#include <algorithm>

#include "ParallelDomainBase.h"
#include "ParMetisPartitioner.h"
#include "Mesh.h"
#include "Traverse.h"
#include "ElInfo.h"
#include "Element.h"
#include "MacroElement.h"
#include "PartitionElementData.h"
#include "DOFMatrix.h"
#include "DOFVector.h"
#include "SystemVector.h"
#include "VtkWriter.h"
#include "ElementDofIterator.h"
#include "ProblemStatBase.h"
#include "StandardProblemIteration.h"
#include "ElementFileWriter.h"
#include "VertexVector.h"
#include "StdMpi.h"
#include "MeshStructure.h"
#include "Debug.h"

#include "petscksp.h"

namespace AMDiS {

  PetscErrorCode myKSPMonitor(KSP ksp, PetscInt iter, PetscReal rnorm, void *)
  {    
    if (iter % 100 == 0 && MPI::COMM_WORLD.Get_rank() == 0)
      std::cout << "  Petsc-Iteration " << iter << ": " << rnorm << std::endl;

    return 0;
  }

  inline bool cmpDofsByValue(const DegreeOfFreedom* dof1, const DegreeOfFreedom* dof2)
  {
    return (*dof1 < *dof2);
  }

  ParallelDomainBase::ParallelDomainBase(ProblemIterationInterface *iIF,
					 ProblemTimeInterface *tIF,
					 FiniteElemSpace *fe,
					 RefinementManager *refinementManager)
    : iterationIF(iIF),
      timeIF(tIF),
      name(iIF->getName()),
      feSpace(fe),
      mesh(fe->getMesh()),
      refineManager(refinementManager),
      initialPartitionMesh(true),
      nRankDofs(0),
      rstart(0),
      nComponents(1),
      deserialized(false),
      lastMeshChangeIndex(0)
  {
    FUNCNAME("ParallelDomainBase::ParalleDomainBase()");

    TEST_EXIT(mesh->getNumberOfDOFAdmin() == 1)
      ("Only meshes with one DOFAdmin are supported!\n");
    TEST_EXIT(mesh->getDOFAdmin(0).getNumberOfPreDOFs(0) == 0)
      ("Wrong pre dof number for DOFAdmin!\n");

    mpiRank = MPI::COMM_WORLD.Get_rank();
    mpiSize = MPI::COMM_WORLD.Get_size();
    mpiComm = MPI::COMM_WORLD;
    partitioner = new ParMetisPartitioner(mesh, &mpiComm);
  }

  void ParallelDomainBase::initParallelization(AdaptInfo *adaptInfo)
  {
    FUNCNAME("ParallelDomainBase::initParallelization()");

    TEST_EXIT(mpiSize > 1)
      ("Parallelization does not work with only one process!\n");

    // If the problem has been already read from a file, we do not need to do anything.
    if (deserialized)
      return;

    // Test, if the mesh is the macro mesh only! Paritioning of the mesh is supported
    // only for macro meshes, so it will not work yet if the mesh is already refined
    // in some way.
    testForMacroMesh();

    MSG("START PARTITIONING!\n");

    // create an initial partitioning of the mesh
    partitioner->createPartitionData();
    // set the element weights, which are 1 at the very first begin
    setElemWeights(adaptInfo);
    // and now partition the mesh
    partitionMesh(adaptInfo);   

#if (DEBUG != 0)
    ElementIdxToDofs elMap;
    dbgCreateElementMap(elMap);
    if (mpiRank == 0) {
      int writePartMesh = 1;
      GET_PARAMETER(0, "dbg->write part mesh", "%d", &writePartMesh);

      if (writePartMesh > 0)
	writePartitioningMesh("part.vtu");
      else 
	MSG("Skip write part mesh!\n");
    }
#endif

    // === Create interior boundary information. ===

    createInteriorBoundaryInfo();

    // === Create new global and local DOF numbering. ===

    createLocalGlobalNumbering();

    // === Remove all macro elements that are not part of the rank partition. ===

    removeMacroElements();

    // === Reset all DOFAdmins of the mesh. ===

    updateDofAdmins();

    // === If in debug mode, make some tests. ===

#if (DEBUG != 0)
    MSG("AMDiS runs in debug mode, so make some test ...\n");
    dbgTestElementMap(elMap);
    dbgTestInteriorBoundary();
    dbgTestCommonDofs(true);
    MSG("Debug mode tests finished!\n");

    debug::writeMesh(feSpace, -1, "macromesh");   
#endif

    // === Create periodic dof mapping, if there are periodic boundaries. ===

    createPeriodicMap();

    // === Global refinements. ===

    int globalRefinement = 0;
    GET_PARAMETER(0, mesh->getName() + "->global refinements", "%d", &globalRefinement);

    if (globalRefinement > 0) {
      refineManager->globalRefine(mesh, globalRefinement);

      updateLocalGlobalNumbering();

      // === Update periodic mapping, if there are periodic boundaries. ===

      createPeriodicMap();
    }
  }


  void ParallelDomainBase::exitParallelization(AdaptInfo *adaptInfo)
  {}

  
  void ParallelDomainBase::updateDofAdmins()
  {
    FUNCNAME("ParallelDomainBase::updateDofAdmins()");

    for (int i = 0; i < mesh->getNumberOfDOFAdmin(); i++) {
      DOFAdmin& admin = const_cast<DOFAdmin&>(mesh->getDOFAdmin(i));

      // There must be always more allocated DOFs than used DOFs in DOFAdmin. Otherwise,
      // it is not possible to define a first DOF hole.
      if (static_cast<unsigned int>(admin.getSize()) == mapLocalGlobalDofs.size())
	admin.enlargeDOFLists();
      
      for (int j = 0; j < admin.getSize(); j++)
	admin.setDOFFree(j, true);
      for (unsigned int j = 0; j < mapLocalGlobalDofs.size(); j++)
 	admin.setDOFFree(j, false);

      admin.setUsedSize(mapLocalGlobalDofs.size());
      admin.setUsedCount(mapLocalGlobalDofs.size());
      admin.setFirstHole(mapLocalGlobalDofs.size());
    }
  }


  void ParallelDomainBase::testForMacroMesh()
  {
    FUNCNAME("ParallelDomainBase::testForMacroMesh()");

    int nMacroElements = 0;

    TraverseStack stack;
    ElInfo *elInfo = stack.traverseFirst(mesh, -1, Mesh::CALL_LEAF_EL);
    while (elInfo) {
      TEST_EXIT(elInfo->getLevel() == 0)
	("Mesh is already refined! This does not work with parallelization!\n");
      
      nMacroElements++;

      elInfo = stack.traverseNext(elInfo);
    }

    TEST_EXIT(nMacroElements >= mpiSize)
      ("The mesh has less macro elements than number of mpi processes!\n");
  }


  void ParallelDomainBase::setDofMatrix(DOFMatrix* mat, int dispMult, 
					int dispAddRow, int dispAddCol)
  {
    FUNCNAME("ParallelDomainBase::setDofMatrix()");

    TEST_EXIT(mat)("No DOFMatrix!\n");

    using mtl::tag::row; using mtl::tag::nz; using mtl::begin; using mtl::end;
    namespace traits= mtl::traits;
    typedef DOFMatrix::base_matrix_type Matrix;

    traits::col<Matrix>::type col(mat->getBaseMatrix());
    traits::const_value<Matrix>::type value(mat->getBaseMatrix());

    typedef traits::range_generator<row, Matrix>::type cursor_type;
    typedef traits::range_generator<nz, cursor_type>::type icursor_type;

    std::vector<int> cols;
    std::vector<double> values;
    cols.reserve(300);
    values.reserve(300);

    // === Traverse all rows of the dof matrix and insert row wise the values ===
    // === to the petsc matrix.                                               ===

    for (cursor_type cursor = begin<row>(mat->getBaseMatrix()), 
	   cend = end<row>(mat->getBaseMatrix()); cursor != cend; ++cursor) {

      cols.clear();
      values.clear();

      // Global index of the current row dof.
      int globalRowDof = mapLocalGlobalDofs[*cursor];
      // Test if the current row dof is a periodic dof.
      bool periodicRow = (periodicDof.count(globalRowDof) > 0);


      // === Traverse all non zero entries of the row and produce vector cols ===
      // === with the column indices of all row entries and vector values     ===
      // === with the corresponding values.                                   ===

      for (icursor_type icursor = begin<nz>(cursor), icend = end<nz>(cursor); 
	   icursor != icend; ++icursor) {

	// Set only non null values.
	if (value(*icursor) != 0.0) {
	  // Global index of the current column index.
	  int globalColDof = mapLocalGlobalDofs[col(*icursor)];
	  // Calculate the exact position of the column index in the petsc matrix.
	  int colIndex = globalColDof * dispMult + dispAddCol;

	  // If the current row is not periodic, but the current dof index is periodic,
	  // we have to duplicate the value to the other corresponding periodic columns.
 	  if (periodicRow == false && periodicDof.count(globalColDof) > 0) {
	    // The value is assign to n matrix entries, therefore, every entry 
	    // has only 1/n value of the original entry.
	    double scalFactor = 1.0 / (periodicDof[globalColDof].size() + 1.0);

	    // Insert original entry.
 	    cols.push_back(colIndex);
 	    values.push_back(value(*icursor) * scalFactor);

