Open MPI logo

Open MPI User's Mailing List Archives

  |   Home   |   Support   |   FAQ   |   all Open MPI User's mailing list

Subject: [OMPI users] MPI_Bsend vs. MPI_Ibsend
From: Jovana Knezevic (jovana.knezevic.83_at_[hidden])
Date: 2010-05-06 04:43:43

Dear all,

Could anyone please clarify me the difference between MPI_Bsend and
MPI_Ibsend? Or, in other words, what exactly is "blocking" in
MPI_Bsend, when the data is stored in the buffer and we "return"? :-)
Another, but similar, question:

What about the data-buffer - when can it be reused in each of the
cases - simple examples:

for (i=0; i<NUMBER_OF_SLAVES; i++) {

MPI_Bsend (&data_buffer[0], ..., slave_id1...);

} // Can any problem occur here, since we send the data_buffer several times?

for (i=0; i<NUMBER_OF_SLAVES; i++) {

MPI_Ibsend (&data_buffer[0], ..., slave[i]..., &request);

} // Any difference to previous example? Concerning the re-use of data_buffer?

Thank you a lot in advance.