| 1 | /** | 
| 2 | * @file Communicator.hpp | 
| 3 | * @author Charles Vardeman <cvardema.at.nd.edu> | 
| 4 | * @date 08/18/2010 | 
| 5 | * @version 1.0 | 
| 6 | * | 
| 7 | * @section LICENSE | 
| 8 | * Copyright (c) 2010 The University of Notre Dame. All Rights Reserved. | 
| 9 | * | 
| 10 | * The University of Notre Dame grants you ("Licensee") a | 
| 11 | * non-exclusive, royalty free, license to use, modify and | 
| 12 | * redistribute this software in source and binary code form, provided | 
| 13 | * that the following conditions are met: | 
| 14 | * | 
| 15 | * 1. Redistributions of source code must retain the above copyright | 
| 16 | *    notice, this list of conditions and the following disclaimer. | 
| 17 | * | 
| 18 | * 2. Redistributions in binary form must reproduce the above copyright | 
| 19 | *    notice, this list of conditions and the following disclaimer in the | 
| 20 | *    documentation and/or other materials provided with the | 
| 21 | *    distribution. | 
| 22 | * | 
| 23 | * This software is provided "AS IS," without a warranty of any | 
| 24 | * kind. All express or implied conditions, representations and | 
| 25 | * warranties, including any implied warranty of merchantability, | 
| 26 | * fitness for a particular purpose or non-infringement, are hereby | 
| 27 | * excluded.  The University of Notre Dame and its licensors shall not | 
| 28 | * be liable for any damages suffered by licensee as a result of | 
| 29 | * using, modifying or distributing the software or its | 
| 30 | * derivatives. In no event will the University of Notre Dame or its | 
| 31 | * licensors be liable for any lost revenue, profit or data, or for | 
| 32 | * direct, indirect, special, consequential, incidental or punitive | 
| 33 | * damages, however caused and regardless of the theory of liability, | 
| 34 | * arising out of the use of or inability to use software, even if the | 
| 35 | * University of Notre Dame has been advised of the possibility of | 
| 36 | * such damages. | 
| 37 | * | 
| 38 | * SUPPORT OPEN SCIENCE!  If you use OpenMD or its source code in your | 
| 39 | * research, please cite the appropriate papers when you publish your | 
| 40 | * work.  Good starting points are: | 
| 41 | * | 
| 42 | * [1]  Meineke, et al., J. Comp. Chem. 26, 252-271 (2005). | 
| 43 | * [2]  Fennell & Gezelter, J. Chem. Phys. 124, 234104 (2006). | 
| 44 | * [3]  Sun, Lin & Gezelter, J. Chem. Phys. 128, 234107 (2008). | 
| 45 | * [4]  Kuang & Gezelter,  J. Chem. Phys. 133, 164101 (2010). | 
| 46 | * [5]  Vardeman, Stocker & Gezelter, J. Chem. Theory Comput. 7, 834 (2011). | 
| 47 | */ | 
| 48 |  | 
| 49 | #ifndef PARALLEL_COMMUNICATOR_HPP | 
| 50 | #define PARALLEL_COMMUNICATOR_HPP | 
| 51 |  | 
| 52 | #include <config.h> | 
| 53 | #include <mpi.h> | 
| 54 | #include "math/SquareMatrix3.hpp" | 
| 55 |  | 
| 56 | using namespace std; | 
| 57 | namespace OpenMD{ | 
| 58 |  | 
| 59 | #ifdef IS_MPI | 
| 60 |  | 
| 61 | enum communicatorType { | 
| 62 | Global = 0, | 
| 63 | Row = 1, | 
| 64 | Column = 2 | 
| 65 | }; | 
| 66 |  | 
| 67 | template<class T> | 
| 68 | class MPITraits { | 
| 69 | public: | 
| 70 | static MPI::Datatype Type(); | 
| 71 | static int Length() { return 1; }; | 
| 72 | }; | 
| 73 |  | 
| 74 | template<> inline MPI::Datatype MPITraits<int>::Type() { return MPI::INT; } | 
| 75 | template<> inline MPI::Datatype MPITraits<RealType>::Type() { return MPI::REALTYPE; } | 
| 76 |  | 
| 77 | template<class T, unsigned int Dim> | 
| 78 | class MPITraits< Vector<T, Dim> > { | 
| 79 | public: | 
| 80 | static MPI::Datatype Type() { return MPITraits<T>::Type(); } | 
| 81 | static int Length() {return Dim;} | 
| 82 | }; | 
| 83 |  | 
| 84 | template<class T> | 
| 85 | class MPITraits< Vector3<T> > { | 
