操作系统课程设计

操作系统课程设计班级：计科4班组员：实验名称CPU进程调度和内存分配实验内容一、选择一个调度算法，实现处理机调度二、处理机调度过程中，主存储器空间的分配和回收实验目的加深对CPU进程调度和内存分配的了解，进一步了解操作系统中各功能的实现,了解在不同的存储管理方式下，应怎样实现主存空间的分配和回收。实验内容一、（1）设计一个按照优先权调度算法实现处理机调度的程序（2）设计按时间片轮转实现处理机调度的程序二、在可变分区管理方式下，采用最先适应算法实现主存空间的分配和回收；实验过程及分析1.原理知识：（1）作业进入内存中，由CPU分配产生PCB属性，并通过PCB记录进程状态，实验即以PCB代表进程模拟调度过程；（2）在多道系统中，当就绪进程数大于处理机数时，须按照某种策略决定哪些进程优先占用处理机，本设计采用优先级；（3）进程调度时，规定若就绪队列进程数少于6个，则自动从后备队列调入一个作业；（4）系统会将占有较多资源、预期结果不符合要求的进程自动挂起，并回收所占资源，而本实验设置为手动挂起；（5）在适宜条件下，系统会将挂起的进程自动解挂，而且只解挂到就绪队列；本设计为简化操作，设置为手动解挂，若解挂条件合适（即CPU各种资源可用），则解挂到就绪队列，并分配内存；若解挂条件不适宜，则解挂至后备队列，但不分配内存；2、实验程序设计：（1）本实验采用java语言编程，并实现界面显示。（2）为体现java语言面对对象程序设计的特点，实验设计为ProcessPCB、MemoryItem类封装PCB和所分配的内存各自的属性与方法；用ProcessRecords、MemoryRecords类封装数组方法；用SingleCPUScheduling实现GUI界面显示；（3）ProcessPCB类中，定义PCB的进程名、要求运行时间、优先级、状态、主存起始位置、所需内存大小这6个属性，并定义各属性的get和set方法，定义equals方法用于对比类的属性，定义toString方法得到类属性的字符串，定义run方法封装优先权-1/要求运行时间-1的过程；MemoryItem类中，定义可分分区表每一可分记录的主存起始位置、内存大小及其get和set方法，定义toString方法得到可在界面显示的字符串；（4）ProcessRecords封装PCB数组的添加元素addItem和删除元素removeItem方法，并构造函数getItem通过参数ProcessPCB和String查找数组元素，定义getNumberOfItems取数组大小，定义getItemsPriorities方法取所有数组元素的toString方法用于界面显示，定义iterator方法取得数组的迭代器；（5）MemoryRecords用同样的设计思想封装以MemoryItem为数组元素的各属性和方法；（6）SingleCPUScheduling类继承JFrame类，实现界面化显示；与上面相对应，实例化ProcessRecords（3次）和MemoryRecords（1次）作为私有变量，分别作为后备队列、就绪队列、挂起队列和内存可分分区表；在界面设计中，设计后备队列、挂起队列（附带解挂umount按钮）、就绪队列（附带挂起suspend按钮）可分分区表列表显示框，设置PCB添加框，附带添加至后备队列（addToBackup）、添加至就绪队列（addToReady）按钮，以及CPU当前执行状态显示框、系统日志显示框，和开始调度（systemStart）按钮，优先级和时间片单选按钮，以及时间片显示标签和文本编辑框；（7）界面设计详解；后备队列显示框用于显示已添加至后备队列的ProcessRecords属性信息，其中主存起始位置默认为-1，表示未分配；挂起队列显示框用于显示从就绪队列挂起的PCB，其中属性“主存起始位置”（MemoryBase）将由非负数变为-1，表示挂起后收回内存；就绪队列显示框中显示就绪队列属性，其中“主存起始位置”均为非负，表示一分配内存；PCB信息添加框分列PCB6个属性显示标签和可编辑文本框，和添加按钮，用于添加PCB；系统日志显示框附属时间片显示标签和可编辑文本编辑框，可由用户决定时间片大小；（8）附属功能添加完善；最重要的是为程序添加线程，是程序能以停顿一段时间的频率自动运行；后备队列、挂起队列添加total显示标签和不可编辑文本显示框，用于显示各自数组中元素数目，挂起队列附属删除（remove）按钮，可删除挂起队列中的元素；后备、挂起、就绪队列均添加监听器，用于响应用户单击操作，可以在PCB信息添加框显示用户单击的那一条PCB的信息；PCB信息添加框附属reset按钮，用于一键清空信息框中信息，方便输入；系统日志面板附属系统暂停（systemPause）和系统重置（systemReset）按钮，分别用于暂停运行（方便用户观察当前运行结果）和重置系统（方便用户重复使用程序，免去关闭后重启本程序的麻烦）；最终界面如图：设计结果报告和分析本程序还存在一些技术上的问题，使得程序不能尽善尽美；如，PCB信息添加框没有“随机置入就绪队列”功能，添加PCB信息仍显得繁琐；就绪队列的挂起功能在程序自动运行时，存在反应异常（反应延迟或直接无反映）；可分分区表只显示了当前可分的内存，没有显示已分的PCB及其对应内存使用情况，且没有利用图形和丰富的颜色来更好的展示；时间片设计还需要改进，使用效率不高；系统重置功能存在响应延迟的问题；另外，界面不够美观；还需要不断改进。设计感想通过这次实验，我们对操作系统的进程调度和内存分配管理有了更加深入的了解，对操作系统内部的工作原理有了进一步的认识。通过编程，也巩固了我们的程序设计和代码编写的能力，实验过程中遇到的各种问题以及解决问题的过程与方法，都是我们获益匪浅。同时，程序的不完善，也将促使我们在课程之后，继续学习、理解课程内容，并尽一切努力不断完善程序，做到尽善尽美。