Fix synchronization in LocalCheckpointTracker#contains (#38755)

We are accessing the `CountedBitSet` in `LocalCheckpointTracker#contains` without proper synchronization. Relates #33871
elastic · Feb 12, 2019 · eca5404 · eca5404
1 parent 225ebb6
commit eca5404
Showing 1 changed file with 3 additions and 3 deletions.
diff --git a/server/src/main/java/org/elasticsearch/index/seqno/LocalCheckpointTracker.java b/server/src/main/java/org/elasticsearch/index/seqno/LocalCheckpointTracker.java
@@ -157,11 +157,11 @@ public boolean contains(final long seqNo) {
             return true;
         }
         final long bitSetKey = getBitSetKey(seqNo);
-        final CountedBitSet bitSet;
+        final int bitSetOffset = seqNoToBitSetOffset(seqNo);
         synchronized (this) {
-            bitSet = processedSeqNo.get(bitSetKey);
+            final CountedBitSet bitSet = processedSeqNo.get(bitSetKey);
+            return bitSet != null && bitSet.get(bitSetOffset);
         }
-        return bitSet != null && bitSet.get(seqNoToBitSetOffset(seqNo));
     }
 
     /**