Master-Worker模式是常用的并行设计模式，可以将大任务划分为小任务，是一种分而治之的设计理念。
系统由两个角色组成，Master和Worker，Master负责接收和分配任务，Worker负责处理任务 。子进程处理完成以后，会把结果返回给Master。
原理图如下
下面代码演示
public abstract class Worker implements Runnable {
// 任务队列，用于取得子任务
protected Queue<Object> workQueue;
// 子任务处理结果集
protected Map<String, Object> resultMap;
public void setWorkQueue(Queue<Object> workQueue) {
this.workQueue = workQueue;
}
public void setResultMap(Map<String, Object> resultMap) {
this.resultMap = resultMap;
}
@Override
public void run() {
while (true) {
Object object = workQueue.poll(); //因为当空的时候 会返回空
if(object==null){
break;
}
Object rtn = handle(object);
resultMap.put(rtn.hashCode() + "", rtn);
}
}
//具体的执行逻辑 交给子类
public abstract Object handle(Object input) ;
}
public class PlusWorker extends Worker {
@Override
public Object handle(Object input) {
Integer i =(Integer)input;
return i;
}
}
public class Master {
// 存放提交的任务
Queue<Object> planQueue = new ConcurrentLinkedQueue<>();
// 处理任务的线程
Map<String, Thread> threads = new HashMap<String, Thread>();
// 存储每个任务的完成结果
private Map<String, Object> result = new ConcurrentHashMap<String, Object>();
public Master(Worker w, int workerNum) {
if (workerNum <= 0) {
throw new RuntimeException("workerNum 不能《=0");
}
w.setResultMap(result);
w.setWorkQueue(planQueue);
for (int i = 0; i < workerNum; i++) {
threads.put(i + "", new Thread(w, i + ""));
}
}
// 添加任务的方法
public void submit(Object obj) {
planQueue.add(obj);
}
public void execute() {
for (Map.Entry<String, Thread> entry : threads.entrySet()) {
entry.getValue().start();
}
}
public Map<String, Object> getResMap() {
return result;
}
// 判断所有工作线程是否执行完毕
public boolean isComplete() {
for (Map.Entry<String, Thread> entry : threads.entrySet()) {
if (entry.getValue().getState() != Thread.State.TERMINATED) {
return false;
}
}
return true;
}
// 返回结果集
public Object getRes() {
Integer re = 0;
Map<String, Object> resultMap = result;
for (String string : resultMap.keySet()) {
Integer ob = (Integer) resultMap.get(string);
re = ob + re;
}
return re;
}
}
测试类
public class Main {
public static void main(String[] args) {
// long now = System.currentTimeMillis();
Master master = new Master(new PlusWorker(), 1);
for (int i = 1; i <= 1000; i++) {
master.submit(i);
}
master.execute();
//保存最终结算结果
while(true)
{
if(master.isComplete()){
System.out.println(master.getRes());
break;
}
}
}
}
注意::::重量级的工作配合多核cpu效果不错，轻量级的程序单线程工作效果不一定比并发的差.