	    // Insert the periodic entries.
 	    for (std::set<DegreeOfFreedom>::iterator it = 
		   periodicDof[globalColDof].begin();
 		 it != periodicDof[globalColDof].end(); ++it) {
 	      cols.push_back(*it * dispMult + dispAddCol);
 	      values.push_back(value(*icursor) * scalFactor);
	    }
 	  } else {
	    // Neigher row nor column dof index is periodic, simple add entry.
	    cols.push_back(colIndex);
	    values.push_back(value(*icursor));
	  }
	}
      }


      // === Up to now we have assembled on row. Now, the row must be send to the ===
      // === corresponding rows to the petsc matrix.                              ===

      // Calculate petsc row index.
      int rowIndex = globalRowDof * dispMult + dispAddRow;
      
      if (periodicRow) {
	// The row dof is periodic, so send dof to all the corresponding rows.

	double scalFactor = 1.0 / (periodicDof[globalRowDof].size() + 1.0);
	
	int diagIndex = -1;
	for (int i = 0; i < static_cast<int>(values.size()); i++) {
	  // Change only the non diagonal values in the col. For the diagonal test
	  // we compare the global dof indices of the dof matrix (not of the petsc
	  // matrix!).
	  if ((cols[i] - dispAddCol) / dispMult != globalRowDof)
	    values[i] *= scalFactor;
	  else
	    diagIndex = i;
	}
	
	// Send the main row to the petsc matrix.
	MatSetValues(petscMatrix, 1, &rowIndex, cols.size(), 
		     &(cols[0]), &(values[0]), ADD_VALUES);	
 
	// Set diagonal element to zero, i.e., the diagonal element of the current
	// row is not send to the periodic row indices.
	if (diagIndex != -1)
	  values[diagIndex] = 0.0;

	// Send the row to all periodic row indices.
	for (std::set<DegreeOfFreedom>::iterator it = periodicDof[globalRowDof].begin();
	     it != periodicDof[globalRowDof].end(); ++it) {
	  int perRowIndex = *it * dispMult + dispAddRow;
	  MatSetValues(petscMatrix, 1, &perRowIndex, cols.size(), 
		       &(cols[0]), &(values[0]), ADD_VALUES);
	}

      } else {
	// The row dof is not periodic, simply send the row to the petsc matrix.
	MatSetValues(petscMatrix, 1, &rowIndex, cols.size(), 
		     &(cols[0]), &(values[0]), ADD_VALUES);
      }    
    }
  }


  void ParallelDomainBase::setDofVector(Vec& petscVec, DOFVector<double>* vec, 
					int dispMult, int dispAdd)
  {
    // Traverse all used dofs in the dof vector.
    DOFVector<double>::Iterator dofIt(vec, USED_DOFS);
    for (dofIt.reset(); !dofIt.end(); ++dofIt) {
      // Calculate global row index of the dof.
      int globalRow = mapLocalGlobalDofs[dofIt.getDOFIndex()];
      // Calculate petsc index of the row dof.
      int index = globalRow * dispMult + dispAdd;

      if (periodicDof.count(globalRow) > 0) {
	// The dof index is periodic, so devide the value to all dof entries.

	double value = *dofIt / (periodicDof[globalRow].size() + 1.0);
	VecSetValues(petscVec, 1, &index, &value, ADD_VALUES);

	for (std::set<DegreeOfFreedom>::iterator it = periodicDof[globalRow].begin();
	     it != periodicDof[globalRow].end(); ++it) {
	  index = *it * dispMult + dispAdd;
	  VecSetValues(petscVec, 1, &index, &value, ADD_VALUES);
	}

      } else {
	// The dof index is not periodic.
	double value = *dofIt;
	VecSetValues(petscVec, 1, &index, &value, ADD_VALUES);
      }
    }    
  }


  void ParallelDomainBase::fillPetscMatrix(Matrix<DOFMatrix*> *mat, SystemVector *vec)
  {
    FUNCNAME("ParallelDomainBase::fillPetscMatrix()");

    clock_t first = clock();

    // === Create PETSc vector (rhs, solution and a temporary vector). ===

    VecCreate(PETSC_COMM_WORLD, &petscRhsVec);
    VecSetSizes(petscRhsVec, nRankRows, nOverallRows);
    VecSetType(petscRhsVec, VECMPI);

    VecCreate(PETSC_COMM_WORLD, &petscSolVec);
    VecSetSizes(petscSolVec, nRankRows, nOverallRows);
    VecSetType(petscSolVec, VECMPI);

    VecCreate(PETSC_COMM_WORLD, &petscTmpVec);
    VecSetSizes(petscTmpVec, nRankRows, nOverallRows);
    VecSetType(petscTmpVec, VECMPI);

    using mtl::tag::row; using mtl::tag::nz; using mtl::begin; using mtl::end;
    namespace traits = mtl::traits;
    typedef DOFMatrix::base_matrix_type Matrix;
    typedef std::vector<std::pair<int, int> > MatrixNnzEntry;

    int d_nnz[nRankRows];
    int o_nnz[nRankRows];
    for (int i = 0; i < nRankRows; i++) {
      d_nnz[i] = 0;
      o_nnz[i] = 0;
    }

    // Stores to each rank a list of nnz entries (i.e. pairs of row and column index)
    // that this rank will send to. This nnz entries will be assembled on this rank,
    // but because the row DOFs are not DOFs of this rank they will be send to the
    // owner of the row DOFs.
    std::map<int, MatrixNnzEntry> sendMatrixEntry;

    for (int i = 0; i < nComponents; i++) {
      for (int j = 0; j < nComponents; j++) {
 	if ((*mat)[i][j]) {
	  Matrix bmat = (*mat)[i][j]->getBaseMatrix();

	  traits::col<Matrix>::type col(bmat);
	  traits::const_value<Matrix>::type value(bmat);
	  
	  typedef traits::range_generator<row, Matrix>::type cursor_type;
	  typedef traits::range_generator<nz, cursor_type>::type icursor_type;
	  
	  for (cursor_type cursor = begin<row>(bmat), 
		 cend = end<row>(bmat); cursor != cend; ++cursor) {

	    // Map the local row number to the global DOF index and create from it
	    // the global PETSc row index of this DOF.
	    int petscRowIdx = mapLocalGlobalDofs[*cursor] * nComponents + i;

	    if (isRankDof[*cursor]) {

	      // === The current row DOF is a rank dof, so create the corresponding ===
	      // === nnz values directly on rank's nnz data.                        ===

	      // This is the local row index of the local PETSc matrix.
	      int localPetscRowIdx = petscRowIdx - rstart * nComponents;

#if (DEBUG != 0)    
	      if (localPetscRowIdx < 0 || localPetscRowIdx >= nRankRows) {
		std::cout << "ERROR in rank: " << mpiRank << std::endl;
		std::cout << "  Wrong r = " << localPetscRowIdx << " " << *cursor 
			  << " " << mapLocalGlobalDofs[*cursor] << " " 
			  << nRankRows << std::endl;
		ERROR_EXIT("Should not happen!\n");
	      }
#endif
	      
	      // Traverse all non zero entries in this row.
	      for (icursor_type icursor = begin<nz>(cursor), 
		     icend = end<nz>(cursor); icursor != icend; ++icursor) {
		if (value(*icursor) != 0.0) {
		  int petscColIdx = mapLocalGlobalDofs[col(*icursor)] * nComponents + j;

		  // The row DOF is a rank DOF, if also the column is a rank DOF, 
		  // increment the d_nnz values for this row, otherwise the o_nnz value.
		  if (petscColIdx >= rstart * nComponents && 
		      petscColIdx < rstart * nComponents + nRankRows)
		    d_nnz[localPetscRowIdx]++;
		  else
		    o_nnz[localPetscRowIdx]++;
		}    
	      }
	    } else {
	      
	      // === The current row DOF is not a rank dof, i.e., it will be created ===
	      // === on this rank, but after this it will be send to another rank    ===
	      // === matrix. So we need to send also the corresponding nnz structure ===
	      // === of this row to the corresponding rank.                          ===

	      // Find out who is the member of this DOF.
	      int sendToRank = -1;
	      for (RankToDofContainer::iterator it = recvDofs.begin();
		   it != recvDofs.end(); ++it) {
		for (DofContainer::iterator dofIt = it->second.begin();
		     dofIt != it->second.end(); ++dofIt) {
		  if (**dofIt == *cursor) {

		    if (petscRowIdx == 6717) {
		      debug::writeDofMesh(mpiRank, *cursor, feSpace);
		      MSG("SEND DOF TO: %d/%d\n", it->first, *cursor);
		    }

		    sendToRank = it->first;
		    break;
		  }
		}

		if (sendToRank != -1)
		  break;
	      }

	      TEST_EXIT_DBG(sendToRank != -1)("Should not happen!\n");

	      // Send all non zero entries to the member of the row DOF.
	      for (icursor_type icursor = begin<nz>(cursor), 
		     icend = end<nz>(cursor); icursor != icend; ++icursor) {
		if (value(*icursor) != 0.0) {
		  int petscColIdx = mapLocalGlobalDofs[col(*icursor)] * nComponents + j;
		  
		  sendMatrixEntry[sendToRank].
		    push_back(std::make_pair(petscRowIdx, petscColIdx));
		}
	      }

	    } // if (isRankDof[*cursor]) ... else ...
	  } // for each row in mat[i][j]
	} // if mat[i][j]
      } 
    }

