vtk-m/vtkm/cont/AssignerMultiBlock.cxx

94 lines
2.8 KiB
C++

//============================================================================
// Copyright (c) Kitware, Inc.
// All rights reserved.
// See LICENSE.txt for details.
// This software is distributed WITHOUT ANY WARRANTY; without even
// the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
// PURPOSE. See the above copyright notice for more information.
//
// Copyright 2015 National Technology & Engineering Solutions of Sandia, LLC (NTESS).
// Copyright 2015 UT-Battelle, LLC.
// Copyright 2015 Los Alamos National Security.
//
// Under the terms of Contract DE-NA0003525 with NTESS,
// the U.S. Government retains certain rights in this software.
//
// Under the terms of Contract DE-AC52-06NA25396 with Los Alamos National
// Laboratory (LANL), the U.S. Government retains certain rights in
// this software.
//============================================================================
#include <vtkm/cont/AssignerMultiBlock.h>
#include <vtkm/cont/EnvironmentTracker.h>
#include <vtkm/cont/MultiBlock.h>
// clang-format off
VTKM_THIRDPARTY_PRE_INCLUDE
#include VTKM_DIY(diy/mpi.hpp)
VTKM_THIRDPARTY_POST_INCLUDE
// clang-format on
#include <algorithm> // std::lower_bound
#include <numeric> // std::iota
namespace vtkm
{
namespace cont
{
VTKM_CONT
AssignerMultiBlock::AssignerMultiBlock(const vtkm::cont::MultiBlock& mb)
: AssignerMultiBlock(mb.GetNumberOfBlocks())
{
}
VTKM_CONT
AssignerMultiBlock::AssignerMultiBlock(vtkm::Id num_blocks)
: diy::StaticAssigner(vtkm::cont::EnvironmentTracker::GetCommunicator().size(), 1)
, IScanBlockCounts()
{
auto comm = vtkm::cont::EnvironmentTracker::GetCommunicator();
if (comm.size() > 1)
{
vtkm::Id iscan;
diy::mpi::scan(comm, num_blocks, iscan, std::plus<vtkm::Id>());
diy::mpi::all_gather(comm, iscan, this->IScanBlockCounts);
}
else
{
this->IScanBlockCounts.push_back(num_blocks);
}
this->set_nblocks(static_cast<int>(this->IScanBlockCounts.back()));
}
VTKM_CONT
void AssignerMultiBlock::local_gids(int my_rank, std::vector<int>& gids) const
{
const size_t s_rank = static_cast<size_t>(my_rank);
if (my_rank == 0)
{
assert(this->IScanBlockCounts.size() > 0);
gids.resize(static_cast<size_t>(this->IScanBlockCounts[s_rank]));
std::iota(gids.begin(), gids.end(), 0);
}
else if (my_rank > 0 && s_rank < this->IScanBlockCounts.size())
{
gids.resize(
static_cast<size_t>(this->IScanBlockCounts[s_rank] - this->IScanBlockCounts[s_rank - 1]));
std::iota(gids.begin(), gids.end(), static_cast<int>(this->IScanBlockCounts[s_rank - 1]));
}
}
VTKM_CONT
int AssignerMultiBlock::rank(int gid) const
{
return static_cast<int>(
std::lower_bound(this->IScanBlockCounts.begin(), this->IScanBlockCounts.end(), gid + 1) -
this->IScanBlockCounts.begin());
}
} // vtkm::cont
} // vtkm