java实现页式存储管理

基本框架

page.java

//page类package pagedStorageManagement;public class page {    private int pageNumber;//页号    private int physicsNumber;//物理页号    private boolean state;//状态位    private int visitCount;//访问字段    private boolean change;//修改位    private int CRTAddress;//外存地址    public page()    {        this.pageNumber = -1;        this.physicsNumber = -1;        this.state = false;        this.visitCount = 0;        this.change = false;        this.CRTAddress = -1;    }    public page( int pageNumber, int physicsNumber, boolean state, int visitCount, boolean change, int CRTAddress)    {        this.pageNumber = pageNumber;        this.physicsNumber = physicsNumber;        this.state = state;        this.visitCount = visitCount;        this.change = change;        this.CRTAddress = CRTAddress;    }    public void setPageNumber( int pageNumber )    {        this.pageNumber = pageNumber;    }    public void setPhysicsNumber( int physicsNumber )    {        this.physicsNumber = physicsNumber;    }    public void setState (boolean state )    {        this.state=state;    }    public void setVisitCount( int visitCount )    {        this.visitCount = visitCount;    }    public void setChange( boolean change )    {        this.change = change;    }    public void setCRTAddress( int CRTAddress )    {        this.CRTAddress = CRTAddress;    }    public int getPageNumber( )    {        return this.pageNumber;    }    public int getPhysicsNumber()    {        return this.physicsNumber;    }    public boolean getState()    {        return this.state;    }     public int getVisitCount()    {        return this.visitCount;    }    public boolean getChange()    {        return this.change;    }    public int getCRTAddress()    {        return this.CRTAddress;    }}

