sys/mpiDummyWorld.h

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/**
 *  @file      mpiDummyWorld.h
 *  @brief     A dummy message passing interface (MPI).
 *  @author    Mikica Kocic
 *  @copyright GNU General Public License (GPLv3).
 */

/** Implements a dummy message passing interface (MPI).
 *  To enable a real MPI, use `mpic++` with `-D_USEMPI`.
 *
 *  @warning The maximal slicing is not compliant with MPI since the boundary value
 *  problem for the slicing differential equation requires access to the whole grid!
 */
class DummyMPIWorld
{
public:
    int size () const { return 1; } //!< The size of the MPI world
    int rank () const { return 0; } //!< Our rank in the MPI world

    bool isFirstInRank () const { return true; }
    bool isLastInRank () const { return true; }

    /** Exchange the boundary data with the neighboring ranks.
     */
    void exchangeBoundaries
    (
        void* left_ghost,  //!< Where to put the right edge of the left neighbor
        void* left_edge,   //!< Pointer to the left edge of our data
        void* right_edge,  //!< Pointer to the right edge of our data
        void* right_ghost, //!< Where to put the left edge of the right neighbor
        int   edge_size    //!< The edge (or ghost) size
        )
    {}

    /** Wait the other ranks to have received our edges.
     */
    void waitExchange ()
    {}
};

typedef DummyMPIWorld MPIWorld;