程序代码：packagesrc;publicclassMemoryItem{ privateintmemoryBase=0; privateintmemoryLimit=0; privateintavailableStatus=0; publicMemoryItem(intinitMemoryBase,intinitMemoryLimit){ this.memoryBase=initMemoryBase; this.memoryLimit=initMemoryLimit; } publicintgetMemoryBase(){ returnthis.memoryBase; }publicintgetMemoryLimit(){ returnthis.memoryLimit; }publicintgetStatus(){ returnthis.availableStatus; }publicStringtoString(){ returnthis.getMemoryBase()+"_"+this.getMemoryLimit()+"\n";}}packagesrc;publicclassProcessPCB{// backupBAK后备ready就绪suspend挂起memory内存 privateStringPID; privateintRequiredTime; privateintPriority; privateStringStatus; privateintMwmoryBase=0000; privateintMemoryLimit;// privateStringPCBPointer; publicProcessPCB(StringinitpID,intinitRTime,intinitpriority, Stringstatus,intinitBase,intinitLimit){ this.PID=initpID; this.RequiredTime=initRTime; this.Priority=initpriority; this.Status=status; this.MwmoryBase=initBase; this.MemoryLimit=initLimit; } publicStringgetPID(){ if(this.PID==null) return""; else returnthis.PID; } publicintgetRequiredTime(){ returnthis.RequiredTime; } publicintgetPriority(){ returnthis.Priority; } publicStringgetStatus(){ if(this.Status==null) return""; else returnthis.Status; } publicintgetMemoryBase(){ returnthis.MwmoryBase; } publicintgetMemoryLimit(){ returnthis.MemoryLimit; } publicbooleanequals(ProcessPCBpcb){ if(pcb.getPID()==this.getPID()){ returntrue; } elsereturnfalse; } publicStringtoString(){ returnthis.getPID()+"_"+this.getRequiredTime()+"_"+this.getPriority()+"_" +this.getStatus()+"_"+this.getMemoryBase()+"_"+this.getMemoryLimit()+"\n"; } publicvoidrun(){ this.RequiredTime=this.RequiredTime-1; this.Priority=this.Priority-1; } }packagesrc;importjava.util.ArrayList;importjava.util.Iterator;publicclassPCBRecordsimplementsIterable<ProcessPCB>{ privateArrayList<ProcessPCB>PCBItems; publicArrayList<ProcessPCB>getPCBItems(){ returnthis.PCBItems; }publicPCBRecords(){ this.PCBItems=newArrayList<ProcessPCB>(); }publicvoidaddItem(ProcessPCBPcbItem){ this.PCBItems.add(PcbItem); }publicvoidremoveItem(ProcessPCBPCbItem){ this.PCBItems.remove(PCbItem); }publicProcessPCBgetItem(ProcessPCBprocessPCB){ for(ProcessPCBpCbItem:this.PCBItems){ if(pCbItem.equals(processPCB)){ returnpCbItem; } } returnnull; } publicProcessPCBgetItem(Stringpid){ for(ProcessPCBpcBItem:this.PCBItems){ if(pcBItem.getPID().equals(pid)){ returnpcBItem; } } returnnull; }publicintgetNumberOfItems(){ returnthis.PCBItems.size(); }publicString[]getItemsProperties(){ StringitemsProperties[]=newString[getNumberOfItems()]; inti=0;for(Iteratoriterator1=PCBItems.iterator();iterator1.hasNext();){ ProcessPCBstu_Item=(ProcessPCB)iterator1.next(); itemsProperties[i++]=stu_Item.toString();}returnitemsProperties; } publicIterator<ProcessPCB>iterator(){ returnthis.PCBItems.iterator(); }}packagesrc;importjava.util.ArrayList;importjava.util.Iterator;publicclassMemoryRecordsimplementsIterable<MemoryItem>{ privateArrayList<MemoryItem>memoryItems; publicIterator<MemoryItem>iterator(){ //TODOAuto-generatedmethodstub returnthis.memoryItems.iterator(); }publicArrayList<MemoryItem>getMemoryItems(){ returnthis.memoryItems; }publicMemoryRecords(){ this.memoryItems=newArrayList<MemoryItem>();}publicvoidaddItem(MemoryItemnewMemoryItem){ this.memoryItems.add(newMemoryItem);}publicvoidremoveItem(MemoryItemmomoryItem){ this.memoryItems.remove(momoryItem);}publicMemoryItemgetMomoryItem(MemoryItemitem){ for(MemoryItemmItem:this.memoryItems){ if(mItem.equals(item)){ returnmItem; } } returnnull;}publicMemoryItemgetMemoryItem(intbase){ for(MemoryItemmItem:this.memoryItems){ if(mItem.getMemoryBase()==base){ returnmItem; } } returnnull;}publicintgetNumberOfItems(){ returnthis.memoryItems.size(); }publicString[]getItemsProperties(){ StringitemsProperties[]=newString[getNumberOfItems()]; inti=0; for(Iteratoriterator1=this.memoryItems.iterator();iterator1.hasNext();){ MemoryItemmmItem=(MemoryItem)iterator1.next(); itemsProperties[i++]=mmItem.toString(); } if(itemsProperties==null){ itemsProperties[0]=""; } returnitemsProperties;}}packagesrc;importjava.util.*;importjava.awt.*;importjava.awt.event.*;importjavax.swing.*;importjavax.swing.event.*;importsrc.SingleCPUSchedulingGUI03.AddToBAKListener;importsrc.SingleCPUSchedulingGUI03.AddToReadyListener;importsrc.SingleCPUSchedulingGUI03.DisplayBackupProcessListener;importsrc.SingleCPUSchedulingGUI03.DisplaySuspendedProcessListener;importsrc.SingleCPUSchedulingGUI03.DisplayreadyProcessListener;importsrc.SingleCPUSchedulingGUI03.RemoveListener;importsrc.SingleCPUSchedulingGUI03.ResetListener;importsrc.SingleCPUSchedulingGUI03.ResetSystemListener;importsrc.SingleCPUSchedulingGUI03.StartSystemListener;importsrc.SingleCPUSchedulingGUI03.SuspendListener;importsrc.SingleCPUSchedulingGUI03.UmountListener;//importsrc.myframe.MyWindowMonitor;importjava.io.*;importjava.text.*;publicclassSingleCPUSchedulingGUI03extendsJFrame{ /*Standarerrorstream*/ staticprivatePrintWriterstdErr=newPrintWriter(System.err,true); staticprivateintWIDTH=800,HEIGHT=750;//thesizeoftheFrame主面板 /*各列表对应的面板规格*//* 对应各名词释义backupBAK后备ready就绪suspend挂起memory内存*/ staticprivateintBackupBAK_CELL_SIZE=250,BackupBAK_LIST_ROWS=10; //后备队列 staticprivateintSuspend_CELL_SIZE=250,Suspend_LIST_ROWS=10; //挂起队列 staticprivateintReady_CELL_SIZE=200,Ready_LIST_ROWS=6; //就绪队列 staticprivateintMemory_CELL_SIZE=200,Memory_LIST_ROWS=10;//内存队列 staticprivateintCPU_ROWS=12,CPU_COLS=22;//CPU面板 staticprivateintSTATUS_ROWS=8,STATUS_COLS=30;//系统状态面板privateinttimeslice=1;//设置时间片大小privateintsystemStatus=0;//设置系统状态0——系统预备状态，等待开始，1——系统运行状态，2——系统暂停状态 staticprivateintTOTAL__TEXTFIELD_SIZE=10; //Sizetotaltextfield记录各队列元素个数 privateJListbackupList,suspendList,readyList,memoryList;//各队列相对应的数组列表 privateJButtonaddToBAKButton,addToReadyButton,resetButton;// 进程添加框中的"添加至后备队列"，"添加至就绪队列"，"重置"Button privateJButtonsuspendButton,umountButton,removeButton;//就绪队列框中的"挂起"，挂起队列框中的"解挂"，"删除"Button privateJButtonstartButton,pauseButton,resetSyatemButton;//Status面板中的"启动系统"，"重置系统"Button //优先级和时间片单选钮及时间片显示框 privateJRadioButtonpriorityJRB,timesliceJRB; privateJLabeltimesliceSizeLabel; privateJTextFieldtimesliceJtf; privateJPanelbackupBAKPanel,PCBItemPanel,suspendedPanel,memoryPanel;//后备面板、进程添加面板、挂起面板、内存面板 privateJLabelbackupTotalLabel,suspendTotalLabel;//后备队列、挂起队列元素总数标签 