mirror of
https://gitlab.kitware.com/vtk/vtk-m
synced 2024-09-19 10:35:42 +00:00
69bacdfca8
The examples do not get compiled as often as the test, so minor issues sometimes creep in. The histogram example was still using some deprecated methods.
115 lines
3.4 KiB
C++
115 lines
3.4 KiB
C++
//============================================================================
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// Copyright (c) Kitware, Inc.
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// All rights reserved.
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// See LICENSE.txt for details.
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//
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// This software is distributed WITHOUT ANY WARRANTY; without even
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// the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
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// PURPOSE. See the above copyright notice for more information.
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//============================================================================
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/*
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* This example demonstrates how one can write a filter that uses MPI
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* for hybrid-parallelism. The `vtkm::filter::Histogram` is another approach for
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* implementing the same that uses DIY. This example doesn't use DIY, instead
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* uses MPI calls directly.
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*/
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#include "HistogramMPI.h"
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#include <vtkm/cont/ArrayPortalToIterators.h>
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#include <vtkm/cont/EnvironmentTracker.h>
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#include <vtkm/cont/Initialize.h>
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#include <vtkm/thirdparty/diy/diy.h>
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#include <mpi.h>
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#include <algorithm>
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#include <numeric>
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#include <random>
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#include <utility>
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#include <vector>
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namespace
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{
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template <typename T>
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VTKM_CONT vtkm::cont::ArrayHandle<T> CreateArray(T min, T max, vtkm::Id numVals)
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{
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std::mt19937 gen;
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std::uniform_real_distribution<double> dis(static_cast<double>(min), static_cast<double>(max));
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vtkm::cont::ArrayHandle<T> handle;
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handle.Allocate(numVals);
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std::generate(vtkm::cont::ArrayPortalToIteratorBegin(handle.WritePortal()),
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vtkm::cont::ArrayPortalToIteratorEnd(handle.WritePortal()),
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[&]() { return static_cast<T>(dis(gen)); });
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return handle;
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}
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}
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int main(int argc, char* argv[])
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{
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//parse out all vtk-m related command line options
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auto opts =
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vtkm::cont::InitializeOptions::DefaultAnyDevice | vtkm::cont::InitializeOptions::Strict;
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vtkm::cont::Initialize(argc, argv, opts);
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// setup MPI environment.
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vtkmdiy::mpi::environment env(argc, argv); // will finalize on destruction
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vtkmdiy::mpi::communicator world; // the default is MPI_COMM_WORLD
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// tell VTK-m the communicator to use.
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vtkm::cont::EnvironmentTracker::SetCommunicator(world);
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int rank, size;
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MPI_Comm_rank(vtkmdiy::mpi::mpi_cast(world.handle()), &rank);
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MPI_Comm_size(vtkmdiy::mpi::mpi_cast(world.handle()), &size);
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if (argc != 2)
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{
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if (rank == 0)
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{
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std::cout << "Usage: " << std::endl << "$ " << argv[0] << " <num-bins>" << std::endl;
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}
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return EXIT_FAILURE;
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}
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const vtkm::Id num_bins = static_cast<vtkm::Id>(std::atoi(argv[1]));
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const vtkm::Id numVals = 1024;
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vtkm::cont::PartitionedDataSet pds;
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vtkm::cont::DataSet ds;
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ds.AddPointField("pointvar", CreateArray(-1024, 1024, numVals));
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pds.AppendPartition(ds);
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example::HistogramMPI histogram;
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histogram.SetActiveField("pointvar");
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histogram.SetNumberOfBins(std::max<vtkm::Id>(1, num_bins));
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vtkm::cont::PartitionedDataSet result = histogram.Execute(pds);
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vtkm::cont::ArrayHandle<vtkm::Id> bins;
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result.GetPartition(0).GetField("histogram").GetData().AsArrayHandle(bins);
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auto binPortal = bins.ReadPortal();
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if (rank == 0)
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{
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// print histogram.
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std::cout << "Histogram (" << num_bins << ")" << std::endl;
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vtkm::Id count = 0;
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for (vtkm::Id cc = 0; cc < num_bins; ++cc)
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{
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std::cout << " bin[" << cc << "] = " << binPortal.Get(cc) << std::endl;
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count += binPortal.Get(cc);
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}
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if (count != numVals * size)
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{
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std::cout << "ERROR: bins mismatched!" << std::endl;
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return EXIT_FAILURE;
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}
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}
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return EXIT_SUCCESS;
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}
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