YARN-4298. Fix findbugs warnings in hadoop-yarn-common. Contributed by Sunil G.

hadoop-yarn-project/CHANGES.txt

@@ -1061,6 +1061,9 @@ Release 2.8.0 - UNRELEASED
 
     YARN-4367. SLS webapp doesn't load. (kasha).
 
+    YARN-4298. Fix findbugs warnings in hadoop-yarn-common.
+    (Sunil G via aajisaka)
+
 Release 2.7.3 - UNRELEASED
 
   INCOMPATIBLE CHANGES

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-common/src/main/java/org/apache/hadoop/yarn/api/protocolrecords/impl/pb/AllocateResponsePBImpl.java

@@ -386,7 +386,7 @@ public class AllocateResponsePBImpl extends AllocateResponse {
   }
 
   @Override
-  public Priority getApplicationPriority() {
+  public synchronized Priority getApplicationPriority() {
     AllocateResponseProtoOrBuilder p = viaProto ? proto : builder;
     if (this.appPriority != null) {
       return this.appPriority;
@@ -399,7 +399,7 @@ public class AllocateResponsePBImpl extends AllocateResponse {
   }
 
   @Override
-  public void setApplicationPriority(Priority priority) {
+  public synchronized void setApplicationPriority(Priority priority) {
     maybeInitBuilder();
     if (priority == null)
       builder.clearApplicationPriority();