ceph/src/boost/libs/mpi/example/cartesian_communicator.cpp

   1 //          Copyright Alain Miniussi 2014.
   2 // Distributed under the Boost Software License, Version 1.0.
   3 //    (See accompanying file LICENSE_1_0.txt or copy at
   4 //          http://www.boost.org/LICENSE_1_0.txt)
   5
   6 // Authors: Alain Miniussi
   7
   8 #include <vector>
   9 #include <iostream>
  10
  11 #include <boost/mpi/communicator.hpp>
  12 #include <boost/mpi/collectives.hpp>
  13 #include <boost/mpi/environment.hpp>
  14 #include <boost/mpi/cartesian_communicator.hpp>
  15
  16 namespace mpi = boost::mpi;
  17 // Curly brace init make this useless, but
  18 //  - Need to support obsolete like g++ 4.3.x. for some reason
  19 //  - Can't conditionnaly compile with bjam (unless you find
  20 //  the doc, and read it, which would only make sense if you
  21 //  actually wan't to use bjam, which does not (make sense))
  22 typedef mpi::cartesian_dimension cd;
  23
  24 int main(int argc, char* argv[])
  25 {
  26   mpi::environment  env;
  27   mpi::communicator world;
  28
  29   if (world.size() != 24)  return -1;
  30   mpi::cartesian_dimension dims[] = {cd(2, true), cd(3,true), cd(4,true)};
  31   mpi::cartesian_communicator cart(world, mpi::cartesian_topology(dims));
  32   for (int r = 0; r < cart.size(); ++r) {
  33     cart.barrier();
  34     if (r == cart.rank()) {
  35       std::vector<int> c = cart.coordinates(r);
  36       std::cout << "rk :" << r << " coords: "
  37                 << c[0] << ' ' << c[1] << ' ' << c[2] << '\n';
  38     }
  39   }
  40   return 0;
  41 }
  42