| 86 | public: | 
| 87 | static MPI::Datatype Type() { return MPITraits<T>::Type(); } | 
| 88 | static int Length() {return 3;} | 
| 89 | }; | 
| 90 |  | 
| 91 | template<class T, unsigned int R, unsigned int C> | 
| 92 | class MPITraits< RectMatrix<T, R, C> > { | 
| 93 | public: | 
| 94 | static MPI::Datatype Type() { return MPITraits<T>::Type(); } | 
| 95 | static int Length() {return R * C;} | 
| 96 | }; | 
| 97 |  | 
| 98 | template<class T> | 
| 99 | class MPITraits< SquareMatrix3<T> > { | 
| 100 | public: | 
| 101 | static MPI::Datatype Type() { return MPITraits<T>::Type(); } | 
| 102 | static int Length() {return 9;} | 
| 103 | }; | 
| 104 |  | 
| 105 |  | 
| 106 | template<communicatorType D> | 
| 107 | class Communicator { | 
| 108 | public: | 
| 109 |  | 
| 110 | Communicator<D>() { | 
| 111 |  | 
| 112 | int nProc = MPI::COMM_WORLD.Get_size(); | 
| 113 | int myRank = MPI::COMM_WORLD.Get_rank(); | 
| 114 |  | 
| 115 | int nColumnsMax = (int) sqrt(RealType(nProc)); | 
| 116 |  | 
| 117 | int nColumns; | 
| 118 | for (int i = 1; i < nColumnsMax + 1; i++) { | 
| 119 | if (nProc % i == 0) nColumns = i; | 
| 120 | } | 
| 121 |  | 
| 122 | // int nRows = nProc / nColumns; | 
| 123 | rowIndex_ = myRank / nColumns; | 
| 124 | columnIndex_ = myRank % nColumns; | 
| 125 |  | 
| 126 | switch(D) { | 
| 127 | case Row : | 
| 128 | myComm = MPI::COMM_WORLD.Split(rowIndex_, 0); | 
| 129 | break; | 
| 130 | case Column: | 
| 131 | myComm = MPI::COMM_WORLD.Split(columnIndex_, 0); | 
| 132 | break; | 
| 133 | case Global: | 
| 134 | myComm = MPI::COMM_WORLD.Split(myRank, 0); | 
| 135 | } | 
| 136 |  | 
| 137 | } | 
| 138 |  | 
| 139 | MPI::Intracomm getComm() { return myComm; } | 
| 140 |  | 
| 141 | private: | 
| 142 | int rowIndex_; | 
| 143 | int columnIndex_; | 
| 144 | MPI::Intracomm myComm; | 
| 145 | }; | 
| 146 |  | 
| 147 |  | 
| 148 | template<typename T> | 
| 149 | class Plan { | 
| 150 | public: | 
| 151 |  | 
| 152 | Plan<T>(MPI::Intracomm comm, int nObjects) : myComm(comm) { | 
| 153 | int nCommProcs = myComm.Get_size(); | 
| 154 |  | 
| 155 | counts.resize(nCommProcs, 0); | 
| 156 | displacements.resize(nCommProcs, 0); | 
| 157 |  | 
| 158 | planSize_ = MPITraits<T>::Length() * nObjects; | 
| 159 |  | 
| 160 | myComm.Allgather(&planSize_, 1, MPI::INT, &counts[0], 1, MPI::INT); | 
| 161 |  | 
| 162 | displacements[0] = 0; | 
| 163 | for (int i = 1; i < nCommProcs; i++) { | 
| 164 | displacements[i] = displacements[i-1] + counts[i-1]; | 
| 165 | } | 
| 166 |  | 
| 167 | size_ = 0; | 
| 168 | for (int i = 0; i < nCommProcs; i++) { | 
| 169 | size_ += counts[i]; | 
| 170 | } | 
| 171 | } | 
| 172 |  | 
| 173 |  | 
| 174 | void gather(vector<T>& v1, vector<T>& v2) { | 
| 175 |  | 
| 176 | // an assert would be helpful here to make sure the vectors are the | 
| 177 | // correct geometry | 
| 178 |  | 
| 179 | myComm.Allgatherv(&v1[0], | 
| 180 | planSize_, | 
| 181 | MPITraits<T>::Type(), | 
| 182 | &v2[0], | 
| 183 | &counts[0], | 
| 184 | &displacements[0], | 
| 185 | MPITraits<T>::Type()); | 
| 186 | } | 
| 187 |  | 
| 188 | void scatter(vector<T>& v1, vector<T>& v2) { | 
| 189 | // an assert would be helpful here to make sure the vectors are the | 
| 190 | // correct geometry | 
| 191 |  | 
| 192 | myComm.Reduce_scatter(&v1[0], &v2[0], &counts[0], | 
| 193 | MPITraits<T>::Type(), MPI::SUM); | 
| 194 | } | 
| 195 |  | 
| 196 | int getSize() { | 
| 197 | return size_; | 
| 198 | } | 
| 199 |  | 
| 200 | private: | 
| 201 | int planSize_;     ///< how many are on local proc | 
| 202 | int size_; | 
| 203 | vector<int> counts; | 
| 204 | vector<int> displacements; | 
| 205 | MPI::Intracomm myComm; | 
| 206 | }; | 
| 207 |  | 
| 208 | #endif | 
| 209 | } | 
| 210 | #endif | 
| 211 |  | 
| 212 |  |