    // === Send and recv the nnz row structure to/from other ranks. ===

    StdMpi<MatrixNnzEntry, MatrixNnzEntry> stdMpi(mpiComm, true);
    stdMpi.send(sendMatrixEntry);
    stdMpi.recv(sendDofs);
    stdMpi.startCommunication<int>(MPI_INT);

    // === Evaluate the nnz structure this rank got from other ranks and add it to ===
    // === the PETSc nnz data structure.                                           ===

    for (std::map<int, MatrixNnzEntry>::iterator it = stdMpi.getRecvData().begin();
	 it != stdMpi.getRecvData().end(); ++it) {
      if (it->second.size() > 0) {
	for (unsigned int i = 0; i < it->second.size(); i++) {
	  int r = it->second[i].first;
	  int c = it->second[i].second;

	  int localRowIdx = r - rstart * nComponents;

	  TEST_EXIT_DBG(localRowIdx >= 0 && localRowIdx < nRankRows)
	    ("Got row index %d/%d (nRankRows = %d) from rank %d. Should not happen!\n",
	     r, localRowIdx, nRankRows, it->first);
	  
	  if (c < rstart * nComponents || c >= rstart * nComponents + nRankRows)
	    o_nnz[localRowIdx]++;
	  else
	    d_nnz[localRowIdx]++;
	}
      }
    }  

    // === Create PETSc matrix with the computed nnz data structure. ===

    MatCreateMPIAIJ(PETSC_COMM_WORLD, nRankRows, nRankRows, nOverallRows, nOverallRows,
		    0, d_nnz, 0, o_nnz, &petscMatrix);

#if (DEBUG != 0)
    int a, b;
    MatGetOwnershipRange(petscMatrix, &a, &b);
    TEST_EXIT(a == rstart * nComponents)("Wrong matrix ownership range!\n");
    TEST_EXIT(b == rstart * nComponents + nRankRows)("Wrong matrix ownership range!\n");
#endif

    // === Transfer values from DOF matrices to the PETSc matrix. === 

    for (int i = 0; i < nComponents; i++)
      for (int j = 0; j < nComponents; j++)
	if ((*mat)[i][j])
	  setDofMatrix((*mat)[i][j], nComponents, i, j);

    MatAssemblyBegin(petscMatrix, MAT_FINAL_ASSEMBLY);
    MatAssemblyEnd(petscMatrix, MAT_FINAL_ASSEMBLY);

    // === Transfer values from DOF vector to the PETSc vector. === 

    for (int i = 0; i < nComponents; i++)
      setDofVector(petscRhsVec, vec->getDOFVector(i), nComponents, i);

    VecAssemblyBegin(petscRhsVec);
    VecAssemblyEnd(petscRhsVec);

    INFO(info, 8)("Fill petsc matrix needed %.5f seconds\n", TIME_USED(first, clock()));
  }


  void ParallelDomainBase::solvePetscMatrix(SystemVector &vec)
  {
    FUNCNAME("ParallelDomainBase::solvePetscMatrix()");

#if 0
    // Set old solution to be initiual guess for petsc solver.
    for (int i = 0; i < nComponents; i++)
      setDofVector(petscSolVec, vec->getDOFVector(i), nComponents, i);

    VecAssemblyBegin(petscSolVec);
    VecAssemblyEnd(petscSolVec);
#endif

    // === Init Petsc solver. ===

    KSP solver;
    KSPCreate(PETSC_COMM_WORLD, &solver);
    KSPSetOperators(solver, petscMatrix, petscMatrix, SAME_NONZERO_PATTERN); 
    KSPSetTolerances(solver, 0.0, 1e-8, PETSC_DEFAULT, PETSC_DEFAULT);
    KSPSetType(solver, KSPBCGS);
    KSPMonitorSet(solver, myKSPMonitor, PETSC_NULL, 0);
    KSPSetFromOptions(solver);
    // Do not delete the solution vector, use it for the initial guess.
    //    KSPSetInitialGuessNonzero(solver, PETSC_TRUE);


    // === Run Petsc. ===

    KSPSolve(solver, petscRhsVec, petscSolVec);

    // === Transfere values from Petsc's solution vectors to the dof vectors.
    PetscScalar *vecPointer;
    VecGetArray(petscSolVec, &vecPointer);

    for (int i = 0; i < nComponents; i++) {
      DOFVector<double> *dofvec = vec.getDOFVector(i);
      for (int j = 0; j < nRankDofs; j++)
	(*dofvec)[mapLocalToDofIndex[j]] = vecPointer[j * nComponents + i];      
    }

    VecRestoreArray(petscSolVec, &vecPointer);


    // === Synchronize dofs at common dofs, i.e., dofs that correspond to more ===
    // === than one partition.                                                 ===
    synchVectors(vec);


    // === Print information about solution process. ===

    int iterations = 0;
    KSPGetIterationNumber(solver, &iterations);
    MSG("  Number of iterations: %d\n", iterations);
    
    double norm = 0.0;
    MatMult(petscMatrix, petscSolVec, petscTmpVec);
    VecAXPY(petscTmpVec, -1.0, petscRhsVec);
    VecNorm(petscTmpVec, NORM_2, &norm);
    MSG("  Residual norm: %e\n", norm);


    // === Destroy Petsc's variables. ===

    MatDestroy(petscMatrix);
    VecDestroy(petscRhsVec);
    VecDestroy(petscSolVec);
    VecDestroy(petscTmpVec);
    KSPDestroy(solver);
  }
  
  void ParallelDomainBase::synchVectors(SystemVector &vec)
  {
#if 0
    StdMpi<std::vector<double>, std::vector<double> > stdMpi(mpiComm);

    for (RankToDofContainer::iterator sendIt = sendDofs.begin();
	 sendIt != sendDofs.end(); ++sendIt, i++) {
      std::vector<double> dofs;
      int nSendDOFs = sendIt->second.size();
      dofs.reserve(nComponents * sendIt->second.size());
      
      for (int j = 0; j < nComponents; j++) {
	DOFVector<double> *dofvec = vec.getDOFVector(j);
	for (int k = 0; k < nSendDOFs; k++)
	  dofs.push_back((*dofvec)[*((sendIt->second)[k])]);
      }

      stdMpi.send(sendIt->first, dofs);
    }

    stdMpi.startCommunication<int>();
#endif

#if 1

    std::vector<double*> sendBuffers(sendDofs.size());
    std::vector<double*> recvBuffers(recvDofs.size());

    MPI::Request request[sendDofs.size() + recvDofs.size()];
    int requestCounter = 0;
    
    int i = 0;
    for (RankToDofContainer::iterator sendIt = sendDofs.begin();
	 sendIt != sendDofs.end(); ++sendIt, i++) {
      int nSendDOFs = sendIt->second.size();
      sendBuffers[i] = new double[nSendDOFs * nComponents];

      int counter = 0;
      for (int j = 0; j < nComponents; j++) {
	DOFVector<double> *dofvec = vec.getDOFVector(j);
	for (int k = 0; k < nSendDOFs; k++)
	  sendBuffers[i][counter++] = (*dofvec)[*((sendIt->second)[k])];
      }

      request[requestCounter++] = mpiComm.Isend(sendBuffers[i], nSendDOFs * nComponents,
						MPI_DOUBLE, sendIt->first, 0);
    }

    i = 0;
    for (RankToDofContainer::iterator recvIt = recvDofs.begin();
	 recvIt != recvDofs.end(); ++recvIt, i++) {
      int nRecvDOFs = recvIt->second.size() * nComponents;
      recvBuffers[i] = new double[nRecvDOFs];

      request[requestCounter++] =
	mpiComm.Irecv(recvBuffers[i], nRecvDOFs, MPI_DOUBLE, recvIt->first, 0);
    }

    MPI::Request::Waitall(requestCounter, request);

    i = 0;
    for (RankToDofContainer::iterator recvIt = recvDofs.begin();
	 recvIt != recvDofs.end(); ++recvIt, i++) {
      int nRecvDOFs = recvIt->second.size();

      int counter = 0;
      for (int j = 0; j < nComponents; j++) {
	DOFVector<double> *dofvec = vec.getDOFVector(j);
 	for (int k = 0; k < nRecvDOFs; k++)
	  (*dofvec)[*(recvIt->second)[k]] = recvBuffers[i][counter++];
      }

      delete [] recvBuffers[i];
    }
    
    for (int i = 0; i < static_cast<int>(sendBuffers.size()); i++)
      delete [] sendBuffers[i];
#endif
  }


  void ParallelDomainBase::checkMeshChange()
  {
    FUNCNAME("ParallelDomainBase::checkMeshChange()");

    // === If mesh has not been changed on all ranks, return. ===

    int recvAllValues = 0;
    int sendValue = static_cast<int>(mesh->getChangeIndex() != lastMeshChangeIndex);
    mpiComm.Allreduce(&sendValue, &recvAllValues, 1, MPI_INT, MPI_SUM);

    if (recvAllValues == 0)
      return;

    // === At least one rank mesh has been changed, so the boundaries must be ===
    // === adapted to the new mesh structure.                                 ===

    clock_t first = clock();
    
    do {
      // To check the interior boundaries, the ownership of the boundaries is not 
      // important. Therefore, we add all boundaries to one boundary container.
      RankToBoundMap allBound = myIntBoundary.boundary;
      for (RankToBoundMap::iterator it = otherIntBoundary.boundary.begin(); 
	   it != otherIntBoundary.boundary.end(); ++it)
	allBound[it->first] = it->second;

