From ebb698fd094d8b09e498c88c107a1a2ddd20eb25 Mon Sep 17 00:00:00 2001
From: Jean-Daniel Cryans <jdcryans@apache.org>
Date: Sun, 20 Jun 2010 01:01:11 +0000
Subject: [PATCH] HBASE-2737  CME in ZKW introduced in HBASE-2694 (Karthik
 Ranganathan via JD)

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@956314 13f79535-47bb-0310-9956-ffa450edef68
---
 CHANGES.txt                                                   | 1 +
 .../org/apache/hadoop/hbase/zookeeper/ZooKeeperWrapper.java   | 4 ++--
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/CHANGES.txt b/CHANGES.txt
index cec907be6fd..b2076eaf360 100644
--- a/CHANGES.txt
+++ b/CHANGES.txt
@@ -396,6 +396,7 @@ Release 0.21.0 - Unreleased
    HBASE-2725  Shutdown hook management is gone in trunk; restore
    HBASE-2740  NPE in ReadWriteConsistencyControl
    HBASE-2752  Don't retry forever when waiting on too many store files
+   HBASE-2737  CME in ZKW introduced in HBASE-2694 (Karthik Ranganathan via JD)
 
   IMPROVEMENTS
    HBASE-1760  Cleanup TODOs in HTable
diff --git a/src/main/java/org/apache/hadoop/hbase/zookeeper/ZooKeeperWrapper.java b/src/main/java/org/apache/hadoop/hbase/zookeeper/ZooKeeperWrapper.java
index 9f346026569..b26c071839e 100644
--- a/src/main/java/org/apache/hadoop/hbase/zookeeper/ZooKeeperWrapper.java
+++ b/src/main/java/org/apache/hadoop/hbase/zookeeper/ZooKeeperWrapper.java
@@ -219,11 +219,11 @@ public class ZooKeeperWrapper implements Watcher {
     }    
   }
 
-  public void registerListener(Watcher watcher) {
+  public synchronized void registerListener(Watcher watcher) {
     listeners.add(watcher);
   }
 
-  public void unregisterListener(Watcher watcher) {
+  public synchronized void unregisterListener(Watcher watcher) {
     listeners.remove(watcher);
   }