Method CreateProcessCellCountData

Filters/Parallel/vtkPKdTree.cxx:2550–2685

//------------------------------------------------------------------------------

int vtkPKdTree::CreateProcessCellCountData()
{
  int proc, reg;
  int retval = 0;
  char *procData(nullptr), *myData(nullptr);

  this->SubGroup = vtkSubGroup::New();
  this->SubGroup->Initialize(
    0, this->NumProcesses - 1, this->MyId, 0x0000f000, this->Controller->GetCommunicator());

  this->AllocateAndZeroProcessDataLists();

  int fail = this->Top ? 0 : 1;

  if (this->AllCheckForFailure(fail, "BuildRegionProcessTables", "memory allocation"))
  {
    this->FreeProcessDataLists();
    this->SubGroup->Delete();
    this->SubGroup = nullptr;
    return 1;
  }

  // Build table indicating which processes have data for which regions

  std::vector<int> cellCounts;
  fail = this->CollectLocalRegionProcessData(cellCounts) ? 0 : 1;

  if (this->AllCheckForFailure(fail, "BuildRegionProcessTables", "error"))
  {
    this->FreeProcessDataLists();
    return 1;
  }

  myData = &(this->DataLocationMap[this->MyId * this->GetNumberOfRegions()]);

  for (reg = 0; reg < this->GetNumberOfRegions(); reg++)
  {
    if (cellCounts[reg] > 0)
      myData[reg] = 1;
  }

  if (this->NumProcesses > 1)
  {
    this->SubGroup->Gather(myData, this->DataLocationMap.data(), this->GetNumberOfRegions(), 0);
    this->SubGroup->Broadcast(
      this->DataLocationMap.data(), this->GetNumberOfRegions() * this->NumProcesses, 0);
  }

  // Other helpful tables - not the fastest way to create this
  //   information, but it uses the least memory

  procData = this->DataLocationMap.data();

  for (proc = 0; proc < this->NumProcesses; proc++)
  {
    for (reg = 0; reg < this->GetNumberOfRegions(); reg++)
    {
      if (*procData)