47 lines
1.3 KiB
C++
47 lines
1.3 KiB
C++
// Copyright (C) 2013 Andreas Hehn <hehn@phys.ethz.ch>, ETH Zurich
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// based on
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// hellp-world_broadcast.cpp (C) 2006 Douglas Gregor <doug.gregor@gmail.com>
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// Use, modification and distribution is subject to the Boost Software
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// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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// A simple Hello world! example
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// using boost::mpi::group and boost::mpi::broadcast()
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#include <stdexcept>
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#include <boost/mpi/environment.hpp>
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#include <boost/mpi/communicator.hpp>
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#include <boost/mpi/group.hpp>
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#include <boost/mpi/collectives.hpp>
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#include <boost/serialization/string.hpp>
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namespace mpi = boost::mpi;
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int main(int argc, char* argv[])
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{
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mpi::environment env(argc, argv);
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mpi::communicator world;
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if(world.size() < 2)
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throw std::runtime_error("Please run with at least 2 MPI processes!");
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int group_a_ranks[2] = {0,1};
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mpi::group world_group = world.group();
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mpi::group group_a = world_group.include(group_a_ranks,group_a_ranks+2);
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mpi::communicator comm_a(world,group_a);
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std::string value("Hello world!");
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if(comm_a)
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{
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if(comm_a.rank() == 0) {
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value = "Hello group a!";
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}
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mpi::broadcast(comm_a, value, 0);
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}
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std::cout << "Process #" << world.rank() << " says " << value << std::endl;
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return 0;
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}
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