计算机体系结构实验--使用LRU方法更新Cache

1、精选优质文档-倾情为你奉上CENTRAL SOUTH UNIVERSITY 计算机体系结构实验报告题 目 使用LRU方法更新Cache 一、实验目的了解和掌握寄存器分配和内存分配的有关技术。二、实验环境Eclipse IDE for Java Developers（Version: Kepler Release）Win7三、实验内容结合数据结构的相关知识，使用LRU的策略，对一组访问序列进行内部的Cache更新。LRU置换算法是选择最近最久未使用的页面予以置换。该算法赋予每个页面一个访问字段，用来记录一个页面自上次被访问以来经历的时间T，当须淘汰一个页面时，选择现有页面中T值最大的，即最近最久

2、没有访问的页面。这是一个比较合理的置换算法。举例说明此问题，例如：有一个CACHE采用组相连映象方式。每组有四块，为了实现LRU置换算法，在快表中为每块设置一个2位计数器。我们假设访问序列为“1,1,2,4,3,5,2,1,6,7,1,3”。在访问CACHE的过程中，块的装入，置换及命中时，具体情况如下表所示：四、关键代码程序分情况讨论了，当一个cache装满的情况下，2个，3个4个装满的情况下，当输入访问序列的时候，自动进行识别，并进行相应的处理，这个就是当四个块都被装满的情况else /四个cache块都装满的情况if(jtf2.getText().equals(jt.getValueAt

3、(list-3, 1) /要访问的页面刚好在cache0中 dtm.addRow(new Objectjtf2.getText(), jt.getValueAt(list-3, 1), jt.getValueAt(list-3, 2), jt.getValueAt(list-3, 3), jt.getValueAt(list-3, 4), "命中");System.out.println(1);time1 = 0;time2+;time3+;time4+;jtf2.setText("");jlabel2.setText("请输入第"

4、+ list + "个访问页面:");五、运行截图及源代码如果按照访问序列“1,1,2,4,3,5,2,1,6,7,1,3”输入，运行结果如图可以看到，始终满足的是LRU源代码:package 使用LRU方法更新Cache;import java.awt.*;import java.awt.event.*;import javax.swing.*;import javax.swing.table.*;public class LRUCache extends Frame public static void main(String args) JFrame.setDefau

5、ltLookAndFeelDecorated(true);LRUCache lruc = new LRUCache();lruc.lauchFrame();JLabel jlabel2;JTextField jtf2;JButton jb_input;JScrollPane jsp;JTable jt;DefaultTableModel dtm;static int list = 1, count = list - 1;int time1 = 0;int time2 = 0;int time3 = 0;int time4 = 0;public void lauchFrame() this.se

6、tLayout(null);this.setBounds(100, 100, 540, 320);this.setBackground(Color.cyan);this.setVisible(true);jlabel2 = new JLabel("请输入第" + list + "个访问页面:");jtf2 = new JTextField();jb_input = new JButton("输入"); jlabel2.setBounds(20, 50, 140, 20);jtf2.setBounds(155, 50, 50, 20);

7、jb_input.setBounds(240, 50, 60, 20);this.add(jlabel2);this.add(jtf2);this.add(jb_input);this.addWindowListener(new WindowAdapter() public void windowClosing(WindowEvent e) System.exit(0););jb_input.addActionListener(new InputActionListener();Object title = "访问序列","Cache块0", "

8、;Cache块1", "Cache块2", "Cache块3", "状态"dtm = new DefaultTableModel(title, 0);jt = new JTable(dtm);jsp = new JScrollPane(jt);jsp.setBounds(50, 80, 440, 197);jsp.setBackground(Color.black);this.add(jsp);class InputActionListener implements ActionListener public void ac

9、tionPerformed(ActionEvent e) if(jtf2.getText().equals("") Object options = "OK" ;JOptionPane.showOptionDialog(null, "你的输入存在“”，请按提示输入！", "警告", JOptionPane.DEFAULT_OPTION, JOptionPane.WARNING_MESSAGE,null, options, options0);list+;if(count < 4) /count记录装入cach

10、e块的页面数switch(count) case 0:/cache块中没有装入页面的情况dtm.addRow(new Objectjtf2.getText(), jtf2.getText(), "", "", "", "装入");time2+;time3+;time4+;count+;jtf2.setText("");jlabel2.setText("请输入第" + list + "个访问页面:");break;case 1:/cache块中装入一个页面的

11、情况if(jtf2.getText().equals(jt.getValueAt(list-3, 1) /要访问的页面刚好在cache0中dtm.addRow(new Objectjtf2.getText(), jt.getValueAt(list-3, 1), "", "", "", "命中");time2+;time3+;time4+;jtf2.setText("");jlabel2.setText("请输入第" + list + "个访问页面:");

12、 else /要访问的页面不在cache块中dtm.addRow(new Objectjtf2.getText(), jt.getValueAt(list-3, 1), jtf2.getText(), "", "", "装入");time1+;time2 = 0;time3+;time4+;count+;jtf2.setText("");jlabel2.setText("请输入第" + list + "个访问页面:");break;case 2:/cache块中装入两个页面的

13、情况if(jtf2.getText().equals(jt.getValueAt(list-3, 1) /要访问的页面刚好在cache0中dtm.addRow(new Objectjtf2.getText(), jt.getValueAt(list-3, 1), jt.getValueAt(list-3, 2), "", "", "命中");time1 =0;time2+;time3+;time4+;jtf2.setText("");jlabel2.setText("请输入第" + list +

