Java tutorial
/* * Copyright 2018 Qunar, Inc. * * 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 qunar.tc.qmq.service; import io.netty.util.HashedWheelTimer; import io.netty.util.Timeout; import io.netty.util.TimerTask; import qunar.tc.qmq.common.Disposable; import qunar.tc.qmq.concurrent.NamedThreadFactory; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ConcurrentMap; import java.util.concurrent.TimeUnit; /** * @author yunfeng.yang * @since 2017/9/19 */ public class HeartbeatManager<T> implements Disposable { private final HashedWheelTimer timer; private final ConcurrentMap<T, Timeout> timeouts; public HeartbeatManager() { this.timeouts = new ConcurrentHashMap<>(); this.timer = new HashedWheelTimer(new NamedThreadFactory("qmq-heartbeat")); this.timer.start(); } public void cancel(T key) { Timeout timeout = timeouts.remove(key); if (timeout == null) return; timeout.cancel(); } public void refreshHeartbeat(T key, TimerTask task, long timeout, TimeUnit unit) { Timeout context = timer.newTimeout(task, timeout, unit); final Timeout old = timeouts.put(key, context); if (old != null && !old.isCancelled() && !old.isExpired()) { old.cancel(); } } @Override public void destroy() { timer.stop(); } }