From 31d73a4bdec59ba2ca6bdc04d881f2bc3726e903 Mon Sep 17 00:00:00 2001
From: Enis Soztutar <enis@apache.org>
Date: Tue, 15 Dec 2015 11:57:28 -0800
Subject: [PATCH] HBASE-14977 ChoreService.shutdown may result in
 ConcurrentModificationException (Vladimir Rodionov)

---
 .../src/main/java/org/apache/hadoop/hbase/ChoreService.java     | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hbase-common/src/main/java/org/apache/hadoop/hbase/ChoreService.java b/hbase-common/src/main/java/org/apache/hadoop/hbase/ChoreService.java
index 091d8541388..5c3d2158538 100644
--- a/hbase-common/src/main/java/org/apache/hadoop/hbase/ChoreService.java
+++ b/hbase-common/src/main/java/org/apache/hadoop/hbase/ChoreService.java
@@ -317,7 +317,7 @@ public class ChoreService implements ChoreServicer {
    * in the middle of execution will be interrupted and shutdown. This service will be unusable
    * after this method has been called (i.e. future scheduling attempts will fail).
    */
-  public void shutdown() {
+  public synchronized void shutdown() {
     scheduler.shutdownNow();
     if (LOG.isInfoEnabled()) {
       LOG.info("Chore service for: " + coreThreadPoolPrefix + " had " + scheduledChores.keySet()