From 1f8b98550da902c880d85afbafc4ce08e88831bc Mon Sep 17 00:00:00 2001
From: John Blum <jblum@pivotal.io>
Date: Wed, 23 May 2018 20:00:52 -0700
Subject: [PATCH] Add synchronizaton block surrounding the
 TimeUnit.timedWait(..) invocation inside getResult(duration:long, :TimeUnit).

---
 .../gemfire/function/execution/AbstractResultCollector.java | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/geode-spring-boot-starter/src/main/java/org/springframework/data/gemfire/function/execution/AbstractResultCollector.java b/geode-spring-boot-starter/src/main/java/org/springframework/data/gemfire/function/execution/AbstractResultCollector.java
index 263251aa..8b300031 100644
--- a/geode-spring-boot-starter/src/main/java/org/springframework/data/gemfire/function/execution/AbstractResultCollector.java
+++ b/geode-spring-boot-starter/src/main/java/org/springframework/data/gemfire/function/execution/AbstractResultCollector.java
@@ -33,6 +33,8 @@ import org.apache.geode.cache.execute.ResultCollector;
 @SuppressWarnings("unused")
 public abstract class AbstractResultCollector<T, S> implements ResultCollector<T, S> {
 
+	private static final Object MUTEX = new Object();
+
 	protected static final String NOT_IMPLEMENTED = "Not Implemented";
 
 	protected static final TimeUnit DEFAULT_TIME_UNIT = TimeUnit.MILLISECONDS;
@@ -57,7 +59,9 @@ public abstract class AbstractResultCollector<T, S> implements ResultCollector<T
 			Math.min(durationInMilliseconds / 5, durationInMilliseconds));
 
 		while (getResult() == null && System.currentTimeMillis() < timeout) {
-			unit.timedWait(this, waitInMilliseconds);
+			synchronized (MUTEX) {
+				unit.timedWait(MUTEX, waitInMilliseconds);
+			}
 		}
 
 		return getResult();