| 1 | /** | 
| 2 | * @file ForceDecomposition.cpp | 
| 3 | * @author Charles Vardeman <cvardema.at.nd.edu> | 
| 4 | * @date 08/18/2010 | 
| 5 | * @time 11:56am | 
| 6 | * @version 1.0 | 
| 7 | * | 
| 8 | * @section LICENSE | 
| 9 | * Copyright (c) 2010 The University of Notre Dame. All Rights Reserved. | 
| 10 | * | 
| 11 | * The University of Notre Dame grants you ("Licensee") a | 
| 12 | * non-exclusive, royalty free, license to use, modify and | 
| 13 | * redistribute this software in source and binary code form, provided | 
| 14 | * that the following conditions are met: | 
| 15 | * | 
| 16 | * 1. Redistributions of source code must retain the above copyright | 
| 17 | *    notice, this list of conditions and the following disclaimer. | 
| 18 | * | 
| 19 | * 2. Redistributions in binary form must reproduce the above copyright | 
| 20 | *    notice, this list of conditions and the following disclaimer in the | 
| 21 | *    documentation and/or other materials provided with the | 
| 22 | *    distribution. | 
| 23 | * | 
| 24 | * This software is provided "AS IS," without a warranty of any | 
| 25 | * kind. All express or implied conditions, representations and | 
| 26 | * warranties, including any implied warranty of merchantability, | 
| 27 | * fitness for a particular purpose or non-infringement, are hereby | 
| 28 | * excluded.  The University of Notre Dame and its licensors shall not | 
| 29 | * be liable for any damages suffered by licensee as a result of | 
| 30 | * using, modifying or distributing the software or its | 
| 31 | * derivatives. In no event will the University of Notre Dame or its | 
| 32 | * licensors be liable for any lost revenue, profit or data, or for | 
| 33 | * direct, indirect, special, consequential, incidental or punitive | 
| 34 | * damages, however caused and regardless of the theory of liability, | 
| 35 | * arising out of the use of or inability to use software, even if the | 
| 36 | * University of Notre Dame has been advised of the possibility of | 
| 37 | * such damages. | 
| 38 | * | 
| 39 | * SUPPORT OPEN SCIENCE!  If you use OpenMD or its source code in your | 
| 40 | * research, please cite the appropriate papers when you publish your | 
| 41 | * work.  Good starting points are: | 
| 42 | * | 
| 43 | * [1]  Meineke, et al., J. Comp. Chem. 26, 252-271 (2005). | 
| 44 | * [2]  Fennell & Gezelter, J. Chem. Phys. 124, 234104 (2006). | 
| 45 | * [3]  Sun, Lin & Gezelter, J. Chem. Phys. 128, 24107 (2008). | 
| 46 | * [4]  Vardeman & Gezelter, in progress (2009). | 
| 47 | */ | 
| 48 |  | 
| 49 |  | 
| 50 |  | 
| 51 | /*  -*- c++ -*-  */ | 
| 52 | #include "config.h" | 
| 53 | #include <stdlib.h> | 
| 54 | #ifdef IS_MPI | 
| 55 | #include <mpi.h> | 
| 56 | #endif | 
| 57 |  | 
| 58 | #include <iostream> | 
| 59 | #include <vector> | 
| 60 | #include <algorithm> | 
| 61 | #include <cmath> | 
| 62 | #include "parallel/ForceDecomposition.hpp" | 
| 63 |  | 
| 64 |  | 
| 65 | using namespace std; | 
| 66 | using namespace OpenMD; | 
| 67 |  | 
| 68 | //__static | 
| 69 | #ifdef IS_MPI | 
| 70 | static vector<MPI:Comm> communictors; | 
| 71 | #endif | 
| 72 |  | 
| 73 | //____ MPITypeTraits | 
| 74 | template<typename T> | 
| 75 | struct MPITypeTraits; | 
| 76 |  | 
| 77 | #ifdef IS_MPI | 
| 78 | template<> | 
| 79 | struct MPITypeTraits<RealType> { | 
| 80 | static const MPI::Datatype datatype; | 
| 81 | }; | 
| 82 | const MPI_Datatype MPITypeTraits<RealType>::datatype = MY_MPI_REAL; | 
| 83 |  | 
| 84 | template<> | 
| 85 | struct MPITypeTraits<int> { | 
| 86 | static const MPI::Datatype datatype; | 
| 87 | }; | 
| 88 | const MPI::Datatype MPITypeTraits<int>::datatype = MPI_INT; | 
| 89 | #endif | 
| 90 |  | 
| 91 | /** | 
| 92 | * Constructor for ForceDecomposition Parallel Decomposition Method | 
| 93 | * Will try to construct a symmetric grid of processors. Ideally, the | 
| 94 | * number of processors will be a square ex: 4, 9, 16, 25. | 
| 95 | * | 
| 96 | */ | 
| 97 |  | 
| 98 | ForceDecomposition::ForceDecomposition() { | 
| 99 |  | 
| 100 | #ifdef IS_MPI | 
| 101 | int nProcs = MPI::COMM_WORLD.Get_size(); | 
| 102 | int worldRank = MPI::COMM_WORLD.Get_rank(); | 
| 103 | #endif | 
| 104 |  | 
| 105 | // First time through, construct column stride. | 
| 106 | if (communicators.size() == 0) | 
| 107 | { | 
| 108 | int nColumnsMax = (int) round(sqrt((float) nProcs)); | 
| 109 | for (int i = 0; i < nProcs; ++i) | 
| 110 | { | 
| 111 | if (nProcs%i==0) nColumns=i; | 
| 112 | } | 
| 113 |  | 
| 114 | int nRows = nProcs/nColumns; | 
| 115 | myRank_ = (int) worldRank%nColumns; | 
| 116 | } | 
| 117 | else | 
| 118 | { | 
| 119 | myRank_ = myRank/nColumns; | 
| 120 | } | 
| 121 | MPI::Comm newComm = MPI:COMM_WORLD.Split(myRank_,0); | 
| 122 |  | 
| 123 | isColumn_ = false; | 
| 124 |  | 
| 125 | } | 
| 126 |  | 
| 127 | ForceDecomposition::gather(sendbuf, receivebuf){ | 
| 128 | communicators(myIndex_).Allgatherv(); | 
| 129 | } | 
| 130 |  | 
| 131 |  | 
| 132 |  | 
| 133 | ForceDecomposition::scatter(sbuffer, rbuffer){ | 
| 134 | communicators(myIndex_).Reduce_scatter(sbuffer, recevbuf. recvcounts, MPI::DOUBLE, MPI::SUM); | 
| 135 | } | 
| 136 |  | 
| 137 |  |