shell.java

//shell类package pagedStorageManagement;import java.util.Scanner;public class shell {    page shell[];    private int current;    private int length;    public shell(){};    public shell( int length )    {        this.length = length;        this.current = 0;        shell = new page[length];        for( int i = 0; i < length ; i++ )        {            this.shell[i] = new page();        }    }    public void setCurrent( int current )    {        this.current = current;    }    public int getCurrent()    {        return this.current;    }    public int searchPage( int pageNumber )    {        int i = 0;        if( this.current == 0 )        {            return -2;        }        else        {            while( i < this.current )            {                if( this.shell[i].getPageNumber() == pageNumber )                {                    return i;                }                i++;            }            return -1;        }    }    public void inChange( int b[], String ch, int number )    {        Scanner a = new Scanner( System.in );        switch( ch )        {            case "yes":            {                System.out.println("请输入一个新的数据");                b[this.shell[number].getPhysicsNumber() ] = a.nextInt();                this.shell[number].setChange( true );                System.out.println("修改成功");                break;            }            case "no":            {                break;            }            default:            {                System.out.println("输入字符有误，将退出程序！");                System.exit(0);            }        }    }    public int isOver()    {        if( this.current >= this.length )        {            return 1;        }        else            return 0;    }    public int minVisitCount()    {        int i,t=0;        for (i=1; i<this.current; i++)         {            if( this.shell[i].getVisitCount() < this.shell[t].getVisitCount() )            {                t = i;            }        }        return t;    }    public int isChange( int number )    {        if( this.shell[number].getChange() == true )        {            return 1;        }        else            return 0;    }    public void printPageShell()    {        System.out.println("页表:");        System.out.println("索引\t"+"页号\t"+"物理块号\t"+"状态\t"+"访问次数\t"+"修改\t"+"外存地址\t");        for( int i=0; i<this.length; i++ )        {            System.out.println(i+"\t"+this.shell[i].getPageNumber()+"\t"+this.shell[i] .getPhysicsNumber()+"\t"+this.shell[i].getState()+"\t"+this.shell[i].getVisitCount()+"\t"+this.shell[i].getChange()+"\t"+this.shell[i].getCRTAddress());        }    }    public void programFunction()    {        System.out.println("***********************请求分页存储系统***********************");        System.out.println("功能:");        System.out.println("\t 1.查看页表");        System.out.println("\t 2.查看快表");        System.out.println("\t 3.查看外存");        System.out.println("\t 4.在内存修改数据");        System.out.println("\t 5.继续访问页面");        System.out.println("\t 6.退出程序");    }    public void dealFunction( int i, KShell TLB, source s[], int b[] )    {        if (i == 1 )        {            this.printPageShell();        }         else if ( i == 2)         {            TLB.printKShell();        }        else if ( i ==3 )         {            System.out.println("外存：");            System.out.println("外存地址\t"+"页号\t"+"数据\n");            for (int k=0; k<20; k++)             {                s[k].printSource(k);            }        }        else if ( i == 4)         {            String ch = "yes";            int pageNumber;            Scanner a = new Scanner( System.in );            System.out.println("请输入一个页号:");            pageNumber = a.nextInt();            int number = this.searchPage( pageNumber );            if( number <0 )            {                System.out.println("内存中没有此页号");            }            else            {                this.inChange( b,ch,number );            }        }        else if ( i == 6)         {            System.out.println("结束程序");            System.exit(0);        }    }    public static void main( String[] args )    {        Scanner a = new Scanner( System.in );        int i,number = -10,k1,k2,result;        int k3 = 0;//当前存储的内存地址        int t;//页表中访问次数最小的索引        int b[] = new int[10];//内存中存储的数据        String ch;        int sLength,pLength,tLength,data;        System.out.println("请输入外存大小：");        sLength = a.nextInt();        System.out.println("请输入页表大小：");        pLength = a.nextInt();        System.out.print("请输入快表大小:");         tLength = a.nextInt();        //定义页表,快表，外存        shell pageShell = new shell( pLength );//页表        source s[] = new source[sLength];//外表        KShell TLB = new KShell( tLength );//快表        System.out.println("产生一个随机序列作为外存数据！");        //录入外存地址和数据        for( i = 0; i < sLength; i++ )            {                 data = (int)( 100 * Math.random() );                 System.out.print( data + "\t");                 s[i] = new source( i, data );            }            System.out.println("\n外存设置成功");            //请求页表            do            {                //TLB.printKShell();//打印当前快表的情况                //pageShell.printPageShell();//打印当前页表的情况                System.out.println("请输入一个页面的页号(0-19):");                k1 = a.nextInt();                if( k1 >= 20 || k1 < 0 )                {                    System.out.println("输入数据有错，将退出程序!");                    System.exit(0);                }                //检测快表,快表存储当前的页表项，即当快表满时采用最近最久未被使用算法置换快表                System.out.println("进入快表检测");                if( TLB.getCurrent() > 0 )                {                    number = TLB.searchPage(k1);                    if( number!=-1 && number!=-2 )                    {                        result = b[TLB.shell[number].getPhysicsNumber()];                        System.out.println("在快表中找到，结果为：" + result );                        //找出该页号在页表中的位置并修改访问字段                        number = TLB.shell[number].getCRTAddress();                        pageShell.shell[number].setVisitCount(pageShell.shell[number].getVisitCount()+1 );                    }                }                if( TLB.getCurrent() <= 0 || number == -1 )                {                    System.out.println("在快表中找不到！" + "进入内存检测：");                    //在快表中找不到,去内存区的页表找                    if( pageShell.current>0 )                    {                        number = pageShell.searchPage(k1);//页号k1所在的下标                        if( number !=-1 && number!=-2 )                        {                            result = b[pageShell.shell[number].getPhysicsNumber()];                            System.out.println("在页表中找到,结果为:" + result );                            //修改访问字段和状态位                            pageShell.shell[number].setVisitCount(pageShell.shell[number].getVisitCount()+1);                            //修改快表                            TLB.changeKShell( pageShell,number );                        }                    }                    if( pageShell.current <= 0 || number== -1 )                    {                        System.out.println("在内存中找不到！");                        System.out.println("从外存中调入内存：");                        //在页表找不到，去外存区找                        for( i=0; i<sLength ; i++ )                        {                            if( k1 ==s[i].getPageNumber() )//在外存找到了缺页                            {                                k2 = pageShell.isOver();                                if( k2 == 1 )//内存已满                                {                                    t = pageShell.minVisitCount();                                    System.out.println("内存已满!即将调出页号 " + pageShell.shell[t].getPageNumber());                                }                                else                                {                                    t = pageShell.current;                                    pageShell.setCurrent( pageShell.getCurrent() + 1 );                                }                                //判断是否修改了内存的数据                                if( pageShell.isChange(t) == 1 )                                {                                    s[pageShell.shell[t].getCRTAddress()].setSts(b[pageShell.shell[t].getPhysicsNumber()]);                                }                                //调入内存                                pageShell.shell[t].setPageNumber(k1);                                if( k2 == 1 )                                {                                    b[pageShell.shell[t].getPhysicsNumber()] = s[i].getSts();                                }                                else                                {                                    pageShell.shell[t].setPhysicsNumber(k3);//未满则设置物理块号,满了只改变其他5个字段                                    b[k3] = s[i].getSts();                                    k3++;//物理块号                                }                                pageShell.shell[t].setState(true);                                pageShell.shell[t].setVisitCount(1);                                pageShell.shell[t].setChange(false);                                pageShell.shell[t].setCRTAddress(i);                                System.out.println("调入内存成功！");                                //修改快表                                TLB.changeKShell(pageShell,t);                                System.out.println("修改快表成功！");                                System.out.println("结果为：" + b[ k3-1 ]);                                break;                            }                        }                    }                }                do                {                    pageShell.programFunction();                    System.out.println("请输入一个整数(1-6)：");                    i = a.nextInt();                    while( i<1 || i>6 )                    {                                               System.out.println("输入有误，请重新输入（1-6）：");                        i = a.nextInt();                    }                    pageShell.dealFunction( i,TLB,s,b );                }while( i != 5 );            }while(i==5);            System.out.println("退出程序!");    }}

