ceph/src/boost/libs/numeric/odeint/include/boost/numeric/odeint/external/mpi/mpi_vector_state.hpp

   1 /*
   2  [auto_generated]
   3  boost/numeric/odeint/external/mpi/mpi_vector_state.hpp
   4
   5  [begin_description]
   6  Copying a container from/to an mpi_state splits/joins it.
   7  [end_description]
   8
   9  Copyright 2013 Karsten Ahnert
  10  Copyright 2013 Mario Mulansky
  11  Copyright 2013 Pascal Germroth
  12
  13  Distributed under the Boost Software License, Version 1.0.
  14  (See accompanying file LICENSE_1_0.txt or
  15  copy at http://www.boost.org/LICENSE_1_0.txt)
  16  */
  17
  18
  19 #ifndef BOOST_NUMERIC_ODEINT_EXTERNAL_MPI_MPI_VECTOR_STATE_HPP_INCLUDED
  20 #define BOOST_NUMERIC_ODEINT_EXTERNAL_MPI_MPI_VECTOR_STATE_HPP_INCLUDED
  21
  22 #include <vector>
  23 #include <algorithm>
  24 #include <boost/mpi.hpp>
  25 #include <boost/numeric/odeint/util/copy.hpp>
  26 #include <boost/numeric/odeint/util/split_adaptor.hpp>
  27 #include <boost/numeric/odeint/algebra/algebra_dispatcher.hpp>
  28 #include <boost/numeric/odeint/external/mpi/mpi_state.hpp>
  29
  30 namespace boost {
  31 namespace numeric {
  32 namespace odeint {
  33
  34
  35 /** \brief Split data from some container on node 0 to the slaves.
  36  * Source must be a model of Random Access Range. */
  37 template< class Source , class InnerState >
  38 struct split_impl< Source, mpi_state< InnerState >,
  39     typename boost::enable_if< boost::has_range_const_iterator<Source> >::type >
  40 {
  41     typedef typename boost::range_iterator<const Source>::type iterator;
  42
  43     static void split( const Source &from, mpi_state< InnerState > &to )
  44     {
  45         std::vector< InnerState > pieces;
  46         if(to.world.rank() == 0) {
  47             const size_t num = static_cast<size_t>(to.world.size());
  48             pieces.resize(num);
  49             for(size_t i = 0 ; i < num ; i++) {
  50                 iterator_range<iterator> part = detail::make_split_range(from, i, num);
  51                 boost::numeric::odeint::resize(pieces[i], part);
  52                 boost::numeric::odeint::copy(part, pieces[i]);
  53             }
  54         }
  55         // send to nodes
  56         boost::mpi::scatter(to.world, pieces, to(), 0);
  57     }
  58 };
  59
  60 /** \brief Merge data from an mpi_state to some container on node 0.
  61  * Target must be a model Single Pass Range. */
  62 template< class Target, class InnerState >
  63 struct unsplit_impl< mpi_state< InnerState >, Target,
  64     typename boost::enable_if< boost::has_range_iterator<Target> >::type >
  65 {
  66     typedef typename boost::range_iterator<Target>::type iterator;
  67
  68     static void unsplit( const mpi_state< InnerState > &from , Target &to )
  69     {
  70         std::vector< InnerState > pieces;
  71         // send data to root
  72         boost::mpi::gather(from.world, from(), pieces, 0);
  73         if(from.world.rank() == 0) {
  74             // check target size
  75             size_t total_size = 0;
  76             for(size_t i = 0 ; i < pieces.size() ; i++)
  77                 total_size += boost::size(pieces[i]);
  78             BOOST_ASSERT( total_size <= boost::size(to) );
  79             // copy parts
  80             iterator out = boost::begin(to);
  81             for(size_t i = 0 ; i < pieces.size() ; i++)
  82                 out = boost::copy(pieces[i], out);
  83         }
  84     }
  85 };
  86
  87
  88 }
  89 }
  90 }
  91
  92
  93 #endif
  94