内存的分配与回收

一、 实验目的

用高级语言完成一个主存空间的分配和回收程序，以加深对动态分区分配方式及其算法的理解。

二、 实验内容和要求

采用连续分配方式之动态分区分配存储管理，使用首次适应算法、循环首次适应算法、最佳适应算法和最坏适应算法4种算法完成设计(任选两种算法)。

（1）**设计一个作业申请队列以及作业完成后的释放顺序，实现主存的分配和回收。采用分区说明表进行。

（2）或在程序运行过程，由用户指定申请与释放。

（3）设计一个空闲区说明表，以保存某时刻主存空间占用情况。把空闲区说明表的变化情况以及各作业的申请、释放情况显示。

三、 实验方法、步骤及结果测试

1. 原理分析及流程图

程序名：best.rar

2. 步骤：

创建项目：best

创建包：best

创建类：bestFit.java 、firstFit.java、 MainFrame.java

编写代码

3. 主要程序段及其解释

package best;
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.Font;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.border.EtchedBorder;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JLabel;
import java.awt.Color;
import javax.swing.SwingConstants;
import javax.swing.JTextField;
public class bestFit extends JFrame {
private JPanel contentPane;
private JTextField everySize;
private JTextField workname;
private JTextField count;
private JFrame frame;
private JTextField location;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
bestFit frame = new bestFit();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/** * Create the frame. */
class pointer
{
public int prepointer;
public int nextpoint;
public int length;
public int signal;
pointer()
{
prepointer=0;
nextpoint=0;
length=0;
signal=0;
}
}
public bestFit() {
setTitle("");
setResizable(false);
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
setBounds(300, 200, 559, 447);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(null);
JPanel panel = new JPanel();
panel.setLayout(null);
panel.setBorder(new EtchedBorder(EtchedBorder.LOWERED, Color.DARK_GRAY, Color.PINK));
panel.setBounds(10, 10, 324, 399);
contentPane.add(panel);
JLabel label = new JLabel("模拟内存");
label.setHorizontalAlignment(SwingConstants.CENTER);
label.setForeground(Color.GRAY);
label.setFont(new Font("微软雅黑", Font.BOLD, 18));
label.setBounds(64, 0, 118, 36);
panel.add(label);
JPanel panel_1 = new JPanel();
panel_1.setLayout(null);
panel_1.setBorder(new EtchedBorder(EtchedBorder.LOWERED, Color.BLACK, Color.DARK_GRAY));
panel_1.setBounds(99, 50, 176, 312);
panel.add(panel_1);
JPanel one = new JPanel();
one.setLayout(null);
one.setBorder(new EtchedBorder(EtchedBorder.RAISED, Color.BLACK, null));
one.setBounds(0, 0, 176, 54);
panel_1.add(one);
JPanel two = new JPanel();
two.setLayout(null);
two.setBorder(new EtchedBorder(EtchedBorder.RAISED, new Color(0, 0, 0), null));
two.setBounds(0, 54, 176, 104);
panel_1.add(two);
JPanel three = new JPanel();
three.setLayout(null);
three.setBorder(new EtchedBorder(EtchedBorder.RAISED, Color.BLACK, null));
three.setBounds(0, 158, 176, 154);
panel_1.add(three);
JLabel label_1 = new JLabel("50KB");
label_1.setHorizontalAlignment(SwingConstants.CENTER);
label_1.setFont(new Font("微软雅黑", Font.BOLD, 14));
label_1.setBounds(270, 68, 54, 19);
panel.add(label_1);
JLabel label_2 = new JLabel("100KB");
label_2.setHorizontalAlignment(SwingConstants.CENTER);
label_2.setFont(new Font("微软雅黑", Font.BOLD, 14));
label_2.setBounds(270, 144, 54, 19);
panel.add(label_2);
JLabel label_3 = new JLabel("150KB");
label_3.setHorizontalAlignment(SwingConstants.CENTER);
label_3.setFont(new Font("微软雅黑", Font.BOLD, 14));
label_3.setBounds(270, 292, 54, 19);
panel.add(label_3);
JPanel panel_5 = new JPanel();
panel_5.setLayout(null);
panel_5.setBorder(new EtchedBorder(EtchedBorder.LOWERED, Color.DARK_GRAY, Color.PINK));
