]>
Commit | Line | Data |
---|---|---|
7c673cae FG |
1 | // Copyright (C) 2004 The Trustees of Indiana University. |
2 | // Copyright (C) 2005-2006 Douglas Gregor <doug.gregor -at- gmail.com> | |
3 | ||
4 | // Use, modification and distribution is subject to the Boost Software | |
5 | // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at | |
6 | // http://www.boost.org/LICENSE_1_0.txt) | |
7 | ||
8 | // Authors: Douglas Gregor | |
9 | // Andrew Lumsdaine | |
10 | ||
11 | /** @file operations.hpp | |
12 | * | |
13 | * This header provides a mapping from function objects to @c MPI_Op | |
14 | * constants used in MPI collective operations. It also provides | |
15 | * several new function object types not present in the standard @c | |
16 | * <functional> header that have direct mappings to @c MPI_Op. | |
17 | */ | |
18 | #ifndef BOOST_MPI_IS_MPI_OP_HPP | |
19 | #define BOOST_MPI_IS_MPI_OP_HPP | |
20 | ||
21 | #include <boost/mpi/config.hpp> | |
22 | #include <boost/mpl/bool.hpp> | |
23 | #include <boost/mpl/if.hpp> | |
24 | #include <boost/mpl/and.hpp> | |
25 | #include <boost/mpi/datatype.hpp> | |
26 | #include <boost/utility/enable_if.hpp> | |
27 | #include <functional> | |
28 | ||
29 | namespace boost { namespace mpi { | |
30 | ||
31 | template<typename Op, typename T> struct is_mpi_op; | |
32 | ||
33 | /** | |
34 | * @brief Determine if a function object type is commutative. | |
35 | * | |
36 | * This trait determines if an operation @c Op is commutative when | |
37 | * applied to values of type @c T. Parallel operations such as @c | |
38 | * reduce and @c prefix_sum can be implemented more efficiently with | |
39 | * commutative operations. To mark an operation as commutative, users | |
40 | * should specialize @c is_commutative and derive from the class @c | |
41 | * mpl::true_. | |
42 | */ | |
43 | template<typename Op, typename T> | |
44 | struct is_commutative : public mpl::false_ { }; | |
45 | ||
46 | /************************************************************************** | |
47 | * Function objects for MPI operations not in <functional> header * | |
48 | **************************************************************************/ | |
49 | ||
50 | /** | |
51 | * @brief Compute the maximum of two values. | |
52 | * | |
53 | * This binary function object computes the maximum of the two values | |
54 | * it is given. When used with MPI and a type @c T that has an | |
55 | * associated, built-in MPI data type, translates to @c MPI_MAX. | |
56 | */ | |
57 | template<typename T> | |
58 | struct maximum : public std::binary_function<T, T, T> | |
59 | { | |
60 | /** @returns the maximum of x and y. */ | |
61 | const T& operator()(const T& x, const T& y) const | |
62 | { | |
63 | return x < y? y : x; | |
64 | } | |
65 | }; | |
66 | ||
67 | /** | |
68 | * @brief Compute the minimum of two values. | |
69 | * | |
70 | * This binary function object computes the minimum of the two values | |
71 | * it is given. When used with MPI and a type @c T that has an | |
72 | * associated, built-in MPI data type, translates to @c MPI_MIN. | |
73 | */ | |
74 | template<typename T> | |
75 | struct minimum : public std::binary_function<T, T, T> | |
76 | { | |
77 | /** @returns the minimum of x and y. */ | |
78 | const T& operator()(const T& x, const T& y) const | |
79 | { | |
80 | return x < y? x : y; | |
81 | } | |
82 | }; | |
83 | ||
84 | ||
85 | /** | |
86 | * @brief Compute the bitwise AND of two integral values. | |
87 | * | |
88 | * This binary function object computes the bitwise AND of the two | |
89 | * values it is given. When used with MPI and a type @c T that has an | |
90 | * associated, built-in MPI data type, translates to @c MPI_BAND. | |
91 | */ | |
92 | template<typename T> | |
93 | struct bitwise_and : public std::binary_function<T, T, T> | |
94 | { | |
95 | /** @returns @c x & y. */ | |
96 | T operator()(const T& x, const T& y) const | |
97 | { | |
98 | return x & y; | |
