mpi_vector.h

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#pragma once
 
#include <cassert>
#include <thrust/host_vector.h>
#include <thrust/gather.h>
#include "exceptions.h"
#include "tensor_traits.h"
#include "blas1_dispatch_shared.h"
#include "mpi_datatype.h"
#include "memory.h"
#include "config.h"
 
namespace dg
{
 
template<class container>
struct MPI_Vector
{
    using container_type = container;
 
    MPI_Vector()
    : m_comm ( MPI_COMM_NULL)
    {
    }
    MPI_Vector( container data, MPI_Comm comm)
    : m_data( data), m_comm(comm)
    {
    }
 
    template<class OtherContainer>
    MPI_Vector( const MPI_Vector<OtherContainer>& src)
    : m_data( src.data()), m_comm(src.communicator())
    {
    }
 
    const container& data() const {return m_data;}
 
    container& data() {return m_data;}
 
    MPI_Comm communicator() const{return m_comm;}
 
    void set_communicator(MPI_Comm comm)
    {
        m_comm = comm;
    }
 
    unsigned size() const{return m_data.size();}
 
    void swap( MPI_Vector& src)
    {
        m_data.swap(src.m_data);
        std::swap( m_comm , src.m_comm);
    }
    friend void swap( MPI_Vector<container>& first, MPI_Vector<container>& second)
    {
        //free function as required by the std to be swappable
        //https://en.cppreference.com/w/cpp/named_req/Swappable
        //even though with move assignments std::swap also works as fast
        first.swap(second);
    }
  private:
    container m_data;
    MPI_Comm m_comm;
 
};
 
 
template<class container>
struct TensorTraits<MPI_Vector<container> > {
    using value_type = get_value_type<container>;
    using tensor_category = MPIVectorTag;
    using execution_policy = get_execution_policy<container>;
};
 
}//namespace dg