*/
private static class SkylinePool {
//线程池的线程数
private final int coreSize;
//线程池中的线程的集合
private final TaskHandler[] threads;
//线程池中任务的等待队列
private final TaskQueue taskQueue;
//指针，指向threads的末尾
private int endPoint;
//是否已停止
private boolean shutDown;
//拒绝策略
private final RejectStrategy rejectStrategy;
/**
-
构造函数
-
@param coreSize 线程池中的线程个数
-
@param maxQueueSize 等待队列中的元素的最大个数
-
@param rejectStrategy 当等待队列已满时需要执行的逻辑
*/
private SkylinePool(int coreSize,int maxQueueSize,RejectStrategy rejectStrategy) {
this.coreSize = coreSize;
this.threads = new TaskHandler[coreSize];
taskQueue = new TaskQueue(maxQueueSize);
this.rejectStrategy = rejectStrategy;
}
/**
-
向线程池中提交一个任务
-
@param task
*/
public void submit(Task task) {
//如果线程池已经停止，那就不再允许提交了
if (shutDown) {
return;
}
//如果线程数还没满，那就先创建线程
if (endPoint < coreSize) {
logger.info("线程池还没到最大限度，任务[{}]被直接启动执行",task.getTaskNum());
TaskHandler taskHandler = new TaskHandler(task, taskQueue, "t"+endPoint);
threads[endPoint] = taskHandler;
taskHandler.start();
endPoint++;
} else {
//线程数已经满了之后就只能尝试放入队列了，这个try就有aqs那味儿了
logger.info("线程池已到达最大限度，任务[{}]尝试进入队列",task.getTaskNum());
boolean tryPush = taskQueue.tryPush(task);
//尝试放入队列失败，一般就是队列满了，那就执行拒绝策略
if (!tryPush) {
rejectStrategy.handle(taskQueue, task);
}
}
}
public void shutDown(){
shutDown = true;
for (int i = 0; i < coreSize; i++) {
TaskHandler thread = threads[i];
if (thread == null) {
continue;
}
while (thread.isAlive() && !thread.isInterrupted()){
logger.info("尝试打断[{}]",thread.getName());
thread.interrupt();
try {
//等待1秒是为了让出CPU
TimeUnit.SECONDS.sleep(1);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
threads[i] = null;
}
}
}
/**
- 任务队列，尝试写了一个双端同步FIFO队列
*/
private static class TaskQueue{
//队列中元素的最大值
private final int maxSize;
private final Task[] taskDeque;
//头索引
private int headIndex;
//尾索引
private int tailIndex;
//同步锁
private final Lock lock = new ReentrantLock();
//条件锁，当队列为空时会阻塞
private final Condition emptyCondition = lock.newCondition();
//条件锁，当队列已满时会阻塞
private final Condition fullCondition = lock.newCondition();
/**
-
初始化一个任务队列
-
@param maxSize
*/
private TaskQueue(int maxSize) {
if (maxSize<=0) {
throw new RuntimeException("maxSize不能小于0");
}
this.maxSize = maxSize;
//初始化队列
taskDeque = new Task[maxSize];
}
/**
-
从任务队列中取出一个task，如果没有，就阻塞
-
@return
*/
public Task take(){
//如果当前线程已经被打断，那就直接返回null
if (Thread.currentThread().isInterrupted()) {
logger.info("[{}]已经被打断",Thread.currentThread().getName());
return null;
}
//抢锁，准备取出一个任务
logger.info("[{}]开始获取任务",Thread.currentThread().getName());
lock.lock();
try {
//如果队列为空，那就阻塞，这里需要是while而不是if，因为下面调用的是signalAll，而且也可以防止意外唤醒
while (checkIsEmpty()){
logger.info("队列为空，等待其他线程放入任务后，才能取出任务,[{}]",Thread.currentThread().getName());
try {
emptyCondition.await();
} catch (InterruptedException e) {
logger.info("[{}]已经被打断",Thread.currentThread().getName());
Thread.currentThread().interrupt();
return null;
}
}
logger.info("取出了一个任务,[{}]",Thread.currentThread().getName());
Task task = doPop();
//取出一个任务后，列表肯定不是full的状态了
fullCondition.signalAll();
return task;
}finally {
lock.unlock();
}
}
/**
-
从列表中取出一个任务
-
@return
*/
public Task doPop(){
Task pop = taskDeque[headIndex];
taskDeque[headIndex] = null;
headIndex++;
headIndex = headIndex%maxSize;
return pop;
}
/**
-
判断数组是否已经满了
-
1、head...tail
-
2、...tail,head...
