AHeise commented on code in PR #152: URL: https://github.com/apache/flink-connector-kafka/pull/152#discussion_r1954062766
########## flink-connector-kafka/src/main/java/org/apache/flink/connector/kafka/sink/internal/BackchannelImpl.java: ########## @@ -0,0 +1,198 @@ +/* + * 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.connector.kafka.sink.internal; + +import org.apache.flink.annotation.Internal; +import org.apache.flink.annotation.VisibleForTesting; +import org.apache.flink.api.java.tuple.Tuple2; + +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import javax.annotation.Nullable; +import javax.annotation.concurrent.GuardedBy; +import javax.annotation.concurrent.ThreadSafe; + +import java.util.ArrayDeque; +import java.util.Deque; +import java.util.HashMap; +import java.util.Map; +import java.util.concurrent.ConcurrentLinkedDeque; +import java.util.function.Consumer; + +import static org.apache.flink.util.Preconditions.checkState; + +/** + * A backchannel for communication between the Kafka committer -> writer. It's used to recycle + * producer and signal that certain transactions have been committed on recovery. + */ +@Internal +@ThreadSafe +public class BackchannelImpl<T> implements Backchannel<T> { + private static final Logger LOG = LoggerFactory.getLogger(BackchannelImpl.class); + + /** + * The map of backchannels, keyed by the subtask id and transactional id prefix to uniquely + * identify the backchannel while establishing the connection. + */ + @GuardedBy("this") Review Comment: From the documentation ``` GuardedBy The field or method to which this annotation is applied can only be accessed when holding a particular lock, which may be a built-in (synchronization) lock, or may be an explicit java.util.concurrent.Lock. The argument determines which lock guards the annotated field or method: this : The string literal "this" means that this field is guarded by the class in which it is defined. class-name.this : For inner classes, it may be necessary to disambiguate 'this'; the class-name.this designation allows you to specify which 'this' reference is intended itself : For reference fields only; the object to which the field refers. field-name : The lock object is referenced by the (instance or static) field specified by field-name. class-name.field-name : The lock object is reference by the static field specified by class-name.field-name. method-name() : The lock object is returned by calling the named nil-ary method. class-name.class : The Class object for the specified class should be used as the lock object. ``` So `this` is incorrect, it should be `@GuardedBy("BACKCHANNEL")`. -- 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: issues-unsubscr...@flink.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