      // === Check the boundaries and adapt mesh if necessary. ===

      bool meshChanged = checkAndAdaptBoundary(allBound);

      // === Check on all ranks if at least one rank's mesh has changed. ===

      int sendValue = static_cast<int>(!meshChanged);
      recvAllValues = 0;
      mpiComm.Allreduce(&sendValue, &recvAllValues, 1, MPI_INT, MPI_SUM);
    } while (recvAllValues != 0);


#if (DEBUG != 0)
    debug::writeMesh(feSpace, -1, "mesh");
#endif

    INFO(info, 8)("Parallel mesh adaption needed %.5f seconds\n", 
		  TIME_USED(first, clock()));

    // === Because the mesh has been changed, update the DOF numbering and mappings. ===
   
    updateLocalGlobalNumbering();
  }

  
  bool ParallelDomainBase::checkAndAdaptBoundary(RankToBoundMap &allBound)
  {
    FUNCNAME("ParallelDomainBase::checkAndAdaptBoundary()");

    // === Create mesh structure codes for all ranks boundary elements. ===
       
    std::map<int, MeshCodeVec> sendCodes;
   
    for (RankToBoundMap::iterator it = allBound.begin(); it != allBound.end(); ++it) {
      for (std::vector<AtomicBoundary>::iterator boundIt = it->second.begin();
	   boundIt != it->second.end(); ++boundIt) {
	MeshStructure elCode;
	elCode.init(boundIt->rankObj);
	sendCodes[it->first].push_back(elCode);
      }
    }

    StdMpi<MeshCodeVec, MeshCodeVec> stdMpi(mpiComm, true);
    stdMpi.send(sendCodes);
    stdMpi.recv(allBound);
    stdMpi.startCommunication<unsigned long int>(MPI_UNSIGNED_LONG);
 
    // === Compare received mesh structure codes. ===
    
    bool meshFitTogether = true;

    for (RankToBoundMap::iterator it = allBound.begin(); it != allBound.end(); ++it) {
      
      MeshCodeVec &recvCodes = stdMpi.getRecvData()[it->first];
      int i = 0;
      
      for (std::vector<AtomicBoundary>::iterator boundIt = it->second.begin();
	   boundIt != it->second.end(); ++boundIt) {
	
	MeshStructure elCode;	
	elCode.init(boundIt->rankObj);
	
	if (elCode.getCode() != recvCodes[i].getCode()) {
	  TEST_EXIT_DBG(refineManager)("Refinement manager is not set correctly!\n");
	  
	  bool b = fitElementToMeshCode(refineManager, 
					recvCodes[i], 
					boundIt->rankObj.el,
					boundIt->rankObj.ithObj, 
					boundIt->rankObj.elType);  
	  if (b)
	    meshFitTogether = false;
	}
	
	i++;
      }
    }

    return meshFitTogether;
  }
  
  
  void ParallelDomainBase::serialize(std::ostream &out, DofContainer &data)
  {
    int vecSize = data.size();
    SerUtil::serialize(out, vecSize);
    for (int i = 0; i < vecSize; i++) {
      int dofIndex = (*data[i]);
      SerUtil::serialize(out, dofIndex);
    }
  }


  void ParallelDomainBase::deserialize(std::istream &in, DofContainer &data,
				       std::map<int, const DegreeOfFreedom*> &dofMap)
  {
    FUNCNAME("ParallelDomainBase::deserialize()");

    int vecSize = 0;
    SerUtil::deserialize(in, vecSize);
    data.resize(vecSize);
    for (int i = 0; i < vecSize; i++) {
      int dofIndex = 0;
      SerUtil::deserialize(in, dofIndex);

      TEST_EXIT_DBG(dofMap.count(dofIndex) != 0)
	("Dof index could not be deserialized correctly!\n");

      data[i] = dofMap[dofIndex];
    }
  }


  void ParallelDomainBase::serialize(std::ostream &out, RankToDofContainer &data)
  {
    int mapSize = data.size();
    SerUtil::serialize(out, mapSize);
    for (RankToDofContainer::iterator it = data.begin(); it != data.end(); ++it) {
      int rank = it->first;
      SerUtil::serialize(out, rank);
      serialize(out, it->second);
    }
  }

  
  void ParallelDomainBase::deserialize(std::istream &in, RankToDofContainer &data,
				       std::map<int, const DegreeOfFreedom*> &dofMap)
  {
    int mapSize = 0;
    SerUtil::deserialize(in, mapSize);
    for (int i = 0; i < mapSize; i++) {
      int rank = 0;
      SerUtil::deserialize(in, rank);
      deserialize(in, data[rank], dofMap);      
    }
  }


  double ParallelDomainBase::setElemWeights(AdaptInfo *adaptInfo) 
  {
    double localWeightSum = 0.0;
    int elNum = -1;

    elemWeights.clear();

    TraverseStack stack;
    ElInfo *elInfo = stack.traverseFirst(mesh, -1, Mesh::CALL_EVERY_EL_PREORDER);
    while (elInfo) {
      Element *element = elInfo->getElement();

      // get partition data
      PartitionElementData *partitionData = dynamic_cast<PartitionElementData*>
	(element->getElementData(PARTITION_ED));

      if (partitionData && partitionData->getPartitionStatus() == IN) {
	if (partitionData->getLevel() == 0)
	  elNum = element->getIndex();
	
	TEST_EXIT_DBG(elNum != -1)("invalid element number\n");
	if (element->isLeaf()) {
	  elemWeights[elNum] += 1.0;
	  localWeightSum += 1.0;
	}
      }

      elInfo = stack.traverseNext(elInfo);
    }

    return localWeightSum;
  }


  void ParallelDomainBase::partitionMesh(AdaptInfo *adaptInfo)
  {
    FUNCNAME("ParallelDomainBase::partitionMesh()");

    if (initialPartitionMesh) {
      initialPartitionMesh = false;
      partitioner->fillCoarsePartitionVec(&oldPartitionVec);
      partitioner->partition(&elemWeights, INITIAL);
    } else {
      oldPartitionVec = partitionVec;
      partitioner->partition(&elemWeights, ADAPTIVE_REPART, 100.0 /*0.000001*/);
    }    

    partitioner->fillCoarsePartitionVec(&partitionVec);
  }


  void ParallelDomainBase::createInteriorBoundaryInfo()
  {
    FUNCNAME("ParallelDomainBase::createInteriorBoundaryInfo()");

    int nNeighbours = mesh->getGeo(NEIGH);
    int dim = mesh->getDim();
    GeoIndex subObj = CENTER;
    switch (dim) {
    case 2:
      subObj = EDGE;
      break;
    case 3:
      subObj = FACE;
      break;
    default:
      ERROR_EXIT("What is this?\n");
    }     

    // === First, traverse the mesh and search for all elements that have an  ===
    // === boundary with an element within another partition.                 ===

    TraverseStack stack;
    ElInfo *elInfo = 
      stack.traverseFirst(mesh, -1, 
			  Mesh::CALL_LEAF_EL | Mesh::FILL_NEIGH | Mesh::FILL_BOUND);
    while (elInfo) {
      Element *element = elInfo->getElement();
      PartitionElementData *partitionData = 
	dynamic_cast<PartitionElementData*>(element->getElementData(PARTITION_ED));   

      // Check, if the element is within rank's partition.
      if (partitionData->getPartitionStatus() == IN) {
	for (int i = 0; i < nNeighbours; i++) {
	  if (!elInfo->getNeighbour(i))
	    continue;

	  PartitionElementData *neighbourPartitionData =
	    dynamic_cast<PartitionElementData*>(elInfo->getNeighbour(i)->
						getElementData(PARTITION_ED));

 	  if (neighbourPartitionData->getPartitionStatus() == OUT) {

	    // We have found an element that is in rank's partition, but has a 
	    // neighbour outside of the rank's partition.

