/usr/include/boost/mpi/collectives/gather.hpp is in libboost1.46-dev 1.46.1-7ubuntu3.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 | // Copyright (C) 2005, 2006 Douglas Gregor.
// Use, modification and distribution is subject to the Boost Software
// License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
// Message Passing Interface 1.1 -- Section 4.5. Gather
#ifndef BOOST_MPI_GATHER_HPP
#define BOOST_MPI_GATHER_HPP
#include <boost/mpi/exception.hpp>
#include <boost/mpi/datatype.hpp>
#include <vector>
#include <boost/mpi/packed_oarchive.hpp>
#include <boost/mpi/packed_iarchive.hpp>
#include <boost/mpi/detail/point_to_point.hpp>
#include <boost/mpi/communicator.hpp>
#include <boost/mpi/environment.hpp>
#include <boost/assert.hpp>
namespace boost { namespace mpi {
namespace detail {
// We're gathering at the root for a type that has an associated MPI
// datatype, so we'll use MPI_Gather to do all of the work.
template<typename T>
void
gather_impl(const communicator& comm, const T* in_values, int n,
T* out_values, int root, mpl::true_)
{
MPI_Datatype type = get_mpi_datatype<T>(*in_values);
BOOST_MPI_CHECK_RESULT(MPI_Gather,
(const_cast<T*>(in_values), n, type,
out_values, n, type, root, comm));
}
// We're gathering from a non-root for a type that has an associated MPI
// datatype, so we'll use MPI_Gather to do all of the work.
template<typename T>
void
gather_impl(const communicator& comm, const T* in_values, int n, int root,
mpl::true_)
{
MPI_Datatype type = get_mpi_datatype<T>(*in_values);
BOOST_MPI_CHECK_RESULT(MPI_Gather,
(const_cast<T*>(in_values), n, type,
0, n, type, root, comm));
}
// We're gathering at the root for a type that does not have an
// associated MPI datatype, so we'll need to serialize
// it. Unfortunately, this means that we cannot use MPI_Gather, so
// we'll just have all of the non-root nodes send individual
// messages to the root.
template<typename T>
void
gather_impl(const communicator& comm, const T* in_values, int n,
T* out_values, int root, mpl::false_)
{
int tag = environment::collectives_tag();
int size = comm.size();
for (int src = 0; src < size; ++src) {
if (src == root)
std::copy(in_values, in_values + n, out_values + n * src);
else
comm.recv(src, tag, out_values + n * src, n);
}
}
// We're gathering at a non-root for a type that does not have an
// associated MPI datatype, so we'll need to serialize
// it. Unfortunately, this means that we cannot use MPI_Gather, so
// we'll just have all of the non-root nodes send individual
// messages to the root.
template<typename T>
void
gather_impl(const communicator& comm, const T* in_values, int n, int root,
mpl::false_)
{
int tag = environment::collectives_tag();
comm.send(root, tag, in_values, n);
}
} // end namespace detail
template<typename T>
void
gather(const communicator& comm, const T& in_value, T* out_values, int root)
{
if (comm.rank() == root)
detail::gather_impl(comm, &in_value, 1, out_values, root,
is_mpi_datatype<T>());
else
detail::gather_impl(comm, &in_value, 1, root, is_mpi_datatype<T>());
}
template<typename T>
void gather(const communicator& comm, const T& in_value, int root)
{
BOOST_ASSERT(comm.rank() != root);
detail::gather_impl(comm, &in_value, 1, root, is_mpi_datatype<T>());
}
template<typename T>
void
gather(const communicator& comm, const T& in_value, std::vector<T>& out_values,
int root)
{
if (comm.rank() == root) {
out_values.resize(comm.size());
::boost::mpi::gather(comm, in_value, &out_values[0], root);
} else {
::boost::mpi::gather(comm, in_value, root);
}
}
template<typename T>
void
gather(const communicator& comm, const T* in_values, int n, T* out_values,
int root)
{
if (comm.rank() == root)
detail::gather_impl(comm, in_values, n, out_values, root,
is_mpi_datatype<T>());
else
detail::gather_impl(comm, in_values, n, root, is_mpi_datatype<T>());
}
template<typename T>
void
gather(const communicator& comm, const T* in_values, int n,
std::vector<T>& out_values, int root)
{
::boost::mpi::gather(comm, in_values, n, &out_values[0], root);
}
template<typename T>
void gather(const communicator& comm, const T* in_values, int n, int root)
{
BOOST_ASSERT(comm.rank() != root);
detail::gather_impl(comm, in_values, n, root, is_mpi_datatype<T>());
}
} } // end namespace boost::mpi
#endif // BOOST_MPI_GATHER_HPP
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