Hybrid OpenMP+MPI: How to synchronize access to MPI shared RMA window by multiple OpenMP threads ?

Dear Collegues,

I've developed parallel code that implements both OpenMP + MPI hybrid parallelization and allocates a shared RMA window by calling MPI_Win_allocate_shared function to store the data shared among multiple OpenMP threads executed withing several MPI processes.

Is there any chance to synchronize access to the shared RMA window by the number of OpenMP threads executed within multiple MPI processes.?

Is there any pattern for hybrid OpenMP + MPI programming ?

Thanks for your replies in advance.

Cheers, Arthur.