✨ TimingWheel 完善，待添加进业务。

mica-mqtt-core/src/main/java/net/dreamlu/iot/mqtt/core/util/timer/TimingWheelThread.java

+/*
+ * Copyright (c) 2019-2029, Dreamlu 卢春梦 (596392912@qq.com & dreamlu.net).
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package net.dreamlu.iot.mqtt.core.util.timer;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.concurrent.CountDownLatch;
+
+/**
+ * TimingWheelThread
+ *
+ * @author L.cm
+ */
+public class TimingWheelThread extends Thread {
+	private static final Logger log = LoggerFactory.getLogger(TimingWheelThread.class);
+
+	private final Timer timer;
+	private final long workTimeoutMs;
+	private final CountDownLatch shutdownInitiated;
+	private final CountDownLatch shutdownComplete;
+	private volatile boolean isStarted = false;
+
+	public TimingWheelThread(Timer timer) {
+		this(timer, 200L);
+	}
+
+	public TimingWheelThread(Timer timer, long workTimeoutMs) {
+		super();
+		this.timer = timer;
+		this.workTimeoutMs = workTimeoutMs;
+		this.shutdownInitiated = new CountDownLatch(1);
+		this.shutdownComplete = new CountDownLatch(1);
+		this.setDaemon(false);
+	}
+
+	public boolean isShutdownInitiated() {
+		return shutdownInitiated.getCount() == 0;
+	}
+
+	public boolean isRunning() {
+		return !isShutdownInitiated();
+	}
+
+	@Override
+	public void run() {
+		isStarted = true;
+		log.info("Starting");
+		try {
+			while (isRunning()) {
+				timer.advanceClock(workTimeoutMs);
+			}
+		} catch (Exception e) {
+			if (isRunning()) {
+				log.error("Error due to", e);
+			}
+		} finally {
+			shutdownComplete.countDown();
+		}
+		log.info("Stopped");
+	}
+
+	public void shutdown() {
+		initiateShutdown();
+		awaitShutdown();
+	}
+
+	private void initiateShutdown() {
+		synchronized (this) {
+			if (isRunning()) {
+				shutdownInitiated.countDown();
+			}
+		}
+	}
+
+	/**
+	 * After calling initiateShutdown(), use this API to wait until the shutdown is complete
+	 */
+	private void awaitShutdown() {
+		if (!isShutdownInitiated()) {
+			throw new IllegalStateException("initiateShutdown() was not called before awaitShutdown()");
+		} else {
+			if (isStarted) {
+				try {
+					shutdownComplete.await();
+				} catch (InterruptedException e) {
+					Thread.currentThread().interrupt();
+				}
+			}
+		}
+	}
+
+}

mica-mqtt-core/src/test/java/net/dreamlu/iot/mqtt/core/timer/SystemTimerTest.java

 package net.dreamlu.iot.mqtt.core.timer;
 
 import net.dreamlu.iot.mqtt.core.util.timer.SystemTimer;
+import net.dreamlu.iot.mqtt.core.util.timer.TimingWheelThread;
 
 public class SystemTimerTest {
-    public static void main(String[] args) {
-        SystemTimer systemTimer = new SystemTimer("timer");
-        System.out.println(System.currentTimeMillis());
-        systemTimer.add(new DelayedOperation(5000));
-        systemTimer.add(new DelayedOperation(7000));
-        systemTimer.add(new DelayedOperation(10000));
-        systemTimer.add(new DelayedOperation(14000));
-        System.out.println(System.nanoTime());
-        boolean flag = true;
-        while (flag) {
-            boolean b = systemTimer.advanceClock(200);
-            if (b) {
-                System.out.println(systemTimer.size());
-            }
-        }
-    }
+
+	public static void main(String[] args) throws InterruptedException {
+		SystemTimer systemTimer = new SystemTimer("timer");
+
+		TimingWheelThread timingWheelThread = new TimingWheelThread(systemTimer);
+		timingWheelThread.start();
+
+		System.out.println(System.currentTimeMillis());
+		systemTimer.add(new DelayedOperation(5000));
+		systemTimer.add(new DelayedOperation(7000));
+		systemTimer.add(new DelayedOperation(10000));
+		systemTimer.add(new DelayedOperation(14000));
+		System.out.println(System.nanoTime());
+
+		Thread.sleep(100000L);
+	}
 }