HDFS-4035. LightWeightGSet and LightWeightHashSet increment a volatile without synchronization. Contributed by Eli Collins

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1430595 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -467,6 +467,9 @@ Release 2.0.3-alpha - Unreleased
 
     HDFS-4034. Remove redundant null checks. (eli)
 
+    HDFS-4035. LightWeightGSet and LightWeightHashSet increment a
+    volatile without synchronization. (eli)
+
   OPTIMIZATIONS
 
   BUG FIXES

hadoop-hdfs-project/hadoop-hdfs/dev-support/findbugsExcludeFile.xml

@@ -308,4 +308,20 @@
        <Field name="pendingReceivedRequests" />
        <Bug pattern="VO_VOLATILE_INCREMENT" />
      </Match>
+     <!-- The "LightWeight" classes are explicitly not thread safe -->
+     <Match>
+       <Class name="org.apache.hadoop.hdfs.util.LightWeightGSet" />
+       <Field name="modification" />
+       <Bug pattern="VO_VOLATILE_INCREMENT" />
+     </Match>
+     <Match>
+       <Class name="org.apache.hadoop.hdfs.util.LightWeightHashSet" />
+       <Field name="modification" />
+       <Bug pattern="VO_VOLATILE_INCREMENT" />
+     </Match>
+     <Match>
+       <Class name="org.apache.hadoop.hdfs.util.LightWeightLinkedSet" />
+       <Field name="modification" />
+       <Bug pattern="VO_VOLATILE_INCREMENT" />
+     </Match>
  </FindBugsFilter>