1 // Copyright (C) 2005, 2006 Douglas Gregor <doug.gregor -at- gmail.com>.
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 4.4. Broadcast
8 #ifndef BOOST_MPI_BROADCAST_HPP
9 #define BOOST_MPI_BROADCAST_HPP
10
11 #include <boost/mpi/collectives_fwd.hpp>
12 #include <boost/mpi/exception.hpp>
13 #include <boost/mpi/datatype.hpp>
14 #include <boost/mpi/communicator.hpp>
15
16 namespace boost { namespace mpi {
17
18 /************************************************************************
19 * Specializations *
20 ************************************************************************/
21
22 /**
23 * INTERNAL ONLY
24 */
25 template<>
26 BOOST_MPI_DECL void
27 broadcast<const packed_oarchive>(const communicator& comm,
28 const packed_oarchive& oa,
29 int root);
30
31 /**
32 * INTERNAL ONLY
33 */
34 template<>
35 BOOST_MPI_DECL void
36 broadcast<packed_oarchive>(const communicator& comm, packed_oarchive& oa,
37 int root);
38
39 /**
40 * INTERNAL ONLY
41 */
42 template<>
43 BOOST_MPI_DECL void
44 broadcast<packed_iarchive>(const communicator& comm, packed_iarchive& ia,
45 int root);
46
47 /**
48 * INTERNAL ONLY
49 */
50 template<>
51 BOOST_MPI_DECL void
52 broadcast<const packed_skeleton_oarchive>(const communicator& comm,
53 const packed_skeleton_oarchive& oa,
54 int root);
55
56 /**
57 * INTERNAL ONLY
58 */
59 template<>
60 void
61 broadcast<packed_skeleton_oarchive>(const communicator& comm,
62 packed_skeleton_oarchive& oa, int root);
63
64 /**
65 * INTERNAL ONLY
66 */
67 template<>
68 void
69 broadcast<packed_skeleton_iarchive>(const communicator& comm,
70 packed_skeleton_iarchive& ia, int root);
71
72 /**
73 * INTERNAL ONLY
74 */
75 template<>
76 void broadcast<content>(const communicator& comm, content& c, int root);
77
78 /**
79 * INTERNAL ONLY
80 */
81 template<>
82 void broadcast<const content>(const communicator& comm, const content& c,
83 int root);
84
85 /************************************************************************
86 * broadcast() implementation *
87 ************************************************************************/
88 namespace detail {
89 // We're sending a type that has an associated MPI datatype, so
90 // we'll use MPI_Bcast to do all of the work.
91 template<typename T>
92 void
broadcast_impl(const communicator & comm,T * values,int n,int root,mpl::true_)93 broadcast_impl(const communicator& comm, T* values, int n, int root,
94 mpl::true_)
95 {
96 BOOST_MPI_CHECK_RESULT(MPI_Bcast,
97 (values, n,
98 boost::mpi::get_mpi_datatype<T>(*values),
99 root, MPI_Comm(comm)));
100 }
101
102 // We're sending a type that does not have an associated MPI
103 // datatype, so we'll need to serialize it.
104 template<typename T>
105 void
broadcast_impl(const communicator & comm,T * values,int n,int root,mpl::false_ non_mpi_datatype)106 broadcast_impl(const communicator& comm, T* values, int n, int root,
107 mpl::false_ non_mpi_datatype)
108 {
109 // Implementation proposed by Lorenz Hübschle-Schneider
110 if (comm.rank() == root) {
111 packed_oarchive oa(comm);
112 for (int i = 0; i < n; ++i) {
113 oa << values[i];
114 }
115 std::size_t asize = oa.size();
116 broadcast(comm, asize, root);
117 void const* aptr = oa.address();
118 BOOST_MPI_CHECK_RESULT(MPI_Bcast,
119 (const_cast<void*>(aptr), asize,
120 MPI_BYTE,
121 root, MPI_Comm(comm)));
122 } else {
123 packed_iarchive ia(comm);
124 std::size_t asize;
125 broadcast(comm, asize, root);
126 ia.resize(asize);
127 void* aptr = ia.address();
128 BOOST_MPI_CHECK_RESULT(MPI_Bcast,
129 (aptr, asize,
130 MPI_BYTE,
131 root, MPI_Comm(comm)));
132 for (int i = 0; i < n; ++i)
133 ia >> values[i];
134 }
135 }
136 } // end namespace detail
137
138 template<typename T>
broadcast(const communicator & comm,T & value,int root)139 void broadcast(const communicator& comm, T& value, int root)
140 {
141 detail::broadcast_impl(comm, &value, 1, root, is_mpi_datatype<T>());
142 }
143
144 template<typename T>
broadcast(const communicator & comm,T * values,int n,int root)145 void broadcast(const communicator& comm, T* values, int n, int root)
146 {
147 detail::broadcast_impl(comm, values, n, root, is_mpi_datatype<T>());
148 }
149
150 } } // end namespace boost::mpi
151
152 // If the user has already included skeleton_and_content.hpp, include
153 // the code to broadcast skeletons and content.
154 #ifdef BOOST_MPI_SKELETON_AND_CONTENT_HPP
155 # include <boost/mpi/detail/broadcast_sc.hpp>
156 #endif
157
158 #endif // BOOST_MPI_BROADCAST_HPP
159