panel_5.setBounds(344, 10, 199, 399);
contentPane.add(panel_5);
JButton back = new JButton("回收进程");
back.setFont(new Font("微软雅黑", Font.BOLD, 15));
back.setBounds(49, 316, 132, 34);
panel_5.add(back);
JLabel label_4 = new JLabel("进程大小");
label_4.setOpaque(true);
label_4.setHorizontalAlignment(SwingConstants.CENTER);
label_4.setForeground(Color.GRAY);
label_4.setFont(new Font("微软雅黑", Font.BOLD, 15));
label_4.setBounds(15, 119, 65, 27);
panel_5.add(label_4);
everySize = new JTextField();
everySize.setHorizontalAlignment(SwingConstants.CENTER);
everySize.setFont(new Font("微软雅黑", Font.BOLD, 15));
everySize.setColumns(10);
everySize.setBounds(91, 121, 65, 21);
panel_5.add(everySize);
JLabel label_5 = new JLabel("进程名");
label_5.setOpaque(true);
label_5.setHorizontalAlignment(SwingConstants.CENTER);
label_5.setForeground(Color.GRAY);
label_5.setFont(new Font("微软雅黑", Font.BOLD, 15));
label_5.setBounds(15, 64, 65, 27);
panel_5.add(label_5);
workname = new JTextField();
workname.setHorizontalAlignment(SwingConstants.CENTER);
workname.setFont(new Font("微软雅黑", Font.BOLD, 15));
workname.setColumns(10);
workname.setBounds(91, 66, 65, 21);
panel_5.add(workname);
JLabel label_6 = new JLabel("KB");
label_6.setHorizontalAlignment(SwingConstants.CENTER);
label_6.setForeground(Color.GRAY);
label_6.setFont(new Font("微软雅黑", Font.BOLD, 15));
label_6.setBounds(155, 122, 26, 21);
panel_5.add(label_6);
JButton startbutton = new JButton("开始分配");
startbutton.setFont(new Font("微软雅黑", Font.BOLD, 15));
startbutton.setBounds(49, 178, 132, 34);
panel_5.add(startbutton);
JButton restartbutton = new JButton("重新开始");
restartbutton.setFont(new Font("微软雅黑", Font.BOLD, 15));
restartbutton.setBounds(49, 245, 132, 34);
panel_5.add(restartbutton);
count = new JTextField();
count.setText("0");
count.setEnabled(false);
count.setEditable(false);
count.setColumns(10);
count.setBounds(72, 253, 19, 15);
panel_5.add(count);
count.setVisible(false);
location = new JTextField();
location.setEditable(false);
location.setEnabled(false);
location.setText("0");
location.setBounds(72, 324, 66, 21);
panel_5.add(location);
location.setColumns(10);
location.setVisible(false);
final JLabel name[]=new JLabel[20];
for(int i=0;i<20;i++)
{
name[i]=new JLabel();
name[i].setFont(new Font("微软雅黑",Font.BOLD,12));
name[i].setHorizontalAlignment(SwingConstants.CENTER);
panel.add(name[i]);
}
final JLabel blocks[]=new JLabel[300];
for(int i=0;i<50;i++)
{
blocks[i] = new JLabel("");
blocks[i].setOpaque(false);
one.add(blocks[i]);
}
for(int i=50;i<150;i++)
{
blocks[i] = new JLabel("");
blocks[i].setOpaque(false);
two.add(blocks[i]);
}
for(int i=150;i<300;i++)
{
blocks[i] = new JLabel("");
blocks[i].setOpaque(false);
three.add(blocks[i]);
}
//设置前指针和后指针，以及空闲区的初始长度
final pointer pt[]=new pointer[3];
for(int i=0;i<3;i++)
{
pt[i]=new pointer();
}
pt[0].prepointer=0;
pt[0].nextpoint=50;
pt[0].length=50;
pt[0].signal=0;
pt[1].prepointer=50;
pt[1].nextpoint=150;
pt[1].length=100;
pt[1].signal=0;
pt[2].prepointer=150;
pt[2].nextpoint=300;
pt[2].length=150;
pt[2].signal=0;
startbutton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String str=everySize.getText();
int size=Integer.parseInt(str);
String str1=count.getText();
int num=Integer.parseInt(str1);
String str2=workname.getText();

