Function syncValues

IO/EnSight/vtkEnSightSOSGoldReader.cxx:85–152

#if VTK_MODULE_ENABLE_VTK_ParallelMPI
template <class T>
bool syncValues(T* data, int numValues, int numPieces, vtkMultiProcessController* controller)
{
  // Compare values on all processes that will read real pieces.
  // Returns whether the values match.  If they match, all processes'
  // values are modified to match that of node 0.  This will leave the
  // values unchanged on processes that will read real data, but
  // inform the other processes of the proper values.

  if (!controller)
  {
    return true;
  }

  vtkMPICommunicator* communicator =
    vtkMPICommunicator::SafeDownCast(controller->GetCommunicator());

  if (!communicator)
  {
    if (controller->GetNumberOfProcesses() == 1)
    {
      return true;
    }
    else
    {
      return false;
    }
  }

  int numProcs = controller->GetNumberOfProcesses();
  int myid = controller->GetLocalProcessId();

  // Collect all the values to node 0.
  T* values = new T[numProcs * numValues];
  communicator->Gather(data, values, numValues, 0);

  int result = VTK_OK;
  // Node 0 compares its values to those from other processes that
  // will actually be reading data.
  if (myid == 0)
  {
    for (int i = 1; result && (i < numPieces); i++)
    {
      for (int j = 0; result && (j < numValues); j++)
      {
        if (values[i * numValues + j] != values[j])
        {
          result = VTK_ERROR;
        }
      }
    }
  }

  // Free buffer where values were collected.
  delete[] values;

  // Broadcast result of comparison to all processes.
  communicator->Broadcast(&result, 1, 0);