HDF5 1.8.12 thread-safe option

Would you comment on Thread-safety option of an application compiled with HDF5 1.8.12 library
and executed on CentOS Linux release 7.2

  1. An application is running 2 threads: Thread-1 and Thread-2
  2. The application stores content in a single HDF5 file
  3. Thread-1 opens HDF5 file (H5Fopen) and notifies Thread-2 on HDF5 file opening
  4. Thread-1 opens HDF5 Group-A (H5Gopen) with a H5PT Packet Table element to store and retrieve content (H5PTread_packets, H5PTappend)
  5. Thread-2 opens HDF5 Group-B (H5Gopen) with another H5PT Packet Table element to store and retrieve content (H5PTread_packets, H5PTappend)

Would you expect to implement the thread synchronization for HDF5 content read/write operations?
Would you address HDF5 race condition concern?

Thank you,

Leon