int i;
for(i=0;i<3;i++)
{
if(pt[i].length>size)
{
break;
}
}
if(i==3)
{
JOptionPane.showMessageDialog(frame, "没有合适的空闲分区！", null, JOptionPane.WARNING_MESSAGE);
}
else
{
int sig=min(pt[0].length,pt[1].length,pt[2].length,size);
for(int j=0;j<size;j++)
{
if(pt[sig].prepointer<50)
{
blocks[j+pt[sig].prepointer].setBounds(2, j+2+pt[sig].prepointer, 172, 1);
blocks[j+pt[sig].prepointer].setBackground(new Color(250,0,0));                    blocks[j+pt[sig].prepointer].setOpaque(true);
}                            if(pt[sig].prepointer<150&&pt[sig].prepointer>=50)                            {
blocks[j+pt[sig].prepointer].setBounds(2, j+2+pt[sig].prepointer-50, 172, 1);
blocks[j+pt[sig].prepointer].setBackground(new Color(0,250,0));                                blocks[j+pt[sig].prepointer].setOpaque(true);
}
if(pt[sig].prepointer<300&&pt[sig].prepointer>=150)
{                                blocks[j+pt[sig].prepointer].setBounds(2, j+2+pt[sig].prepointer-150, 172, 1);
blocks[j+pt[sig].prepointer].setBackground(new Color(0,0,250));                                blocks[j+pt[sig].prepointer].setOpaque(true);
}
}                    pt[sig].prepointer=pt[sig].prepointer+size;
pt[sig].length=pt[sig].length-size;
name[num].setText(str2+" "+size+"KB");
name[num].setBounds(10, pt[sig].prepointer+50-size, 79, 15);
num++;
count.setText(num+"");
}
}
});
restartbutton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
pt[0].prepointer=0;
pt[0].nextpoint=50;
pt[0].length=50;
pt[0].signal=0;
pt[1].prepointer=50;
pt[1].nextpoint=150;
pt[1].length=100;
pt[1].signal=0;
pt[2].prepointer=150;
pt[2].nextpoint=300;
pt[2].length=150;
pt[2].signal=0;
for(int i=0;i<300;i++)
{
blocks[i].setOpaque(false);
blocks[i].setBackground(new Color(240,240,240));
}
everySize.setText("");
for(int i=0;i<20;i++)
{
name[i].setText("");
}
workname.setText("");
}
});
back.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String str2=workname.getText();
System.out.println(str2);
if(str2.equals("1")==true){
System.out.println("haha");
pt[0].prepointer=0;
pt[0].nextpoint=50;
pt[0].length=50;
pt[0].signal=0;
for(int i=0;i<50;i++)
{
blocks[i].setOpaque(false);
blocks[i].setBackground(new Color(240,240,240));
}
name[0].setText("");
}
if(str2.equals("3")==true){
System.out.println("haha");
pt[2].prepointer=150;
pt[2].nextpoint=300;
pt[2].length=150;
pt[2].signal=0;
for(int i=150;i<300;i++)
{
blocks[i].setOpaque(false);
blocks[i].setBackground(new Color(240,240,240));
}
name[2].setText("");
}
if(str2.equals("2")==true){
System.out.println("haha");
pt[1].prepointer=50;
pt[1].nextpoint=150;
pt[1].length=100;
pt[1].signal=0;
for(int i=50;i<150;i++)
{
blocks[i].setOpaque(false);
blocks[i].setBackground(new Color(240,240,240));
}
name[1].setText("");
}
}
});
}
int min(int a,int b,int c,int d)
