1 // Copyright (C) 2006 Douglas Gregor <doug.gregor@gmail.com>
2 
3 // Use, modification and distribution is subject to the Boost Software
4 // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
5 // http://www.boost.org/LICENSE_1_0.txt)
6 
7 // A simple Hello, world! example using Boost.MPI message passing.
8 
9 #include <boost/mpi.hpp>
10 #include <iostream>
11 #include <boost/serialization/string.hpp> // Needed to send/receive strings!
12 namespace mpi = boost::mpi;
13 
main(int argc,char * argv[])14 int main(int argc, char* argv[])
15 {
16   mpi::environment env(argc, argv);
17   mpi::communicator world;
18 
19   if (world.rank() == 0) {
20     mpi::request reqs[2];
21     std::string msg, out_msg = "Hello";
22     reqs[0] = world.isend(1, 0, out_msg);
23     reqs[1] = world.irecv(1, 1, msg);
24     mpi::wait_all(reqs, reqs + 2);
25     std::cout << msg << "!" << std::endl;
26   } else {
27     mpi::request reqs[2];
28     std::string msg, out_msg = "world";
29     reqs[0] = world.isend(0, 1, out_msg);
30     reqs[1] = world.irecv(0, 0, msg);
31     mpi::wait_all(reqs, reqs + 2);
32     std::cout << msg << ", ";
33   }
34 
35   return 0;
36 }
37