KShell.java

//KShell类package pagedStorageManagement;public class KShell {    page shell[];    private int current;    private int length;    private int changeNumber;//修改快表的次数    public KShell(){};    public KShell( int length )    {        this.length = length;        this.current = 0;        this.changeNumber = 0;        shell = new page[length];        for (int i=0; i<length; i++)         {            this.shell[i] = new page();        }    }    public void setCurrent( int current )    {        this.current = current;    }    public void setChangeNumber( int changeNumber )    {        this.changeNumber = changeNumber;    }    public int getCurrent()    {        return current;    }    public int getChangeNumber()    {        return changeNumber;    }    public int getLength()    {        return length;    }    public int searchPage( int pageNumber )    {        int i = 0;        if( this.changeNumber == 0 && this.current == 0 )        {            return -2;        }        else if( this.changeNumber < this.length )        {            while( i < this.current )            {                if( this.shell[i].getPageNumber() == pageNumber )                {                    return i;                }                i++;            }            return -1;        }        else        {            while( i < this.length )            {                if( this.shell[i].getPageNumber() == pageNumber )                {                    return i;                }                i++;            }            return -1;        }    }    public void changeKShell( shell pageShell, int number )    {        if( this.getChangeNumber() >= this.getLength() )        {            if ( this.getCurrent() == this.getLength() )             {                this.setCurrent(0);            }            System.out.println("快表已满，快表中即将调出页号" + this.shell[ this.current ].getPageNumber() );        }        if ( this.getCurrent() < this.getLength() )         {            this.shell[this.getCurrent()].setCRTAddress(number);            this.shell[this.getCurrent()].setPageNumber(pageShell.shell[number].getPageNumber());            this.shell[this.getCurrent()].setPhysicsNumber(pageShell.shell[number].getPhysicsNumber());            this.setCurrent( this.getCurrent()+1 );            this.setChangeNumber( this.getChangeNumber() + 1 );        }    }    public void printKShell()    {        System.out.println("快表：");        System.out.println("索引\t"+"页号\t"+"物理块号\t"+"在页表下的索引");        for( int i=0; i<this.length; i++ )        {            System.out.println( i + "\t" + this.shell[i].getPageNumber() + "\t" + this.shell[i] .getPhysicsNumber() + "\t" + this.shell[i].getCRTAddress() );        }    }}

source.java

//source类package pagedStorageManagement;public class source {    private int pageNumber;//页号    private int sts;//数据    private int length;    public source(){};    public source( int pageNumber , int sts )    {        this.pageNumber = pageNumber;        this.sts = sts;    }    public void setPageNumber( int pageNumber )    {        this.pageNumber = pageNumber;    }    public void setSts( int sts )    {        this.sts = sts;    }    public int getPageNumber()    {        return pageNumber;    }        public int getSts()    {        return sts;    }    public void printSource( int i )    {        System.out.println( i + "\t" + this.pageNumber + "\t" + this.sts + "\n" );    }}

使用说明

本程序是使用java语言编写的实现请求分页存储管理的程序，是在eclipise下运行的结果，只需运行Shell类就行了。
首先先设置外存，页表和快表的大小，然后输入一个请求访问的页面。

测试样例

源码下载

请点击右侧地址：Paged Storage Management
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