{
int n1=a-d;
int n2=b-d;
int n3=c-d;
if(n1<0)
{
if(n2<0)
{
return 2;
}
else
{
if(n3<0)
{
return 3;
}
else
{
if(n2<=n3)
{
return 1;
}
else
{
return 2;
}
}
}
}
else
{
if(n2<0)
{
if(n3<0)
{
return 0;
}
else
{
if(n1<=n3)
{
return 0;
}
else
{
return 2;
}
}
}
else
{
if(n3<0)
{
if(n1<=n2)
{
return 0;
}
else
{
return 1;
}
}
else
{
if(n1<=n2)
{
if(n1<=n3)
{
return 0;
}
else
{
return 2;
}
}
else
{
if(n2<=n3)
{
return 1;
}
else
{
return 0;
}
}
}
}
}
}
}
//首次适应算法
package best;
import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.Graphics;
import java.awt.Graphics2D;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JButton;
import java.awt.Font;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JLabel;
import javax.swing.SwingConstants;
import java.awt.Color;
import javax.swing.JOptionPane;
import javax.swing.JTextField;
import javax.swing.UIManager;
import javax.swing.ImageIcon;
import java.awt.event.ContainerAdapter;
import java.awt.event.ContainerEvent;
import javax.swing.border.EtchedBorder;
class pointer
{
public int prepointer;
public int nextpoint;
public int length;
public int signal;
pointer()
{
prepointer=0;
nextpoint=0;
length=0;
signal=0;
}
}
public class firstFit extends JFrame {
private JPanel contentPane;
private JTextField everySize;
private JFrame frame;
private JTextField workname;
private JTextField count;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
firstFit frame = new firstFit();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
*/
public firstFit() {
setResizable(false);
setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
setBounds(300, 200, 559, 447);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
setContentPane(contentPane);
contentPane.setLayout(null);
JPanel panel = new JPanel();
panel.setBorder(new EtchedBorder(EtchedBorder.LOWERED, Color.DARK_GRAY, Color.PINK));
panel.setBounds(344, 10, 199, 399);
contentPane.add(panel);
panel.setLayout(null);
JLabel label = new JLabel("进程大小");
label.setHorizontalAlignment(SwingConstants.CENTER);
label.setForeground(Color.GRAY);
label.setFont(new Font("微软雅黑", Font.BOLD, 15));
label.setBounds(15, 119, 65, 27);
panel.add(label);
label.setOpaque(true);
everySize = new JTextField();
everySize.setHorizontalAlignment(SwingConstants.CENTER);
everySize.setFont(new Font("微软雅黑", Font.BOLD, 15));
everySize.setColumns(10);
everySize.setBounds(91, 121, 65, 21);
panel.add(everySize);
JLabel label_2 = new JLabel("进程名称");
label_2.setOpaque(true);
label_2.setHorizontalAlignment(SwingConstants.CENTER);
label_2.setForeground(Color.GRAY);
label_2.setFont(new Font("微软雅黑", Font.BOLD, 15));
label_2.setBounds(15, 64, 65, 27);
panel.add(label_2);
workname = new JTextField();
workname.setHorizontalAlignment(SwingConstants.CENTER);
workname.setFont(new Font("微软雅黑", Font.BOLD, 15));