	    // === Create information about the boundary between the two elements. ===

	    AtomicBoundary bound;	    	    
	    bound.rankObj.el = element;
	    bound.rankObj.elIndex = element->getIndex();
	    bound.rankObj.elType = elInfo->getType();
	    bound.rankObj.subObj = subObj;
	    bound.rankObj.ithObj = i;

	    bound.neighObj.el = elInfo->getNeighbour(i);
	    bound.neighObj.elIndex = elInfo->getNeighbour(i)->getIndex();
	    bound.neighObj.elType = -1;
	    bound.neighObj.subObj = subObj;
	    bound.neighObj.ithObj = elInfo->getSideOfNeighbour(i);
	    
	    if (dim == 2) {
	      // i == 2  =>  getSideOfNeighbour(i) == 2
	      TEST_EXIT_DBG(i != 2 || elInfo->getSideOfNeighbour(i) == 2)
		("Should not happen!\n");
	    }

	    // Get rank number of the neighbouring element.
	    int otherElementRank = partitionVec[elInfo->getNeighbour(i)->getIndex()];


	    // === Add the boundary information object to the corresponding overall ===
	    // === boundary. There are three possibilities: if the boundary is a    ===
	    // === periodic boundary, just add it to \ref periodicBounadry. Here it ===
	    // === does not matter which rank is responsible for this boundary.     ===
	    // === Otherwise, the boundary is added either to \ref myIntBoundary or ===
	    // === to \ref otherIntBoundary. It dependes on which rank is respon-   ===
	    // === sible for this boundary.                                         ===

	    if (BoundaryManager::isBoundaryPeriodic(elInfo->getBoundary(subObj, i))) {	      
	      // We have found an element that is at an interior, periodic boundary.
	      AtomicBoundary& b = periodicBoundary.getNewAtomic(otherElementRank);
	      b = bound;
	    } else {
	      // We have found an element that is at an interior, non-periodic boundary.
	      if (mpiRank > otherElementRank) {
		AtomicBoundary& b = myIntBoundary.getNewAtomic(otherElementRank);
		b = bound;
		b.rankObj.setReverseMode(b.neighObj, feSpace);
	      } else {
		AtomicBoundary& b = otherIntBoundary.getNewAtomic(otherElementRank);
		b = bound;	 
		b.neighObj.setReverseMode(b.rankObj, feSpace);
	      }	      
	    }
 	  }
	}
      }

      elInfo = stack.traverseNext(elInfo);
    }


    // === Seach for all edges which are part of an interior boundary, but are not ===
    // === a part of some elements at the interior bouundary.                      ===

    const BasisFunction *basFcts = feSpace->getBasisFcts();
    int nBasFcts = basFcts->getNumber();
    std::vector<DegreeOfFreedom> localIndices(nBasFcts, 0);

    // Maps each edge in the whole domain to the rank that ownes this edge.
    std::map<GlobalEdge, int> edgeOwner;
    // Maps each edge in ranks part of the domain to the element object that contains
    // this edge.
    std::map<GlobalEdge, BoundaryObject> rankEdges;

    std::map<DegreeOfFreedom, int> dofOwner;
    std::map<DegreeOfFreedom, BoundaryObject> rankDofs;

    // === Traverse whole mesh and fill the maps edgeOwner and rankEdges. ===

    elInfo = stack.traverseFirst(mesh, -1, Mesh::CALL_LEAF_EL);
    while (elInfo) {
      Element *el = elInfo->getElement();
      basFcts->getLocalIndices(el, feSpace->getAdmin(), localIndices);

      PartitionElementData *partitionData = dynamic_cast<PartitionElementData*>
	(el->getElementData(PARTITION_ED));
      
      // Traverse all edges of current element.
      for (int i = 0; i < 6; i++) {
	DegreeOfFreedom dof0 = localIndices[el->getVertexOfEdge(i, 0)];
	DegreeOfFreedom dof1 = localIndices[el->getVertexOfEdge(i, 1)];
	GlobalEdge edge = std::make_pair(min(dof0, dof1), max(dof0, dof1));	

	// Update the owner of the current edge.
	edgeOwner[edge] = max(edgeOwner[edge], partitionVec[el->getIndex()]);
	dofOwner[dof0] = max(dofOwner[dof0], partitionVec[el->getIndex()]);
	dofOwner[dof1] = max(dofOwner[dof1], partitionVec[el->getIndex()]);

	// If the edge is part of an element that is part of rank's domain, add it
	// to the set of all rank's edges.
	if (partitionData && partitionData->getPartitionStatus() == IN) {
	  BoundaryObject b(el, elInfo->getType(), EDGE, i);
	  rankEdges[edge] = b;
	  rankDofs[dof0] = b;
	  rankDofs[dof1] = b;
	}
      }      

      elInfo = stack.traverseNext(elInfo);
    }

    // === Create a set of all edges at rank's interior boundaries. ===

    // Stores all edges at rank's interior boundaries.
    std::set<GlobalEdge> rankBoundaryEdges;

    std::set<DegreeOfFreedom> rankBoundaryDofs;

    // First, traverse the rank owned elements af the interior boundaries.
    for (RankToBoundMap::iterator rankIt = myIntBoundary.boundary.begin();
	 rankIt != myIntBoundary.boundary.end(); ++rankIt) {
      for (unsigned int i = 0; i < rankIt->second.size(); i++) {
	Element *el = rankIt->second[i].rankObj.el;
	basFcts->getLocalIndices(el, feSpace->getAdmin(), localIndices);

	for (int j = 0; j < 3; j++) {
	  int edgeNo = el->getEdgeOfFace(rankIt->second[i].rankObj.ithObj, j);
	  DegreeOfFreedom dof0 = localIndices[el->getVertexOfEdge(edgeNo, 0)];
	  DegreeOfFreedom dof1 = localIndices[el->getVertexOfEdge(edgeNo, 1)];
	  GlobalEdge edge = std::make_pair(min(dof0, dof1), max(dof0, dof1));	
	  
	  // If the edge at rank's interior boundarie has a higher owner rank, than
	  // we have to remove this edge from the corresponding boundary element.
	  // Otherwise, it is part of the interior boundary and we add it to the set
	  // rankBoundaryEdges.
	  if (edgeOwner[edge] > mpiRank)
	    rankIt->second[i].rankObj.notIncludedSubStructures.push_back(std::pair<GeoIndex, int>(EDGE, edgeNo));
	  else
	    rankBoundaryEdges.insert(edge);
	}
      
	for (int j = 0; j < 3; j++) {
	  int dofNo = el->getVertexOfPosition(FACE, rankIt->second[i].rankObj.ithObj, j);
	  DegreeOfFreedom dof = localIndices[dofNo];

	  if (dofOwner[dof] > mpiRank)
	    rankIt->second[i].rankObj.notIncludedSubStructures.push_back(std::pair<GeoIndex, int>(VERTEX, dofNo));
	  else
	    rankBoundaryDofs.insert(dof);
	}
      }
    }

    // Now, do the same with all other elements at the interio boundaries.
    for (RankToBoundMap::iterator rankIt = otherIntBoundary.boundary.begin();
	 rankIt != otherIntBoundary.boundary.end(); ++rankIt) {
      for (unsigned int i = 0; i < rankIt->second.size(); i++) {
	Element *el = rankIt->second[i].rankObj.el;
	basFcts->getLocalIndices(el, feSpace->getAdmin(), localIndices);

	for (int j = 0; j < 3; j++) {
	  int edgeNo = el->getEdgeOfFace(rankIt->second[i].rankObj.ithObj, j);
	  DegreeOfFreedom dof0 = localIndices[el->getVertexOfEdge(edgeNo, 0)];
	  DegreeOfFreedom dof1 = localIndices[el->getVertexOfEdge(edgeNo, 1)];
	  GlobalEdge edge = std::make_pair(min(dof0, dof1), max(dof0, dof1));	

	  if (edgeOwner[edge] > rankIt->first)
	    rankIt->second[i].rankObj.notIncludedSubStructures.push_back(std::pair<GeoIndex, int>(EDGE, edgeNo));
	  else
	    rankBoundaryEdges.insert(edge);

	}

	for (int j = 0; j < 3; j++) {
	  int dofNo = el->getVertexOfPosition(FACE, rankIt->second[i].rankObj.ithObj, j);
	  DegreeOfFreedom dof = localIndices[dofNo];
	  
	  if (dofOwner[dof] > rankIt->first)
	    rankIt->second[i].rankObj.notIncludedSubStructures.push_back(std::pair<GeoIndex, int>(VERTEX, dofNo));
	  else
	    rankBoundaryDofs.insert(dof);
	}	
      }
    }


    // === Create the new interior boundaries consisting only of edges. This    ===
    // === boundaries are created on that ranks, which do not own the boundary  ===
    // === but are on the other side of the edge. Than, theses ranks inform the ===
    // === owner of the edge, that they both share them.                        ===

    // Maps that stores to each rank number the global edges this rank has an 
    // interior boundary with. 
    std::map<int, std::vector<GlobalEdge> > recvEdges;
    // Stores to the map above the corresponding element objects that include the edge.
    std::map<int, std::vector<BoundaryObject> > recvEdgesObj;
    for (int i = 0; i < mpiSize; i++) {
      recvEdges[i].clear();
      recvEdgesObj[i].clear();
    }

    // Traverse all edges in rank's domain.
    for (std::map<GlobalEdge, BoundaryObject>::iterator it = rankEdges.begin();
	 it != rankEdges.end(); ++it) {
      // If we have found an edge in rank's domain that has an owner with a higher
      // rank number, i.e., it must be part of an interior domain, but have not found
      // it before to be part of an interior domain, we have found an edge interior
      // domain we have to add to the corresponding interior domain object.

      if (edgeOwner[it->first] > mpiRank && rankBoundaryEdges.count(it->first) == 0) {
	std::vector<GlobalEdge> &ownerEdges = recvEdges[edgeOwner[it->first]];
	
	// Check, we have not add this edge before.
	if (find(ownerEdges.begin(), ownerEdges.end(), it->first) == ownerEdges.end()) {
	  ownerEdges.push_back(it->first);	
	  recvEdgesObj[edgeOwner[it->first]].push_back(it->second);

	  rankBoundaryDofs.insert(it->first.first);
	  rankBoundaryDofs.insert(it->first.second);
	}
      }
    }


    // === Send all edge interior boundary infos to the owner of the new edge === 
    // === interior boundaries.                                               ===

    StdMpi<std::vector<GlobalEdge>, std::vector<GlobalEdge> > stdMpiEdge(mpiComm, true);
    stdMpiEdge.send(recvEdges);
    stdMpiEdge.recvFromAll();
    stdMpiEdge.startCommunication<int>(MPI_INT);

