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/*
* Distributed under the OSI-approved Apache License, Version 2.0. See
* accompanying file Copyright.txt for details.
*
* bpStepsWriteRead.cpp Simple example of writing and reading data through ADIOS2 BP engine with
* multiple simulations steps for every IO step.
*
* Created on: Feb 16, 2017
* Author: William F Godoy godoywf@ornl.gov
*/
#include <algorithm> // std::for_each
#include <ios> // std::ios_base::failure
#include <iostream> // std::cout
#if ADIOS2_USE_MPI
#include <mpi.h>
#endif
#include <stdexcept> //std::invalid_argument std::exception
#include <vector>
#include <adios2.h>
void update_array(std::vector<float> &array, int val)
{
std::transform(array.begin(), array.end(), array.begin(),
[val](float v) -> float { return v + static_cast<float>(val); });
}
void writer(adios2::ADIOS &adios, const std::string &engine, const std::string &fname,
const size_t Nx, unsigned int nSteps, int rank, int size)
{
std::vector<float> simData(Nx, 0);
adios2::IO bpIO = adios.DeclareIO("WriteIO");
bpIO.SetEngine(engine);
const adios2::Dims shape{static_cast<size_t>(size * Nx)};
const adios2::Dims start{static_cast<size_t>(rank * Nx)};
const adios2::Dims count{Nx};
auto bpFloats = bpIO.DefineVariable<float>("bpFloats", shape, start, count);
auto bpStep = bpIO.DefineVariable<unsigned int>("bpStep");
adios2::Engine bpWriter = bpIO.Open(fname, adios2::Mode::Write);
for (unsigned int step = 0; step < nSteps; ++step)
{
const adios2::Box<adios2::Dims> sel({0}, {Nx});
bpFloats.SetSelection(sel);
bpWriter.BeginStep();
bpWriter.Put(bpFloats, simData.data());
bpWriter.Put(bpStep, step);
bpWriter.EndStep();
// Update values in the simulation data
update_array(simData, 10);
}
bpWriter.Close();
}
void reader(adios2::ADIOS &adios, const std::string &engine, const std::string &fname,
const size_t Nx, unsigned int /*nSteps*/, int rank, int /*size*/)
{
adios2::IO bpIO = adios.DeclareIO("ReadIO");
bpIO.SetEngine(engine);
adios2::Engine bpReader = bpIO.Open(fname, adios2::Mode::Read);
std::vector<float> simData(Nx, 0);
unsigned int inStep = 0;
for (unsigned int step = 0; bpReader.BeginStep() == adios2::StepStatus::OK; ++step)
{
auto bpFloats = bpIO.InquireVariable<float>("bpFloats");
if (bpFloats)
{
const adios2::Box<adios2::Dims> sel({{Nx * rank}, {Nx}});
bpFloats.SetSelection(sel);
bpReader.Get(bpFloats, simData.data());
}
auto bpStep = bpIO.InquireVariable<unsigned int>("bpStep");
if (bpStep)
{
bpReader.Get(bpStep, &inStep);
}
bpReader.EndStep();
if (inStep != step)
{
std::cout << "ERROR: step mismatch\n";
return;
}
}
bpReader.Close();
}
int main(int argc, char *argv[])
{
int rank, size;
#if ADIOS2_USE_MPI
int provided;
// MPI_THREAD_MULTIPLE is only required if you enable the SST MPI_DP
MPI_Init_thread(&argc, &argv, MPI_THREAD_MULTIPLE, &provided);
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
MPI_Comm_size(MPI_COMM_WORLD, &size);
#else
rank = 0;
size = 1;
#endif
const std::string engine = argv[1] ? argv[1] : "BPFile";
std::cout << "Using engine " << engine << std::endl;
const std::string filename = engine + "StepsWriteRead.bp";
const unsigned int nSteps = 10;
const unsigned int Nx = 60000;
try
{
/** ADIOS class factory of IO class objects */
#if ADIOS2_USE_MPI
adios2::ADIOS adios(MPI_COMM_WORLD);
#else
adios2::ADIOS adios;
#endif
writer(adios, engine, filename, Nx, nSteps, rank, size);
reader(adios, engine, filename, Nx, nSteps, rank, size);
}
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";
}
#if ADIOS2_USE_MPI
MPI_Finalize();
#endif
return 0;
}
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