workname.setColumns(10);
workname.setBounds(91, 66, 65, 21);
panel.add(workname);
JLabel label_1 = new JLabel("KB");
label_1.setHorizontalAlignment(SwingConstants.CENTER);
label_1.setForeground(Color.GRAY);
label_1.setFont(new Font("微软雅黑", Font.BOLD, 15));
label_1.setBounds(155, 122, 26, 21);
panel.add(label_1);
JPanel panel_1 = new JPanel();
panel_1.setBorder(new EtchedBorder(EtchedBorder.LOWERED, Color.DARK_GRAY, Color.PINK));
panel_1.setBounds(10, 10, 324, 399);
contentPane.add(panel_1);
panel_1.setLayout(null);
JLabel lblNewLabel_2 = new JLabel("模拟内存");
lblNewLabel_2.setForeground(Color.GRAY);
lblNewLabel_2.setHorizontalAlignment(SwingConstants.CENTER);
lblNewLabel_2.setFont(new Font("微软雅黑", Font.BOLD, 18));
lblNewLabel_2.setBounds(64, 0, 118, 36);
panel_1.add(lblNewLabel_2);
JPanel panel_2 = new JPanel();
panel_2.setBorder(new EtchedBorder(EtchedBorder.LOWERED, Color.BLACK, Color.DARK_GRAY));
panel_2.setBounds(99, 50, 176, 312);
panel_1.add(panel_2);
panel_2.setLayout(null);
final JPanel one = new JPanel();
one.setBorder(new EtchedBorder(EtchedBorder.RAISED, Color.BLACK, null));
one.setBounds(0, 0, 176, 54);
panel_2.add(one);
one.setLayout(null);
JPanel two = new JPanel();
two.setBorder(new EtchedBorder(EtchedBorder.RAISED, new Color(0, 0, 0), null));
two.setBounds(0, 54, 176, 104);
panel_2.add(two);
two.setLayout(null);
JPanel three = new JPanel();
three.setBorder(new EtchedBorder(EtchedBorder.RAISED, Color.BLACK, null));
three.setBounds(0, 158, 176, 154);
panel_2.add(three);
three.setLayout(null);
final JLabel sizelabel = new JLabel("50KB");
sizelabel.setHorizontalAlignment(SwingConstants.CENTER);
sizelabel.setFont(new Font("微软雅黑", Font.BOLD, 14));
sizelabel.setBounds(270, 68, 54, 19);
panel_1.add(sizelabel);
JLabel lblkb = new JLabel("100KB");
lblkb.setHorizontalAlignment(SwingConstants.CENTER);
lblkb.setFont(new Font("微软雅黑", Font.BOLD, 14));
lblkb.setBounds(270, 144, 54, 19);
panel_1.add(lblkb);
JLabel lblkb_1 = new JLabel("150KB");
lblkb_1.setHorizontalAlignment(SwingConstants.CENTER);
lblkb_1.setFont(new Font("微软雅黑", Font.BOLD, 14));
lblkb_1.setBounds(270, 292, 54, 19);
panel_1.add(lblkb_1);
final JLabel name[]=new JLabel[20];
for(int i=0;i<20;i++)
{
name[i]=new JLabel();
name[i].setFont(new Font("微软雅黑",Font.BOLD,12));
name[i].setHorizontalAlignment(SwingConstants.CENTER);
panel_1.add(name[i]);
}
final JLabel blocks[]=new JLabel[300];
for(int i=0;i<50;i++)
{
blocks[i] = new JLabel("");
blocks[i].setOpaque(false);
one.add(blocks[i]);
}
for(int i=50;i<150;i++)
{
blocks[i] = new JLabel("");
blocks[i].setOpaque(false);
two.add(blocks[i]);
}
for(int i=150;i<300;i++)
{
blocks[i] = new JLabel("");
blocks[i].setOpaque(false);
three.add(blocks[i]);
}
//设置前指针和后指针，以及空闲区的初始长度
final pointer pt[]=new pointer[3];
