dajac commented on code in PR #13820: URL: https://github.com/apache/kafka/pull/13820#discussion_r1229326517
########## server-common/src/main/java/org/apache/kafka/server/util/timer/TimerTaskList.java: ########## @@ -0,0 +1,122 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one or more + * contributor license agreements. See the NOTICE file distributed with + * this work for additional information regarding copyright ownership. + * The ASF licenses this file to You 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 org.apache.kafka.server.util.timer; + +import org.apache.kafka.common.utils.Time; + +import java.util.concurrent.Delayed; +import java.util.concurrent.TimeUnit; +import java.util.concurrent.atomic.AtomicInteger; +import java.util.concurrent.atomic.AtomicLong; +import java.util.function.Consumer; + +class TimerTaskList implements Delayed { + final AtomicInteger taskCounter; + final AtomicLong expiration; + + // TimerTaskList forms a doubly linked cyclic list using a dummy root entry + // root.next points to the head + // root.prev points to the tail + private TimerTaskEntry root; + + TimerTaskList( + AtomicInteger taskCounter + ) { + this.taskCounter = taskCounter; + this.expiration = new AtomicLong(-1L); + this.root = new TimerTaskEntry(null, -1L); + this.root.next = root; + this.root.prev = root; + } + + public boolean setExpiration(long expirationMs) { + return expiration.getAndSet(expirationMs) != expirationMs; + } + + public long getExpiration() { + return expiration.get(); + } + + public synchronized void foreach(Consumer<TimerTask> f) { + TimerTaskEntry entry = root.next; + while (entry != root) { + TimerTaskEntry nextEntry = entry.next; + if (!entry.cancelled()) f.accept(entry.timerTask); + entry = nextEntry; + } + } + + public void add(TimerTaskEntry timerTaskEntry) { + boolean done = false; + while (!done) { + // Remove the timer task entry if it is already in any other list + // We do this outside of the sync block below to avoid deadlocking. + // We may retry until timerTaskEntry.list becomes null. + timerTaskEntry.remove(); + + synchronized (this) { + synchronized (timerTaskEntry) { + if (timerTaskEntry.list == null) { + // put the timer task entry to the end of the list. (root.prev points to the tail entry) + TimerTaskEntry tail = root.prev; + timerTaskEntry.next = root; + timerTaskEntry.prev = tail; + timerTaskEntry.list = this; + tail.next = timerTaskEntry; + root.prev = timerTaskEntry; + taskCounter.incrementAndGet(); + done = true; + } + } + } + } + } + + public synchronized void remove(TimerTaskEntry timerTaskEntry) { + synchronized (timerTaskEntry) { + if (timerTaskEntry.list == this) { + timerTaskEntry.next.prev = timerTaskEntry.prev; + timerTaskEntry.prev.next = timerTaskEntry.next; + timerTaskEntry.next = null; + timerTaskEntry.prev = null; + timerTaskEntry.list = null; + taskCounter.decrementAndGet(); + } + } + } + + public synchronized void flush(Consumer<TimerTaskEntry> f) { + TimerTaskEntry head = root.next; + while (head != root) { + remove(head); + f.accept(head); + head = root.next; + } + expiration.set(-1L); + } + + @Override + public long getDelay(TimeUnit unit) { + return unit.convert(Math.max(getExpiration() - Time.SYSTEM.hiResClockMs(), 0), TimeUnit.MICROSECONDS); Review Comment: It is not... Let me fix this. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: jira-unsubscr...@kafka.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
