message: removed the mutex for single thread case
diff: @@ -1008,6 +1008,36 @@ BP4Serializer::DeserializeIndicesPerRankThreads(
  std::unordered_map<std::string, std::vector<SerialElementIndex>>
  deserialized;
  + auto lf_Deserialize_no_mutex = [&](const int rankSource,
  + const size_t serializedPosition,
  + const bool isRankConstant) {
  +
  + size_t localPosition = serializedPosition;
  + ElementIndexHeader header =
  + ReadElementIndexHeader(serialized, localPosition);
  +
  + if (isRankConstant)
  + {
  + if (deserialized.count(header.Name) == 1)
  + {
  + return;
  + }
  + }
  +
  + std::vector<BP4Base::SerialElementIndex> *deserializedIndexes;
  +
  + deserializedIndexes = &(deserialized.emplace(std::piecewise_construct,
  + std::forward_as_tuple(header.Name),
  + std::forward_as_tuple(
  + m_SizeMPI, SerialElementIndex(header.MemberID, 0))).first->second);
  +
  +
  + const size_t bufferSize = static_cast<size_t>(header.Length) + 4;
  + SerialElementIndex &index = deserializedIndexes->at(rankSource);
  + helper::InsertToBuffer(index.Buffer, &serialized[serializedPosition],
  + bufferSize);
  + };
  +
  auto lf_Deserialize = [&](const int rankSource,
  const size_t serializedPosition,
  const bool isRankConstant) {
  @@ -1065,7 +1095,7 @@ BP4Serializer::DeserializeIndicesPerRankThreads(
  if (serializedPosition <= serializedSize)
  {
  - lf_Deserialize(rankSource, serializedPosition, isRankConstant);
  + lf_Deserialize_no_mutex(rankSource, serializedPosition, isRankConstant);
  }
  const size_t bufferSize = static_cast<size_t>(
  