guozhangwang commented on code in PR #12737: URL: https://github.com/apache/kafka/pull/12737#discussion_r993978872
########## streams/src/main/java/org/apache/kafka/streams/processor/internals/tasks/TaskExecutor.java: ########## @@ -0,0 +1,57 @@ +/* + * 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.streams.processor.internals.tasks; + +import org.apache.kafka.common.KafkaFuture; +import org.apache.kafka.streams.processor.internals.ReadOnlyTask; +import org.apache.kafka.streams.processor.internals.StreamTask; + +import java.time.Duration; + +public interface TaskExecutor { + + /** + * Starts the task processor. + */ + void start(); + + /** + * Shuts down the task processor updater. + * + * @param timeout duration how long to wait until the state updater is shut down + * + * @throws + * org.apache.kafka.streams.errors.StreamsException if the state updater thread cannot shutdown within the timeout + */ + void shutdown(final Duration timeout); + + /** + * Get the current assigned processing task. The task returned is read-only and cannot be modified. + * + * @return the current processing task + */ + ReadOnlyTask currentTask(); + + /** + * Unassign the current processing task from the task processor and give it back to the state manager. + * + * The paused task must be flushed since it may be committed or closed by the task manager next. + * + * This method does not block, instead a future is returned. + */ + KafkaFuture<StreamTask> unassign(); Review Comment: The asymmetry is actually intentional indeed -- I will improve the javadocs a bit more in the next PR when I gave the default impl class. The reason is, grabbing a task from task manager to the task executor is always initiated by the task executor itself, while returning a task could be triggered either way: the task executor could return it proactively when it finds the current task not processable any more, and the task manager can also force asking the task executor to return it when it needs to commit / close it. -- 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