    StdMpi<std::vector<BoundaryObject>, std::vector<BoundaryObject> > stdMpiEdgeObj(mpiComm, true);
    stdMpiEdgeObj.send(recvEdgesObj);
    stdMpiEdgeObj.recvFromAll();
    stdMpiEdgeObj.startCommunication<int>(MPI_INT);


    // The owner of an edge interior boundary must send back information about the
    // mesh element that stores the edge at the owners domain. These information are
    // stored in this map.
    std::map<int, std::vector<BoundaryObject> > sendObjects;
    for (int i = 0; i < mpiSize; i++)
      sendObjects[i].clear();
    
    // === All owner of a new edge interior boundary will create this now from the ===
    // === received data.                                                          ===

    for (std::map<int, std::vector<GlobalEdge> >::iterator it = stdMpiEdge.getRecvData().begin();
	 it != stdMpiEdge.getRecvData().end(); ++it) {
      for (unsigned int i = 0; i < it->second.size(); i++) {
	TEST_EXIT_DBG(stdMpiEdgeObj.getRecvData(it->first).size() > i)
	  ("Should not happen!\n");
	
	AtomicBoundary& b = myIntBoundary.getNewAtomic(it->first); 
	b.rankObj = rankEdges[it->second[i]];
	b.neighObj = stdMpiEdgeObj.getRecvData(it->first)[i];
	
	sendObjects[it->first].push_back(b.rankObj);

	rankBoundaryDofs.insert(it->second[i].first);
	rankBoundaryDofs.insert(it->second[i].second);
      }
    }

    // === Send the information about the elements on the owners side of the new ===
    // === edge interior boundaries.                                             ===
    
    stdMpiEdgeObj.clear();
    stdMpiEdgeObj.send(sendObjects);
    stdMpiEdgeObj.recvFromAll();
    stdMpiEdgeObj.startCommunication<int>(MPI_INT);

    // === To the last, all non-owners of a edge interior boundary will now create ===
    // === the necessary boundary objects.                                         ===

    for (std::map<int, std::vector<BoundaryObject> >::iterator it = recvEdgesObj.begin();
	it != recvEdgesObj.end(); ++it) {
      if (it->second.size() > 0) {	
	TEST_EXIT_DBG(it->second.size() == stdMpiEdgeObj.getRecvData(it->first).size())
	  ("Should not happen!\n");

	for (unsigned int i = 0; i < it->second.size(); i++) {
	  AtomicBoundary& b = otherIntBoundary.getNewAtomic(it->first); 
	  b.rankObj = it->second[i];
	  b.neighObj = stdMpiEdgeObj.getRecvData(it->first)[i];  	  
	}
      }
    }


    for (std::map<DegreeOfFreedom, BoundaryObject>::iterator it = rankDofs.begin();
	 it != rankDofs.end(); ++it) {
      if (dofOwner[it->first] > mpiRank && rankBoundaryDofs.count(it->first) == 0) {
	MSG("HAB DICH: %d\n", it->first);
      }
    }
    

    // === Once we have this information, we must care about the order of the atomic ===
    // === bounds in the three boundary handling object. Eventually all the bound-   ===
    // === aries have to be in the same order on both ranks that share the bounday.  ===

    StdMpi<std::vector<AtomicBoundary>, std::vector<AtomicBoundary> > stdMpi(mpiComm);
    stdMpi.send(myIntBoundary.boundary);
    stdMpi.recv(otherIntBoundary.boundary);
    stdMpi.startCommunication<int>(MPI_INT);
   
    // === The information about all neighbouring boundaries has been received. So ===
    // === the rank tests if its own atomic boundaries are in the same order. If   ===
    // === not, the atomic boundaries are swaped to the correct order.             ===

    for (RankToBoundMap::iterator rankIt = otherIntBoundary.boundary.begin();
	 rankIt != otherIntBoundary.boundary.end(); ++rankIt) {

      // === We have received from rank "rankIt->first" the ordered list of element ===
      // === indices. We now have to sort the corresponding list in this rank to    ===
      // === get the same order.                                                    ===
      
      for (int j = 0; j < static_cast<int>(rankIt->second.size()); j++) {
	// If the expected object is not at place, search for it.

	BoundaryObject &recvedBound = stdMpi.getRecvData()[rankIt->first][j].rankObj;

	if ((rankIt->second)[j].neighObj != recvedBound) {
	  int k = j + 1;
	  for (; k < static_cast<int>(rankIt->second.size()); k++)
 	    if ((rankIt->second)[k].neighObj == recvedBound)
	      break;

	  // The element must always be found, because the list is just in another order.
	  TEST_EXIT_DBG(k < static_cast<int>(rankIt->second.size()))
	    ("Should never happen!\n");

	  // Swap the current with the found element.
	  AtomicBoundary tmpBound = (rankIt->second)[k];
	  (rankIt->second)[k] = (rankIt->second)[j];
	  (rankIt->second)[j] = tmpBound;	
	}
      }
    }

    // === Do the same for the periodic boundaries. ===

    if (periodicBoundary.boundary.size() > 0) {
      stdMpi.clear();

      InteriorBoundary sendBounds, recvBounds;     
      for (RankToBoundMap::iterator rankIt = periodicBoundary.boundary.begin();
	   rankIt != periodicBoundary.boundary.end(); ++rankIt) {

	TEST_EXIT_DBG(rankIt->first != mpiRank)
	  ("It is no possible to have an interior boundary within a rank partition!\n");

	if (rankIt->first < mpiRank)
	  sendBounds.boundary[rankIt->first] = rankIt->second;
	else
	  recvBounds.boundary[rankIt->first] = rankIt->second;
      }

      stdMpi.send(sendBounds.boundary);
      stdMpi.recv(recvBounds.boundary);
      stdMpi.startCommunication<int>(MPI_INT);

      for (RankToBoundMap::iterator rankIt = periodicBoundary.boundary.begin();
	   rankIt != periodicBoundary.boundary.end(); ++rankIt) {
	if (rankIt->first <= mpiRank)
	  continue;
	  
	for (int j = 0; j < static_cast<int>(rankIt->second.size()); j++) {
	  
	  BoundaryObject &recvedBound = stdMpi.getRecvData()[rankIt->first][j].rankObj;
	  
	  if (periodicBoundary.boundary[rankIt->first][j].neighObj != recvedBound) {    
	    int k = j + 1;	    
	    for (; k < static_cast<int>(rankIt->second.size()); k++)
	      if (periodicBoundary.boundary[rankIt->first][k].neighObj == recvedBound)
		break;
	    
	    // The element must always be found, because the list is just in 
	    // another order.
	    TEST_EXIT_DBG(k < static_cast<int>(rankIt->second.size()))
	      ("Should never happen!\n");
	    
	    // Swap the current with the found element.
	    AtomicBoundary tmpBound = (rankIt->second)[k];
	    (rankIt->second)[k] = (rankIt->second)[j];
	    (rankIt->second)[j] = tmpBound;	
	  }  	  
	}
      }     
    } // periodicBoundary.boundary.size() > 0

    //    exit(0);
  }


  void ParallelDomainBase::removeMacroElements()
  {
    FUNCNAME("ParallelDomainBase::removeMacroElements()");

    std::set<MacroElement*> macrosToRemove;
    for (std::deque<MacroElement*>::iterator it = mesh->firstMacroElement();
	 it != mesh->endOfMacroElements();
	 ++it) {
      PartitionElementData *partitionData = 
	dynamic_cast<PartitionElementData*>
	((*it)->getElement()->getElementData(PARTITION_ED));
      if (partitionData->getPartitionStatus() != IN)
	macrosToRemove.insert(*it);
    }

    mesh->removeMacroElements(macrosToRemove, feSpace);
  }


  void ParallelDomainBase::createLocalGlobalNumbering()
  {
    FUNCNAME("ParallelDomainBase::createLocalGlobalNumbering()");

    // === Get rank information about DOFs. ===

    // Stores to each DOF pointer the set of ranks the DOF is part of.
    DofToPartitions partitionDofs;
    DofContainer rankDofs, rankAllDofs;
    DofToRank boundaryDofs;

    createDofMemberInfo(partitionDofs, rankDofs, rankAllDofs, boundaryDofs, vertexDof);

    nRankDofs = rankDofs.size();
    int nOverallDofs = partitionDofs.size();


    // === Get starting position for global rank dof ordering. ====

    rstart = 0;
    mpiComm.Scan(&nRankDofs, &rstart, 1, MPI_INT, MPI_SUM);
    rstart -= nRankDofs;

    // === Create for all dofs in rank new indices. The new index must start at ===
    // === index 0, must be continues and have the same order as the indices    ===
    // === had before.                                                          ===

    // Do not change the indices now, but create a new indexing and store it here.
    DofIndexMap rankDofsNewLocalIndex;
    isRankDof.clear();
    int i = 0;
    for (DofContainer::iterator dofIt = rankAllDofs.begin();
	 dofIt != rankAllDofs.end(); ++dofIt) {
      rankDofsNewLocalIndex[*dofIt] = i;
      // First, we set all dofs in ranks partition to be owend by the rank. Later,
      // the dofs in ranks partition that are owned by other rank are set to false.
      isRankDof[i] = true;
      i++;
    }


    // === Create for all rank owned dofs a new global indexing. ===

    // Stores for dofs in rank a new global index.
    DofIndexMap rankDofsNewGlobalIndex;
    // Stores for all rank owned dofs a continues local index.
    DofIndexMap rankOwnedDofsNewLocalIndex;

    i = 0;
    for (DofContainer::iterator dofIt = rankDofs.begin();
	 dofIt != rankDofs.end(); ++dofIt) {
      rankDofsNewGlobalIndex[*dofIt] = i + rstart;
      rankOwnedDofsNewLocalIndex[*dofIt] = i;
      i++;
    }


    // === Create information which dof indices must be send and which must  ===
    // === be received.                                                      ===

    // Stores to each rank a map from DOF pointers (which are all owned by the rank
    // and lie on an interior boundary) to new global DOF indices.
    std::map<int, DofIndexMap> sendNewDofs;

    // Maps to each rank the number of new DOF indices this rank will receive from.
    // All these DOFs are at an interior boundary on this rank, but are owned by
    // another rank.
    std::map<int, int> recvNewDofs;

    for (DofToRank::iterator it = boundaryDofs.begin(); it != boundaryDofs.end(); ++it) {

      if (it->second == mpiRank) {
	// If the boundary dof is a rank dof, it must be send to other ranks.

