From 6a7883431fc4bae8d06f973553bede7463574e47 Mon Sep 17 00:00:00 2001
From: Viraj Jasani <vjasani@apache.org>
Date: Mon, 9 Aug 2021 14:27:53 +0530
Subject: [PATCH] HADOOP-17841. Remove ListenerHandle from Hadoop registry
 (#3278)

---
 .../client/impl/zk/CuratorService.java        |  4 +--
 .../client/impl/zk/ListenerHandle.java        | 25 -------------------
 2 files changed, 1 insertion(+), 28 deletions(-)
 delete mode 100644 hadoop-common-project/hadoop-registry/src/main/java/org/apache/hadoop/registry/client/impl/zk/ListenerHandle.java

diff --git a/hadoop-common-project/hadoop-registry/src/main/java/org/apache/hadoop/registry/client/impl/zk/CuratorService.java b/hadoop-common-project/hadoop-registry/src/main/java/org/apache/hadoop/registry/client/impl/zk/CuratorService.java
index 3457fa28634..0388973edd9 100644
--- a/hadoop-common-project/hadoop-registry/src/main/java/org/apache/hadoop/registry/client/impl/zk/CuratorService.java
+++ b/hadoop-common-project/hadoop-registry/src/main/java/org/apache/hadoop/registry/client/impl/zk/CuratorService.java
@@ -824,9 +824,8 @@ protected String dumpRegistryRobustly(boolean verbose) {
    * Registers a listener to path related events.
    *
    * @param listener the listener.
-   * @return a handle allowing for the management of the listener.
    */
-  public ListenerHandle registerPathListener(final PathListener listener) {
+  public void registerPathListener(final PathListener listener) {
 
     CuratorCacheListener cacheListener = CuratorCacheListener.builder()
         .forCreatesAndChanges((oldNode, node) -> {
@@ -854,7 +853,6 @@ public ListenerHandle registerPathListener(final PathListener listener) {
         .build();
 
     curatorCacheBridge.listenable().addListener(cacheListener);
-    return () -> curatorCacheBridge.listenable().removeListener(cacheListener);
   }
 
   // TODO: should caches be stopped and then restarted if need be?
diff --git a/hadoop-common-project/hadoop-registry/src/main/java/org/apache/hadoop/registry/client/impl/zk/ListenerHandle.java b/hadoop-common-project/hadoop-registry/src/main/java/org/apache/hadoop/registry/client/impl/zk/ListenerHandle.java
deleted file mode 100644
index e43dbbe8417..00000000000
--- a/hadoop-common-project/hadoop-registry/src/main/java/org/apache/hadoop/registry/client/impl/zk/ListenerHandle.java
+++ /dev/null
@@ -1,25 +0,0 @@
-/*
- * 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.hadoop.registry.client.impl.zk;
-
-/**
- *
- */
-public interface ListenerHandle {
-  void remove();
-}