-
@return
*/
private boolean checkIsFull(){
int i = tailIndex - headIndex;
return i == maxSize-1 || i == -1;
}
/**
-
判断数组是否为空的
-
@return
*/
private boolean checkIsEmpty(){
return tailIndex==headIndex;
}
/**
-
尝试放入一个任务
-
@param task
-
@return
*/
public boolean tryPush(Task task){
//抢锁，尝试放入
logger.info("[{}]开始尝试放入任务[{}]",Thread.currentThread().getName(),task.getTaskNum());
lock.lock();
try {
//如果已经满了，那就直接返回，aqs风格
if (checkIsFull()){
return false;
}
//队列中有空闲位置的话，那就放入任务
logger.info("任务[{}]成功进入队列,[{}]",task.getTaskNum(),Thread.currentThread().getName());
doAdd(task);
//放入之后，列表一定不为空了
emptyCondition.signalAll();
return true;
}finally {
lock.unlock();
}
}
/**
-
放入一个任务
-
@param task
*/
public void doAdd(Task task){
taskDeque[tailIndex]=task;
tailIndex++;
tailIndex=tailIndex%maxSize;
}
/**
-
向队列中添加一个任务，如果队列到达最大长度，那就阻塞
-
@param task
*/
public void push(Task task){
logger.info("[{}]开始放入任务[{}]",Thread.currentThread().getName(),task.getTaskNum());
lock.lock();
try {
while (checkIsFull()){
logger.info("队列已满，等待任务被取出后，才能继续,[{}]",Thread.currentThread().getName());
try {
fullCondition.await();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
logger.info("任务[{}]成功进入队列,[{}]",task.getTaskNum(),Thread.currentThread().getName());
doAdd(task);
emptyCondition.signalAll();
}finally {
lock.unlock();
}
}
}
/**
- 任务处理器，其实就是线程
*/
private static class TaskHandler extends Thread{
//当前要处理的任务
private Task task;
//待处理任务的队列
private final TaskQueue taskQueue;
/**
-
任务处理器
-
@param task 初始时的任务
-
@param taskQueue 待处理任务的队列
-
@param name 任务处理器名称（线程名）
*/
public TaskHandler(Task task, TaskQueue taskQueue, String name){
this.task = task;
this.taskQueue = taskQueue;
setName(name);
}
@Override
public void run() {
//如果有当前任务或者队列中可以获取到任务
while (task!=null || (task=taskQueue.take())!=null){
logger.info("[{}]开始执行任务[{}]",Thread.currentThread().getName(),task.getTaskNum());
task.run();
if (Thread.currentThread().isInterrupted()) {
logger.info("[{}]已经被打断",Thread.currentThread().getName());
return;
}
//将当前任务置为null
task = null;
}
logger.info("[{}]no task",Thread.currentThread().getName());
}
}
/**
- 任务，基于Runnable
*/
private static abstract class Task implements Runnable{
//任务编号
private final int taskNum;
/**
-
任务
-
@param taskNum 任务编号
*/
private Task(int taskNum) {
this.taskNum = taskNum;
}
public int getTaskNum() {
return taskNum;
}
}
/**
- 拒绝策略
*/
private interface RejectStrategy{
/**
-
当队列已满时会触发的具体逻辑
-
@param taskQueue
