LoadBalanceMngInternal.cc

// -*- 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
//-----------------------------------------------------------------------------
/*---------------------------------------------------------------------------*/
/* LoadBalanceMngInternal.cc                                   (C) 2000-2024 */
/*                                                                           */
/* Internal class managing mesh load balancing.                              */
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
#include "arcane/impl/internal/LoadBalanceMngInternal.h"
 
#include "arcane/utils/PlatformUtils.h"
#include "arcane/utils/StringBuilder.h"
#include "arcane/utils/MultiArray2.h"
#include "arcane/utils/ITraceMng.h"
 
#include "arcane/core/IMesh.h"
#include "arcane/core/IModule.h"
#include "arcane/core/ItemPrinter.h"
#include "arcane/core/ItemEnumerator.h"
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
namespace Arcane
{
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/

class ProxyItemVariableNull
: public IProxyItemVariable
{
 public:
 
  ProxyItemVariableNull() {}
  ~ProxyItemVariableNull() {}
 
  Real operator[](ItemEnumerator) const
  {
    return 1;
  }
  Integer getPos() const
  {
    return 0;
  }
 
 protected:
 
  void deleteMe() {}
};

static ProxyItemVariableNull nullProxy;
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
template <typename DataType> class ProxyItemVariable
: public IProxyItemVariable
{
 public:
 
  explicit ProxyItemVariable(IVariable* var, Integer pos = 0)
  : m_var(var)
  , m_pos(pos)
  {
  }
  ~ProxyItemVariable() {}
 
  Real operator[](ItemEnumerator i) const
  {
    return static_cast<Real>(m_var[i]);
  }
  Integer getPos() const
  {
    return m_pos;
  }
 
 private:
 
  ItemVariableScalarRefT<DataType> m_var;
  Integer m_pos;
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/

IProxyItemVariable* StoreIProxyItemVariable::
proxyItemVariableFactory(IVariable* var, Integer pos)
{
  if (!var)
    return &nullProxy;
  switch (var->dataType()) {
  case DT_Real:
    return new ProxyItemVariable<Real>(var, pos);
    break;
  case DT_Int32:
    return new ProxyItemVariable<Int32>(var, pos);
    break;
  default:
    // TODO : throw an exception
    return &nullProxy;
  }
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
CriteriaMng::
CriteriaMng(bool use_legacy_init)
: m_nb_cells_as_criterion(!use_legacy_init)
, m_cell_comm(use_legacy_init)
, m_need_compute_comm(use_legacy_init)
, m_criteria(new PartitionerMemoryInfo())
{
  resetCriteria();
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void CriteriaMng::
init(IMesh* mesh)
{
  MeshHandle mesh_handle = mesh->handle();
  int vflags = IVariable::PExecutionDepend | IVariable::PNoDump | IVariable::PTemporary;
 
  m_cell_new_owner = new VariableCellInt32(VariableBuildInfo(mesh_handle, "CellFamilyNewOwner", IVariable::PExecutionDepend | IVariable::PNoDump));
  m_comm_costs = new VariableFaceReal(VariableBuildInfo(mesh_handle, "LbMngCommCost", vflags));
  m_mass_over_weight = new VariableCellReal(VariableBuildInfo(mesh_handle, "LbMngOverallMass", vflags));
  m_mass_res_weight = new VariableCellReal(VariableBuildInfo(mesh_handle, "LbMngResidentMass", vflags));
  m_event_weights = new VariableCellArrayReal(VariableBuildInfo(mesh_handle, "LbMngMCriteriaWgt", vflags));
 
  m_comm_costs->fill(1);
  m_mass_over_weight->fill(1);
  m_mass_res_weight->fill(1);
  m_is_init = true;
  m_mesh = mesh;
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void CriteriaMng::
resetCriteria()
{
  m_mass_vars.clear();
  m_comm_vars.clear();
  m_event_vars.resize(1); // First slot booked by MemoryOverAll
 
  clearVariables();
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void CriteriaMng::
clearVariables()
{
  m_event_weights = nullptr;
  m_mass_res_weight = nullptr;
  m_mass_over_weight = nullptr;
  m_comm_costs = nullptr;
  m_is_init = false;
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
Integer CriteriaMng::
nbCriteria()
{
  Integer count;
 
