操作系统之时间片轮转算法

//时间片轮转算法
class ListQueue {
// 链队列
class Link {
private String name;
private int sertime;
private int priority;
public Link next;
public Link() {
}
public Link(String name, int sertime, int priority) {
this.name = name;
this.sertime = sertime;
this.priority = priority;
}
public void displayLink() {
System.out.println("进程名 " + name + "服务时间 " + sertime + "优先级"

• priority);
  }
  }
  public static Link head;
  public static Link rear;
  public boolean isEmptyQueue() {
  return head == null;
  }
  public ListQueue() {
  head = rear = null;
  }
  // 从尾部插入
  public void insertToQueue(String name, int sertime, int priority) {
  Link newLink = new Link(name, sertime, priority);
  // 第一次的链接点为head端
  if (isEmptyQueue()) {
  head = newLink;
  } else {
  rear.next = newLink;
  }
  rear = newLink;
  }
  // 从头部删除
  public void removeFromQueue() {
  if (isEmptyQueue()) {
  System.out.println("Queue is empty");
  } else {
  if (null == head.next) {
  rear = null;
  }
  head = head.next;
  }
  }
  public void displayQueue() {
  Link currentLink = head;
  while (null != currentLink) {
  currentLink.displayLink();
  currentLink = currentLink.next;
  }
  }
  public static void main(String[] args) {
  int i = 0;
  ListQueue lq = new ListQueue();
  // 插入数据
  lq.insertToQueue("A", 3, 12);
  lq.insertToQueue("B", 5, 31);
  lq.insertToQueue("C", 2, 21);
  lq.insertToQueue("D", 4, 10);
  System.out.println("时间片轮转算法:");
  for (Link visitLink = head; visitLink != null; visitLink = visitLink.next) {
  System.out.print("t=" + i + " " + visitLink.name + "执行");
  if (visitLink.sertime <= 2) {
  System.out.println(" 完成任务");
  lq.removeFromQueue();
  } else {
  System.out.println(" 未完成任务");
  lq.insertToQueue(visitLink.name, visitLink.sertime - 2,
  visitLink.priority);
  lq.removeFromQueue();
  }
  i++;
  }
  }
  }