Teuchos_MpiReductionOpSetter.hpp

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.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are
// met:
//
// 1. Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// 3. Neither the name of the Corporation nor the names of the
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY SANDIA CORPORATION "AS IS" AND ANY
// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
// PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SANDIA CORPORATION OR THE
// CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
// EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
// PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
// PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
// NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
// SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
//
// Questions? Contact Michael A. Heroux (maherou@sandia.gov)
//
// ***********************************************************************
// @HEADER
 
#ifndef TEUCHOS_MPI_REDUCTION_OP_SETTER_HPP
#define TEUCHOS_MPI_REDUCTION_OP_SETTER_HPP

 
#include <Teuchos_ConfigDefs.hpp>
 
#ifdef HAVE_MPI
#include "Teuchos_ReductionOp.hpp"
#include <mpi.h>
 
namespace Teuchos {
namespace Details {

class TEUCHOSCOMM_LIB_DLL_EXPORT MpiReductionOpBase :
    virtual public Describable {
public:
  virtual void
  reduce (void* invec, void* inoutvec,
          int* len, MPI_Datatype* datatype) const = 0;
};

template<typename OrdinalType>
class MpiReductionOp : public MpiReductionOpBase {
public:
  MpiReductionOp (const ValueTypeReductionOp<OrdinalType,char>& reductOp)
    : reductOp_ (reductOp)
  {}
 
  void
  reduce (void* invec, void* inoutvec, int* len, MPI_Datatype* datatype) const
  {
#ifdef TEUCHOS_DEBUG
    TEUCHOS_TEST_FOR_EXCEPT(!len);
    TEUCHOS_TEST_FOR_EXCEPT(!datatype);
#endif
    // mfh 23 Nov 2014: Ross made the unfortunate decision initially
    // to mash everything into MPI_CHAR.  This means that we have to
    // do a lot of type casting here.  Of course, most implementations
    // of ValueTypeReductionOp will immediately cast back from char*
    // to the actual type of interest.
    int sz;
    MPI_Type_size (*datatype, &sz);
    (void) datatype;
    reductOp_.reduce ((*len) * sz, reinterpret_cast<char*> (invec),
                      reinterpret_cast<char*> (inoutvec));
  }
 
private:
  const ValueTypeReductionOp<OrdinalType, char>& reductOp_;
  // Not defined and not to be called
  MpiReductionOp ();
  MpiReductionOp (const MpiReductionOp&);
  MpiReductionOp& operator= (const MpiReductionOp&);
};

MPI_Op setMpiReductionOp (const MpiReductionOpBase& reductOp);
 
} // namespace Details
} // namespace Teuchos
 
#endif // HAVE_MPI
 
#endif // TEUCHOS_MPI_REDUCTION_OP_SETTER_HPP