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/*
* Distributed under the OSI-approved Apache License, Version 2.0. See
* accompanying file Copyright.txt for details.
*
* bpReaderHeatMap2D.cpp : Writes a heat map in a regular 2D mesh,
* values grow from 0 in increments of 1
*
* temperature[gNx, Ny]
* where: gNx = MPI_size_x * Nx
*
* 0 1 2 ... Ny-1
* Ny Ny+1 Ny+2 ... 2*Ny-1
* ...
* ...
* (gNx-1)*Ny ... gNx*Ny-1
*
*
* Created on: Nov 1, 2017
* Author: William F Godoy godoywf@ornl.gov
*/
#include <algorithm>
#include <ios> //std::ios_base::failure
#include <iostream> //std::cout
#include <mpi.h>
#include <stdexcept> //std::invalid_argument std::exception
#include <vector>
#include <adios2.h>
int main(int argc, char *argv[])
{
int provided;
// MPI_THREAD_MULTIPLE is only required if you enable the SST MPI_DP
MPI_Init_thread(&argc, &argv, MPI_THREAD_MULTIPLE, &provided);
int rank, size;
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
MPI_Comm_size(MPI_COMM_WORLD, &size);
/** Application variable dimensions */
constexpr std::size_t Nx = 10;
constexpr std::size_t Ny = 10;
const adios2::Dims count{Nx, Ny};
const adios2::Dims start{rank * Nx, 0};
const adios2::Dims shape{size * Nx, Ny};
// populate local temperature values
std::vector<unsigned int> temperatures(Nx * Ny);
for (unsigned int i = 0; i < Nx; ++i)
{
const unsigned int iGlobal = static_cast<unsigned int>(start[0] + i);
for (unsigned int j = 0; j < Ny; ++j)
{
const unsigned int value = static_cast<unsigned int>(iGlobal * shape[1] + j);
temperatures[i * Ny + j] = value;
}
}
try
{
/** ADIOS class factory of IO class objects, Debug is ON by default */
adios2::ADIOS adios(MPI_COMM_WORLD);
// ************************** WRITE
/*** IO class object: settings and factory of Settings: Variables,
* Parameters, Transports, and Execution: Engines */
adios2::IO putHeatMap = adios.DeclareIO("HeatMapWriter");
adios2::Variable<unsigned int> outTemperature = putHeatMap.DefineVariable<unsigned int>(
"temperature", shape, start, count, adios2::ConstantDims);
/** Will create HeatMap.bp */
adios2::Engine bpWriter = putHeatMap.Open("HeatMap2D.bp", adios2::Mode::Write);
bpWriter.BeginStep();
bpWriter.Put(outTemperature, temperatures.data());
bpWriter.EndStep();
bpWriter.Close();
// ************************** READ
if (rank == 0)
{
adios2::IO getHeatMap = adios.DeclareIO("HeatMapReader");
adios2::Engine bpReader =
getHeatMap.Open("HeatMap2D.bp", adios2::Mode::Read, MPI_COMM_SELF);
bpReader.BeginStep();
// this just discovers in the metadata file that the variable exists
adios2::Variable<unsigned int> inTemperature =
getHeatMap.InquireVariable<unsigned int>("temperature");
// now read the variable
if (inTemperature)
{
inTemperature.SetSelection({{2, 2}, {6, 1}});
size_t elementsSize = inTemperature.SelectionSize();
std::vector<unsigned int> inTemperatures(elementsSize);
std::cout << "Pre-allocated " << elementsSize << " elements, "
<< elementsSize * sizeof(unsigned int) << " bytes\n";
bpReader.Get(inTemperature, inTemperatures.data(), adios2::Mode::Sync);
std::cout << "Incoming temperature map:\n";
for (size_t i = 0; i < inTemperatures.size(); ++i)
{
std::cout << inTemperatures[i] << " ";
if ((i + 1) % inTemperature.Count().back() == 0)
{
std::cout << "\n";
}
}
std::cout << "\n";
}
bpReader.EndStep();
bpReader.Close();
}
}
catch (std::invalid_argument &e)
{
std::cout << "Invalid argument exception, STOPPING PROGRAM from rank " << rank << "\n";
std::cout << e.what() << "\n";
}
catch (std::ios_base::failure &e)
{
std::cout << "IO System base failure exception, STOPPING PROGRAM "
"from rank "
<< rank << "\n";
std::cout << e.what() << "\n";
}
catch (std::exception &e)
{
std::cout << "Exception, STOPPING PROGRAM from rank " << rank << "\n";
std::cout << e.what() << "\n";
}
MPI_Finalize();
return 0;
}
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