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authorDongHun Kwak <dh0128.kwak@samsung.com>2019-12-05 15:12:59 +0900
committerDongHun Kwak <dh0128.kwak@samsung.com>2019-12-05 15:12:59 +0900
commitb8cf34c691623e4ec329053cbbf68522a855882d (patch)
tree34da08632a99677f6b79ecb65e5b655a5b69a67f /boost/mpi/collectives/all_gather.hpp
parent3fdc3e5ee96dca5b11d1694975a65200787eab86 (diff)
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Imported Upstream version 1.67.0upstream/1.67.0
Diffstat (limited to 'boost/mpi/collectives/all_gather.hpp')
-rw-r--r--boost/mpi/collectives/all_gather.hpp131
1 files changed, 93 insertions, 38 deletions
diff --git a/boost/mpi/collectives/all_gather.hpp b/boost/mpi/collectives/all_gather.hpp
index da73186c64..4adaeb9c87 100644
--- a/boost/mpi/collectives/all_gather.hpp
+++ b/boost/mpi/collectives/all_gather.hpp
@@ -1,52 +1,107 @@
-// Copyright (C) 2005-2006 Douglas Gregor <doug.gregor -at- gmail.com>.
+// 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 4.7. Gather-to-all
-#ifndef BOOST_MPI_ALL_GATHER_HPP
-#define BOOST_MPI_ALL_GATHER_HPP
+// Message Passing Interface 1.1 -- Section 4.5. Gather
+#ifndef BOOST_MPI_ALLGATHER_HPP
+#define BOOST_MPI_ALLGATHER_HPP
+#include <cassert>
+#include <cstddef>
+#include <numeric>
#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>
+#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/mpi/detail/offsets.hpp>
+#include <boost/mpi/detail/antiques.hpp>
+#include <boost/assert.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 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 = 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);
+// We're all-gathering for a type that does not have an
+// associated MPI datatype, so we'll need to serialize
+// it.
+template<typename T>
+void
+all_gather_impl(const communicator& comm, const T* in_values, int n,
+ T* out_values, int const* sizes, int const* skips, mpl::false_)
+{
+ int nproc = comm.size();
+ // first, gather all size, these size can be different for
+ // each process
+ packed_oarchive oa(comm);
+ for (int i = 0; i < n; ++i) {
+ oa << in_values[i];
}
+ std::vector<int> oasizes(nproc);
+ int oasize = oa.size();
+ BOOST_MPI_CHECK_RESULT(MPI_Allgather,
+ (&oasize, 1, MPI_INTEGER,
+ c_data(oasizes), 1, MPI_INTEGER,
+ MPI_Comm(comm)));
+ // Gather the archives, which can be of different sizes, so
+ // we need to use allgatherv.
+ // Every thing is contiguous, so the offsets can be
+ // deduced from the collected sizes.
+ std::vector<int> offsets(nproc);
+ sizes2offsets(oasizes, offsets);
+ packed_iarchive::buffer_type recv_buffer(std::accumulate(oasizes.begin(), oasizes.end(), 0));
+ BOOST_MPI_CHECK_RESULT(MPI_Allgatherv,
+ (const_cast<void*>(oa.address()), int(oa.size()), MPI_BYTE,
+ c_data(recv_buffer), c_data(oasizes), c_data(offsets), MPI_BYTE,
+ MPI_Comm(comm)));
+ for (int src = 0; src < nproc; ++src) {
+ int nb = sizes ? sizes[src] : n;
+ int skip = skips ? skips[src] : 0;
+ std::advance(out_values, skip);
+ if (src == comm.rank()) { // this is our local data
+ for (int i = 0; i < nb; ++i) {
+ *out_values++ = *in_values++;
+ }
+ } else {
+ packed_iarchive ia(comm, recv_buffer, boost::archive::no_header, offsets[src]);
+ for (int i = 0; i < nb; ++i) {
+ ia >> *out_values++;
+ }
+ }
+ }
+}
+
+// We're all-gathering for a type that does not have an
+// associated MPI datatype, so we'll need to serialize
+// it.
+template<typename T>
+void
+all_gather_impl(const communicator& comm, const T* in_values, int n,
+ T* out_values, mpl::false_ isnt_mpi_type)
+{
+ all_gather_impl(comm, in_values, n, out_values, (int const*)0, (int const*)0, isnt_mpi_type);
+}
} // end namespace detail
template<typename T>
-inline void
+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>());
@@ -54,15 +109,15 @@ all_gather(const communicator& comm, const T& in_value, T* out_values)
template<typename T>
void
-all_gather(const communicator& comm, const T& in_value,
- std::vector<T>& out_values)
+all_gather(const communicator& comm, const T& in_value, std::vector<T>& out_values)
{
+ using detail::c_data;
out_values.resize(comm.size());
- ::boost::mpi::all_gather(comm, &in_value, 1, &out_values[0]);
+ ::boost::mpi::all_gather(comm, in_value, c_data(out_values));
}
template<typename T>
-inline void
+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>());
@@ -70,11 +125,11 @@ all_gather(const communicator& comm, const T* in_values, int n, T* out_values)
template<typename T>
void
-all_gather(const communicator& comm, const T* in_values, int n,
- std::vector<T>& out_values)
+all_gather(const communicator& comm, const T* in_values, int n, std::vector<T>& out_values)
{
+ using detail::c_data;
out_values.resize(comm.size() * n);
- ::boost::mpi::all_gather(comm, in_values, n, &out_values[0]);
+ ::boost::mpi::all_gather(comm, in_values, n, c_data(out_values));
}
} } // end namespace boost::mpi