Re: [Boost-users] [mpi] irecv / send problem

Subject: Re: [Boost-users] [mpi] irecv / send problem
From: Nick Collier (nick.collier_at_[hidden])
Date: 2009-06-15 16:24:38

The first bit of code is the C example. My translation into boost::mpi  
follows it. It keeps the same irecv / send pattern but incorporates  
serialization etc.

Nick

On Jun 15, 2009, at 4:04 PM, Brian Wood wrote:

> Nick Collier writes:
> > Hmm, I think it should work. Thanks though. The example I posted was
> > modified from:
> > http://ci-tutor.ncsa.illinois.edu/content.php?cid=1137
>
> > Namely,
>
> > /* deadlock avoided */
> > #include <stdio.h>
> > #include <mpi.h>
>
> > void main (int argc, char **argv) {
>
> > int myrank;
> > MPI_Request request;
> > MPI_Status status;
> > double a[100], b[100];
>
> > MPI_Init(&argc, &argv);  /* Initialize MPI */
> > MPI_Comm_rank(MPI_COMM_WORLD, &myrank); /* Get rank */
> > if( myrank == 0 ) {
> >   /* Post a receive, send a message, then wait */
> >   MPI_Irecv( b, 100, MPI_DOUBLE, 1, 19, MPI_COMM_WORLD, &request );
> >   MPI_Send( a, 100, MPI_DOUBLE, 1, 17, MPI_COMM_WORLD );
> >   MPI_Wait( &request, &status );
> >  }
> >  else if( myrank == 1 ) {
> >   /* Post a receive, send a message, then wait */
> >   MPI_Irecv( b, 100, MPI_DOUBLE, 0, 17, MPI_COMM_WORLD, &request );
> >   MPI_Send( a, 100, MPI_DOUBLE, 0, 19, MPI_COMM_WORLD );
> >   MPI_Wait( &request, &status );
> >  }
>
> > MPI_Finalize();          /* Terminate MPI */
>
> > }
> >
>
> I am not sure why MPI was added to Boost.  Recently there was an
> effort to get Boost libs ready for the next C++ standard.  I don't  
> think
> the MPI library was considered in that as it's ties to C are so  
> strong.
> Having to specify MPI_DOUBLE above when a and b are both declared
> of type double is sad.  Naming it "Message Passing Interface" when
> you are restricted to messages of a single type is hardly an apt name.
> If it's going to be in Boost, it may wind up being called the Most  
> Pitiful
> Interface.
>
> -- 
> Brian Wood
> Ebenezer Enterprises
> www.webEbenezer.net
>
> "The New Deal and Great Society entrenched a welfare mentality in
> [the US].  The idea of the federal government as the great provider
> has even moved to the level of corporate America, with business
> 'leaders' flying to Washington in private jets to beg Congress for
> handouts to keep their companies afloat."    Bill Ragle
>
>
> _______________________________________________
> Boost-users mailing list
> Boost-users_at_[hidden]
> http://lists.boost.org/mailman/listinfo.cgi/boost-users