Line data    Source code

       1             : // Copyright (C) 2015 Technische Universitaet Muenchen
       2             : // This file is part of the Mamico project. For conditions of distribution
       3             : // and use, please see the copyright notice in Mamico's main folder, or at
       4             : // www5.in.tum.de/mamico
       5             : #ifndef _TARCH_UTILS_MULTIMDSERVICE_H_
       6             : #define _TARCH_UTILS_MULTIMDSERVICE_H_
       7             : 
       8             : #include "tarch/TarchDefinitions.h"
       9             : #include "tarch/la/Vector.h"
      10             : #include <cstdlib>
      11             : #include <numeric>
      12             : #include <vector>
      13             : #if (TARCH_PARALLEL == TARCH_YES)
      14             : #include <mpi.h>
      15             : #endif
      16             : 
      17             : namespace tarch {
      18             : namespace utils {
      19             : template <unsigned int dim> class MultiMDService;
      20             : }
      21             : } // namespace tarch
      22             : 
      23             : /** maps a number of MD simulations onto the total number of available ranks.
      24             :  *  For each MD simulation, a regular domain decomposition into n0 x n1 x ... x
      25             :  * nD processes is assumed.
      26             :  *  We further assume that the total number of processes can be divided by the
      27             :  * number of processes required by each MD simulation.
      28             :  *  @author Philipp Neumann
      29             :  */
      30             : template <unsigned int dim> class tarch::utils::MultiMDService {
      31             : public:
      32             :   MultiMDService(const tarch::la::Vector<dim, unsigned int>& numberProcesses, const unsigned int& totalNumberMDSimulations
      33             : #if (TARCH_PARALLEL == TARCH_YES)
      34             :                  ,
      35             :                  MPI_Comm globalComm = MPI_COMM_WORLD
      36             : #endif
      37             :   );
      38             :   ~MultiMDService();
      39             : 
      40             :   unsigned int getGlobalNumberOfLocalMDSimulation(unsigned int localMDSimulation) const;
      41             : 
      42             :   int getLocalNumberOfGlobalMDSimulation(unsigned int globalMDSimulation) const;
      43             : 
      44          48 :   unsigned int getLocalNumberOfMDSimulations() const { return _thisNumberMDSimulations; }
      45             : 
      46          36 :   unsigned int getAvgNumberOfMDSimulations() const { return _avgNumberMDSimulationsPerLocalComm; }
      47             : 
      48             :   tarch::la::Vector<dim, unsigned int> getNumberProcessesPerMDSimulation() const { return _numberProcessesPerMDSimulation; }
      49             : 
      50             : #if (TARCH_PARALLEL == TARCH_YES)
      51          12 :   MPI_Comm getLocalCommunicator() const { return _localComm; }
      52             : #endif
      53             :   unsigned int getLocalRank() const { return _localRank; }
      54             :   unsigned int getLocalSize() const { return _localSize; }
      55             : 
      56             : #if (TARCH_PARALLEL == TARCH_YES)
      57         136 :   MPI_Comm getGlobalCommunicator() const { return _globalComm; }
      58             : #endif
      59             :   unsigned int getGlobalRank() const { return _globalRank; }
      60             :   unsigned int getGlobalSize() const { return _globalSize; }
      61             : 
      62             :   // TODO: unused function
      63             :   void setTotalNumberMDSimulations(unsigned int n) { _totalNumberMDSimulations = n; }
      64           1 :   unsigned int getTotalNumberOfMDSimulations() { return _totalNumberMDSimulations; }
      65             : 
      66             :   void addMDSimulationBlock() {
      67             :     _totalNumberMDSimulations += _numberLocalComms;
      68             :     _avgNumberMDSimulationsPerLocalComm = _totalNumberMDSimulations / _numberLocalComms;
      69             :     if ((unsigned int)(_globalRank / _localSize + 1) == _numberLocalComms) {
      70             :       _thisNumberMDSimulations = _totalNumberMDSimulations - _avgNumberMDSimulationsPerLocalComm * (_numberLocalComms - 1);
      71             :     } else {
      72             :       _thisNumberMDSimulations = _avgNumberMDSimulationsPerLocalComm;
      73             :     }
      74             :   }
      75             : 
      76             :   void removeMDSimulationBlock() {
      77             :     _totalNumberMDSimulations -= _numberLocalComms;
      78             :     _avgNumberMDSimulationsPerLocalComm = _totalNumberMDSimulations / _numberLocalComms;
      79             :     if ((unsigned int)(_globalRank / _localSize + 1) == _numberLocalComms) {
      80             :       _thisNumberMDSimulations = _totalNumberMDSimulations - _avgNumberMDSimulationsPerLocalComm * (_numberLocalComms - 1);
      81             :     } else {
      82             :       _thisNumberMDSimulations = _avgNumberMDSimulationsPerLocalComm;
      83             :     }
      84             :   }
      85             : 
      86             :   int getRank() const { return this->_globalRank; }
      87             :   int getSize() const { return this->_globalSize; }
      88             : 
      89          21 :   unsigned int getNumberLocalComms() const { return _numberLocalComms; }
      90             : 
      91             : private:
      92             : #if (TARCH_PARALLEL == TARCH_YES)
      93             :   MPI_Comm _localComm;  // communicator of "local" MD simulation
      94             :   MPI_Comm _globalComm; // normally MPI_COMM_WORLD, unless there are ranks outside all MD simulations (e.g. due to PinT)
      95             : #endif
      96             :   // number of processes used for a single MD simulation. Currently, the total
      97             :   // number of MPI processes needs to
      98             :   // be a multiple of the number of processes per MD simulation (=product of the
      99             :   // vector components)
     100             :   const tarch::la::Vector<dim, unsigned int> _numberProcessesPerMDSimulation;
     101             :   // number of local communicators
     102             :   unsigned int _numberLocalComms;
     103             :   // total number of MD simulations
     104             :   unsigned int _totalNumberMDSimulations;
     105             :   // average number of MD simulations that is processed per local communicator.
     106             :   // If we have 4 processes per MD simulation and 12 processes available and
     107             :   // want to run 26 MD simulations,
     108             :   // then this value is given by 26/(12/4) = 26/3 = 8
     109             :   unsigned int _avgNumberMDSimulationsPerLocalComm;
     110             :   // number of MD simulations for this current local communicator. Except for
     111             :   // the "last communicator", this value
     112             :   // equals _avgNumberMDSimulationsPerLocalComm. The last comunicator group
     113             :   // fills up the missing MD simulations.
     114             :   // If we have 4 processes per MD simulation and 12 processes available and
     115             :   // want to run 26 MD simulations,
     116             :   // then we have 12/4=3 communicator groups, of which group 0 and 1 handle
     117             :   // 26/3=8 MD simulations. The last group 2
     118             :   // handles 26-2*8 = 10 MD simulations.
     119             :   unsigned int _thisNumberMDSimulations;
     120             : 
     121             :   int _globalSize; // global number of available MPI processes
     122             :   int _globalRank; // rank in global communicator getGlobalCommunicator()
     123             : 
     124             :   int _localSize; // size of communicator _localComm
     125             :   int _localRank; // local rank in communicator _localComm
     126             : };
     127             : 
     128             : #include "tarch/utils/MultiMDService.cpph"
     129             : #endif