Re: [Boost-users] mpi isend to group

Subject: Re: [Boost-users] mpi isend to group
From: Riccardo Murri (riccardo.murri_at_[hidden])
Date: 2012-12-28 15:57:27

On Thu, Dec 27, 2012 at 3:15 PM, Philipp Kraus
<philipp.kraus_at_[hidden]> wrote:
> Is there a way to create a non-blocking group communication? How can I send if data exists, a message
> to all nodes and receive it on each node also with non-blocking communication?

I'm afraid there's no non-blocking collective communication primitive
in MPI 2.  Hence, no such feature in Boost.MPI.

The "broadcast" collective apparently is the closest match to your
requirements, except that it's blocking:

http://www.boost.org/doc/libs/1_52_0/doc/html/boost/mpi/broadcast.html

Use of `broadcast` would imply that your code sends an id value even
when there is nothing to send.  Another option would be to write your
own "ibroadcast" on top of isend/irecv, e.g., rank n sends the id
value to ranks 2n and 2n+1.

Cheers,
Riccardo