chia7712 commented on a change in pull request #8657: URL: https://github.com/apache/kafka/pull/8657#discussion_r479689381
########## File path: core/src/main/scala/kafka/server/ActionQueue.scala ########## @@ -0,0 +1,46 @@ +/** + * 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 kafka.server + +import java.util.concurrent.LinkedBlockingDeque + +/** + * This queue is used to collect actions which need to be executed later. One use case is that ReplicaManager#appendRecords + * produces record changes so we need to check and complete delayed requests. In order to avoid conflicting locking, + * we add those actions to this queue and then complete them at the end of KafkaApis.handle() or DelayedJoin.onExpiration. + */ +class ActionQueue { + private val queue = new LinkedBlockingDeque[() => Unit]() + + /** + * add action to this queue. + * @param action action + */ + def add(action: () => Unit): Unit = queue.put(action) + + /** + * picks up an action to complete. + */ + def tryCompleteAction(): Unit = { Review comment: @junrao @ijuma please take a look at this method ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: us...@infra.apache.org
