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/** |
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* @file Communicator.hpp |
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* @author Charles Vardeman <cvardema.at.nd.edu> |
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* @date 08/18/2010 |
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* @time 11:56am |
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* @version 1.0 |
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* |
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* @section LICENSE |
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* Copyright (c) 2010 The University of Notre Dame. All Rights Reserved. |
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* |
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* The University of Notre Dame grants you ("Licensee") a |
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* non-exclusive, royalty free, license to use, modify and |
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* redistribute this software in source and binary code form, provided |
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* that the following conditions are met: |
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* |
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* 1. Redistributions of source code must retain the above copyright |
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* notice, this list of conditions and the following disclaimer. |
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* |
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* 2. Redistributions in binary form must reproduce the above copyright |
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* notice, this list of conditions and the following disclaimer in the |
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* documentation and/or other materials provided with the |
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* distribution. |
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* |
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* This software is provided "AS IS," without a warranty of any |
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* kind. All express or implied conditions, representations and |
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* warranties, including any implied warranty of merchantability, |
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* fitness for a particular purpose or non-infringement, are hereby |
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* excluded. The University of Notre Dame and its licensors shall not |
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* be liable for any damages suffered by licensee as a result of |
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* using, modifying or distributing the software or its |
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* derivatives. In no event will the University of Notre Dame or its |
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* licensors be liable for any lost revenue, profit or data, or for |
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* direct, indirect, special, consequential, incidental or punitive |
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* damages, however caused and regardless of the theory of liability, |
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* arising out of the use of or inability to use software, even if the |
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* University of Notre Dame has been advised of the possibility of |
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* such damages. |
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* |
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* SUPPORT OPEN SCIENCE! If you use OpenMD or its source code in your |
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* research, please cite the appropriate papers when you publish your |
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* work. Good starting points are: |
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* |
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* [1] Meineke, et al., J. Comp. Chem. 26, 252-271 (2005). |
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* [2] Fennell & Gezelter, J. Chem. Phys. 124, 234104 (2006). |
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* [3] Sun, Lin & Gezelter, J. Chem. Phys. 128, 24107 (2008). |
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* [4] Vardeman & Gezelter, in progress (2009). |
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*/ |
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|
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#ifndef PARALLEL_COMMUNICATOR_HPP |
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#define PARALLEL_COMMUNICATOR_HPP |
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|
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#include <config.h> |
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#include <mpi.h> |
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#include "math/SquareMatrix3.hpp" |
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|
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namespace OpenMD{ |
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|
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#ifdef IS_MPI |
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|
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enum direction { |
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Row = 0, |
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Column = 1 |
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}; |
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|
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template<typename T> |
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struct MPITraits |
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{ |
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static const MPI::Datatype datatype; |
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static const int dim; |
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}; |
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|
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template<> const MPI::Datatype MPITraits<int>::datatype = MPI_INT; |
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template<> const int MPITraits<int>::dim = 1; |
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template<> const MPI::Datatype MPITraits<RealType>::datatype = MPI_REALTYPE; |
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template<> const int MPITraits<RealType>::dim = 1; |
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template<> const MPI::Datatype MPITraits<Vector3d>::datatype = MPI_REALTYPE; |
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template<> const int MPITraits<Vector3d>::dim = 3; |
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template<> const MPI::Datatype MPITraits<Mat3x3d>::datatype = MPI_REALTYPE; |
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template<> const int MPITraits<Mat3x3d>::dim = 9; |
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|
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template<direction D, typename T> |
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class Communicator { |
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public: |
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|
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Communicator<D, T>(int nObjects) { |
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|
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int nProc = MPI::COMM_WORLD.Get_size(); |
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int myRank = MPI::COMM_WORLD.Get_rank(); |
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|
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int nColumnsMax = (int) sqrt(RealType(nProc)); |
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|
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int nColumns; |
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for (int i = 1; i < nColumnsMax + 1; i++) { |
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if (nProc % i == 0) nColumns = i; |
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} |
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|
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int nRows = nProc / nColumns; |
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rowIndex_ = myRank / nColumns; |
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columnIndex_ = myRank % nColumns; |
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|
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if (D == Row) { |
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myComm = MPI::COMM_WORLD.Split(rowIndex_, 0); |
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} else { |
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myComm = MPI::COMM_WORLD.Split(columnIndex_, 0); |
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} |
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|
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int nCommProcs = myComm.Get_size(); |
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|
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counts.reserve(nCommProcs); |
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displacements.reserve(nCommProcs); |
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|
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planSize_ = MPITraits<T>::dim * nObjects; |
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|
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myComm.Allgather(&planSize_, 1, MPI::INT, &counts[0], 1, MPI::INT); |
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|
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displacements[0] = 0; |
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for (int i = 1; i < nCommProcs; i++) { |
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displacements[i] = displacements[i-1] + counts[i-1]; |
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size_ += counts[i-1]; |
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} |
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|
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size_ = 0; |
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for (int i = 0; i < nCommProcs; i++) { |
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size_ += counts[i]; |
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} |
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} |
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|
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|
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void gather(std::vector<T>& v1, std::vector<T>& v2) { |
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|
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myComm.Allgatherv(&v1[0], |
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planSize_, |
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MPITraits<T>::datatype, |
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&v2[0], |
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&counts[0], |
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&displacements[0], |
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MPITraits<T>::datatype); |
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} |
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|
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|
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|
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void scatter(std::vector<T>& v1, std::vector<T>& v2) { |
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|
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myComm.Reduce_scatter(&v1[0], &v2[0], &counts[0], |
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MPITraits<T>::datatype, MPI::SUM); |
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} |
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|
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int getSize() { |
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return size_; |
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} |
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|
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private: |
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int planSize_; ///< how many are on local proc |
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int rowIndex_; |
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int columnIndex_; |
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int size_; |
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std::vector<int> counts; |
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std::vector<int> displacements; |
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MPI::Intracomm myComm; |
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}; |
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|
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#endif |
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} |
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#endif |
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|
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