VariableSynchronizer.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
//-----------------------------------------------------------------------------
/*---------------------------------------------------------------------------*/
/* VariableSynchronizer.cc                                     (C) 2000-2024 */
/*                                                                           */
/* Variable synchronization service.                                         */
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
#include "arcane/impl/internal/VariableSynchronizer.h"
 
#include "arcane/utils/PlatformUtils.h"
#include "arcane/utils/NotSupportedException.h"
#include "arcane/utils/FatalErrorException.h"
#include "arcane/utils/ITraceMng.h"
#include "arcane/utils/ValueConvert.h"
#include "arcane/utils/MemoryUtils.h"
#include "arcane/utils/internal/MemoryBuffer.h"
 
#include "arcane/core/VariableSynchronizerEventArgs.h"
#include "arcane/core/IParallelMng.h"
#include "arcane/core/IItemFamily.h"
#include "arcane/core/ItemPrinter.h"
#include "arcane/core/IVariable.h"
#include "arcane/core/IData.h"
#include "arcane/core/VariableCollection.h"
#include "arcane/core/Timer.h"
#include "arcane/core/IMesh.h"
#include "arcane/core/IVariableMng.h"
#include "arcane/core/IVariableSynchronizerMng.h"
#include "arcane/core/parallel/IStat.h"
#include "arcane/core/internal/IDataInternal.h"
#include "arcane/core/internal/IParallelMngInternal.h"
#include "arcane/core/internal/IVariableSynchronizerMngInternal.h"
 
#include "arcane/impl/DataSynchronizeInfo.h"
#include "arcane/impl/internal/VariableSynchronizerComputeList.h"
#include "arcane/impl/internal/IBufferCopier.h"
 
#include <algorithm>
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
namespace Arcane
{
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
extern "C++" Ref<IDataSynchronizeImplementationFactory>
arcaneCreateSimpleVariableSynchronizerFactory(IParallelMng* pm);
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/

class VariableSynchronizer::SyncMessage
{
  class ScopedBuffer
  {
   public:
 
    ScopedBuffer(IVariableSynchronizerMngInternal* sync_mng, IMemoryAllocator* allocator)
    : m_synchronizer_mng(sync_mng)
    , m_allocator(allocator)
    , m_buffer(sync_mng->createSynchronizeBuffer(allocator))
    {
    }
    ~ScopedBuffer() noexcept(false)
    {
      m_synchronizer_mng->releaseSynchronizeBuffer(m_allocator, m_buffer.get());
    }
 
   public:
 
    IVariableSynchronizerMngInternal* m_synchronizer_mng = nullptr;
    IMemoryAllocator* m_allocator = nullptr;
    Ref<MemoryBuffer> m_buffer;
  };
 
 public:
 
  SyncMessage(const DataSynchronizeDispatcherBuildInfo& bi, VariableSynchronizer* var_syncer,
              IMemoryAllocator* allocator)
  : m_variable_synchronizer_mng(var_syncer->synchronizeMng())
  , m_dispatcher(IDataSynchronizeDispatcher::create(bi))
  , m_multi_dispatcher(IDataSynchronizeMultiDispatcher::create(bi))
  , m_event_args(var_syncer)
  , m_allocator(allocator)
  {
    if (!m_dispatcher)
      ARCANE_FATAL("No synchronizer created");
    if (!m_multi_dispatcher)
      ARCANE_FATAL("No multi synchronizer created");
  }
  ~SyncMessage()
  {
    delete m_multi_dispatcher;
  }
 
 public:
 
  void compute()
  {
    m_dispatcher->compute();
    m_multi_dispatcher->compute();
  }
 
  void initialize(IVariable* var)
  {
    _reset();
    m_event_args.initialize(var);
    _addVariable(var);
  }
 
  void initialize(const VariableCollection& vars)
  {
    _reset();
    m_event_args.initialize(vars);
    for (VariableCollectionEnumerator v(vars); ++v;)
      _addVariable(*v);
  }
 
