broadcast.hpp

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// Copyright (c) 2020-2023 Simons Foundation
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0.txt
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Authors: Olivier Parcollet, Nils Wentzell
 
#pragma once
 
#include "../basic_functions.hpp"
#include "../concepts.hpp"
#include "../exceptions.hpp"
#include "../traits.hpp"
 
#include <mpi/mpi.hpp>
 
namespace nda {
 
  template <typename A>
  void mpi_broadcast(A &a, mpi::communicator comm = {}, int root = 0)
    requires(is_regular_or_view_v<A>)
  {
    static_assert(has_contiguous_layout<A>, "Error in MPI broadcast for nda::Array: Array needs to be contiguous");
    auto dims = a.shape();
    MPI_Bcast(&dims[0], dims.size(), mpi::mpi_type<typename decltype(dims)::value_type>::get(), root, comm.get());
    if (comm.rank() != root) { resize_or_check_if_view(a, dims); }
    MPI_Bcast(a.data(), a.size(), mpi::mpi_type<typename A::value_type>::get(), root, comm.get());
  }
 
} // namespace nda