myprocess.java

只是一个简单模拟操作系统

/*
 * Process.java
 *
 * Created on 2006年3月16日, 下午8:06
 *
 *The Process Class
 *Including the common view of a process
 */

package os.process;

/**
 *
 * @author Vernkin
 */


public class MyProcess {
    
    /**allocate for process ID**/
    private static int ID_COUNT = 0;
    /**allocate for system id
     *(A process may have different system id at different time)
     *Determined by the num enter into ProcessManager*/
    private static int SYSTEM_ID_COUNT = 0;
    
    private String name;
    private String status;
    /**priority 1 ~ 7 as 1 is least and 7 is largest. Defualt 4 **/
    private int priority;
    private int id;
    private int system_id;
    private boolean isLoad;
    private int allocatedMemory;
    /** Creates a new instance of Process */
    public MyProcess(String name){
        this(name,4);
    }
    
    public MyProcess(String name,int priority) {
        this.name = name;
        //check for priority
        if(priority < 1) 
            priority = 1;
        else if(priority > 7) 
            priority = 1;
        
        this.priority = priority;
        id = ID_COUNT++;
        system_id = 0;
        System.out.println("Create Process "+name+"  "+id);
    }
    
    /**Whether the first param(Process) have right to run first
     *Principial : first priority,then system_id(system_id smaller = larger) **/
    public static boolean firstRun(MyProcess first,MyProcess second){
        if(first.priority > second.priority)
            return true;
        if(first.priority < second.priority)
            return false;
        /**Two process have the same priority**/
        if(first.system_id < second.system_id)
            return true;
        if(first.system_id > second.system_id)
            return false;
        
        return true;
    }
    
    public void setStatus(String in){
        status = in;
    }
    
    
    public String getStatus(){
        return status;
    }
    
    
    public int getAllocatedMemory(){
        return allocatedMemory;
    }
    
    public void setAllocatedMemory(int in){
        allocatedMemory = in;
    }
    public void setSystemID(){
        this.system_id = this.SYSTEM_ID_COUNT++;
    }
    
    public int getSystemIDCount(){
        return SYSTEM_ID_COUNT;
    }
    
    public int getSystemID(){
        return system_id;
    }
    
    public int getID(){
        return id;
    }
    
    public String getName(){
        return name;
    }
    
    public boolean getIsLoad(){
        return isLoad;
    }
    
    public int getPriority(){
        return priority;
    }
    
    public void setPriority(int in){
        priority = in;
    }
    
    public void setIsLoad(boolean new_value){
        isLoad = new_value;
     }
    
    public String toString(){
        return "["+name+" "+id+"]";
    }
    
    public static void main(String[] args) {
        // TODO code application logic here
  /*     MyProcess s1 = new MyProcess("s1");
       MyProcess s2 = new MyProcess("s2");
       MyProcess s3 = new MyProcess("s3", 5);
       s1.setSystemID();
       s2.setSystemID();
       System.out.println(MyProcess.firstRun(s1, s2));
       System.out.println(MyProcess.firstRun(s1, s3));
 */
        String s = "01234567";
        System.out.println(s.substring(0,4));
   }
    
}