privateJLabelPIDLabel,requiredTimeLabel,priorityLabel,statuesLabel,baseLabel,limitLabel;// 进程信息标签进程编号PID,所需运行时间requiredTime,优先级priority,当前状态statues,内存中的基址base,所需内存大小limit privateJTextFieldbackupTotalTextField,suspendTotalTextField;// 后备队列、挂起队列元素总数文本框（不可编辑） privateJTextFieldPIDTextField,requiredTimeTextField,priorityTextField,statusTextField,baseTextField,limitTextField;//CPU状态显示文本域(不可编辑)，status信息文本域(用于现实程序每一步的操作和影响，不可编辑) privateJTextAreaCPUTextArea,statuesTextArea; //后备队列PCB数组,就绪、挂起，——内存（可分分区表） PCBRecordsbackupPCB,readyPCB,suspendedPCB; privateMemoryRecordsmemoryItems; privatebooleanflag=false;//main函数 publicstaticvoidmain(String[]args)throwsIOException{ newSingleCPUSchedulingGUI03().initFrame(); } //初始化Frame publicvoidinitFrame(){ backupList=newJList(); backupList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION); backupList.setVisibleRowCount(BackupBAK_LIST_ROWS); backupList.setFixedCellWidth(BackupBAK_CELL_SIZE); suspendList=newJList(); suspendList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION); suspendList.setVisibleRowCount(Suspend_LIST_ROWS); suspendList.setFixedCellWidth(Suspend_CELL_SIZE); readyList=newJList(); readyList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION); readyList.setVisibleRowCount(Ready_LIST_ROWS); readyList.setFixedCellWidth(Ready_CELL_SIZE); memoryList=newJList(); memoryList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION); memoryList.setVisibleRowCount(Memory_LIST_ROWS); memoryList.setFixedCellWidth(Memory_CELL_SIZE); suspendButton=newJButton("挂起"); addToBAKButton=newJButton("添加至后备队列"); addToReadyButton=newJButton("添加至就绪队列"); resetButton=newJButton("重置"); umountButton=newJButton("解挂"); removeButton=newJButton("删除"); startButton=newJButton("开始调度"); pauseButton=newJButton("暂停"); resetSyatemButton=newJButton("重启系统"); priorityJRB=newJRadioButton("优先权",true); timesliceJRB=newJRadioButton("时间片"); backupTotalLabel=newJLabel("总计:"); backupTotalTextField=newJTextField("0",TOTAL__TEXTFIELD_SIZE); backupTotalTextField.setEditable(false); suspendTotalLabel=newJLabel("总计:"); suspendTotalTextField=newJTextField("0",TOTAL__TEXTFIELD_SIZE); suspendTotalTextField.setEditable(false); timesliceSizeLabel=newJLabel("时间片"); timesliceJtf=newJTextField("3",5); timesliceJtf.setEditable(true); CPUTextArea=newJTextArea(CPU_ROWS,CPU_COLS); CPUTextArea.setEditable(false); statuesTextArea=newJTextArea(STATUS_ROWS,STATUS_COLS); statuesTextArea.setEditable(false); /*northpanel*/ JPanelnorthPanel=newJPanel(newGridLayout(1,3)); //ProcessPCBiteminformationPanel PCBItemPanel=newJPanel(newBorderLayout()); PCBItemPanel.setBorder( BorderFactory.createTitledBorder("PCB信息")); JPanelPCBItemButtonJPanel=newJPanel(newGridLayout(3,1)); PCBItemButtonJPanel.add(addToBAKButton); PCBItemButtonJPanel.add(addToReadyButton); PCBItemButtonJPanel.add(resetButton); PCBItemPanel.add(this.initPCBItemPanel(),BorderLayout.CENTER); PCBItemPanel.add(PCBItemButtonJPanel,BorderLayout.SOUTH); //backupBAKListPanel