Function testParallelContext

Tests/Particles/ParallelContext/main.cpp:352–464

}

void testParallelContext ()
{
    BL_PROFILE("testParallelContext");

    // we always make two subcommunicators.
    // one takes the left half of the domain in direction 0, the other the right.
    int rank_n = ParallelContext::NProcsSub();
    int myproc = ParallelContext::MyProcSub();
    int task_me = myproc / (amrex::max(rank_n, 2) / 2);

    if (task_me > 1) { task_me = 1; }

#ifdef BL_USE_MPI
    MPI_Comm new_comm;
    MPI_Comm_split(ParallelContext::CommunicatorSub(), task_me, myproc, &new_comm);
#else
    MPI_Comm new_comm = ParallelContext::CommunicatorSub();
#endif

    const int io_rank = 0;
    ParallelContext::push(new_comm, task_me, io_rank);

    {
        TestParams params;
        get_test_params(params, "redistribute");

        int is_per[] = {AMREX_D_DECL(params.is_periodic,
                                     params.is_periodic,
                                     params.is_periodic)};

        // Each comm gets a different domain
        IntVect hs = params.size / 2;

        RealBox real_box;
        for (int n = 0; n < BL_SPACEDIM; n++)
        {
            Real physlo = (n == 0) ? task_me*hs[n] : 0.0;
            Real physhi = (n == 0) ? task_me*hs[n] + hs[n] : params.size[n];
            real_box.setLo(n, physlo);
            real_box.setHi(n, physhi);
        }

        IntVect domain_lo(AMREX_D_DECL(task_me*hs[0], 0, 0));
        IntVect domain_hi(AMREX_D_DECL(task_me*hs[0] + hs[0] - 1,
                                       params.size[1] - 1,
                                       params.size[2] - 1));
        const Box base_domain(domain_lo, domain_hi);

        Geometry geom;
        geom.define(base_domain, &real_box, CoordSys::cartesian, is_per);

        BoxArray ba;
        ba.define(base_domain);
        ba.maxSize(params.max_grid_size);

        DistributionMapping dm;
        dm.define(ba, ParallelContext::NProcsSub());