Tpetra_Details_extractMpiCommFromTeuchos.cpp

// @HEADER
// *****************************************************************************
//          Tpetra: Templated Linear Algebra Services Package
//
// Copyright 2008 NTESS and the Tpetra contributors.
// SPDX-License-Identifier: BSD-3-Clause
// *****************************************************************************
// @HEADER

#include "Tpetra_Details_extractMpiCommFromTeuchos.hpp"

#ifdef HAVE_TPETRACORE_MPI
#include "Teuchos_DefaultMpiComm.hpp"
#include "Teuchos_DefaultSerialComm.hpp"
#include <stdexcept>
#endif  // HAVE_TPETRACORE_MPI

namespace Tpetra {
namespace Details {

#ifdef HAVE_TPETRACORE_MPI
MPI_Comm
extractMpiCommFromTeuchos(const Teuchos::Comm<int>& comm) {
  using ::Teuchos::MpiComm;
  using ::Teuchos::SerialComm;

  const MpiComm<int>* mpiComm = dynamic_cast<const MpiComm<int>*>(&comm);
  if (mpiComm != NULL) {  // It's an MpiComm; extract the MPI_Comm
    MPI_Comm rawComm = *(mpiComm->getRawMpiComm());
    return rawComm;
  } else {
    const SerialComm<int>* serialComm =
        dynamic_cast<const SerialComm<int>*>(&comm);
    if (serialComm != NULL) {
      return MPI_COMM_SELF;  // single-process comm including this process
    } else {
      throw std::invalid_argument(
          "Tpetra::Details::extractMpiCommFromTeuchos: "
          "Input Teuchos::Comm is "
          "neither a Teuchos::MpiComm, "
          "nor a Teuchos::SerialComm.  "
          "As a result, I don't know "
          "how to get the MPI_Comm out of it.");
    }
  }
}
#endif  // HAVE_TPETRACORE_MPI

#ifdef HAVE_TPETRACORE_MPI
bool teuchosCommIsAnMpiComm(const Teuchos::Comm<int>& comm) {
  const Teuchos::MpiComm<int>* mpiComm =
      dynamic_cast<const Teuchos::MpiComm<int>*>(&comm);
  return mpiComm != nullptr;
}
#else
bool teuchosCommIsAnMpiComm(const Teuchos::Comm<int>&) {
  return false;
}
#endif  // HAVE_TPETRACORE_MPI

}  // namespace Details
}  // namespace Tpetra