操作系统-磁盘调度算法:先来先服务,最短寻道时间优先,scan算法 (一)

1.先来先服务
[java]
public class FCFS {

/**
* 磁盘调度:先来先服务
*/
private static int startPosition = 100 ;//磁头开始位置
private static int totalMoving = 0;
private static List visitList = new ArrayList();//访问磁道列表
public static void main(String[] args) {
System.out.println("------磁盘调度:先来先服务算法模拟---------");
input();
running();
display(); www.2cto.com
}
//接收用户输入列表
public static void input(){
System.out.print("请输入磁道访问列表,以空格分开:");
Scanner sc = new Scanner(System.in);
String input = sc.nextLine();
String[] inputList = input.split("\\s");
try{
for(String in : inputList){
visitList.add(Integer.valueOf(in));
}
}
catch(Exception e){
System.out.println("输入的必须是数字,请重新开始！！！");
System.exit(1);
}
}

//运行
public static void running(){
Iterator it = visitList.listIterator();
int thisPosition = 0;
while(it.hasNext()){
thisPosition = it.next();
totalMoving += Math.abs(startPosition-thisPosition);
startPosition = thisPosition;
System.out.println("当前访问磁道号:"+thisPosition);
}
}
public static void display(){
System.out.println("平均寻道时间是:"+(double)totalMoving/visitList.size());
}

}
public class FCFS {

/**
* 磁盘调度:先来先服务
*/
private static int startPosition = 100 ;//磁头开始位置
private static int totalMoving = 0;
private static List visitList = new ArrayList();//访问磁道列表
public static void main(String[] args) {
System.out.println("------磁盘调度:先来先服务算法模拟---------");
input();
running();
display();
}
//接收用户输入列表
public static void input(){
System.out.print("请输入磁道访问列表,以空格分开:");
Scanner sc = new Scanner(System.in);
String input = sc.nextLine();
String[] inputList = input.split("\\s");
try{
for(String in : inputList){
visitList.add(Integer.valueOf(in));
}
}
catch(Exception e){
System.out.println("输入的必须是数字,请重新开始！！！");
System.exit(1);
}
}

//运行
public static void running(){
Iterator it = visitList.listIterator();
int thisPosition = 0;
while(it.hasNext()){
thisPosition = it.next();
totalMoving += Math.abs(startPosition-thisPosition);
startPosition = thisPosition;
System.out.println("当前访问磁道号:"+thisPosition);
}
}
public static void display(){
System.out.println("平均寻道时间是:"+(double)totalMoving/visitList.size());
}

}

2.最短寻道时间优先

[java]
public class SSTF {

/**
*磁盘调度:最短寻道时间优先
*/
private static int startPosition = 100 ;//磁头开始位置
private static int totalMoving = 0;
private static List visitList = new LinkedList();//访问磁道列表
private static int size;
public static void main(String[] args) {
System.out.println("------磁盘调度:最短寻道时间优先算法模拟---------");
input();
running();
display();

}

//接收用户输入列表
public static void input(){
System.out.print("请输入磁道访问列表,以空格分开:");
Scanner sc = new Scanner(System.in);
String input = sc.nextLine();
String[] inputList = input.split("\\s");
try{
for(String in : inputList){
visitList.add(Integer.valueOf(in));
}