14、 "个访问页面:"); else if(jtf2.getText().equals(jt.getValueAt(list-3, 2) /要访问的页面刚好在cache1中dtm.addRow(new Objectjtf2.getText(), jt.getValueAt(list-3, 1), jt.getValueAt(list-3, 2), "", "", "命中");time1+;time2 = 0;time3+;time4+;jtf2.setText("");jlabel2.setText

15、("请输入第" + list + "个访问页面:"); else /要访问的页面不在cache块中dtm.addRow(new Objectjtf2.getText(), jt.getValueAt(list-3, 1), jt.getValueAt(list-3, 2), jtf2.getText(), "", "装入");time1+;time2+;time3 =0;time4+;count+;jtf2.setText("");jlabel2.setText("请输入第"

16、 + list + "个访问页面:");break;case 3:/cache块中装入三个页面的情况if(jtf2.getText().equals(jt.getValueAt(list-3, 1) /要访问的页面刚好在cache0中dtm.addRow(new Objectjtf2.getText(), jt.getValueAt(list-3, 1), jt.getValueAt(list-3, 2), jt.getValueAt(list-3, 3), "", "命中");time1 = 0;time2+;time3+;time

17、4+;jtf2.setText("");jlabel2.setText("请输入第" + list + "个访问页面:"); else if(jtf2.getText().equals(jt.getValueAt(list-3, 2) /要访问的页面刚好在cache1中dtm.addRow(new Objectjtf2.getText(), jt.getValueAt(list-3, 1), jt.getValueAt(list-3, 2), jt.getValueAt(list-3, 3), "", "

18、命中");time1+;time2 =0;time3+;time4+;jtf2.setText("");jlabel2.setText("请输入第" + list + "个访问页面:"); else if(jtf2.getText().equals(jt.getValueAt(list-3, 3) /要访问的页面刚好在cache2中dtm.addRow(new Objectjtf2.getText(), jt.getValueAt(list-3, 1), jt.getValueAt(list-3, 2), jt.getVal

19、ueAt(list-3, 3), "", "命中");time1+;time2+;time3 = 0;time4+;jtf2.setText("");jlabel2.setText("请输入第" + list + "个访问页面:");else /要访问的页面不在cache块中dtm.addRow(new Objectjtf2.getText(), jt.getValueAt(list-3, 1), jt.getValueAt(list-3, 2), jt.getValueAt(list-3, 3

20、), jtf2.getText(), "装入");time1+;time2+;time3+;time4 = 0;count+;jtf2.setText("");jlabel2.setText("请输入第" + list + "个访问页面:");break; else /四个cache块都装满的情况if(jtf2.getText().equals(jt.getValueAt(list-3, 1) /要访问的页面刚好在cache0中dtm.addRow(new Objectjtf2.getText(), jt.getV

21、alueAt(list-3, 1), jt.getValueAt(list-3, 2), jt.getValueAt(list-3, 3), jt.getValueAt(list-3, 4), "命中");System.out.println(1);time1 = 0;time2+;time3+;time4+;jtf2.setText("");jlabel2.setText("请输入第" + list + "个访问页面:"); else if(jtf2.getText().equals(jt.getValueAt(

22、list-3, 2) /要访问的页面刚好在cache1中dtm.addRow(new Objectjtf2.getText(), jt.getValueAt(list-3, 1), jt.getValueAt(list-3, 2), jt.getValueAt(list-3, 3), jt.getValueAt(list-3, 4), "命中");System.out.println(2);time1+;time2 = 0;time3+;time4+;jtf2.setText("");jlabel2.setText("请输入第" +

23、list + "个访问页面:"); else if(jtf2.getText().equals(jt.getValueAt(list-3, 3) /要访问的页面刚好在cache2中dtm.addRow(new Objectjtf2.getText(), jt.getValueAt(list-3, 1), jt.getValueAt(list-3, 2), jt.getValueAt(list-3, 3), jt.getValueAt(list-3, 4), "命中");System.out.println(3);time1+;time2+;time3 =

24、 0;time4+;jtf2.setText("");jlabel2.setText("请输入第" + list + "个访问页面:"); else if(jtf2.getText().equals(jt.getValueAt(list-3, 4) /要访问的页面刚好在cache3中dtm.addRow(new Objectjtf2.getText(), jt.getValueAt(list-3, 1), jt.getValueAt(list-3, 2), jt.getValueAt(list-3, 3), jt.getValueAt

25、(list-3, 4), "命中");System.out.println(4);time1+;time2+;time3+;time4 = 0;jtf2.setText("");jlabel2.setText("请输入第" + list + "个访问页面:");else /要访问的页面不在cache块中if(time1>time2 && time1>time3 && time1>time4) /如果cache0的页面最长时间没有被访问，新页面置换cache0中页面d

26、tm.addRow(new Objectjtf2.getText(), jtf2.getText(), jt.getValueAt(list-3, 2), jt.getValueAt(list-3, 3), jt.getValueAt(list-3, 4), "置换");time1 = 0;time2+;time3+;time4+;jtf2.setText("");jlabel2.setText("请输入第" + list + "个访问页面:"); else if(time2>time1 && time2>time3 && time2>time4) /如果cache1的页面最长时间没有被访问，新页面置换cache1中页面dtm.addRow(new Objectjtf2.getText(), jt.getValueAt(list-3, 1), jtf2.getText(), jt.getValueAt(list-3, 3), jt.getValueAt(list-3, 4), "置换"