  Int32 nbVariable() const { return m_variables.size(); }
  ConstArrayView<IVariable*> variables() const { return m_variables; }

  void synchronize()
  {
    Int32 nb_var = m_variables.size();
    if (nb_var == 0)
      return;
    if (nb_var == 1) {
      bool is_compare_sync = m_variable_synchronizer_mng->isSynchronizationComparisonEnabled();
      m_synchronize_result = synchronizeData(m_data_list[0], is_compare_sync);
    }
    if (nb_var >= 2) {
      ScopedBuffer tmp_buf(m_variable_synchronizer_mng->_internalApi(), m_allocator);
      m_multi_dispatcher->setSynchronizeBuffer(tmp_buf.m_buffer);
      m_multi_dispatcher->synchronize(m_variables);
    }
    for (IVariable* var : m_variables)
      var->setIsSynchronized();
  }
 
  DataSynchronizeResult synchronizeData(INumericDataInternal* data, bool is_compare_sync)
  {
    ScopedBuffer tmp_buf(m_variable_synchronizer_mng->_internalApi(), m_allocator);
    m_dispatcher->setSynchronizeBuffer(tmp_buf.m_buffer);
    m_dispatcher->beginSynchronize(data, is_compare_sync);
    return m_dispatcher->endSynchronize();
  }
  const DataSynchronizeResult& result() const { return m_synchronize_result; }
  VariableSynchronizerEventArgs& eventArgs() { return m_event_args; }
 
 private:
 
  IVariableSynchronizerMng* m_variable_synchronizer_mng = nullptr;
  Ref<IDataSynchronizeDispatcher> m_dispatcher;
  IDataSynchronizeMultiDispatcher* m_multi_dispatcher = nullptr;
  VariableSynchronizerEventArgs m_event_args;
  UniqueArray<IVariable*> m_variables;
  UniqueArray<INumericDataInternal*> m_data_list;
  DataSynchronizeResult m_synchronize_result;
  IMemoryAllocator* m_allocator = nullptr;
 
 private:
 
  void _reset()
  {
    m_variables.clear();
    m_data_list.clear();
  }
 
  void _addVariable(IVariable* var)
  {
    INumericDataInternal* numapi = var->data()->_commonInternal()->numericData();
    if (!numapi)
      ARCANE_FATAL("Variable '{0}' can not be synchronized because it is not a numeric data", var->name());
    m_variables.add(var);
    m_data_list.add(numapi);
  }
};
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
VariableSynchronizer::
VariableSynchronizer(IParallelMng* pm, const ItemGroup& group,
                     Ref<IDataSynchronizeImplementationFactory> implementation_factory)
: TraceAccessor(pm->traceMng())
, m_parallel_mng(pm)
, m_item_group(group)
{
  m_sync_info = DataSynchronizeInfo::create();
  m_partial_sync_info = DataSynchronizeInfo::create();
 
  if (!implementation_factory.get())
    implementation_factory = arcaneCreateSimpleVariableSynchronizerFactory(pm);
  m_implementation_factory = implementation_factory;
 
  m_variable_synchronizer_mng = group.itemFamily()->mesh()->variableMng()->synchronizerMng();
 
  {
    String s = platform::getEnvironmentVariable("ARCANE_ALLOW_MULTISYNC");
    if (s == "0" || s == "FALSE" || s == "false")
      m_allow_multi_sync = false;
  }
  {
    String s = platform::getEnvironmentVariable("ARCANE_TRACE_SYNCHRONIZE");
    if (s == "1" || s == "TRUE" || s == "true")
      m_trace_sync = true;
  }
 