	// Search for all ranks that have this dof too.
	for (std::set<int>::iterator itRanks = partitionDofs[it->first].begin();
	     itRanks != partitionDofs[it->first].end();
	     ++itRanks) {
	  if (*itRanks != mpiRank) {
	    TEST_EXIT_DBG(rankDofsNewGlobalIndex.count(it->first) == 1)
	      ("DOF Key not found!\n");

	    sendNewDofs[*itRanks][it->first] = rankDofsNewGlobalIndex[it->first];
	  }
	}
      } else {
	// If the boundary dof is not a rank dof, its new dof index (and later
	// also the dof values) must be received from another rank.
	if (recvNewDofs.find(it->second) == recvNewDofs.end()) 
	  recvNewDofs[it->second] = 1;
	else
	  recvNewDofs[it->second]++;
      }
    }


    // === Send and receive the dof indices at boundary. ===

    sendDofs.clear();
    for (std::map<int, DofIndexMap>::iterator sendIt = sendNewDofs.begin();
	 sendIt != sendNewDofs.end(); ++sendIt)
      for (DofIndexMap::iterator dofIt = sendIt->second.begin();
	   dofIt != sendIt->second.end(); ++dofIt)
	sendDofs[sendIt->first].push_back(dofIt->first);

    StdMpi<DofIndexMap, std::vector<std::pair<DegreeOfFreedom, DegreeOfFreedom> > > stdMpi(mpiComm);
    stdMpi.send(sendNewDofs);
    for (std::map<int, int>::iterator recvIt = recvNewDofs.begin();
	 recvIt != recvNewDofs.end(); ++recvIt, i++)
      stdMpi.recv(recvIt->first, recvIt->second * 2); 
    stdMpi.startCommunication<int>(MPI_INT);
    std::map<int, std::vector<std::pair<DegreeOfFreedom, DegreeOfFreedom> > > &dofMap = stdMpi.getRecvData();


    // === Change dof indices at boundary from other ranks. ===

    // Within this small data structure we track which dof index was already changed.
    // This is used to avoid the following situation: Assume, there are two dof indices
    // a and b in boundaryDofs. Then we have to change index a to b and b to c. When
    // the second rule applies, we have to avoid that not the first b, resulted from
    // changing a to b, is set to c, but the second one. Therefore, after the first
    // rule was applied, the dof pointer is set to false in this data structure and 
    // is not allowed to be changed anymore.
    std::map<const DegreeOfFreedom*, bool> dofChanged;
    recvDofs.clear();

    for (DofToRank::iterator dofIt = boundaryDofs.begin(); dofIt != boundaryDofs.end();
	 ++dofIt)
      dofChanged[dofIt->first] = false;

    for (std::map<int, std::vector<std::pair<DegreeOfFreedom, DegreeOfFreedom> > >::iterator rankIt = dofMap.begin();
 	 rankIt != dofMap.end(); ++rankIt) {
      
      for (std::vector<std::pair<DegreeOfFreedom, DegreeOfFreedom> >::iterator recvDofIt = rankIt->second.begin();
	   recvDofIt != rankIt->second.end(); ++recvDofIt) {

	DegreeOfFreedom oldDof = recvDofIt->first;
	DegreeOfFreedom newGlobalDof = recvDofIt->second;
	
	bool found = false;
	
	// Iterate over all boundary dofs to find the dof which index we have to change.
	
	for (DofToRank::iterator dofIt = boundaryDofs.begin(); 
	     dofIt != boundaryDofs.end(); ++dofIt) {   
	  
	  if (*(dofIt->first) == oldDof && !dofChanged[dofIt->first]) {
	    dofChanged[dofIt->first] = true;
	    
	    recvDofs[rankIt->first].push_back(dofIt->first);
	    rankDofsNewGlobalIndex[dofIt->first] = newGlobalDof;
	    isRankDof[rankDofsNewLocalIndex[dofIt->first]] = false;
	    
	    found = true;
	    break;
	  }
	}
	
	TEST_EXIT_DBG(found)("Should not happen!\n");
      }      
    }


    // === Create now the local to global index and local to dof index mappings.  ===

    createLocalMappings(rankDofsNewLocalIndex, rankOwnedDofsNewLocalIndex,
			rankDofsNewGlobalIndex);

    nRankRows = nRankDofs * nComponents;
    nOverallRows = nOverallDofs * nComponents;

    lastMeshChangeIndex = mesh->getChangeIndex();
  }


  void ParallelDomainBase::updateLocalGlobalNumbering()
  {
    FUNCNAME("ParallelDomainBase::updateLocalGlobalNumbering()");

#if (DEBUG != 0)
    ElementIdxToDofs elMap;
    dbgCreateElementMap(elMap);
#endif

    typedef std::set<const DegreeOfFreedom*> DofSet;

    // === Get all DOFs in ranks partition. ===

    ElementDofIterator elDofIt(feSpace);
    DofSet rankDofSet;
    
    // The vertexDof list must be recreated from the scratch. Otherwise, it is possible
    // that it maps dofs, that were removed (this is also possible, if the mesh was
    // refined, e.g., center dofs of an element are not dofs of the children).
    DofToBool oldVertexDof = vertexDof;
    vertexDof.clear();

    TraverseStack stack;
    ElInfo *elInfo = stack.traverseFirst(mesh, -1, Mesh::CALL_LEAF_EL);
    while (elInfo) {
      Element *element = elInfo->getElement();     
      elDofIt.reset(element);
      do {
	rankDofSet.insert(elDofIt.getDofPtr());

	if (elDofIt.getCurrentPos() == 0) 
	  vertexDof[elDofIt.getDofPtr()] = true;
	else
	  vertexDof[elDofIt.getDofPtr()] = false;
      } while(elDofIt.next());

      elInfo = stack.traverseNext(elInfo);
    }

    DofContainer rankAllDofs;
    for (DofSet::iterator dofIt = rankDofSet.begin(); dofIt != rankDofSet.end(); ++dofIt)
      rankAllDofs.push_back(*dofIt);    
    sort(rankAllDofs.begin(), rankAllDofs.end(), cmpDofsByValue);
    DofContainer rankDofs = rankAllDofs;


    // === Traverse on interior boundaries and move all not ranked owned DOFs from ===
    // === rankDofs to boundaryDOFs.                                               ===

    RankToDofContainer oldSendDofs = sendDofs;
    RankToDofContainer oldRecvDofs = recvDofs;

    sendDofs.clear();
    recvDofs.clear();

    for (RankToDofContainer::iterator it = oldSendDofs.begin();
	 it != oldSendDofs.end(); ++it) {
      for (DofContainer::iterator dofIt = it->second.begin();
	   dofIt != it->second.end(); ++dofIt) {
	if (oldVertexDof[*dofIt])
	  sendDofs[it->first].push_back(*dofIt);
      }
    }

    for (RankToDofContainer::iterator it = oldRecvDofs.begin();
	 it != oldRecvDofs.end(); ++it) {
      for (DofContainer::iterator dofIt = it->second.begin();
	   dofIt != it->second.end(); ++dofIt) {
	if (oldVertexDof[*dofIt]) {
	  recvDofs[it->first].push_back(*dofIt);

	  DofContainer::iterator eraseIt = 
	    find(rankDofs.begin(), rankDofs.end(), *dofIt);
	  if (eraseIt != rankDofs.end())
	    rankDofs.erase(eraseIt);    
	}
      }
    }

    
    for (RankToBoundMap::iterator it = myIntBoundary.boundary.begin();
	 it != myIntBoundary.boundary.end(); ++it) {    
     
      DofContainer &dofsToSend = sendDofs[it->first];

      for (std::vector<AtomicBoundary>::iterator boundIt = it->second.begin();
	   boundIt != it->second.end(); ++boundIt) {
	DofContainer dofs;	
	boundIt->rankObj.el->getVertexDofs(feSpace, boundIt->rankObj, dofs);
   	boundIt->rankObj.el->getNonVertexDofs(feSpace, boundIt->rankObj, dofs);

	for (int i = 0; i < static_cast<int>(dofs.size()); i++)
	  dofsToSend.push_back(dofs[i]);
      }
    } 

    for (RankToBoundMap::iterator it = otherIntBoundary.boundary.begin();
	 it != otherIntBoundary.boundary.end(); ++it) {

