src/parallel/Communicator.hpp

/**
 * @file Communicator.hpp
 * @author Charles Vardeman <cvardema.at.nd.edu>
 * @date 08/18/2010
 * @time 11:56am
 * @version 1.0
 *
 * @section LICENSE
 * Copyright (c) 2010 The University of Notre Dame. All Rights Reserved.
 *
 * The University of Notre Dame grants you ("Licensee") a
 * non-exclusive, royalty free, license to use, modify and
 * redistribute this software in source and binary code form, provided
 * that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the
 *    distribution.
 *
 * This software is provided "AS IS," without a warranty of any
 * kind. All express or implied conditions, representations and
 * warranties, including any implied warranty of merchantability,
 * fitness for a particular purpose or non-infringement, are hereby
 * excluded.  The University of Notre Dame and its licensors shall not
 * be liable for any damages suffered by licensee as a result of
 * using, modifying or distributing the software or its
 * derivatives. In no event will the University of Notre Dame or its
 * licensors be liable for any lost revenue, profit or data, or for
 * direct, indirect, special, consequential, incidental or punitive
 * damages, however caused and regardless of the theory of liability,
 * arising out of the use of or inability to use software, even if the
 * University of Notre Dame has been advised of the possibility of
 * such damages.
 *
 * SUPPORT OPEN SCIENCE!  If you use OpenMD or its source code in your
 * research, please cite the appropriate papers when you publish your
 * work.  Good starting points are:
 *                                                                      
 * [1]  Meineke, et al., J. Comp. Chem. 26, 252-271 (2005).             
 * [2]  Fennell & Gezelter, J. Chem. Phys. 124, 234104 (2006).          
 * [3]  Sun, Lin & Gezelter, J. Chem. Phys. 128, 24107 (2008).          
 * [4]  Vardeman & Gezelter, in progress (2009).                        
 */

#ifndef PARALLEL_COMMUNICATOR_HPP
#define PARALLEL_COMMUNICATOR_HPP

#include <config.h>
#include <mpi.h>
#include "math/SquareMatrix3.hpp"

namespace OpenMD{
  
#ifdef IS_MPI

  enum communicatorType {
    Global = 0,
    Row = 1,
    Column = 2
  };
    
  template<typename T> 
  struct MPITraits
  {
    static const MPI::Datatype datatype;
    static const int dim;
  };
  
  template<> const MPI::Datatype MPITraits<int>::datatype = MPI_INT;
  template<> const int MPITraits<int>::dim = 1;
  template<> const MPI::Datatype MPITraits<RealType>::datatype = MPI_REALTYPE;
  template<> const int MPITraits<RealType>::dim = 1;
  template<> const MPI::Datatype MPITraits<Vector3d>::datatype = MPI_REALTYPE;
  template<> const int MPITraits<Vector3d>::dim = 3;
  template<> const MPI::Datatype MPITraits<Mat3x3d>::datatype = MPI_REALTYPE;
  template<> const int MPITraits<Mat3x3d>::dim = 9;
  
  template<communicatorType D, typename T>
  class Communicator { 
  public: 
    
    Communicator<D, T>(int nObjects) {
      
      int nProc = MPI::COMM_WORLD.Get_size();
      int myRank = MPI::COMM_WORLD.Get_rank();

      int nColumnsMax = (int) sqrt(RealType(nProc));

      int nColumns;
      for (int i = 1; i < nColumnsMax + 1; i++) {
        if (nProc % i == 0) nColumns = i;        
      }
        
      int nRows = nProc / nColumns;
      rowIndex_ = myRank / nColumns;      
      columnIndex_ = myRank % nColumns;

      switch(D) {
      case Row :
        myComm = MPI::COMM_WORLD.Split(rowIndex_, 0);
        break;
      case Column:
        myComm = MPI::COMM_WORLD.Split(columnIndex_, 0);
        break;
      case Global:
        myComm = MPI::COMM_WORLD.Split(myRank, 0);
      }
         
      int nCommProcs = myComm.Get_size();

      counts.reserve(nCommProcs);
      displacements.reserve(nCommProcs);

      planSize_ = MPITraits<T>::dim * nObjects; 

      myComm.Allgather(&planSize_, 1, MPI::INT, &counts[0], 1, MPI::INT);

      displacements[0] = 0;
      for (int i = 1; i < nCommProcs; i++) {
        displacements[i] = displacements[i-1] + counts[i-1];
        size_ += counts[i-1];
      }

      size_ = 0;
      for (int i = 0; i < nCommProcs; i++) {
        size_ += counts[i];
      }
    }


    void gather(std::vector<T>& v1, std::vector<T>& v2) {
      
      myComm.Allgatherv(&v1[0], 
                        planSize_, 
                        MPITraits<T>::datatype, 
                        &v2[0], 
                        &counts[0], 
                        &displacements[0], 
                        MPITraits<T>::datatype);      
    }

    
    void scatter(std::vector<T>& v1, std::vector<T>& v2) {

      myComm.Reduce_scatter(&v1[0], &v2[0], &counts[0], 
                            MPITraits<T>::datatype, MPI::SUM);
    }

    int getSize() {
      return size_;
    }
    
  private:
    int planSize_;     ///< how many are on local proc
    int rowIndex_;
    int columnIndex_;
    int size_;
    std::vector<int> counts;
    std::vector<int> displacements;
    MPI::Intracomm myComm;
  }; 

