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1 | // Copyright (C) 2011 Júlio Hoffimann. |
2 | ||
3 | // Use, modification and distribution is subject to the Boost Software | |
4 | // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at | |
5 | // http://www.boost.org/LICENSE_1_0.txt) | |
6 | ||
7 | // Message Passing Interface 1.1 -- Section 4.5. Gatherv | |
8 | #ifndef BOOST_MPI_GATHERV_HPP | |
9 | #define BOOST_MPI_GATHERV_HPP | |
10 | ||
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11 | #include <vector> |
12 | ||
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13 | #include <boost/mpi/exception.hpp> |
14 | #include <boost/mpi/datatype.hpp> | |
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15 | #include <boost/mpi/packed_oarchive.hpp> |
16 | #include <boost/mpi/packed_iarchive.hpp> | |
17 | #include <boost/mpi/detail/point_to_point.hpp> | |
18 | #include <boost/mpi/communicator.hpp> | |
19 | #include <boost/mpi/environment.hpp> | |
11fdf7f2 | 20 | #include <boost/mpi/detail/offsets.hpp> |
7c673cae | 21 | #include <boost/assert.hpp> |
11fdf7f2 | 22 | #include <boost/scoped_array.hpp> |
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23 | |
24 | namespace boost { namespace mpi { | |
25 | ||
26 | namespace detail { | |
27 | // We're gathering at the root for a type that has an associated MPI | |
28 | // datatype, so we'll use MPI_Gatherv to do all of the work. | |
29 | template<typename T> | |
30 | void | |
31 | gatherv_impl(const communicator& comm, const T* in_values, int in_size, | |
32 | T* out_values, const int* sizes, const int* displs, int root, mpl::true_) | |
33 | { | |
34 | MPI_Datatype type = get_mpi_datatype<T>(*in_values); | |
35 | BOOST_MPI_CHECK_RESULT(MPI_Gatherv, | |
36 | (const_cast<T*>(in_values), in_size, type, | |
37 | out_values, const_cast<int*>(sizes), const_cast<int*>(displs), | |
38 | type, root, comm)); | |
39 | } | |
40 | ||
41 | // We're gathering from a non-root for a type that has an associated MPI | |
42 | // datatype, so we'll use MPI_Gatherv to do all of the work. | |
43 | template<typename T> | |
44 | void | |
45 | gatherv_impl(const communicator& comm, const T* in_values, int in_size, int root, | |
46 | mpl::true_) | |
47 | { | |
48 | MPI_Datatype type = get_mpi_datatype<T>(*in_values); | |
49 | BOOST_MPI_CHECK_RESULT(MPI_Gatherv, | |
50 | (const_cast<T*>(in_values), in_size, type, | |
51 | 0, 0, 0, type, root, comm)); | |
52 | } | |
53 | ||
54 | // We're gathering at the root for a type that does not have an | |
55 | // associated MPI datatype, so we'll need to serialize | |
56 | // it. Unfortunately, this means that we cannot use MPI_Gatherv, so | |
57 | // we'll just have all of the non-root nodes send individual | |
58 | // messages to the root. | |
59 | template<typename T> | |
60 | void | |
61 | gatherv_impl(const communicator& comm, const T* in_values, int in_size, | |
62 | T* out_values, const int* sizes, const int* displs, int root, mpl::false_) | |
63 | { | |
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64 | // convert displacement to offsets to skip |
65 | scoped_array<int> skipped(make_skipped_slots(comm, sizes, displs, root)); | |
66 | gather_impl(comm, in_values, in_size, out_values, sizes, skipped.get(), root, mpl::false_()); | |
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67 | } |
68 | ||
69 | // We're gathering at a non-root for a type that does not have an | |
70 | // associated MPI datatype, so we'll need to serialize | |
11fdf7f2 | 71 | // it. |
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72 | template<typename T> |
73 | void | |
74 | gatherv_impl(const communicator& comm, const T* in_values, int in_size, int root, | |
75 | mpl::false_) | |
76 | { | |
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77 | gather_impl(comm, in_values, in_size, (T*)0,(int const*)0,(int const*)0, root, |
78 | mpl::false_()); | |
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79 | } |
80 | } // end namespace detail | |
81 | ||
82 | template<typename T> | |
83 | void | |
84 | gatherv(const communicator& comm, const T* in_values, int in_size, | |
85 | T* out_values, const std::vector<int>& sizes, const std::vector<int>& displs, | |
86 | int root) | |
87 | { | |
88 | if (comm.rank() == root) | |
89 | detail::gatherv_impl(comm, in_values, in_size, | |
90 | out_values, &sizes[0], &displs[0], | |
91 | root, is_mpi_datatype<T>()); | |
92 | else | |
93 | detail::gatherv_impl(comm, in_values, in_size, root, is_mpi_datatype<T>()); | |
94 | } | |
95 | ||
96 | template<typename T> | |
97 | void | |
98 | gatherv(const communicator& comm, const std::vector<T>& in_values, | |
99 | T* out_values, const std::vector<int>& sizes, const std::vector<int>& displs, | |
100 | int root) | |
101 | { | |
102 | ::boost::mpi::gatherv(comm, &in_values[0], in_values.size(), out_values, sizes, displs, root); | |
103 | } | |
104 | ||
105 | template<typename T> | |
106 | void gatherv(const communicator& comm, const T* in_values, int in_size, int root) | |
107 | { | |
108 | BOOST_ASSERT(comm.rank() != root); | |
109 | detail::gatherv_impl(comm, in_values, in_size, root, is_mpi_datatype<T>()); | |
110 | } | |
111 | ||
112 | template<typename T> | |
113 | void gatherv(const communicator& comm, const std::vector<T>& in_values, int root) | |
114 | { | |
115 | BOOST_ASSERT(comm.rank() != root); | |
116 | detail::gatherv_impl(comm, &in_values[0], in_values.size(), root, is_mpi_datatype<T>()); | |
117 | } | |
118 | ||
119 | /////////////////////// | |
120 | // common use versions | |
121 | /////////////////////// | |
122 | template<typename T> | |
123 | void | |
124 | gatherv(const communicator& comm, const T* in_values, int in_size, | |
125 | T* out_values, const std::vector<int>& sizes, int root) | |
126 | { | |
127 | int nprocs = comm.size(); | |
128 | ||
129 | std::vector<int> displs( nprocs ); | |
130 | for (int rank = 0, aux = 0; rank < nprocs; ++rank) { | |
131 | displs[rank] = aux; | |
132 | aux += sizes[rank]; | |
133 | } | |
134 | ::boost::mpi::gatherv(comm, in_values, in_size, out_values, sizes, displs, root); | |
135 | } | |
136 | ||
137 | template<typename T> | |
138 | void | |
139 | gatherv(const communicator& comm, const std::vector<T>& in_values, | |
140 | T* out_values, const std::vector<int>& sizes, int root) | |
141 | { | |
142 | ::boost::mpi::gatherv(comm, &in_values[0], in_values.size(), out_values, sizes, root); | |
143 | } | |
144 | ||
145 | } } // end namespace boost::mpi | |
146 | ||
147 | #endif // BOOST_MPI_GATHERV_HPP |