OPENDJ-2335: prevent JE index corruption due to phantom reads

Matthew Swift

27.12.2015 2af7525dc754ba78d7dc21d059d7c0b30b97ece9

 opendj-server-legacy/src/main/java/org/opends/server/backends/jeb/JEStorage.java

@@ -464,24 +464,33 @@
    {
      try
      {
        Database tree = getOrOpenTree(treeName);
        DatabaseEntry dbKey = db(key);
        DatabaseEntry dbValue = new DatabaseEntry();

        boolean isDefined = tree.get(txn, dbKey, dbValue, RMW) == SUCCESS;
        final ByteSequence oldValue = valueToBytes(dbValue, isDefined);
        final ByteSequence newValue = f.computeNewValue(oldValue);
        if (!Objects.equals(newValue, oldValue))
        final Database tree = getOrOpenTree(treeName);
        final DatabaseEntry dbKey = db(key);
        final DatabaseEntry dbValue = new DatabaseEntry();
        for (;;)
        {
          final boolean isDefined = tree.get(txn, dbKey, dbValue, RMW) == SUCCESS;
          final ByteSequence oldValue = valueToBytes(dbValue, isDefined);
          final ByteSequence newValue = f.computeNewValue(oldValue);
          if (Objects.equals(newValue, oldValue))
          {
            return false;
          }
          if (newValue == null)
          {
            return tree.delete(txn, dbKey) == SUCCESS;
          }

          setData(dbValue, newValue);
          return tree.put(txn, dbKey, dbValue) == SUCCESS;
          if (isDefined)
          {
            return tree.put(txn, dbKey, dbValue) == SUCCESS;
          }
          else if (tree.putNoOverwrite(txn, dbKey, dbValue) == SUCCESS)
          {
            return true;
          }
          // else retry due to phantom read: another thread inserted a record
        }
        return false;
      }
      catch (DatabaseException e)
      {