst time for each process: ");
for (int i = 0; i < n; i++) {
System.out.print("Process " + (i + 1) + ": ");
bt[i] = scanner.nextInt();
p[i] = i + 1;
}
int temp[] = new int[n];
for (int i = 0; i < n; i++) {
temp[i] = bt[i];
}
int t = 0, i = 0;
while (true) {
boolean flag = true;
for (int j = 0; j < n; j++) {
if (temp[j] > 0) {
flag = false;
if (temp[j] > ts) {
t += ts;
temp[j] -= ts;
} else {
t += temp[j];
wt[j] = t - bt[j];
temp[j] = 0;
}
}
}
if (flag) {
break;
}
}
for (int j = 0; j < n; j++) {
tat[j] = bt[j] + wt[j];
}
float avg_wt = 0, avg_tat = 0;
System.out.println("Process\tBurst Time\tWaiting Time\tTurnaround Time");
for (int j = 0; j < n; j++) {
avg_wt += wt[j];
avg_tat += tat[j];
System.out.println(p[j] + "\t\t" + bt[j] + "\t\t" + wt[j] + "\t\t" + tat[j]);
}
avg_wt /= n;
avg_tat /= n;
System.out.println("Average Waiting Time: " + avg_wt);
System.out.println("Average Turnaround Time: " + avg_tat);
}
}
```
这些代码示例可以帮助你理解基于优先权的进程调度算法和基于时间片轮转调度算法的实现方法。同时,你还需要了解 Java 编程语言的基本语法和操作系统的相关知识,才能够更好地理解和运用这些代码。
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