backupBAKPanel=newJPanel(newBorderLayout()); backupBAKPanel.setBorder(BorderFactory.createTitledBorder("后备列表")); JPanelbackupTotalPAnel=newJPanel();backupTotalPAnel.add(backupTotalLabel);backupTotalPAnel.add(backupTotalTextField);backupBAKPanel.add( newJScrollPane(backupList, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED),BorderLayout.CENTER);backupBAKPanel.add(backupTotalPAnel,BorderLayout.SOUTH);//SuspendListPanelsuspendedPanel=newJPanel(newBorderLayout());suspendedPanel.setBorder(BorderFactory.createTitledBorder("挂起列表"));JPanelsuspendedTotalPAnel=newJPanel();suspendedTotalPAnel.add(suspendTotalLabel);suspendedTotalPAnel.add(suspendTotalTextField);JPanelsuspendComponentPanel=newJPanel(newGridLayout(1,2));suspendComponentPanel.add(umountButton);suspendComponentPanel.add(removeButton);suspendedPanel.add(suspendedTotalPAnel,BorderLayout.NORTH);suspendedPanel.add( newJScrollPane(suspendList, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED),BorderLayout.CENTER);suspendedPanel.add(suspendComponentPanel,BorderLayout.SOUTH);northPanel.add(backupBAKPanel);northPanel.add(PCBItemPanel);northPanel.add(suspendedPanel);/*centerPanel*/JPanelcentrelPanel=newJPanel(newGridLayout(1,3));//readyListpanelJPanelreadyListPanel=newJPanel(newBorderLayout());readyListPanel.setBorder(BorderFactory.createTitledBorder("就绪列表"));readyListPanel.add( newJScrollPane(readyList, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED));readyListPanel.add(suspendButton,BorderLayout.SOUTH);//CPUpanelJPanelCPUPanel=newJPanel();CPUPanel.setBorder(BorderFactory.createTitledBorder("CPU"));CPUPanel.add(newJScrollPane(CPUTextArea, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED));memoryPanel=newJPanel(newBorderLayout());memoryPanel.setBorder(BorderFactory.createTitledBorder("内存列表"));memoryPanel.add( newJScrollPane(memoryList, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED));centrelPanel.add(readyListPanel);centrelPanel.add(CPUPanel);centrelPanel.add(memoryPanel);/*statuespanel*/JPanelsouthPanel=newJPanel(newBorderLayout());JPanelstatuesPanel=newJPanel();statuesPanel.setBorder(BorderFactory.createTitledBorder("状态"));statuesPanel.add(newJScrollPane(statuesTextArea, JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED, JScrollPane.HORIZONTAL_SCROLLBAR_AS_NEEDED));JPanelsystemContralButtonPanel=newJPanel(newGridLayout(6,1));systemContralButtonPanel.setBorder(BorderFactory.createTitledBorder("系统控制"));ButtonGroupgroup=newButtonGroup();group.add(priorityJRB);group.add(timesliceJRB);JPanelporityPanel=newJPanel(newGridLayout(1,2));porityPanel.add(timesliceSizeLabel);porityPanel.add(timesliceJtf);systemContralButtonPanel.add(priorityJRB);systemContralButtonPanel.add(timesliceJRB);systemContralButtonPanel.add(porityPanel);systemContralButtonPanel.add(startButton);systemContralButtonPanel.add(pauseButton);systemContralButtonPanel.add(resetSyatemButton);southPanel.add(statuesPanel,BorderLayout.CENTER);southPanel.add(systemContralButtonPanel,BorderLayout.EAST);// arrangepanelsinwindow