/usr/include/boost/mpi/collectives/all_gather.hpp is in libboost1.55-dev 1.55.0+dfsg-3.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | // Copyright (C) 2005-2006 Douglas Gregor <doug.gregor -at- gmail.com>.
// 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 4.7. Gather-to-all
#ifndef BOOST_MPI_ALL_GATHER_HPP
#define BOOST_MPI_ALL_GATHER_HPP
#include <boost/mpi/exception.hpp>
#include <boost/mpi/datatype.hpp>
#include <vector>
#include <boost/serialization/vector.hpp>
// all_gather falls back to gather+broadcast in some cases
#include <boost/mpi/collectives/broadcast.hpp>
#include <boost/mpi/collectives/gather.hpp>
namespace boost { namespace mpi {
namespace detail {
// We're all-gathering 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
all_gather_impl(const communicator& comm, const T* in_values, int n,
T* out_values, mpl::true_)
{
MPI_Datatype type = boost::mpi::get_mpi_datatype<T>(*in_values);
BOOST_MPI_CHECK_RESULT(MPI_Allgather,
(const_cast<T*>(in_values), n, type,
out_values, n, type, comm));
}
// We're all-gathering for a type that has no associated MPI
// type. So, we'll do a manual gather followed by a broadcast.
template<typename T>
void
all_gather_impl(const communicator& comm, const T* in_values, int n,
T* out_values, mpl::false_)
{
gather(comm, in_values, n, out_values, 0);
broadcast(comm, out_values, comm.size() * n, 0);
}
} // end namespace detail
template<typename T>
inline void
all_gather(const communicator& comm, const T& in_value, T* out_values)
{
detail::all_gather_impl(comm, &in_value, 1, out_values, is_mpi_datatype<T>());
}
template<typename T>
void
all_gather(const communicator& comm, const T& in_value,
std::vector<T>& out_values)
{
out_values.resize(comm.size());
::boost::mpi::all_gather(comm, &in_value, 1, &out_values[0]);
}
template<typename T>
inline void
all_gather(const communicator& comm, const T* in_values, int n, T* out_values)
{
detail::all_gather_impl(comm, in_values, n, out_values, is_mpi_datatype<T>());
}
template<typename T>
void
all_gather(const communicator& comm, const T* in_values, int n,
std::vector<T>& out_values)
{
out_values.resize(comm.size() * n);
::boost::mpi::all_gather(comm, in_values, n, &out_values[0]);
}
} } // end namespace boost::mpi
#endif // BOOST_MPI_ALL_GATHER_HPP
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