  count = m_event_vars.size();
  count -= ((m_use_mass_as_criterion) ? 0 : 1); // First event is mass !
  count += ((m_nb_cells_as_criterion) ? 1 : 0);
  return count;
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
ArrayView<StoreIProxyItemVariable> CriteriaMng::
criteria()
{
  if (m_use_mass_as_criterion) {
    StoreIProxyItemVariable cvar(m_mass_over_weight->variable());
    m_event_vars[0] = cvar;
    return m_event_vars;
  }
  return m_event_vars.subView(1, m_event_vars.size());
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void CriteriaMng::
computeCriteria()
{
  if (needComputeComm() || useMassAsCriterion()) { // Memory useful only for communication cost or mass lb criterion
    m_criteria->computeMemory(m_mesh->variableMng());
    _computeResidentMass();
  }
  if (needComputeComm()) {
    _computeComm();
  }
  if (useMassAsCriterion()) {
    _computeOverallMass();
  }
  _computeEvents();
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void CriteriaMng::
_computeOverallMass()
{
  VariableCellReal& mass_over_weigth = *m_mass_over_weight;
  ENUMERATE_CELL (icell, m_mesh->ownCells()) {
    mass_over_weigth[icell] = m_criteria->getOverallMemory(*icell);
  }
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void CriteriaMng::
_computeComm()
{
  VariableFaceReal& comm_costs = *m_comm_costs;
 
  Integer penalty = 2; // How many times we do synchronization ?
 
  if (!m_comm_vars.empty())
    comm_costs.fill(0);
 
  for (auto& commvar : m_comm_vars) {
    ENUMERATE_FACE (iface, m_mesh->ownFaces()) {
      comm_costs[iface] += commvar[iface] * m_criteria->getResidentMemory(commvar.getPos());
    }
  }
  if (m_cell_comm) {
    VariableCellReal& mass_res_weight = *m_mass_res_weight;
    ENUMERATE_CELL (icell, m_mesh->ownCells()) {
      Real mem = mass_res_weight[icell];
      for (Face face : icell->faces()) {
        comm_costs[face] += mem * penalty;
      }
    }
  }
 
  // Make sure that ghosts contribution is used
  IVariable* ivar = m_comm_costs->variable();
  ivar->itemFamily()->reduceFromGhostItems(ivar, Parallel::ReduceSum);
  m_comm_costs->synchronize();
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void CriteriaMng::
_computeResidentMass()
{
  VariableCellReal& mass_res_weight = *m_mass_res_weight;
  ENUMERATE_CELL (icell, m_mesh->ownCells()) {
    mass_res_weight[icell] = m_criteria->getResidentMemory(*icell);
  }
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void CriteriaMng::
_computeEvents()
{
  ARCANE_CHECK_POINTER(m_mesh);
 
  ITraceMng* tm = m_mesh->traceMng();
  m_event_weights->resize(nbCriteria());
 
  ArrayView<StoreIProxyItemVariable> event_vars = criteria();
 
  const Int32 nb_event_var = event_vars.size();
  const Int32 nb_criteria = nbCriteria();
 
  tm->info() << "CriteriaMng: Compute Events nb_criteria=" << nb_criteria << " nb_event_var=" << nb_event_var;
 
  VariableCellArrayReal& event_weights = *(m_event_weights);
  // If no weight is specified and cells are taken as criteria, then
  // directly fill the weights (otherwise they will not be filled)
  if (nb_event_var == 0 && m_nb_cells_as_criterion) {
    ENUMERATE_CELL (icell, m_mesh->ownCells()) {
      event_weights(icell, 0) = 1.0;
    }
  }
  else {
    for (Integer i = 0; i < event_vars.size(); ++i) {
      ENUMERATE_CELL (icell, m_mesh->ownCells()) {
        Integer count = i;
        if (m_nb_cells_as_criterion) {
          count += 1;
          event_weights(icell, 0) = 1;
        }
        event_weights(icell, count) = event_vars[i][icell];
      }
    }
  }
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
LoadBalanceMngInternal::
LoadBalanceMngInternal(bool mass_as_criterion, bool is_legacy_init)
: m_default_mass_criterion(mass_as_criterion)
, m_is_legacy_init(is_legacy_init)
{}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
CriteriaMng& LoadBalanceMngInternal::
_getCriteria(IMesh* mesh)
{
  auto x = m_mesh_criterion.find(mesh);
  if (x != m_mesh_criterion.end())
    return *(x->second.get());
  auto c = createRef<CriteriaMng>(m_is_legacy_init);
  auto v = m_mesh_criterion.emplace(mesh, c);
  x = v.first;
  return *(x->second.get());
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void LoadBalanceMngInternal::
reset(IMesh* mesh)
{
  _getCriteria(mesh).resetCriteria();
  if (mesh) {
    mesh->traceMng()->debug() << "LoadBalanceInternal -- Mesh : " << mesh->name() << " -- reset()";
  }
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void LoadBalanceMngInternal::
initAccess(IMesh* mesh)
{
  if (!mesh)
    ARCANE_FATAL("Null mesh");
 
  m_mesh_handle = mesh->handle();
 
  CriteriaMng& mesh_criterion = _getCriteria(mesh);
  mesh_criterion.init(mesh);
  mesh_criterion.defaultMassCriterion(m_default_mass_criterion);
 
  mesh->traceMng()->info() << "LoadBalanceMngInternal::initAccess():"
                           << " use_memory=" << mesh_criterion.useMassAsCriterion()
                           << " use_nb_cell=" << mesh_criterion.useNbCellsAsCriterion()
                           << " nb_criteria=" << mesh_criterion.nbCriteria();
 
