src/gromacs/utility/physicalnodecommunicator.h

   1 /*
   2  * This file is part of the GROMACS molecular simulation package.
   3  *
   4  * Copyright (c) 2018,2019, by the GROMACS development team, led by
   5  * Mark Abraham, David van der Spoel, Berk Hess, and Erik Lindahl,
   6  * and including many others, as listed in the AUTHORS file in the
   7  * top-level source directory and at http://www.gromacs.org.
   8  *
   9  * GROMACS is free software; you can redistribute it and/or
  10  * modify it under the terms of the GNU Lesser General Public License
  11  * as published by the Free Software Foundation; either version 2.1
  12  * of the License, or (at your option) any later version.
  13  *
  14  * GROMACS is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  17  * Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public
  20  * License along with GROMACS; if not, see
  21  * http://www.gnu.org/licenses, or write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA.
  23  *
  24  * If you want to redistribute modifications to GROMACS, please
  25  * consider that scientific software is very special. Version
  26  * control is crucial - bugs must be traceable. We will be happy to
  27  * consider code for inclusion in the official distribution, but
  28  * derived work must not be called official GROMACS. Details are found
  29  * in the README & COPYING files - if they are missing, get the
  30  * official version at http://www.gromacs.org.
  31  *
  32  * To help us fund GROMACS development, we humbly ask that you cite
  33  * the research papers on the package. Check out http://www.gromacs.org.
  34  */
  35 /*! \libinternal \file
  36  * \brief
  37  * Declares functionality for communicators across physical nodes.
  38  *
  39  * \inlibraryapi
  40  * \ingroup module_utility
  41  */
  42 #ifndef GMX_MDTYPES_PHYSICALNODECOMMUNICATOR_H
  43 #define GMX_MDTYPES_PHYSICALNODECOMMUNICATOR_H
  44
  45 #include "gromacs/utility/gmxmpi.h"
  46 #include "gromacs/utility/unique_cptr.h"
  47
  48 namespace gmx
  49 {
  50
  51 /*! \brief Wrapper function for RAII-style cleanup.
  52  *
  53  * This is needed to discard the return value so it can be used as a
  54  * deleter by a smart pointer. */
  55 void MPI_Comm_free_wrapper(MPI_Comm* comm);
  56
  57 //! Make a smart pointer for MPI communicators.
  58 using MPI_Comm_ptr = gmx::unique_cptr<MPI_Comm, MPI_Comm_free_wrapper>;
  59
  60 /*! \libinternal \brief Holds a communicator for the physical node of this rank
  61  *
  62  * This communicator should only be used for appropriate tasks,
  63  * e.g. during initialization and finalization. It can contain ranks
  64  * from PP, PME and multiple simulations with multisim, so is not
  65  * suited for general-purpose communication. */
  66 class PhysicalNodeCommunicator
  67 {
  68 public:
  69     /*! \brief Constructor.
  70      *
  71      * Communicates within \c world to make intra-communicator \c
  72      * comm_ between all ranks that share \c physicalNodeId. */
  73     PhysicalNodeCommunicator(MPI_Comm world, int physicalNodeId);
  74     //! Communicator for all ranks on this physical node
  75     MPI_Comm comm_;
  76     //! Number of ranks on this physical node, corresponds to MPI_Comm_size of comm.
  77     int size_;
  78     //! Rank ID within this physical node, corresponds to MPI_Comm_rank of comm.
  79     int rank_;
  80     //! RAII handler for cleaning up \c comm_ only when appropriate.
  81     MPI_Comm_ptr commGuard_;
  82     //! Creates a barrier for all ranks on this physical node.
  83     void barrier() const;
  84 };
  85
  86 } // namespace gmx
  87
  88 #endif