pcb.java

一个简单的操作系统模拟程序 java+swing 可进行一般的文件操作 进程建立及删除等

/*
 * PCB.java ver 0.1.1
 *
 * Created on 2006年12月11日, 下午10:16
 *
 *The ProcessControlBlock for the system
 *
 *History:  2006年12月11日,ver 0.1.0,class create
 *          2006年12月11日,ver 0.1.1,add the setVariableList method 
 *                                   add the initializePCB method
 *                                   add the clearPCB method
 *                                   first release
 *                                   
 */

package ossimulation;

import java.util.ArrayList;
import java.util.Iterator;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreeNode;

/**
 *
 * @author Decell.Zhou
 */
public class PCB {
    
    /** Creates a new instance of PCB */
    public PCB(int argID){
        ID = argID;
        instructionList = new ArrayList();
        variableList = new ArrayList();
        this.clear();
//        name = null;
//        state = 0;
//        lengthOfInstruction = 0;
//        programCounter = 0;
//        ramLength = 0;
//        ramOffset = 0;
//        fileDescriptor = null;
    }
    
    /**get the process id*/
    public int getID(){
        return ID;
    }
       
    /**get the name of the process*/
    public String getName(){
        return name;
    }
        
    /**get the state of the process*/
    public int getstate(){
        return state;
    }
    
    /**set the state of the process*/
    public void setState(int argState){
        state = argState;
    }
    
    /**get the instruction length of the PCB*/
    public int getLengthOfInstruction(){
        return lengthOfInstruction;
    }
    
    /**set the length of the instruction*/
    public void setLengthOfInstruction(int argLengthOfInstruction){
        lengthOfInstruction = argLengthOfInstruction;
    }
    
    /**get the program counter of the pcb*/
    public int getPC(){
        return programCounter;
    }
    
    /**get the variable list*/
    public ArrayList getVariableList(){
        return variableList;
    }
    
    /**set the variable list of the process*/
    private void setVariableList(){
        String instruction;
        Iterator instructionListIterator = instructionList.iterator();
        char[] varInList;
        
        //search for thr whole instruction list
        for(;instructionListIterator.hasNext();){
            //get the instruction
            instruction = (String)instructionListIterator.next();
            //ingore the instruction of D and E
            if(instruction.charAt(0) == 'A' || instruction.charAt(0) == 'B' || instruction.charAt(0) == 'C' ){
                int flag = 0;// flag = 0 indicate that the varibale is not found 
                //sreach the  whole variable list to see if that variable has been exist
                for(Iterator variableListIterator = variableList.iterator();variableListIterator.hasNext();){
                    varInList = (char[])variableListIterator.next();
                    if(varInList[0] == instruction.charAt(1)){
                        flag = 1;
                        break;
                    }
                }
                //if the variable is new to the list, then add it to the variable list
                if(flag == 0){
                    char[] variable =new char[2];
                    variable[0] = instruction.charAt(1);
                    variable[1] = 0;
                    variableList.add(variable);
                }
            }
        }
    }
    
    /**get the instruction that to be executed*/
    public String getInstruction(){
        String instruction ;
        try{
        instruction = (String)instructionList.get(programCounter);
        }
        catch(IndexOutOfBoundsException expt){
            instruction = "N";
        }
        return instruction;
    }
    
    /**prepare to get next instruction*/
    public void increasePC(){
        programCounter ++;
    }
    
    /**get the memory offset for the process*/
    public int getRamtOffset(){
        return ramOffset;
    }
    
    /**get the memory length for the process*/
    public int getRamLength(){
        return ramLength;
    }
    
    /**get the executable file TreeNode of the process*/
    public TreeNode getFileDescriptor(){
        return fileDescriptor;
    }
    
    /**initialize the PCB*/
    public void initialize(String argName, ArrayList argInstructionList, int argLengthOfInstruction, int argRamOffset, int argRamLength,TreeNode argFileDescriptor){
        this.clear();
        name = argName;
        state = 1;
        instructionList = argInstructionList;
        lengthOfInstruction = argLengthOfInstruction;
        ramOffset = argRamOffset;
        ramLength = argRamLength;
        fileDescriptor = (DefaultMutableTreeNode)argFileDescriptor;
        this.setVariableList();
        this.setState(0);
        
    }
    
    /**clear the PCB*/
    public void clear(){
        name = null;
        state = 0;
        instructionList.clear();
        variableList.clear();
        lengthOfInstruction = 0;
        programCounter = 0;
        ramLength = 0;
        ramOffset = 0;
        fileDescriptor = null;
    }
    
    /**the main method,for class debuging */
    public static void main(String[] args){
        
        //test the contruct method for the class
        PCB testPCB = new PCB(1); 
       
        //test the initialize method for the class
        String name = "test";
        
        ArrayList instructions = new ArrayList();
        instructions.add("Ax1");
        instructions.add("AX1");
        instructions.add("By");
        instructions.add("BY");
        instructions.add("Cz");
        instructions.add("CZ");
        instructions.add("DA1");
        instructions.add("E");
        int lengthOfInstruction = instructions.size();
        
        int ramOffset = 0;
        int ramLength = 8;
        
        testPCB.initialize(name,instructions,lengthOfInstruction,ramOffset,ramLength,null);
        System.out.println(testPCB.getID());
        System.out.println(testPCB.getName());
        System.out.println(testPCB.getPC());
        System.out.println(testPCB.getRamLength());
        System.out.println(testPCB.getRamtOffset());
        
    }
    
    /**The data field for the PCB*/
    //PCB relational
    private int ID;//the ID of the PCB
    private String name;//the name of the PCB
    private int state;//the state of the PCB, 1 is running, 0 is dead
    
    //Instruction relational
    private ArrayList instructionList;// List of nstructions 
    private int lengthOfInstruction;//the length of the instruction
    private int programCounter;// the Program Counter
//    private String currentlyInstruction; // the running instruction
//    private String nextInstruction;//the next instruction
    private ArrayList variableList;//the variable list of the program
    
    //Ram allocation relational
    private int ramOffset;//the offset of the ram
    private int ramLength;//the length of the ram area
    
    //File relational
    private DefaultMutableTreeNode fileDescriptor;//the fileTree node for the excutable file;
    
}