Teuchos_MPISession.cpp

Go to the documentation of this file.

// @HEADER
// ***********************************************************************
//
//                    Teuchos: Common Tools Package
//                 Copyright (2004) Sandia Corporation
//
// Under terms of Contract DE-AC04-94AL85000, there is a non-exclusive
// license for use of this work by or on behalf of the U.S. Government.
//
// This library is free software; you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 2.1 of the
// License, or (at your option) any later version.
//
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
// Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public
// License along with this library; if not, write to the Free Software
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
// USA
// Questions? Contact Michael A. Heroux (maherou@sandia.gov)
//
// ***********************************************************************
// @HEADER

#include "Teuchos_MPISession.hpp"
#include "Teuchos_TestForException.hpp"

using namespace Teuchos;

int MPISession::rank_ = 0 ;
int MPISession::nProc_ = 1 ;

void MPISession::init(int* argc, void*** argv)
{
#ifdef HAVE_MPI
  /* initialize MPI */
  int mpiHasBeenStarted = 0;
  MPI_Initialized(& mpiHasBeenStarted);
  int mpierr = 0 ;
  if (!mpiHasBeenStarted)
    {
      mpierr = ::MPI_Init (argc, (char ***) argv);
      TEST_FOR_EXCEPTION(mpierr != 0, std::runtime_error,
                         "Error code=" << mpierr 
                         << " detected in MPI_Init()");
    }
  
  /* find rank */
  mpierr = ::MPI_Comm_rank (MPI_COMM_WORLD, &rank_);
  TEST_FOR_EXCEPTION(mpierr != 0, std::runtime_error,
                     "Error code=" << mpierr 
                     << " detected in MPI_Comm_rank()");

  /* find number of procs */
  mpierr = ::MPI_Comm_size (MPI_COMM_WORLD, &nProc_);

  TEST_FOR_EXCEPTION(mpierr != 0, std::runtime_error,
                     "Error code=" << mpierr 
                     << " detected in MPI_Comm_size()");

  /* get machine name */
  int nameLen;
  char procName[MPI_MAX_PROCESSOR_NAME];
  mpierr = ::MPI_Get_processor_name(procName,&nameLen);

  TEST_FOR_EXCEPTION(mpierr != 0, std::runtime_error,
                     "Error code=" << mpierr 
                     << " detected in MPI_Get_processor_name()");

  if (showStartupMessage())
    {
      std::cerr << "Teuchos::MPISession::init() started processor " 
           << procName << std::endl;
    }
  else
    {
#else
  std::cerr << "Teuchos::MPISession::init() started serial run" << std::endl;
#endif
#ifdef HAVE_MPI
    }
#endif
}

void MPISession::finalize()
{
#ifdef HAVE_MPI
  int mpierr = ::MPI_Finalize();

  TEST_FOR_EXCEPTION(mpierr != 0, std::runtime_error,
                     "Error code=" << mpierr << " detected in MPI_Finalize()");
#endif
}