  // Indicates whether the coherence of synchronized variables is checked
  if (auto v = Convert::Type<Int32>::tryParseFromEnvironment("ARCANE_CHECK_SYNCHRONIZE_COHERENCE", true))
    m_is_check_coherence = (v.value() != 0);
 
  m_default_message = _buildMessage();
  m_partial_message = makeRef<SyncMessage>(_buildMessage(m_partial_sync_info));
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
VariableSynchronizer::
~VariableSynchronizer()
{
  delete m_sync_timer;
  delete m_default_message;
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
VariableSynchronizer::SyncMessage* VariableSynchronizer::
_buildMessage()
{
  auto* internal_pm = m_parallel_mng->_internalApi();
  Runner runner = internal_pm->runner();
  bool is_accelerator_aware = internal_pm->isAcceleratorAware();
 
  if (runner.isInitialized() && is_accelerator_aware) {
    m_runner = runner;
  }
 
  return _buildMessage(m_sync_info);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
VariableSynchronizer::SyncMessage* VariableSynchronizer::
_buildMessage(Ref<DataSynchronizeInfo>& sync_info)
{
  GroupIndexTable* table = nullptr;
  if (!m_item_group.isAllItems())
    table = m_item_group.localIdToIndex().get();
 
  Ref<IBufferCopier> buffer_copier;
  if (table)
    buffer_copier = makeRef<IBufferCopier>(new TableBufferCopier(table));
  else
    buffer_copier = makeRef<IBufferCopier>(new DirectBufferCopier());
 
  auto* internal_pm = m_parallel_mng->_internalApi();
 
  IMemoryAllocator* allocator = nullptr;
  // If the IParallelMng manages accelerator memory, the buffer is allocated
  // on the device. We could use managed memory, but some MPI implementations
  // (i.e.: BXI) do not support it.
  if (m_runner.isInitialized()) {
    buffer_copier->setRunQueue(internal_pm->queue());
    allocator = MemoryUtils::getAllocator(eMemoryRessource::Device);
  }
 
  // Create an instance of the implementation
  Ref<IDataSynchronizeImplementation> sync_impl = m_implementation_factory->createInstance();
  sync_impl->setDataSynchronizeInfo(sync_info.get());
 
  DataSynchronizeDispatcherBuildInfo bi(m_parallel_mng, sync_impl, sync_info, buffer_copier);
  return new SyncMessage(bi, this, allocator);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/

void VariableSynchronizer::
compute()
{
  VariableSynchronizerComputeList computer(this);
  computer.compute();
 
  _setCurrentDevice();
  m_default_message->compute();
  if (m_is_verbose)
    info() << "End compute dispatcher Date=" << platform::getCurrentDateTime();
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void VariableSynchronizer::
_doSynchronize(SyncMessage* message)
{
  IParallelMng* pm = m_parallel_mng;
  ITimeStats* ts = pm->timeStats();
  Timer::Phase tphase(ts, TP_Communication);
 
  _setCurrentDevice();
 
  // Send the start synchronization event
  VariableSynchronizerEventArgs& event_args = message->eventArgs();
  _sendBeginEvent(event_args);
 
  {
    Timer::Sentry ts2(m_sync_timer);
    message->synchronize();
  }
 
  Int32 nb_var = message->nbVariable();
  // If there is only one variable, display the result of the comparison
  // synchronization
  if (nb_var == 1 && m_variable_synchronizer_mng->isSynchronizationComparisonEnabled()) {
    eDataSynchronizeCompareStatus s = message->result().compareStatus();
    if (s == eDataSynchronizeCompareStatus::Different) {
      event_args.setCompareStatus(0, VariableSynchronizerEventArgs::CompareStatus::Different);
    }
    else if (s == eDataSynchronizeCompareStatus::Same) {
      event_args.setCompareStatus(0, VariableSynchronizerEventArgs::CompareStatus::Same);
    }
  }
 
