source: src/interface/interface_fcs.cpp@ 203547

/**
 * @file   interface_fcs.cpp
 * @author Julian Iseringhausen <isering@ins.uni-bonn.de>
 * @date   Mon Apr 18 12:56:20 2011
 *
 * @brief  VMG::InterfaceFCS
 *
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#ifndef HAVE_MPI
#error MPI is needed to use the Scafacos interface.
#endif

#include <mpi.h>

#include "base/object.hpp"
#include "base/timer.hpp"
#include "comm/comm_mpi.hpp"
#include "comm/domain_decomposition_mpi.hpp"
#include "interface/interface_fcs.h"
#include "interface/interface_particles.hpp"
#include "level/level_operator_cs.hpp"
#include "samples/discretization_poisson_fd.hpp"
#include "samples/stencils.hpp"
#include "samples/techniques.hpp"
#include "smoother/gsrb.cpp"
#ifdef HAVE_LAPACK
#include "solver/dgesv.hpp"
#include "solver/dsysv.hpp"
#else
#include "solver/givens.hpp"
#endif
#include "solver/solver_regular.hpp"
#include "solver/solver_singular.hpp"

using namespace VMG;

namespace VMGBackupSettings
{
  static vmg_int level = -1;
  static vmg_int periodic[3] = {-1, -1, -1};
  static vmg_int max_iter = -1;
  static vmg_int smoothing_steps = -1;
  static vmg_int gamma = -1;
  static vmg_float precision = -1;
  static vmg_float box_offset[3];
  static vmg_float box_size = -1.0;
  static vmg_int near_field_cells = -1;
  static MPI_Comm mpi_comm;
}

static void VMG_fcs_init(vmg_int level, vmg_int* periodic,vmg_int max_iter,
                         vmg_int smoothing_steps, vmg_int gamma, vmg_float precision,
                         vmg_float* box_offset, vmg_float box_size,
                         vmg_int near_field_cells, MPI_Comm mpi_comm)
{
  VMGBackupSettings::level = level;
  std::memcpy(VMGBackupSettings::periodic, periodic, 3*sizeof(vmg_int));
  VMGBackupSettings::max_iter = max_iter;
  VMGBackupSettings::smoothing_steps = smoothing_steps;
  VMGBackupSettings::gamma = gamma;
  VMGBackupSettings::precision = precision;
  std::memcpy(VMGBackupSettings::box_offset, box_offset, 3*sizeof(vmg_float));
  VMGBackupSettings::box_size = box_size;
  VMGBackupSettings::near_field_cells = near_field_cells;
  VMGBackupSettings::mpi_comm = mpi_comm;

  const Boundary boundary(periodic[0] ? Periodic : Open,
                          periodic[1] ? Periodic : Open,
                          periodic[2] ? Periodic : Open);

  const bool singular = periodic[0] * periodic[1] * periodic[2];

  /*
   * Register communication class.
   */
  Comm* comm = new CommMPI(boundary, new DomainDecompositionMPI());
  comm->Register("COMM");

  /*
   * Register particle interface.
   */
  Interface* interface = new VMG::InterfaceParticles(boundary, 2, level, Vector(box_offset), box_size, near_field_cells);
  MG::SetInterface(interface, comm);

  /*
   * Use a finite difference discretization of the Poisson equation
   */
  Discretization* discretization = new DiscretizationPoissonFD();
  discretization->Register("DISCRETIZATION");

  /*
   * Use a correction scheme multigrid algorithm with full weight stencils.
   * Since we use the Gauss-Seidel RB smoother here, this may be replaced
   * with a half-weight version once debugging is finished.
   */
  LevelOperator* lop = new LevelOperatorCS(Stencils::RestrictionFullWeight, Stencils::InterpolationTrilinear);
  lop->Register("LEVEL_OPERATOR");

  /*
   * Use Gauss-Seidel Red-Black ordering
   */
  Smoother* smoother = new GaussSeidelRB();
  smoother->Register("SMOOTHER");

  /*
   * Use LAPACK solver when available, otherwise use Givens rotations.
   */
#ifdef HAVE_LAPACK
  Solver* solver = (singular ?
                    static_cast<Solver*>(new DSYSV<SolverSingular>()) :
                    static_cast<Solver*>(new DGESV<SolverRegular>()));
#else
  Solver* solver = (singular ?
                    static_cast<Solver*>(new Givens<SolverSingular>()) :
                    static_cast<Solver*>(new Givens<SolverRegular>()));
#endif
  solver->Register("SOLVER");

  /*
   * Set commands for the actual multigrid cycle
   */
  if (singular)
    Techniques::SetCorrectionSchemePeriodic(2, level, gamma);
  else
    Techniques::SetCorrectionSchemeDirichlet(2, level, gamma);

  /*
   * Register required parameters
   */
  new ObjectStorage<int>("PRESMOOTHSTEPS", smoothing_steps);
  new ObjectStorage<int>("POSTSMOOTHSTEPS", smoothing_steps);
  new ObjectStorage<vmg_float>("PRECISION", precision);
  new ObjectStorage<int>("MAX_ITERATION", max_iter);

  new ObjectStorage<int>("PARTICLE_NEAR_FIELD_CELLS", near_field_cells);

  /*
   * Check whether the library is correctly initialized now.
   */
  MG::IsInitialized();
}

void VMG_fcs_setup(vmg_int level, vmg_int* periodic, vmg_int max_iter,
                   vmg_int smoothing_steps, vmg_int gamma, vmg_float precision,
                   vmg_float* box_offset, vmg_float box_size,
                   vmg_int near_field_cells, MPI_Comm mpi_comm)
{
  if (VMGBackupSettings::level != level ||
      VMGBackupSettings::periodic[0] != periodic[0] ||
      VMGBackupSettings::periodic[1] != periodic[1] ||
      VMGBackupSettings::periodic[2] != periodic[2] ||
      VMGBackupSettings::max_iter != max_iter ||
      VMGBackupSettings::smoothing_steps != smoothing_steps ||
      VMGBackupSettings::gamma != gamma ||
      VMGBackupSettings::precision != precision ||
      VMGBackupSettings::box_offset[0] != box_offset[0] ||
      VMGBackupSettings::box_offset[1] != box_offset[1] ||
      VMGBackupSettings::box_offset[2] != box_offset[2] ||
      VMGBackupSettings::box_size != box_size ||
      VMGBackupSettings::near_field_cells != near_field_cells ||
      VMGBackupSettings::mpi_comm != mpi_comm) {

    VMG_fcs_destroy();
    VMG_fcs_init(level, periodic, max_iter,
                 smoothing_steps, gamma, precision,
                 box_offset, box_size, near_field_cells,
                 mpi_comm);

  }
}

void VMG_fcs_run(vmg_float* x, vmg_float* q, vmg_float* p, vmg_float* f, vmg_int num_particles_local)
{
  /*
   * Register parameters for later use.
   */
  new ObjectStorage<vmg_float*>("PARTICLE_POS_ARRAY", x);
  new ObjectStorage<vmg_float*>("PARTICLE_CHARGE_ARRAY", q);
  new ObjectStorage<vmg_float*>("PARTICLE_POTENTIAL_ARRAY", p);
  new ObjectStorage<vmg_float*>("PARTICLE_FORCE_ARRAY", f);
  new ObjectStorage<vmg_int>("PARTICLE_NUM_LOCAL", num_particles_local);

  /*
   * Start the multigrid solver
   */
  MG::Solve();
}

void VMG_fcs_print_timer()
{
  Timer::Print();
}

void VMG_fcs_destroy(void)
{
  /*
   * Delete all data.
   */
  MG::Destroy();
}