From 24a36b53d5226d4b4fb4bbc26e79ce74ddce4b01 Mon Sep 17 00:00:00 2001 From: Looly Date: Wed, 12 May 2021 01:39:32 +0800 Subject: [PATCH] fix doc --- .../hutool/cron/timingwheel/SystemTimer.java | 8 +- .../cn/hutool/cron/timingwheel/TimerTask.java | 26 +++- .../cron/timingwheel/TimerTaskList.java | 46 +++++-- .../hutool/cron/timingwheel/TimingWheel.java | 125 +++++++++++------- 4 files changed, 134 insertions(+), 71 deletions(-) diff --git a/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/SystemTimer.java b/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/SystemTimer.java index 29fba2eef..29bf5948e 100644 --- a/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/SystemTimer.java +++ b/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/SystemTimer.java @@ -6,6 +6,9 @@ import java.util.concurrent.DelayQueue; import java.util.concurrent.ExecutorService; import java.util.concurrent.TimeUnit; +/** + * 系统计时器， + */ public class SystemTimer { /** * 底层时间轮 @@ -25,10 +28,11 @@ public class SystemTimer { /** * 轮询delayQueue获取过期任务线程 */ - private ExecutorService bossThreadPool; + private final ExecutorService bossThreadPool; /** * 构造函数 + * @param timeout 超时时长 */ public SystemTimer(int timeout) { timeWheel = new TimingWheel(1, 20, System.currentTimeMillis(), delayQueue); @@ -59,7 +63,7 @@ public class SystemTimer { TimerTaskList timerTaskList = delayQueue.poll(timeout, TimeUnit.MILLISECONDS); if (timerTaskList != null) { //推进时间 - timeWheel.advanceClock(timerTaskList.getExpiration()); + timeWheel.advanceClock(timerTaskList.getExpire()); //执行过期任务（包含降级操作） timerTaskList.flush(this::addTask); } diff --git a/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/TimerTask.java b/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/TimerTask.java index f894e88b0..c5ce898cf 100644 --- a/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/TimerTask.java +++ b/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/TimerTask.java @@ -1,6 +1,12 @@ package cn.hutool.cron.timingwheel; +/** + * 延迟任务 + * + * @author eliasyaoyc, looly + */ public class TimerTask { + /** * 延迟时间 */ @@ -27,22 +33,34 @@ public class TimerTask { protected TimerTask prev; /** - * 描述 + * 任务描述 */ public String desc; + /** + * 构造 + * + * @param task 任务 + * @param delayMs 延迟毫秒数（以当前时间为准） + */ public TimerTask(Runnable task, long delayMs) { this.delayMs = System.currentTimeMillis() + delayMs; this.task = task; - this.timerTaskList = null; - this.next = null; - this.prev = null; } + /** + * 获取任务 + * + * @return 任务 + */ public Runnable getTask() { return task; } + /** + * 获取延迟时间点，即创建时间+延迟时长（单位毫秒） + * @return 延迟时间点 + */ public long getDelayMs() { return delayMs; } diff --git a/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/TimerTaskList.java b/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/TimerTaskList.java index c8185adde..3e3d4b342 100644 --- a/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/TimerTaskList.java +++ b/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/TimerTaskList.java @@ -6,41 +6,55 @@ import java.util.concurrent.atomic.AtomicLong; import java.util.function.Consumer; /** - * @Author: siran.yao - * @time: 2020/5/8:上午11:13 + * 任务队列，任务双向链表 + * + * @author siran.yao，looly */ public class TimerTaskList implements Delayed { + /** * 过期时间 */ - private AtomicLong expiration = new AtomicLong(-1L); + private final AtomicLong expire; /** * 根节点 */ - private TimerTask root = new TimerTask( null,-1L); + private final TimerTask root; - { + /** + * 构造 + */ + public TimerTaskList(){ + expire = new AtomicLong(-1L); + + root = new TimerTask( null,-1L); root.prev = root; root.next = root; } /** * 设置过期时间 + * + * @param expire 过期时间，单位毫秒 + * @return 是否设置成功 */ public boolean setExpiration(long expire) { - return expiration.getAndSet(expire) != expire; + return this.expire.getAndSet(expire) != expire; } /** * 获取过期时间 + * @return 过期时间 */ - public long getExpiration() { - return expiration.get(); + public long getExpire() { + return expire.get(); } /** - * 新增任务 + * 新增任务，将任务加入到双向链表的头部 + * + * @param timerTask 延迟任务 */ public void addTask(TimerTask timerTask) { synchronized (this) { @@ -57,6 +71,8 @@ public class TimerTaskList implements Delayed { /** * 移除任务 + * + * @param timerTask 任务 */ public void removeTask(TimerTask timerTask) { synchronized (this) { @@ -71,27 +87,29 @@ public class TimerTaskList implements Delayed { } /** - * 重新分配 + * 重新分配，即将列表中的任务全部处理 + * + * @param flush 任务处理函数 */ public synchronized void flush(Consumer flush) { TimerTask timerTask = root.next; - while (!timerTask.equals(root)) { + while (false == timerTask.equals(root)) { this.removeTask(timerTask); flush.accept(timerTask); timerTask = root.next; } - expiration.set(-1L); + expire.set(-1L); } @Override public long getDelay(TimeUnit unit) { - return Math.max(0, unit.convert(expiration.get() - System.currentTimeMillis(), TimeUnit.MILLISECONDS)); + return Math.max(0, unit.convert(expire.get() - System.currentTimeMillis(), TimeUnit.MILLISECONDS)); } @Override public int compareTo(Delayed o) { if (o instanceof TimerTaskList) { - return Long.compare(expiration.get(), ((TimerTaskList) o).expiration.get()); + return Long.compare(expire.get(), ((TimerTaskList) o).expire.get()); } return 0; } diff --git a/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/TimingWheel.java b/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/TimingWheel.java index 786e91a38..7b53e2990 100644 --- a/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/TimingWheel.java +++ b/hutool-cron/src/main/java/cn/hutool/cron/timingwheel/TimingWheel.java @@ -1,30 +1,40 @@ package cn.hutool.cron.timingwheel; +import cn.hutool.log.StaticLog; + import java.util.concurrent.DelayQueue; +/** + * 多层时间轮，常用于延时任务。
+ * 时间轮是一种环形数据结构，由多个槽组成，每个槽中存放任务集合。
+ * 一个单独的线程推进时间一槽一槽的移动，并执行槽中的任务。 + * + * @author eliasyaoyc, looly + */ public class TimingWheel { + /** * 一个时间槽的范围 */ - private long tickMs; + private final long tickMs; /** - * 时间轮大小 + * 时间轮大小，时间轮中时间槽的个数 */ - private int wheelSize; + private final int wheelSize; /** - * 时间跨度 + * 时间跨度，当前时间轮总间隔，即单个槽的跨度*槽个数 */ - private long interval; + private final long interval; /** * 时间槽 */ - private TimerTaskList[] timerTaskLists; + private final TimerTaskList[] timerTaskLists; /** - * 当前时间 + * 当前时间，指向当前操作的时间格，代表当前时间 */ private long currentTime; @@ -34,10 +44,18 @@ public class TimingWheel { private volatile TimingWheel overflowWheel; /** - * 一个Timer只有一个delayQueue + * 执行等待列表 */ - private DelayQueue delayQueue; + private final DelayQueue delayQueue; + /** + * 构造 + * + * @param tickMs 一个时间槽的范围，单位毫秒 + * @param wheelSize 时间轮大小 + * @param currentTime 当前时间 + * @param delayQueue 执行等待链表 + */ public TimingWheel(long tickMs, int wheelSize, long currentTime, DelayQueue delayQueue) { this.currentTime = currentTime; this.tickMs = tickMs; @@ -47,8 +65,53 @@ public class TimingWheel { //currentTime为tickMs的整数倍 这里做取整操作 this.currentTime = currentTime - (currentTime % tickMs); this.delayQueue = delayQueue; - for (int i = 0; i < wheelSize; i++) { - timerTaskLists[i] = new TimerTaskList(); + } + + /** + * 添加任务到时间轮 + * + * @param timerTask 任务 + */ + public boolean addTask(TimerTask timerTask) { + long expiration = timerTask.getDelayMs(); + //过期任务直接执行 + if (expiration < currentTime + tickMs) { + return false; + } else if (expiration < currentTime + interval) { + //当前时间轮可以容纳该任务 加入时间槽 + long virtualId = expiration / tickMs; + int index = (int) (virtualId % wheelSize); + StaticLog.debug("tickMs: {} ------index: {} ------expiration: {}", tickMs, index, expiration); + + TimerTaskList timerTaskList = timerTaskLists[index]; + if(null == timerTaskList){ + timerTaskList = new TimerTaskList(); + timerTaskLists[index] = timerTaskList; + } + timerTaskList.addTask(timerTask); + if (timerTaskList.setExpiration(virtualId * tickMs)) { + //添加到delayQueue中 + delayQueue.offer(timerTaskList); + } + } else { + //放到上一层的时间轮 + TimingWheel timeWheel = getOverflowWheel(); + timeWheel.addTask(timerTask); + } + return true; + } + + /** + * 推进时间 + * @param timestamp 推进的时间 + */ + public void advanceClock(long timestamp) { + if (timestamp >= currentTime + tickMs) { + currentTime = timestamp - (timestamp % tickMs); + if (overflowWheel != null) { + //推进上层时间轮时间 + this.getOverflowWheel().advanceClock(timestamp); + } } } @@ -65,44 +128,4 @@ public class TimingWheel { } return overflowWheel; } - - /** - * 添加任务到时间轮 - */ - public boolean addTask(TimerTask timerTask) { - long expiration = timerTask.getDelayMs(); - //过期任务直接执行 - if (expiration < currentTime + tickMs) { - return false; - } else if (expiration < currentTime + interval) { - //当前时间轮可以容纳该任务 加入时间槽 - Long virtualId = expiration / tickMs; - int index = (int) (virtualId % wheelSize); - System.out.println("tickMs:" + tickMs + "------index:" + index + "------expiration:" + expiration); - TimerTaskList timerTaskList = timerTaskLists[index]; - timerTaskList.addTask(timerTask); - if (timerTaskList.setExpiration(virtualId * tickMs)) { - //添加到delayQueue中 - delayQueue.offer(timerTaskList); - } - } else { - //放到上一层的时间轮 - TimingWheel timeWheel = getOverflowWheel(); - timeWheel.addTask(timerTask); - } - return true; - } - - /** - * 推进时间 - */ - public void advanceClock(long timestamp) { - if (timestamp >= currentTime + tickMs) { - currentTime = timestamp - (timestamp % tickMs); - if (overflowWheel != null) { - //推进上层时间轮时间 - this.getOverflowWheel().advanceClock(timestamp); - } - } - } }