#endif
}
#endif


Revision:	1549
Committed:	Wed Apr 27 18:38:15 2011 UTC (14 years ago) by gezelter
File size:	5346 byte(s)
Log Message:	a few more tweaks We're getting somewhat closer to deleting fortran.
#	User	Rev	Content
1	gezelter	1539	/**
2			* @file Communicator.hpp
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	gezelter	1544	#ifndef PARALLEL_COMMUNICATOR_HPP
50			#define PARALLEL_COMMUNICATOR_HPP
51	gezelter	1539
52			#include <config.h>
53			#include <mpi.h>
54			#include "math/SquareMatrix3.hpp"
55
56			namespace OpenMD{
57
58			#ifdef IS_MPI
59
60	gezelter	1549	enum communicatorType {
61			Global = 0,
62			Row = 1,
63			Column = 2
64	gezelter	1539	};
65
66			template<typename T>
67			struct MPITraits
68			{
69			static const MPI::Datatype datatype;
70			static const int dim;
71			};
72
73			template<> const MPI::Datatype MPITraits<int>::datatype = MPI_INT;
74			template<> const int MPITraits<int>::dim = 1;
75			template<> const MPI::Datatype MPITraits<RealType>::datatype = MPI_REALTYPE;
76			template<> const int MPITraits<RealType>::dim = 1;
77			template<> const MPI::Datatype MPITraits<Vector3d>::datatype = MPI_REALTYPE;
78			template<> const int MPITraits<Vector3d>::dim = 3;
79			template<> const MPI::Datatype MPITraits<Mat3x3d>::datatype = MPI_REALTYPE;
80			template<> const int MPITraits<Mat3x3d>::dim = 9;
81
82	gezelter	1549	template<communicatorType D, typename T>
83	gezelter	1540	class Communicator {
84	gezelter	1539	public:
85
86	gezelter	1540	Communicator<D, T>(int nObjects) {
87	gezelter	1539
88			int nProc = MPI::COMM_WORLD.Get_size();
89			int myRank = MPI::COMM_WORLD.Get_rank();
90
91			int nColumnsMax = (int) sqrt(RealType(nProc));
92
93			int nColumns;
94			for (int i = 1; i < nColumnsMax + 1; i++) {
95			if (nProc % i == 0) nColumns = i;
96			}
97
98			int nRows = nProc / nColumns;
99			rowIndex_ = myRank / nColumns;
100			columnIndex_ = myRank % nColumns;
101
102	gezelter	1549	switch(D) {
103			case Row :
104	gezelter	1539	myComm = MPI::COMM_WORLD.Split(rowIndex_, 0);
105	gezelter	1549	break;
106			case Column:
107	gezelter	1539	myComm = MPI::COMM_WORLD.Split(columnIndex_, 0);
108	gezelter	1549	break;
109			case Global:
110			myComm = MPI::COMM_WORLD.Split(myRank, 0);
111	gezelter	1539	}
112
113			int nCommProcs = myComm.Get_size();
114
115			counts.reserve(nCommProcs);
116			displacements.reserve(nCommProcs);
117
118			planSize_ = MPITraits<T>::dim * nObjects;
119
120			myComm.Allgather(&planSize_, 1, MPI::INT, &counts[0], 1, MPI::INT);
121
122			displacements[0] = 0;
123			for (int i = 1; i < nCommProcs; i++) {
124			displacements[i] = displacements[i-1] + counts[i-1];
125	gezelter	1544	size_ += counts[i-1];
126	gezelter	1541	}
127
128			size_ = 0;
129			for (int i = 0; i < nCommProcs; i++) {
130			size_ += counts[i];
131			}
132	gezelter	1539	}
133
134
135			void gather(std::vector<T>& v1, std::vector<T>& v2) {
136
137			myComm.Allgatherv(&v1[0],
138			planSize_,
139			MPITraits<T>::datatype,
140			&v2[0],
141			&counts[0],
142			&displacements[0],
143			MPITraits<T>::datatype);
144			}
145
146
147
148			void scatter(std::vector<T>& v1, std::vector<T>& v2) {
149
150			myComm.Reduce_scatter(&v1[0], &v2[0], &counts[0],
151			MPITraits<T>::datatype, MPI::SUM);
152			}
153	gezelter	1541
154			int getSize() {
155			return size_;
156			}
157	gezelter	1539
158			private:
159			int planSize_; ///< how many are on local proc
160			int rowIndex_;
161			int columnIndex_;
162	gezelter	1541	int size_;
163	gezelter	1539	std::vector<int> counts;
164			std::vector<int> displacements;
165			MPI::Intracomm myComm;
166			};
167
168			#endif
169			}
170			#endif
171
172