I believe I found a bug in IntelMPI 2021.3. A call to MPI_Comm_free() does not cause the deleter function for attributes to be called if there is a non-blocking operation in progress. The MPI 3.1 standard specifies that the deleter should be called from MPI_Comm_free (Section 6.4.3, page 248, lines 26-27).
I tested OpenMPI 4.0, MPICH 3.2, and IntelMPI 2018.4, and they all call the deleter as expected.
I have a minimal reproducible example, but my post gets flagged as spam if I include it. Is there some other way to post it?
Thank you for posting in Intel Communities.
Since this is a duplicate thread of "https://community.intel.com/t5/Intel-oneAPI-HPC-Toolkit/Bug-Report-MPI-Comm-attribute-deleter-not-ca...", we will no longer monitor this thread. We will continue addressing this issue in the other thread.
Thanks & Regards,