setLayout(newBorderLayout()); add(northPanel,BorderLayout.NORTH); add(centrelPanel,BorderLayout.CENTER); add(southPanel,BorderLayout.SOUTH);//statuesPanel // startlisteningforlistandbuttonsevents backupList.addListSelectionListener(newDisplayBackupProcessListener()); suspendList.addListSelectionListener(newDisplaySuspendedProcessListener()); readyList.addListSelectionListener(newDisplayreadyProcessListener()); addToBAKButton.addActionListener(newAddToBAKListener()); addToReadyButton.addActionListener(newAddToReadyListener()); resetButton.addActionListener(newResetListener()); suspendButton.addActionListener(newSuspendListener()); umountButton.addActionListener(newUmountListener()); removeButton.addActionListener(newRemoveListener()); startButton.addActionListener(newStartSystemListener()); pauseButton.addActionListener(newSystemPauseListener()); resetSyatemButton.addActionListener(newResetSystemListener()); priorityJRB.addActionListener(newpriotiryListener()); timesliceJRB.addActionListener(newtimeslicListener()); backupPCB=newPCBRecords(); readyPCB=newPCBRecords(); suspendedPCB=newPCBRecords(); memoryItems=newMemoryRecords(); MemoryIteminitMemoryItem=newMemoryItem(0,3000); memoryItems.addItem(initMemoryItem); backupList.setListData(backupPCB.getItemsProperties()); readyList.setListData(readyPCB.getItemsProperties()); suspendList.setListData(suspendedPCB.getItemsProperties()); memoryList.setListData(memoryItems.getItemsProperties()); this.setTitle("CPU调度"); this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); this.setSize(WIDTH,HEIGHT); this.setResizable(true); this.setVisible(true); this.setLocation(200,10); this.addWindowListener(newMyWindowMonitor()); } publicJPanelinitPCBItemPanel(){ JPaneliniPCBItemJPanel=newJPanel(newBorderLayout()); JPaneliniNamePanel=newJPanel(newGridLayout(6,1)); JPaneliniValuePanel=newJPanel(newGridLayout(6,1)); PIDLabel=newJLabel("PID:"); requiredTimeLabel=newJLabel("所需时间:"); priorityLabel=newJLabel("优先权:"); statuesLabel=newJLabel("状态:"); baseLabel=newJLabel("基态:"); limitLabel=newJLabel("限制:"); iniNamePanel.add(PIDLabel); iniNamePanel.add(requiredTimeLabel); iniNamePanel.add(priorityLabel); iniNamePanel.add(statuesLabel); iniNamePanel.add(baseLabel); iniNamePanel.add(limitLabel); PIDTextField=newJTextField("",10); PIDTextField.setEditable(true); requiredTimeTextField=newJTextField("",10); requiredTimeTextField.setEditable(true); priorityTextField=newJTextField("",10); priorityTextField.setEditable(true); statusTextField=newJTextField("",10); statusTextField.setEditable(false); baseTextField=newJTextField("",10); baseTextField.setEditable(false); limitTextField=newJTextField("",10); limitTextField.setEditable(true); iniValuePanel.add(PIDTextField); iniValuePanel.add(requiredTimeTextField); iniValuePanel.add(priorityTextField); iniValuePanel.add(statusTextField); iniValuePanel.add(baseTextField); iniValuePanel.add(limitTextField); iniPCBItemJPanel.add(iniNamePanel,BorderLayout.WEST); iniPCBItemJPanel.add(iniValuePanel,BorderLayout.CENTER); returniniPCBItemJPanel; } classMyWindowMonitorextendsWindowAdapter{ publicvoidwindowClosing(WindowEvente){ System.exit(0); setVisible(false); } } publicvoiddisplayInformation(ProcessPCBpcb){ PIDTextField.setText(pcb.getPID()); requiredTimeTextField.setText(Integer.toString(pcb.getRequiredTime())); priorityTextField.setText(Integer.toString(pcb.getPriority())); statusTextField.setText(pcb.getStatus()); baseTextField.setText(Integer.toString(pcb.getMemoryBase())); limitTextField.setText(Integer.toString(pcb.getMemoryLimit())); } //DisplaystheinformationoftheselectedPCBItem classDisplayBackupProcessListenerimplementsListSelectionListener{ publicvoidvalueChanged(ListSelectionEventevent){ if(!backupList.getValueIsAdjusting()){ Stringid=null,selectedBAKItem=null; selectedBAKItem=(String)backupList.getSelectedValue(); if(selectedBAKItem!=null){ StringTokenizerstringtokenizer=newStringTokenizer(selectedBAKItem,"_"); id=stringtokenizer.nextToken(); ProcessPCBbackupItem=backupPCB.getItem(id); if(backupItem!=null) { displayInformation(backupItem); } statuesTextArea.append(backupItem.toString()+"ProcessItem"+id +"inbackupListhasbeendisplayed!\n"); } } } } classDisplaySuspendedProcessListenerimplementsListSelectionListener{ publicvoidvalueChanged(ListSelectionEventevent){ if(!suspendList.getValueIsAdjusting()){// stdErr.flush(); Stringid=""; Stringstr=(String)suspendList.getSelectedValue(); if(str!=null){ StringTokenizerstrtokenizer=newStringTokenizer(str,"_"); id=strtokenizer.nextToken(); ProcessPCBselectedSuspendedItem=suspendedPCB.getItem(id); if(selectedSuspendedItem!=null) { displayInformation(selectedSuspendedItem); } statuesTextArea.append(selectedSuspendedItem.toString()+"ProcessItem"+id +"insuspendListhasbeendisplayed!\n"); } } } } classDisplayreadyProcessListenerimplementsListSelectionListener{ publicvoidvalueChanged(ListSelectionEventevent){ if(!readyList.getValueIsAdjusting()){ Stringid=null,s=null; s=(String)readyList.getSelectedValue(); if(s!=null){ StringTokenizersttokenizer=newStringTokenizer(s,"_"); id=sttokenizer.nextToken(); ProcessPCBreadyItem=readyPCB.getItem(id); if(readyItem!=null) { displayInformation(readyItem); } statuesTextArea.append(readyItem.toString()+"ProcessItem"+id +"inreadyListhasbeendisplayed!