  // End of synchronization
  _sendEndEvent(event_args);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void VariableSynchronizer::
_rebuildMessage(Int32ConstArrayView local_ids)
{
  // If the localIds have not changed since the last call, we keep
  // the synchronization information already calculated
 
  if (local_ids == m_partial_local_ids.constView()) {
    //debug(Trace::High) << "Proc " << m_parallel_mng->commRank() << " infos for partial synchronisations are up to date";
    return;
  }
 
  //debug(Trace::High) << "Proc " << m_parallel_mng->commRank() << " recompute infos for partial synchronisations";
 
  m_partial_local_ids.copy(local_ids);
 
  UniqueArray<bool> flags(m_item_group.itemFamily()->maxLocalId());
  flags.fill(false);
 
  for (Int32 lid : local_ids) {
    flags[lid] = true;
  }
 
  Int32ConstArrayView comm_ranks = m_sync_info->communicatingRanks();
  Int32 nb_comm_ranks = comm_ranks.size();
 
  const DataSynchronizeBufferInfoList& send_info = m_sync_info->sendInfo();
  const DataSynchronizeBufferInfoList& recv_info = m_sync_info->receiveInfo();
 
  m_partial_sync_info = DataSynchronizeInfo::create();
 
  if (!local_ids.empty()) {
 
    UniqueArray<Int32> recv_grp;
    UniqueArray<Int32> send_grp;
 
    for (Int32 index = 0; index < nb_comm_ranks; ++index) {
      Int32 target_rank = comm_ranks[index];
      ConstArrayView<Int32> send_lids = send_info.localIds(index);
      ConstArrayView<Int32> recv_lids = recv_info.localIds(index);
 
      recv_grp.clear();
      send_grp.clear();
 
      for (Int32 lid : recv_lids) {
        if (flags[lid]) {
          recv_grp.add(lid);
        }
      }
 
      for (Int32 lid : send_lids) {
        if (flags[lid]) {
          send_grp.add(lid);
        }
      }
 
      if ((!send_grp.empty()) || (!recv_grp.empty())) {
        // Adds information about exchanges with target_rank
        m_partial_sync_info->add(VariableSyncInfo(send_grp, recv_grp, target_rank));
      }
    }
  }
 
  m_partial_sync_info->recompute();
  m_partial_message = makeRef<SyncMessage>(_buildMessage(m_partial_sync_info));
  m_partial_message->compute();
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void VariableSynchronizer::
_synchronize(IVariable* var, SyncMessage* message)
{
  message->initialize(var);
 
  IParallelMng* pm = m_parallel_mng;
  if (m_is_check_coherence)
    MessagePassing::namedBarrier(pm, var->name());
  debug(Trace::High) << " Proc " << pm->commRank() << " Sync variable " << var->fullName();
  if (m_trace_sync) {
    info() << " Synchronize variable " << var->fullName()
           << " stack=" << platform::getStackTrace();
  }
  _doSynchronize(message);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void VariableSynchronizer::
synchronize(IVariable* var)
{
  _synchronize(var, m_default_message);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void VariableSynchronizer::
synchronize(IVariable* var, Int32ConstArrayView local_ids)
{
  _rebuildMessage(local_ids);
  _synchronize(var, m_partial_message.get());
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void VariableSynchronizer::
synchronize(VariableCollection vars)
{
  if (vars.empty())
    return;
 
  const bool use_multi = m_allow_multi_sync;
  if (use_multi && _canSynchronizeMulti(vars)) {
    _synchronizeMulti(vars, m_default_message);
  }
  else {
    for (VariableCollection::Enumerator ivar(vars); ++ivar;) {
      _synchronize(*ivar, m_default_message);
    }
  }
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void VariableSynchronizer::
synchronize(VariableCollection vars, Int32ConstArrayView local_ids)
{
  if (vars.empty())
    return;
 
