rkhachatryan commented on a change in pull request #10345: [FLINK-12484][runtime] synchronize all mailbox actions URL: https://github.com/apache/flink/pull/10345#discussion_r351909719
########## File path: flink-streaming-java/src/main/java/org/apache/flink/streaming/runtime/tasks/ExecutionDecorator.java ########## @@ -0,0 +1,120 @@ +/* + * 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.flink.streaming.runtime.tasks; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.streaming.runtime.tasks.mailbox.Mail; +import org.apache.flink.util.function.ThrowingRunnable; + +import java.util.concurrent.Callable; + +/** + * Wraps execution of a {@link Runnable}, {@link ThrowingRunnable}, {@link Callable}, or {@link Mail}. + * Intended to customize execution in sub-types fo {@link org.apache.flink.streaming.runtime.tasks.StreamTask StreamTask}, + * e.g. synchronization in {@link org.apache.flink.streaming.runtime.tasks.SourceStreamTask SourceStreamTask}. + */ +@Internal +public interface ExecutionDecorator { + void run(Runnable runnable); + + <E extends Throwable> void runThrowing(ThrowingRunnable<E> runnable) throws E; + + <R> R call(Callable<R> callable) throws Exception; + + void dispatch(Mail mail); + + ExecutionDecorator NO_OP = new ExecutionDecorator() { + @Override + public void run(Runnable runnable) { + runnable.run(); + } + + @Override + public <E extends Throwable> void runThrowing(ThrowingRunnable<E> runnable) throws E { + runnable.run(); + } + + @Override + public <R> R call(Callable<R> callable) throws Exception { + return callable.call(); + } + + @Override + public void dispatch(Mail mail) { + mail.run(); + } + }; + + /** + * Returns an ExecutionDecorator that synchronizes each invocation. + */ + static SynchronizedExecutionDecorator syncExecutionDecorator() { + return syncExecutionDecorator(new Object()); + } + + /** + * Returns an ExecutionDecorator that synchronizes each invocation on a given object. + */ + static SynchronizedExecutionDecorator syncExecutionDecorator(Object mutex) { + return new SynchronizedExecutionDecorator(mutex); + } + + /** + * A {@link ExecutionDecorator} that synchronizes every operation on the provided mutex. + */ + class SynchronizedExecutionDecorator implements ExecutionDecorator { Review comment: On the other hand, `checkpointLock` is confusing for newcomers:) As it is used not only for checkpoints. I think we can just add Javadoc. ---------------------------------------------------------------- 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 With regards, Apache Git Services
