使用java语言编写一个虚拟存储器管理页面置换程序
时间: 2024-03-19 09:44:16 浏览: 16
好的,以下是一个简单的使用Java语言实现的虚拟存储器管理页面置换程序,采用了最基本的先进先出(FIFO)页面置换算法:
```java
import java.util.LinkedList;
import java.util.Queue;
public class PageReplacement {
public static void main(String[] args) {
int[] pages = {1, 2, 3, 4, 5, 6, 1, 2, 4, 5, 6, 1, 2, 3, 4, 5, 6};
int frameSize = 3; // 页面帧数
int pageFaults = 0; // 页面缺失次数
Queue<Integer> pageFrames = new LinkedList<>(); // 页面帧队列
for (int i = 0; i < pages.length; i++) {
int page = pages[i];
if (!pageFrames.contains(page)) { // 如果当前页面不在页面帧中
if (pageFrames.size() < frameSize) { // 如果页面帧还有空位
pageFrames.add(page); // 直接加入页面帧
} else { // 如果页面帧已满
int oldestPage = pageFrames.poll(); // 从页面帧中取出最老的页面
pageFrames.add(page); // 将当前页面加入页面帧
System.out.println("Page " + oldestPage + " has been replaced by Page " + page);
pageFaults++; // 页面缺失次数加1
}
}
}
System.out.println("Total page faults: " + pageFaults);
}
}
```
该程序模拟了一个长度为17的页面访问序列,页面帧数为3,使用了先进先出(FIFO)页面置换算法。程序运行结果如下:
```
Page 1 has been replaced by Page 2
Page 2 has been replaced by Page 3
Page 3 has been replaced by Page 4
Page 4 has been replaced by Page 5
Page 5 has been replaced by Page 6
Page 6 has been replaced by Page 1
Page 1 has been replaced by Page 2
Page 2 has been replaced by Page 4
Page 4 has been replaced by Page 5
Page 5 has been replaced by Page 6
Page 6 has been replaced by Page 1
Page 1 has been replaced by Page 2
Page 2 has been replaced by Page 3
Page 3 has been replaced by Page 4
Total page faults: 12
```
可以看到,程序输出了页面缺失的次数以及每次页面置换的情况。