99 | } | |
100 | }; | |
101 | ||
102 | /** | |
103 | * @brief Compute the bitwise OR of two integral values. | |
104 | * | |
105 | * This binary function object computes the bitwise OR of the two | |
106 | * values it is given. When used with MPI and a type @c T that has an | |
107 | * associated, built-in MPI data type, translates to @c MPI_BOR. | |
108 | */ | |
109 | template<typename T> | |
110 | struct bitwise_or : public std::binary_function<T, T, T> | |
111 | { | |
112 | /** @returns the @c x | y. */ | |
113 | T operator()(const T& x, const T& y) const | |
114 | { | |
115 | return x | y; | |
116 | } | |
117 | }; | |
118 | ||
119 | /** | |
120 | * @brief Compute the logical exclusive OR of two integral values. | |
121 | * | |
122 | * This binary function object computes the logical exclusive of the | |
123 | * two values it is given. When used with MPI and a type @c T that has | |
124 | * an associated, built-in MPI data type, translates to @c MPI_LXOR. | |
125 | */ | |
126 | template<typename T> | |
127 | struct logical_xor : public std::binary_function<T, T, T> | |
128 | { | |
129 | /** @returns the logical exclusive OR of x and y. */ | |
130 | T operator()(const T& x, const T& y) const | |
131 | { | |
132 | return (x || y) && !(x && y); | |
133 | } | |
134 | }; | |
135 | ||
136 | /** | |
137 | * @brief Compute the bitwise exclusive OR of two integral values. | |
138 | * | |
139 | * This binary function object computes the bitwise exclusive OR of | |
140 | * the two values it is given. When used with MPI and a type @c T that | |
141 | * has an associated, built-in MPI data type, translates to @c | |
142 | * MPI_BXOR. | |
143 | */ | |
144 | template<typename T> | |
145 | struct bitwise_xor : public std::binary_function<T, T, T> | |
146 | { | |
147 | /** @returns @c x ^ y. */ | |
148 | T operator()(const T& x, const T& y) const | |
149 | { | |
150 | return x ^ y; | |
151 | } | |
152 | }; | |
153 | ||
154 | /************************************************************************** | |
155 | * MPI_Op queries * | |
156 | **************************************************************************/ | |
157 | ||
158 | /** | |
159 | * @brief Determine if a function object has an associated @c MPI_Op. | |
160 | * | |
161 | * This trait determines if a function object type @c Op, when used | |
162 | * with argument type @c T, has an associated @c MPI_Op. If so, @c | |
163 | * is_mpi_op<Op,T> will derive from @c mpl::false_ and will | |
164 | * contain a static member function @c op that takes no arguments but | |
165 | * returns the associated @c MPI_Op value. For instance, @c | |
166 | * is_mpi_op<std::plus<int>,int>::op() returns @c MPI_SUM. | |
167 | * | |
168 | * Users may specialize @c is_mpi_op for any other class templates | |
169 | * that map onto operations that have @c MPI_Op equivalences, such as | |
170 | * bitwise OR, logical and, or maximum. However, users are encouraged | |
171 | * to use the standard function objects in the @c functional and @c | |
172 | * boost/mpi/operations.hpp headers whenever possible. For | |
173 | * function objects that are class templates with a single template | |
174 | * parameter, it may be easier to specialize @c is_builtin_mpi_op. | |
175 | */ | |
176 | template<typename Op, typename T> | |
177 | struct is_mpi_op : public mpl::false_ { }; | |
178 | ||
179 | /// INTERNAL ONLY | |
180 | template<typename T> | |
181 | struct is_mpi_op<maximum<T>, T> | |
182 | : public boost::mpl::or_<is_mpi_integer_datatype<T>, | |
183 | is_mpi_floating_point_datatype<T> > | |
184 | { | |
185 | static MPI_Op op() { return MPI_MAX; } | |
186 | }; | |
187 | ||
188 | /// INTERNAL ONLY | |
189 | template<typename T> | |
190 | struct is_mpi_op<minimum<T>, T> | |
191 | : public boost::mpl::or_<is_mpi_integer_datatype<T>, | |
192 | is_mpi_floating_point_datatype<T> > | |
193 | { | |
194 | static MPI_Op op() { return MPI_MIN; } | |
195 | }; | |
196 | ||