\n"); } } } } //内存可分分区表排序，按可用内存大小降序排列 publicvoidsortMemoryList(){ MemoryRecordscurrentListItems=newMemoryRecords(); intnum=memoryItems.getNumberOfItems(); if(num>0){ for(inti=num;i>=1;i--){ IteratormemoryIterator=memoryItems.iterator(); MemoryItemcurrentItem=(MemoryItem)memoryIterator.next(); for(;memoryIterator.hasNext();){ MemoryItemnowItem=(MemoryItem)memoryIterator.next(); if(currentItem.getMemoryLimit()<nowItem.getMemoryLimit()){ currentItem=null; currentItem=nowItem; } } currentListItems.addItem(currentItem); memoryItems.removeItem(currentItem); } memoryItems=null; memoryItems=currentListItems; } memoryList.setListData(memoryItems.getItemsProperties()); } //判断能否为进程分配内存 publicbooleanboolMemoryAllocation(intneededLimit){ if(memoryItems.getNumberOfItems()>0){ IteratormemoryListIteartor=memoryItems.iterator(); MemoryItemlagerestItem=(MemoryItem)memoryListIteartor.next(); if(lagerestItem.getMemoryLimit()>=neededLimit) returntrue; else{ returnfalse; } }else{ returnfalse; } } //内存分配，按最先适应算法原则 publicintMemoryAllocation(intneededLimit){ intcurrentBase=-1,currentLimit=-1; IteratormemoryListIteartor=memoryItems.iterator(); MemoryItemlagerestItem=(MemoryItem)memoryListIteartor.next(); currentBase=lagerestItem.getMemoryBase()+neededLimit; currentLimit=lagerestItem.getMemoryLimit()-neededLimit; memoryItems.removeItem(lagerestItem); if(currentLimit>0){ memoryItems.addItem(newMemoryItem(currentBase,currentLimit)); } sortMemoryList(); returnlagerestItem.getMemoryBase(); } //内存回收 publicvoidmemoryRecall(intnowBase,intnowLimit){ MemoryItemrecallItem=null; intrecalledBase=nowBase; intrecalledLimit=nowLimit; if(memoryItems.getNumberOfItems()>0){ IteratormemoryListIteartor=memoryItems.iterator(); for(;memoryListIteartor.hasNext();){ MemoryItemexistedItem=(MemoryItem)memoryListIteartor.next(); if(existedItem.getMemoryBase()==(nowBase+nowLimit)){ recalledLimit=recalledLimit+existedItem.getMemoryLimit(); memoryItems.removeItem(existedItem); memoryListIteartor=memoryItems.iterator(); }elseif(nowBase==(existedItem.getMemoryBase()+existedItem.getMemoryLimit())){ recalledBase=existedItem.getMemoryBase(); recalledLimit=recalledLimit+existedItem.getMemoryLimit(); memoryItems.removeItem(existedItem); memoryListIteartor=memoryItems.iterator(); } //memoryListIteartor=memoryItems.iterator();//注意此处代码曾引发异常 } //recallItem=newMemoryItem(recalledBase,recalledLimit);//曾产生异常 } recallItem=newMemoryItem(recalledBase,recalledLimit); memoryItems.addItem(recallItem); sortMemoryList(); } publicintreadInteger(Strings){ intnum=-1; try{ num=Integer.parseInt(s); }catch(NumberFormatExceptionnumberformatexception){ statuesTextArea.append("Pleaseinputapositiveinteger!\n"); num=-999; } returnnum; } publicvoidaddToBackupList(StringnewID,ints1,ints2,ints3,Strings){ ProcessPCBitem=backupPCB.getItem(newID); if(item!=null){ statuesTextArea.append("ThePCB"+newID+"hasexistedinBackupList!\n" +"youneedtomodifythePIDoftheselectedPCB!\n"); while(item!=null){ newID=s+newID; item=backupPCB.getItem(newID);} }ProcessPCBnewPCB=newProcessPCB(newID,s1,s2,"Waiting",-1,s3);backupPCB.addItem(newPCB);backupList.setListData(backupPCB.getItemsProperties());backupTotalTextField.setText(Integer.toString(backupPCB.getNumberOfItems())); } publicvoidaddToReadyList(StringnowID,ints1,i