  _rebuildMessage(local_ids);
 
  const bool use_multi = m_allow_multi_sync;
  if (use_multi && _canSynchronizeMulti(vars)) {
    _synchronizeMulti(vars, m_partial_message.get());
  }
  else {
    for (VariableCollection::Enumerator ivar(vars); ++ivar;) {
      _synchronize(*ivar, m_partial_message.get());
    }
  }
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
DataSynchronizeResult VariableSynchronizer::
_synchronize(INumericDataInternal* data, bool is_compare_sync)
{
  return m_default_message->synchronizeData(data, is_compare_sync);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void VariableSynchronizer::
synchronizeData(IData* data)
{
  ARCANE_CHECK_POINTER(data);
  INumericDataInternal* numapi = data->_commonInternal()->numericData();
  if (!numapi)
    ARCANE_FATAL("Data can not be synchronized because it is not a numeric data");
  _synchronize(numapi, false);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void VariableSynchronizer::
changeLocalIds(Int32ConstArrayView old_to_new_ids)
{
  info(4) << "** VariableSynchronizer::changeLocalIds() group=" << m_item_group.name();
  m_sync_info->changeLocalIds(old_to_new_ids);
  m_default_message->compute();
  // Forces recalculation of information for partial synchronizations
  _rebuildMessage(Int32ConstArrayView());
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/

bool VariableSynchronizer::
_canSynchronizeMulti(const VariableCollection& vars)
{
  if (vars.count() == 1)
    return false;
  ItemGroup group;
  bool is_set = false;
  for (VariableCollection::Enumerator ivar(vars); ++ivar;) {
    IVariable* var = *ivar;
    if (var->isPartial())
      return false;
    ItemGroup var_group = var->itemGroup();
    if (!is_set) {
      group = var_group;
      is_set = true;
    }
    if (group != var_group)
      return false;
  }
  return true;
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void VariableSynchronizer::
_synchronizeMulti(const VariableCollection& vars, SyncMessage* message)
{
  message->initialize(vars);
 
  IParallelMng* pm = m_parallel_mng;
  debug(Trace::High) << " Proc " << pm->commRank() << " MultiSync variable";
  if (m_trace_sync) {
    info() << " MultiSynchronize"
           << " stack=" << platform::getStackTrace();
  }
 
  _doSynchronize(message);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
Int32ConstArrayView VariableSynchronizer::
communicatingRanks()
{
  return m_sync_info->communicatingRanks();
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
Int32ConstArrayView VariableSynchronizer::
sharedItems(Int32 index)
{
  return m_sync_info->sendInfo().localIds(index);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
Int32ConstArrayView VariableSynchronizer::
ghostItems(Int32 index)
{
  return m_sync_info->receiveInfo().localIds(index);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void VariableSynchronizer::
_sendBeginEvent(VariableSynchronizerEventArgs& args)
{
  _checkCreateTimer();
  args.setState(VariableSynchronizerEventArgs::State::BeginSynchronize);
  _sendEvent(args);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void VariableSynchronizer::
_sendEndEvent(VariableSynchronizerEventArgs& args)
{
  ARCANE_CHECK_POINTER(m_sync_timer);
  Real elapsed_time = m_sync_timer->lastActivationTime();
  m_parallel_mng->stat()->add("Synchronize", elapsed_time, 1);
  args.setState(VariableSynchronizerEventArgs::State::EndSynchronize);
  args.setElapsedTime(elapsed_time);
  _sendEvent(args);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void VariableSynchronizer::
_sendEvent(VariableSynchronizerEventArgs& args)
{
  m_variable_synchronizer_mng->onSynchronized().notify(args);
  m_on_synchronized.notify(args);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
void VariableSynchronizer::
_checkCreateTimer()
{
  if (!m_sync_timer)
    m_sync_timer = new Timer(m_parallel_mng->timerMng(), "SyncTimer", Timer::TimerReal);
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/

void VariableSynchronizer::
_setCurrentDevice()
{
  if (m_runner.isInitialized())
    m_runner.setAsCurrentDevice();
}
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/
 
} // namespace Arcane
 
/*---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------*/