-
@param task
*/
void handle(TaskQueue taskQueue,Task task);
}
执行结果：
11:03:42.935 [Test worker] INFO c.e.d.DemoApplicationTests9 - 线程池还没到最大限度，任务[0]被直接启动执行
11:03:42.936 [Test worker] INFO c.e.d.DemoApplicationTests9 - 线程池还没到最大限度，任务[1]被直接启动执行
11:03:42.937 [Test worker] INFO c.e.d.DemoApplicationTests9 - 线程池已到达最大限度，任务[2]尝试进入队列
11:03:42.937 [Test worker] INFO c.e.d.DemoApplicationTests9 - [Test worker]开始尝试放入任务[2]
11:03:42.937 [t0 ] INFO c.e.d.DemoApplicationTests9 - [t0]开始执行任务[0]
11:03:42.937 [t1 ] INFO c.e.d.DemoApplicationTests9 - [t1]开始执行任务[1]
11:03:42.937 [Test worker] INFO c.e.d.DemoApplicationTests9 - 任务[2]成功进入队列,[Test worker]
11:03:42.937 [t0 ] INFO c.e.d.DemoApplicationTests9 - [t0]正在执行任务[0]
11:03:42.937 [Test worker] INFO c.e.d.DemoApplicationTests9 - 线程池已到达最大限度，任务[3]尝试进入队列
11:03:42.937 [Test worker] INFO c.e.d.DemoApplicationTests9 - [Test worker]开始尝试放入任务[3]
11:03:42.937 [Test worker] INFO c.e.d.DemoApplicationTests9 - 任务[3]成功进入队列,[Test worker]
11:03:42.937 [t1 ] INFO c.e.d.DemoApplicationTests9 - [t1]正在执行任务[1]
11:03:42.937 [Test worker] INFO c.e.d.DemoApplicationTests9 - 线程池已到达最大限度，任务[4]尝试进入队列
11:03:42.938 [Test worker] INFO c.e.d.DemoApplicationTests9 - [Test worker]开始尝试放入任务[4]
11:03:42.938 [Test worker] INFO c.e.d.DemoApplicationTests9 - 任务[4]成功进入队列,[Test worker]
11:03:42.938 [Test worker] INFO c.e.d.DemoApplicationTests9 - 线程池已到达最大限度，任务[5]尝试进入队列
11:03:42.938 [Test worker] INFO c.e.d.DemoApplicationTests9 - [Test worker]开始尝试放入任务[5]
11:03:42.938 [Test worker] INFO c.e.d.DemoApplicationTests9 - 任务[5]成功进入队列,[Test worker]
11:03:42.938 [Test worker] INFO c.e.d.DemoApplicationTests9 - 线程池已到达最大限度，任务[6]尝试进入队列
11:03:42.938 [Test worker] INFO c.e.d.DemoApplicationTests9 - [Test worker]开始尝试放入任务[6]
11:03:42.938 [Test worker] INFO c.e.d.DemoApplicationTests9 - -----------[Test worker]尝试放入任务[6]
11:03:42.938 [Test worker] INFO c.e.d.DemoApplicationTests9 - [Test worker]开始放入任务[6]
11:03:42.938 [Test worker] INFO c.e.d.DemoApplicationTests9 - 队列已满，等待任务被取出后，才能继续,[Test worker]
11:03:44.950 [t1 ] INFO c.e.d.DemoApplicationTests9 - [t1]执行任务[1]完毕
11:03:44.950 [t0 ] INFO c.e.d.DemoApplicationTests9 - [t0]执行任务[0]完毕
11:03:44.950 [t1 ] INFO c.e.d.DemoApplicationTests9 - [t1]开始获取任务
11:03:44.950 [t1 ] INFO c.e.d.DemoApplicationTests9 - 取出了一个任务,[t1]
11:03:44.950 [t0 ] INFO c.e.d.DemoApplicationTests9 - [t0]开始获取任务
11:03:44.950 [t1 ] INFO c.e.d.DemoApplicationTests9 - [t1]开始执行任务[2]