  // If no criterion is defined, use the number of cells.
  // At least one criterion is needed otherwise there will be no weights in the partitioning graph.
  if (mesh_criterion.nbCriteria() == 0)
    mesh_criterion.setNbCellsAsCriterion(true);
 
  mesh_criterion.computeCriteria();
 
  mesh->traceMng()->debug() << "LoadBalanceInternal -- Mesh : " << mesh->name() << " -- initAccess()";
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void LoadBalanceMngInternal::
endAccess()
{
  IMesh* mesh = m_mesh_handle.mesh();
  if (!mesh)
    return;
 
  _getCriteria(mesh).clearVariables();
 
  mesh->traceMng()->debug() << "LoadBalanceInternal -- Mesh : " << mesh->name() << " -- clearVariables()";
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void LoadBalanceMngInternal::
addMass(VariableCellInt32& count, IMesh* mesh, const String& entity)
{
  CriteriaMng& criterion = _getCriteria(mesh);
  StoreIProxyItemVariable cvar(count.variable(), criterion.addEntity(entity));
  criterion.addMass(cvar);
  mesh->traceMng()->debug() << "Set mass (name=" << count.name() << ") criterion to mesh (name=" << mesh->name() << ")";
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void LoadBalanceMngInternal::
addCriterion(VariableCellInt32& count, IMesh* mesh)
{
  StoreIProxyItemVariable cvar(count.variable());
  _getCriteria(mesh).addCriterion(cvar);
  mesh->traceMng()->debug() << "Set criterion (name=" << count.name() << ") criterion to mesh (name=" << mesh->name() << ")";
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void LoadBalanceMngInternal::
addCriterion(VariableCellReal& count, IMesh* mesh)
{
  //std::cerr << "Adding var " << count.variable()->fullName() << " ref # " << count.variable()->nbReference() << std::endl;
  StoreIProxyItemVariable cvar(count.variable());
  //std::cerr << "Adding var (2)" << count.variable()->fullName() << " ref # " << count.variable()->nbReference() << std::endl;
  _getCriteria(mesh).addCriterion(cvar);
  mesh->traceMng()->debug() << "Set criterion (name=" << count.name() << ") criterion to mesh (name=" << mesh->name() << ")";
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void LoadBalanceMngInternal::
addCommCost(VariableFaceInt32& count, IMesh* mesh, const String& entity)
{
  CriteriaMng& criterion = _getCriteria(mesh);
  StoreIProxyItemVariable cvar(count.variable(), criterion.addEntity(entity));
  criterion.addCommCost(cvar);
  mesh->traceMng()->debug() << "Set CommCost (name=" << count.name() << ") criterion to mesh (name=" << mesh->name() << ")";
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
Integer LoadBalanceMngInternal::
nbCriteria(IMesh* mesh)
{
  return _getCriteria(mesh).nbCriteria();
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void LoadBalanceMngInternal::
setMassAsCriterion(IMesh* mesh, bool active)
{
  _getCriteria(mesh).setMassCriterion(active);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void LoadBalanceMngInternal::
setNbCellsAsCriterion(IMesh* mesh, bool active)
{
  _getCriteria(mesh).setNbCellsAsCriterion(active);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void LoadBalanceMngInternal::
setCellCommContrib(IMesh* mesh, bool active)
{
  _getCriteria(mesh).setCellCommContrib(active);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
bool LoadBalanceMngInternal::
cellCommContrib(IMesh* mesh)
{
  if (m_mesh_criterion.find(mesh) == m_mesh_criterion.end()) {
    return true;
  }
  return _getCriteria(mesh).cellCommContrib();
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void LoadBalanceMngInternal::
setComputeComm(IMesh* mesh, bool active)
{
  _getCriteria(mesh).setComputeComm(active);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
const VariableFaceReal& LoadBalanceMngInternal::
commCost(IMesh* mesh)
{
  return _getCriteria(mesh).commCost();
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
const VariableCellReal& LoadBalanceMngInternal::
massWeight(IMesh* mesh)
{
  return _getCriteria(mesh).massWeight();
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
const VariableCellReal& LoadBalanceMngInternal::
massResWeight(IMesh* mesh)
{
  return _getCriteria(mesh).massResWeight();
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
const VariableCellArrayReal& LoadBalanceMngInternal::
mCriteriaWeight(IMesh* mesh)
{
  return _getCriteria(mesh).criteriaWeight();
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void LoadBalanceMngInternal::
notifyEndPartition()
{
  IMesh* mesh = m_mesh_handle.mesh();
  _getCriteria(mesh).fillCellNewOwner();
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
} // End namespace Arcane
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/