for(int i=0;i<3;i++)
{
pt[i]=new pointer();
}
pt[0].prepointer=0;
pt[0].nextpoint=50;
pt[0].length=50;
pt[0].signal=0;
pt[1].prepointer=50;
pt[1].nextpoint=150;
pt[1].length=100;
pt[1].signal=0;
pt[2].prepointer=150;
pt[2].nextpoint=300;
pt[2].length=150;
pt[2].signal=0;
final JButton restartbutton = new JButton("重新开始");
final JButton startbutton = new JButton("开始分配");
startbutton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
String str=everySize.getText();
int size=Integer.parseInt(str);
String str1=count.getText();
int num=Integer.parseInt(str1);
String str2=workname.getText();
int i;
for(i=0;i<3;i++)
{
if(pt[i].length<size||pt[i].signal==1)
{
continue;
}
else
{
for(int j=0;j<size;j++)
{
if(pt[i].prepointer<50){
blocks[j+pt[i].prepointer].setBounds(2, j+2+pt[i].prepointer, 172, 1);
blocks[j+pt[i].prepointer].setBackground(new Color(250,0,0));
blocks[j+pt[i].prepointer].setOpaque(true);
}
if(pt[i].prepointer<150&&pt[i].prepointer>=50)
{
blocks[j+pt[i].prepointer].setBounds(2, j+2+pt[i].prepointer-50, 172, 1);
blocks[j+pt[i].prepointer].setBackground(new Color(0,250,0));
blocks[j+pt[i].prepointer].setOpaque(true);
}
if(pt[i].prepointer<300&&pt[i].prepointer>=150)
{
blocks[j+pt[i].prepointer].setBounds(2, j+2+pt[i].prepointer-150, 172, 1);
blocks[j+pt[i].prepointer].setBackground(new Color(0,0,250));
blocks[j+pt[i].prepointer].setOpaque(true);
}
}
pt[i].prepointer=pt[i].prepointer+size;
pt[i].length=pt[i].length-size;
break;
}
}
if(i==3)
{JOptionPane.showMessageDialog(frame, "没有合适的空闲分区！", null, JOptionPane.WARNING_MESSAGE);}
else
{
name[num].setText(str2+" "+size+"KB");
name[num].setBounds(10, pt[i].prepointer+50-size, 79, 15);
num++;
count.setText(num+"");
}
}
});
startbutton.setFont(new Font("微软雅黑", Font.BOLD, 15));
startbutton.setBounds(49, 178, 132, 34);
panel.add(startbutton);
restartbutton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
pt[0].prepointer=0;
pt[0].nextpoint=50;
pt[0].length=50;
pt[0].signal=0;
pt[1].prepointer=50;
pt[1].nextpoint=150;
pt[1].length=100;
pt[1].signal=0;
pt[2].prepointer=150;
pt[2].nextpoint=300;
pt[2].length=150;
pt[2].signal=0;
for(int i=0;i<300;i++)
{
blocks[i].setOpaque(false);
blocks[i].setBackground(new Color(240,240,240));
}
everySize.setText("");
for(int i=0;i<20;i++)
{
name[i].setText("");
}
workname.setText("");
}
});
restartbutton.setFont(new Font("微软雅黑", Font.BOLD, 15));
restartbutton.setBounds(49, 245, 132, 34);
panel.add(restartbutton);
count = new JTextField();
count.setEditable(false);
count.setText("0");
count.setEnabled(false);
count.setBounds(72, 253, 19, 15);
panel.add(count);
count.setColumns(10);
count.setVisible(false);
}
}

四、实验总结

一开始在写程序的时候理解错了，导致后面写回收的时候出现了许多问题，导致回收那些代码出现了一点错乱，最后只能整个模块去回收，导致程序不完整。

在编写界面的时候由于对java界面的知识点了解相对比较少，导致在制作界面过程中遇到不少难题，最后是通过上网搜索相关知识和向老师或者同学请教才能解决。