11:03:44.950 [Test worker] INFO c.e.d.DemoApplicationTests9 - 任务[6]成功进入队列,[Test worker]
11:03:44.950 [t1 ] INFO c.e.d.DemoApplicationTests9 - [t1]正在执行任务[2]
11:03:44.951 [Test worker] INFO c.e.d.DemoApplicationTests9 - ------------[Test worker]放入任务[6]成功
11:03:44.951 [t0 ] INFO c.e.d.DemoApplicationTests9 - 取出了一个任务,[t0]
11:03:44.951 [Test worker] INFO c.e.d.DemoApplicationTests9 - 线程池已到达最大限度，任务[7]尝试进入队列
11:03:44.951 [t0 ] INFO c.e.d.DemoApplicationTests9 - [t0]开始执行任务[3]
11:03:44.951 [t0 ] INFO c.e.d.DemoApplicationTests9 - [t0]正在执行任务[3]
11:03:44.951 [Test worker] INFO c.e.d.DemoApplicationTests9 - [Test worker]开始尝试放入任务[7]
11:03:44.951 [Test worker] INFO c.e.d.DemoApplicationTests9 - 任务[7]成功进入队列,[Test worker]
11:03:44.951 [Test worker] INFO c.e.d.DemoApplicationTests9 - 线程池已到达最大限度，任务[8]尝试进入队列
11:03:44.951 [Test worker] INFO c.e.d.DemoApplicationTests9 - [Test worker]开始尝试放入任务[8]
11:03:44.951 [Test worker] INFO c.e.d.DemoApplicationTests9 - -----------[Test worker]尝试放入任务[8]
11:03:44.951 [Test worker] INFO c.e.d.DemoApplicationTests9 - [Test worker]开始放入任务[8]
11:03:44.951 [Test worker] INFO c.e.d.DemoApplicationTests9 - 队列已满，等待任务被取出后，才能继续,[Test worker]
11:03:46.965 [t0 ] INFO c.e.d.DemoApplicationTests9 - [t0]执行任务[3]完毕
11:03:46.965 [t0 ] INFO c.e.d.DemoApplicationTests9 - [t0]开始获取任务
11:03:46.965 [t1 ] INFO c.e.d.DemoApplicationTests9 - [t1]执行任务[2]完毕
11:03:46.965 [t1 ] INFO c.e.d.DemoApplicationTests9 - [t1]开始获取任务
11:03:46.965 [t0 ] INFO c.e.d.DemoApplicationTests9 - 取出了一个任务,[t0]
11:03:46.965 [t0 ] INFO c.e.d.DemoApplicationTests9 - [t0]开始执行任务[4]
11:03:46.965 [t1 ] INFO c.e.d.DemoApplicationTests9 - 取出了一个任务,[t1]
11:03:46.965 [t0 ] INFO c.e.d.DemoApplicationTests9 - [t0]正在执行任务[4]
11:03:46.965 [t1 ] INFO c.e.d.DemoApplicationTests9 - [t1]开始执行任务[5]
11:03:46.965 [t1 ] INFO c.e.d.DemoApplicationTests9 - [t1]正在执行任务[5]
11:03:46.965 [Test worker] INFO c.e.d.DemoApplicationTests9 - 任务[8]成功进入队列,[Test worker]
11:03:46.965 [Test worker] INFO c.e.d.DemoApplicationTests9 - ------------[Test worker]放入任务[8]成功
11:03:46.965 [Test worker] INFO c.e.d.DemoApplicationTests9 - 线程池已到达最大限度，任务[9]尝试进入队列
11:03:46.965 [Test worker] INFO c.e.d.DemoApplicationTests9 - [Test worker]开始尝试放入任务[9]
11:03:46.965 [Test worker] INFO c.e.d.DemoApplicationTests9 - 任务[9]成功进入队列,[Test worker]
11:03:46.966 [Test worker] INFO c.e.d.DemoApplicationTests9 - 尝试打断[t0]
java.lang.InterruptedException: sleep interrupted
