cs_execution_context.h

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#ifndef __CS_EXECUTION_CONTEXT_H__
#define __CS_EXECUTION_CONTEXT_H__
 
/*============================================================================
 * Class to handle different execution policies (MPI, OpenMP, CUDA, ...)
 *============================================================================*/
 
/*
  This file is part of code_saturne, a general-purpose CFD tool.
 
  Copyright (C) 1998-2024 EDF S.A.
 
  This program is free software; you can redistribute it and/or modify it under
  the terms of the GNU General Public License as published by the Free Software
  Foundation; either version 2 of the License, or (at your option) any later
  version.
 
  This program 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 General Public License for more
  details.
 
  You should have received a copy of the GNU General Public License along with
  this program; if not, write to the Free Software Foundation, Inc., 51 Franklin
  Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
 
// Valid only for C++
 
#ifdef __cplusplus
/*----------------------------------------------------------------------------*/
 
#include "cs_defs.h"
 
/*----------------------------------------------------------------------------
 * Standard C++ library headers
 *----------------------------------------------------------------------------*/
 
#include <utility>
 
#if defined(SYCL_LANGUAGE_VERSION)
#include <sycl/sycl.hpp>
#endif
 
/*============================================================================
 * Type definitions
 *============================================================================*/
 
/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
 
class cs_execution_context {
 
/* Public methods
   --------------*/
 
public:
 
  /*--------------------------------------------------------------------------*/
  /*--------------------------------------------------------------------------*/
 
  cs_execution_context()
  {
#if defined(HAVE_MPI)
    this->_comm = MPI_COMM_NULL;
#endif
    this->_comm_rank    = 0;
    this->_comm_n_ranks = 0;
    this->_thread_id    = 0;
  };
 
  /*--------------------------------------------------------------------------*/
  /*--------------------------------------------------------------------------*/
 
  virtual ~cs_execution_context()
  {
  };
 
  /*--------------------------------------------------------------------------*/
  /*--------------------------------------------------------------------------*/
 
  int rank() const
  {
    return _comm_rank;
  };
 
  /*--------------------------------------------------------------------------*/
  /*--------------------------------------------------------------------------*/
 
  int n_ranks() const
  {
    return _comm_n_ranks;
  };
 
  /*--------------------------------------------------------------------------*/
  /*--------------------------------------------------------------------------*/
 
  bool use_mpi() const
  {
    bool retval = (_comm_n_ranks > 1) ? true : false;
    return retval;
  };
 
  /*--------------------------------------------------------------------------*/
  /*--------------------------------------------------------------------------*/
 
  bool is_mpi_root() const
  {
    bool retval = (_comm_rank < 1) ? true : false;
    return retval;
  };
 
  /*--------------------------------------------------------------------------*/
  /*--------------------------------------------------------------------------*/
 
  int thread_id() const
  {
    return _thread_id;
  };
 
  /*--------------------------------------------------------------------------*/
  /*--------------------------------------------------------------------------*/
 
  void
  comm_free()
  {
#if defined(HAVE_MPI)
    if (_comm != MPI_COMM_NULL)
      MPI_Comm_free(&(this->_comm));
    this->_comm = MPI_COMM_NULL;
#endif
  }
 
  /*--------------------------------------------------------------------------*/
  /*--------------------------------------------------------------------------*/
 
  int
  barrier()
  {
    int retval = 0;
#if defined(HAVE_MPI)
    if (_comm != MPI_COMM_NULL)
      retval = MPI_Barrier(_comm);
#endif
    return retval;
  }
 
#if defined(HAVE_MPI)
  /*--------------------------------------------------------------------------*/
  /*--------------------------------------------------------------------------*/
 
  void
  set_comm
  (
    MPI_Comm comm 
  )
  {
    int _initialized;
    MPI_Initialized(&_initialized);
    if (_initialized) {
      this->_comm = comm;
      MPI_Comm_rank(this->_comm, &(this->_comm_rank));
      MPI_Comm_size(this->_comm, &(this->_comm_n_ranks));
    }
  };
 
  /*--------------------------------------------------------------------------*/
  /*--------------------------------------------------------------------------*/
 
  MPI_Comm comm() const
  {
    return _comm;
  };
 
#endif // defined(HAVE_MPI)
/* Private attributes
 -------------------- */
 
private:
 
#if defined(HAVE_MPI)
  MPI_Comm _comm; 
#endif
 
  int _comm_rank;    
  int _comm_n_ranks; 
  int _thread_id;    
#if defined(__NVCC__)
  cudaStream_t _stream; 
#elif defined(SYCL_LANGUAGE_VERSION)
  sycl::queue _queue; 
#endif
 
};
 
/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
 
const cs_execution_context *
cs_execution_context_get(void);
 
/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
 
const cs_execution_context *
cs_execution_context_glob_get(void);
 
#endif /* __cplusplus */
/*----------------------------------------------------------------------------*/
 
BEGIN_C_DECLS
 
/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
 
void
cs_execution_context_glob_init(void);
 
/*----------------------------------------------------------------------------*/
/*----------------------------------------------------------------------------*/
 
void
cs_execution_context_glob_finalize(void);
 
/*----------------------------------------------------------------------------*/
 
END_C_DECLS
 
#endif /* __CS_EXECUTION_CONTEXT_H__ */