From cd80d08e50611b8b909fca8fb9734e738a08c252 Mon Sep 17 00:00:00 2001
From: John Zhao <yunjzhao@ebay.com>
Date: Mon, 14 Mar 2016 16:36:12 -0700
Subject: [PATCH] KYLIN-1493 make ExecutableManager.getInstance thread safe

---
 .../java/org/apache/kylin/job/manager/ExecutableManager.java  | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/core-job/src/main/java/org/apache/kylin/job/manager/ExecutableManager.java b/core-job/src/main/java/org/apache/kylin/job/manager/ExecutableManager.java
index 3effbe7..45e0521 100644
--- a/core-job/src/main/java/org/apache/kylin/job/manager/ExecutableManager.java
+++ b/core-job/src/main/java/org/apache/kylin/job/manager/ExecutableManager.java
@@ -58,12 +58,13 @@ public class ExecutableManager {
     public static ExecutableManager getInstance(KylinConfig config) {
         ExecutableManager r = CACHE.get(config);
         if (r == null) {
-            r = new ExecutableManager(config);
-            CACHE.put(config, r);
-            if (CACHE.size() > 1) {
-                logger.warn("More than one singleton exist");
+            synchronized (ExecutableManager.class) {
+                r = CACHE.get(config);
+                if (r == null) {
+                    r = new ExecutableManager(config);
+                    CACHE.put(config, r);
+                }
             }
-
         }
         return r;
     }
-- 
2.5.4 (Apple Git-61)