mpi_sendrecv.jl

import MPI

function do_sendrecv(N)
    comm = MPI.COMM_WORLD

    MPI.Barrier(comm)

    rank = MPI.Comm_rank(comm)
    size = MPI.Comm_size(comm)

    rank ==0 && print("$N : ")

    dst = rank == 0 ? 1 : 0

    tic()
    for n in 1:10^4
        send_mesg = Array(Float64, N)
        recv_mesg = Array(Float64, N)

        fill!(send_mesg, Float64(n))

        rreq = MPI.Irecv!(recv_mesg, dst, n, comm)

        #println("$rank: Sending   $rank -> $dst = $send_mesg")
        sreq = MPI.Isend(send_mesg, dst, n, comm)

        stats = MPI.Waitall!([rreq, sreq])

        assert(send_mesg[1] == recv_mesg[1])

        #println("$rank: Receiving $src -> $rank = $recv_mesg")
    end
    t=toq()

    rank ==0 && println(t)

    MPI.Barrier(comm)
end

function main()
    MPI.Init()

    do_sendrecv(1)
    for i in 1:6
        do_sendrecv(10^(i-1))
    end

    MPI.Finalize()
end

main()