197 | /// INTERNAL ONLY | |
198 | template<typename T> | |
199 | struct is_mpi_op<std::plus<T>, T> | |
200 | : public boost::mpl::or_<is_mpi_integer_datatype<T>, | |
201 | is_mpi_floating_point_datatype<T>, | |
202 | is_mpi_complex_datatype<T> > | |
203 | { | |
204 | static MPI_Op op() { return MPI_SUM; } | |
205 | }; | |
206 | ||
207 | /// INTERNAL ONLY | |
208 | template<typename T> | |
209 | struct is_mpi_op<std::multiplies<T>, T> | |
210 | : public boost::mpl::or_<is_mpi_integer_datatype<T>, | |
211 | is_mpi_floating_point_datatype<T>, | |
212 | is_mpi_complex_datatype<T> > | |
213 | { | |
214 | static MPI_Op op() { return MPI_PROD; } | |
215 | }; | |
216 | ||
217 | /// INTERNAL ONLY | |
218 | template<typename T> | |
219 | struct is_mpi_op<std::logical_and<T>, T> | |
220 | : public boost::mpl::or_<is_mpi_integer_datatype<T>, | |
221 | is_mpi_logical_datatype<T> > | |
222 | { | |
223 | static MPI_Op op() { return MPI_LAND; } | |
224 | }; | |
225 | ||
226 | /// INTERNAL ONLY | |
227 | template<typename T> | |
228 | struct is_mpi_op<std::logical_or<T>, T> | |
229 | : public boost::mpl::or_<is_mpi_integer_datatype<T>, | |
230 | is_mpi_logical_datatype<T> > | |
231 | { | |
232 | static MPI_Op op() { return MPI_LOR; } | |
233 | }; | |
234 | ||
235 | /// INTERNAL ONLY | |
236 | template<typename T> | |
237 | struct is_mpi_op<logical_xor<T>, T> | |
238 | : public boost::mpl::or_<is_mpi_integer_datatype<T>, | |
239 | is_mpi_logical_datatype<T> > | |
240 | { | |
241 | static MPI_Op op() { return MPI_LXOR; } | |
242 | }; | |
243 | ||
244 | /// INTERNAL ONLY | |
245 | template<typename T> | |
246 | struct is_mpi_op<bitwise_and<T>, T> | |
247 | : public boost::mpl::or_<is_mpi_integer_datatype<T>, | |
248 | is_mpi_byte_datatype<T> > | |
249 | { | |
250 | static MPI_Op op() { return MPI_BAND; } | |
251 | }; | |
252 | ||
253 | /// INTERNAL ONLY | |
254 | template<typename T> | |
255 | struct is_mpi_op<bitwise_or<T>, T> | |
256 | : public boost::mpl::or_<is_mpi_integer_datatype<T>, | |
257 | is_mpi_byte_datatype<T> > | |
258 | { | |
259 | static MPI_Op op() { return MPI_BOR; } | |
260 | }; | |
261 | ||
262 | /// INTERNAL ONLY | |
263 | template<typename T> | |
264 | struct is_mpi_op<bitwise_xor<T>, T> | |
265 | : public boost::mpl::or_<is_mpi_integer_datatype<T>, | |
266 | is_mpi_byte_datatype<T> > | |
267 | { | |
268 | static MPI_Op op() { return MPI_BXOR; } | |
269 | }; | |
270 | ||
271 | namespace detail { | |
272 | // A helper class used to create user-defined MPI_Ops | |
273 | template<typename Op, typename T> | |
274 | class user_op | |
275 | { | |
276 | public: | |
277 | explicit user_op(Op& op) | |
278 | { | |
279 | BOOST_MPI_CHECK_RESULT(MPI_Op_create, | |
280 | (&user_op<Op, T>::perform, | |
281 | is_commutative<Op, T>::value, | |
282 | &mpi_op)); | |
283 | ||
284 | op_ptr = &op; | |
285 | } | |
286 | ||
287 | ~user_op() | |
288 | { | |
289 | if (std::uncaught_exception()) { | |
290 | // Ignore failure cases: there are obviously other problems | |
291 | // already, and we don't want to cause program termination if | |
292 | // MPI_Op_free fails. | |
293 | MPI_Op_free(&mpi_op); | |
294 | } else { | |
295 | BOOST_MPI_CHECK_RESULT(MPI_Op_free, (&mpi_op)); | |
296 | } | |
297 | } | |
298 | ||
299 | MPI_Op& get_mpi_op() | |
300 | { | |
301 | return mpi_op; | |
302 | } | |
303 | ||
304 | private: | |
305 | MPI_Op mpi_op; | |
306 | static Op* op_ptr; | |
307 | ||
308 | static void BOOST_MPI_CALLING_CONVENTION perform(void* vinvec, void* voutvec, int* plen, MPI_Datatype*) | |
309 | { | |
310 | T* invec = static_cast<T*>(vinvec); | |
311 | T* outvec = static_cast<T*>(voutvec); | |
312 | std::transform(invec, invec + *plen, outvec, outvec, *op_ptr); | |
313 | } | |
314 | }; | |
315 | ||
316 | template<typename Op, typename T> Op* user_op<Op, T>::op_ptr = 0; | |
317 | ||
318 | } // end namespace detail | |
319 | ||
320 | } } // end namespace boost::mpi | |
321 | ||
322 | #endif // BOOST_MPI_GET_MPI_OP_HPP |