165 lines
5.8 KiB
Plaintext
165 lines
5.8 KiB
Plaintext
// Copyright (C) 2011 Júlio Hoffimann.
|
|
|
|
// 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. Gatherv
|
|
#ifndef BOOST_MPI_GATHERV_HPP
|
|
#define BOOST_MPI_GATHERV_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_Gatherv to do all of the work.
|
|
template<typename T>
|
|
void
|
|
gatherv_impl(const communicator& comm, const T* in_values, int in_size,
|
|
T* out_values, const int* sizes, const int* displs, int root, mpl::true_)
|
|
{
|
|
MPI_Datatype type = get_mpi_datatype<T>(*in_values);
|
|
BOOST_MPI_CHECK_RESULT(MPI_Gatherv,
|
|
(const_cast<T*>(in_values), in_size, type,
|
|
out_values, const_cast<int*>(sizes), const_cast<int*>(displs),
|
|
type, root, comm));
|
|
}
|
|
|
|
// We're gathering from a non-root for a type that has an associated MPI
|
|
// datatype, so we'll use MPI_Gatherv to do all of the work.
|
|
template<typename T>
|
|
void
|
|
gatherv_impl(const communicator& comm, const T* in_values, int in_size, int root,
|
|
mpl::true_)
|
|
{
|
|
MPI_Datatype type = get_mpi_datatype<T>(*in_values);
|
|
BOOST_MPI_CHECK_RESULT(MPI_Gatherv,
|
|
(const_cast<T*>(in_values), in_size, type,
|
|
0, 0, 0, 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_Gatherv, so
|
|
// we'll just have all of the non-root nodes send individual
|
|
// messages to the root.
|
|
template<typename T>
|
|
void
|
|
gatherv_impl(const communicator& comm, const T* in_values, int in_size,
|
|
T* out_values, const int* sizes, const int* displs, int root, mpl::false_)
|
|
{
|
|
int tag = environment::collectives_tag();
|
|
int nprocs = comm.size();
|
|
|
|
for (int src = 0; src < nprocs; ++src) {
|
|
if (src == root)
|
|
// Our own values will never be transmitted: just copy them.
|
|
std::copy(in_values, in_values + in_size, out_values + displs[src]);
|
|
else {
|
|
// comm.recv(src, tag, out_values + displs[src], sizes[src]);
|
|
// Receive archive
|
|
packed_iarchive ia(comm);
|
|
MPI_Status status;
|
|
detail::packed_archive_recv(comm, src, tag, ia, status);
|
|
for (int i = 0; i < sizes[src]; ++i)
|
|
ia >> out_values[ displs[src] + i ];
|
|
}
|
|
}
|
|
}
|
|
|
|
// 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_Gatherv, so
|
|
// we'll just have all of the non-root nodes send individual
|
|
// messages to the root.
|
|
template<typename T>
|
|
void
|
|
gatherv_impl(const communicator& comm, const T* in_values, int in_size, int root,
|
|
mpl::false_)
|
|
{
|
|
int tag = environment::collectives_tag();
|
|
// comm.send(root, tag, in_values, in_size);
|
|
packed_oarchive oa(comm);
|
|
for (int i = 0; i < in_size; ++i)
|
|
oa << in_values[i];
|
|
detail::packed_archive_send(comm, root, tag, oa);
|
|
}
|
|
} // end namespace detail
|
|
|
|
template<typename T>
|
|
void
|
|
gatherv(const communicator& comm, const T* in_values, int in_size,
|
|
T* out_values, const std::vector<int>& sizes, const std::vector<int>& displs,
|
|
int root)
|
|
{
|
|
if (comm.rank() == root)
|
|
detail::gatherv_impl(comm, in_values, in_size,
|
|
out_values, &sizes[0], &displs[0],
|
|
root, is_mpi_datatype<T>());
|
|
else
|
|
detail::gatherv_impl(comm, in_values, in_size, root, is_mpi_datatype<T>());
|
|
}
|
|
|
|
template<typename T>
|
|
void
|
|
gatherv(const communicator& comm, const std::vector<T>& in_values,
|
|
T* out_values, const std::vector<int>& sizes, const std::vector<int>& displs,
|
|
int root)
|
|
{
|
|
::boost::mpi::gatherv(comm, &in_values[0], in_values.size(), out_values, sizes, displs, root);
|
|
}
|
|
|
|
template<typename T>
|
|
void gatherv(const communicator& comm, const T* in_values, int in_size, int root)
|
|
{
|
|
BOOST_ASSERT(comm.rank() != root);
|
|
detail::gatherv_impl(comm, in_values, in_size, root, is_mpi_datatype<T>());
|
|
}
|
|
|
|
template<typename T>
|
|
void gatherv(const communicator& comm, const std::vector<T>& in_values, int root)
|
|
{
|
|
BOOST_ASSERT(comm.rank() != root);
|
|
detail::gatherv_impl(comm, &in_values[0], in_values.size(), root, is_mpi_datatype<T>());
|
|
}
|
|
|
|
///////////////////////
|
|
// common use versions
|
|
///////////////////////
|
|
template<typename T>
|
|
void
|
|
gatherv(const communicator& comm, const T* in_values, int in_size,
|
|
T* out_values, const std::vector<int>& sizes, int root)
|
|
{
|
|
int nprocs = comm.size();
|
|
|
|
std::vector<int> displs( nprocs );
|
|
for (int rank = 0, aux = 0; rank < nprocs; ++rank) {
|
|
displs[rank] = aux;
|
|
aux += sizes[rank];
|
|
}
|
|
::boost::mpi::gatherv(comm, in_values, in_size, out_values, sizes, displs, root);
|
|
}
|
|
|
|
template<typename T>
|
|
void
|
|
gatherv(const communicator& comm, const std::vector<T>& in_values,
|
|
T* out_values, const std::vector<int>& sizes, int root)
|
|
{
|
|
::boost::mpi::gatherv(comm, &in_values[0], in_values.size(), out_values, sizes, root);
|
|
}
|
|
|
|
} } // end namespace boost::mpi
|
|
|
|
#endif // BOOST_MPI_GATHERV_HPP
|