cn.hutool.cron.timingwheel.SystemTimer Maven / Gradle / Ivy
package cn.hutool.cron.timingwheel;
import cn.hutool.core.thread.ThreadUtil;
import java.util.concurrent.DelayQueue;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.TimeUnit;
/**
* 系统计时器
*
* @author eliasyaoyc, looly
*/
public class SystemTimer {
/**
* 底层时间轮
*/
private final TimingWheel timeWheel;
/**
* 一个Timer只有一个delayQueue
*/
private final DelayQueue delayQueue = new DelayQueue<>();
/**
* 执行队列取元素超时时长，单位毫秒，默认100
*/
private long delayQueueTimeout = 100;
/**
* 轮询delayQueue获取过期任务线程
*/
private ExecutorService bossThreadPool;
private volatile boolean isRunning;
/**
* 构造
*/
public SystemTimer() {
timeWheel = new TimingWheel(1, 20, delayQueue::offer);
}
/**
* 设置执行队列取元素超时时长，单位毫秒
* @param delayQueueTimeout 执行队列取元素超时时长，单位毫秒
* @return this
*/
public SystemTimer setDelayQueueTimeout(long delayQueueTimeout){
this.delayQueueTimeout = delayQueueTimeout;
return this;
}
/**
* 启动，异步
*
* @return this
*/
public SystemTimer start() {
bossThreadPool = ThreadUtil.newSingleExecutor();
isRunning = true;
bossThreadPool.submit(() -> {
while (true) {
if(false == advanceClock()){
break;
}
}
});
return this;
}
/**
* 强制结束
*/
public void stop(){
this.isRunning = false;
this.bossThreadPool.shutdown();
}
/**
* 添加任务
*
* @param timerTask 任务
*/
public void addTask(TimerTask timerTask) {
//添加失败任务直接执行
if (false == timeWheel.addTask(timerTask)) {
ThreadUtil.execAsync(timerTask.getTask());
}
}
/**
* 指针前进并获取过期任务
*
* @return 是否结束
*/
private boolean advanceClock() {
if(false == isRunning){
return false;
}
try {
TimerTaskList timerTaskList = poll();
if (null != timerTaskList) {
//推进时间
timeWheel.advanceClock(timerTaskList.getExpire());
//执行过期任务（包含降级操作）
timerTaskList.flush(this::addTask);
}
} catch (InterruptedException ignore) {
return false;
}
return true;
}
/**
* 执行队列取任务列表
* @return 任务列表
* @throws InterruptedException 中断异常
*/
private TimerTaskList poll() throws InterruptedException {
return this.delayQueueTimeout > 0 ?
delayQueue.poll(delayQueueTimeout, TimeUnit.MILLISECONDS) :
delayQueue.poll();
}
}