MpiMultiMachineShMemWinBaseInternal.h

// -*- tab-width: 2; indent-tabs-mode: nil; coding: utf-8-with-signature -*-
//-----------------------------------------------------------------------------
// Copyright 2000-2026 CEA (www.cea.fr) IFPEN (www.ifpenergiesnouvelles.com)
// See the top-level COPYRIGHT file for details.
// SPDX-License-Identifier: Apache-2.0
//-----------------------------------------------------------------------------
/*---------------------------------------------------------------------------*/
/* MpiMultiMachineShMemWinBaseInternal.h                       (C) 2000-2026 */
/*                                                                           */
/* Class allowing the creation of memory windows for a compute node.         */
/* The segments of these windows are not contiguous in memory and can        */
/* be resized. A process can possess multiple segments.                      */
/*---------------------------------------------------------------------------*/
#ifndef ARCCORE_MESSAGEPASSINGMPI_INTERNAL_MPIMULTIMACHINESHMEMWINBASEINTERNAL_H
#define ARCCORE_MESSAGEPASSINGMPI_INTERNAL_MPIMULTIMACHINESHMEMWINBASEINTERNAL_H
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/*---------------------------------------------------------------------------*/
 
#include "arccore/collections/Array.h"
 
#include "arccore/message_passing_mpi/MessagePassingMpiGlobal.h"
 
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namespace Arcane::MessagePassing::Mpi
{

class ARCCORE_MESSAGEPASSINGMPI_EXPORT MpiMultiMachineShMemWinBaseInternal
{
 
 public:
 
  explicit MpiMultiMachineShMemWinBaseInternal(SmallSpan<Int64> sizeof_segments, Int32 nb_segments_per_proc, Int32 sizeof_type, const MPI_Comm& comm_machine, Int32 comm_machine_rank, Int32 comm_machine_size, ConstArrayView<Int32> machine_ranks);
 
  ~MpiMultiMachineShMemWinBaseInternal();
 
 public:

  Int32 sizeofOneElem() const;

  ConstArrayView<Int32> machineRanks() const;

  void barrier() const;

  Span<std::byte> segmentView(Int32 num_seg);

  Span<std::byte> segmentView(Int32 rank, Int32 num_seg);

  Span<const std::byte> segmentConstView(Int32 num_seg) const;

  Span<const std::byte> segmentConstView(Int32 rank, Int32 num_seg) const;

  void requestAdd(Int32 num_seg, Span<const std::byte> elem);

  void executeAdd();

  void requestAddToAnotherSegment(Int32 thread, Int32 rank, Int32 num_seg, Span<const std::byte> elem);

  void executeAddToAnotherSegment();

  void requestReserve(Int32 num_seg, Int64 new_capacity);

  void executeReserve();

  void requestResize(Int32 num_seg, Int64 new_size);

  void executeResize();

  void executeShrink();
 
 private:

  void _requestRealloc(Int32 owner_pos_segment, Int64 new_capacity) const;

  void _requestRealloc(Int32 owner_pos_segment) const;
  void _executeRealloc();
  void _realloc();
 
  Int32 _worldToMachine(Int32 world) const;
  Int32 _machineToWorld(Int32 machine) const;
 
 private:

  UniqueArray<MPI_Win> m_all_mpi_win;
  UniqueArray<Span<std::byte>> m_reserved_part_span;

  MPI_Win m_win_need_resize;
  Span<Int64> m_need_resize;

  MPI_Win m_win_actual_sizeof;
  Span<Int64> m_sizeof_used_part;

  MPI_Win m_win_target_segments;
  Span<Int32> m_target_segments;
 
  MPI_Comm m_comm_machine;
  Int32 m_comm_machine_size = 0;
  Int32 m_comm_machine_rank = 0;
 
  Int32 m_sizeof_type = 0;
  Int32 m_nb_segments_per_proc = 0;
 
  ConstArrayView<Int32> m_machine_ranks;

  UniqueArray<Span<const std::byte>> m_add_requests;
  bool m_add_requested = false;

  UniqueArray<Int64> m_resize_requests;
  bool m_resize_requested = false;
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
} // namespace Arcane::MessagePassing::Mpi
 
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#endif