      DofContainer &dofsToRecv = recvDofs[it->first];

      for (std::vector<AtomicBoundary>::iterator boundIt = it->second.begin();
	   boundIt != it->second.end(); ++boundIt) {
	DofContainer dofs;
   	boundIt->rankObj.el->getNonVertexDofs(feSpace, boundIt->rankObj, dofs);
	boundIt->rankObj.el->getVertexDofs(feSpace, boundIt->rankObj, dofs);

	for (int i = 0; i < static_cast<int>(dofs.size()); i++) {
	  DofContainer::iterator eraseIt = 
	    find(rankDofs.begin(), rankDofs.end(), dofs[i]);
	  if (eraseIt != rankDofs.end()) 
	    rankDofs.erase(eraseIt);	 
  
	  dofsToRecv.push_back(dofs[i]);
	}
      }
    }

    nRankDofs = rankDofs.size();

    // === Get starting position for global rank dof ordering. ====

    mpiComm.Scan(&nRankDofs, &rstart, 1, MPI_INT, MPI_SUM);
    rstart -= nRankDofs;


    // === Calculate number of overall DOFs of all partitions. ===

    int nOverallDofs = 0;
    mpiComm.Allreduce(&nRankDofs, &nOverallDofs, 1, MPI_INT, MPI_SUM);


    // Do not change the indices now, but create a new indexing and store it here.
    DofIndexMap rankDofsNewLocalIndex;
    isRankDof.clear();
    int i = 0;
    for (DofContainer::iterator dofIt = rankAllDofs.begin();
	 dofIt != rankAllDofs.end(); ++dofIt) {

      rankDofsNewLocalIndex[*dofIt] = i;
      // First, we set all dofs in ranks partition to be owend by the rank. Later,
      // the dofs in ranks partition that are owned by other rank are set to false.
      isRankDof[i] = true;
      i++;
    }

    // Stores for all rank owned dofs a new global index.
    DofIndexMap rankDofsNewGlobalIndex;
    // Stores for all rank owned dofs a continues local index.
    DofIndexMap rankOwnedDofsNewLocalIndex;

    i = 0;
    for (DofContainer::iterator dofIt = rankDofs.begin();
	 dofIt != rankDofs.end(); ++dofIt) {
      rankDofsNewGlobalIndex[*dofIt] = i + rstart;
      rankOwnedDofsNewLocalIndex[*dofIt] = i;
      i++;
    }

    // === Send new DOF indices. ===

#if 0
    StdMpi<std::vector<DegreeOfFreedom>, std::vector<DegreeOfFreedom> > stdMpi(mpiComm);
    for (RankToDofContainer::iterator sendIt = sendDofs.begin();
	 sendIt != sendDofs.end(); ++sendIt, i++) {
      stdMpi.getSendData(sendIt->first).resize(0);
      stdMpi.getSendData(sendIt->first).reserve(sendIt->second.size());
      for (DofContainer::iterator dofIt = sendIt->second.begin();
	   dofIt != sendIt->second.end(); ++dofIt)
	stdMpi.getSendData(sendIt->first).push_back(rankDofsNewGlobalIndex[*dofIt]);
    }
#endif

    std::vector<int*> sendBuffers(sendDofs.size());
    std::vector<int*> recvBuffers(recvDofs.size());

    MPI::Request request[sendDofs.size() + recvDofs.size()];
    int requestCounter = 0;

    i = 0;
    for (RankToDofContainer::iterator sendIt = sendDofs.begin();
	 sendIt != sendDofs.end(); ++sendIt, i++) {
      int nSendDofs = sendIt->second.size();
      sendBuffers[i] = new int[nSendDofs];
      int c = 0;
      for (DofContainer::iterator dofIt = sendIt->second.begin();
	   dofIt != sendIt->second.end(); ++dofIt)
	sendBuffers[i][c++] = rankDofsNewGlobalIndex[*dofIt];

      request[requestCounter++] = 
 	mpiComm.Isend(sendBuffers[i], nSendDofs, MPI_INT, sendIt->first, 0);
    }

    i = 0;
    for (RankToDofContainer::iterator recvIt = recvDofs.begin();
	 recvIt != recvDofs.end(); ++recvIt, i++) {
      int nRecvDofs = recvIt->second.size();
      recvBuffers[i] = new int[nRecvDofs];

      request[requestCounter++] = 
 	mpiComm.Irecv(recvBuffers[i], nRecvDofs, MPI_INT, recvIt->first, 0);
    }

    MPI::Request::Waitall(requestCounter, request);

    for (int j = 0; j < static_cast<int>(sendBuffers.size()); j++)
      delete [] sendBuffers[j];

    i = 0;
    for (RankToDofContainer::iterator recvIt = recvDofs.begin();
	 recvIt != recvDofs.end(); ++recvIt) {      
      int j = 0;
      for (DofContainer::iterator dofIt = recvIt->second.begin();
	   dofIt != recvIt->second.end(); ++dofIt) {

	rankDofsNewGlobalIndex[*dofIt] = recvBuffers[i][j];     
	isRankDof[rankDofsNewLocalIndex[*dofIt]] = false;
	j++;
      }

      delete [] recvBuffers[i++];
    }

    // === Create now the local to global index and local to dof index mappings.  ===

    createLocalMappings(rankDofsNewLocalIndex, rankOwnedDofsNewLocalIndex,
			rankDofsNewGlobalIndex);

    nRankRows = nRankDofs * nComponents;
    nOverallRows = nOverallDofs * nComponents;

    // === Update dof admins due to new number of dofs. ===
  
    updateDofAdmins();

    lastMeshChangeIndex = mesh->getChangeIndex();

#if (DEBUG != 0)
    dbgTestElementMap(elMap);
    dbgTestCommonDofs(true);
#endif
  }

  void ParallelDomainBase::createLocalMappings(DofIndexMap &rankDofsNewLocalIndex,
					       DofIndexMap &rankOwnedDofsNewLocalIndex,
					       DofIndexMap &rankDofsNewGlobalIndex)
  {
    mapLocalGlobalDofs.clear();
    mapLocalToDofIndex.clear();

    for (DofIndexMap::iterator dofIt = rankDofsNewLocalIndex.begin();
	 dofIt != rankDofsNewLocalIndex.end(); ++dofIt) {
      DegreeOfFreedom localDof = dofIt->second;
      DegreeOfFreedom globalDof = rankDofsNewGlobalIndex[dofIt->first];

      *const_cast<DegreeOfFreedom*>(dofIt->first) = localDof;
      mapLocalGlobalDofs[localDof] = globalDof;
    }

    for (DofIndexMap::iterator dofIt = rankOwnedDofsNewLocalIndex.begin();
	 dofIt != rankOwnedDofsNewLocalIndex.end(); ++dofIt)
      mapLocalToDofIndex[dofIt->second] = *(dofIt->first);
  }

  
  void ParallelDomainBase::createDofMemberInfo(DofToPartitions& partitionDofs,
					       DofContainer& rankOwnedDofs,
					       DofContainer& rankAllDofs,
					       DofToRank& boundaryDofs,
					       DofToBool& vertexDof)
  {
    partitionDofs.clear();
    rankOwnedDofs.clear();
    rankAllDofs.clear();
    boundaryDofs.clear();
    vertexDof.clear();

    // === Determine to each dof the set of partitions the dof belongs to. ===

    ElementDofIterator elDofIt(feSpace);

    TraverseStack stack;
    ElInfo *elInfo = stack.traverseFirst(mesh, -1, Mesh::CALL_LEAF_EL);
    while (elInfo) {
      Element *element = elInfo->getElement();
      elDofIt.reset(element);
      do {
	// Determine to each dof the partition(s) it corresponds to.
	partitionDofs[elDofIt.getDofPtr()].insert(partitionVec[element->getIndex()]);

	if (elDofIt.getCurrentPos() == 0) 
	  vertexDof[elDofIt.getDofPtr()] = true;
	else
	  vertexDof[elDofIt.getDofPtr()] = false;
      } while (elDofIt.next());

      elInfo = stack.traverseNext(elInfo);
    }


    // === Determine the set of ranks dofs and the dofs ownership at the boundary. ===

    // iterate over all DOFs
    for (DofToPartitions::iterator it = partitionDofs.begin();
	 it != partitionDofs.end(); ++it) {

      bool isInRank = false;

      // iterate over all partition the current DOF is part of.
      for (std::set<int>::iterator itpart1 = it->second.begin();
	   itpart1 != it->second.end(); ++itpart1) {

	if (*itpart1 == mpiRank) {	  
	  rankAllDofs.push_back(it->first);

	  if (it->second.size() == 1) {
	    rankOwnedDofs.push_back(it->first);
	  } else {	    
	    // This dof is at the ranks boundary. It is owned by the rank only if
	    // the rank number is the highest of all ranks containing this dof.

	    bool insert = true;
	    int highestRank = mpiRank;
	    for (std::set<int>::iterator itpart2 = it->second.begin();
		 itpart2 != it->second.end(); ++itpart2) {
	      if (*itpart2 > mpiRank)
		insert = false;

	      if (*itpart2 > highestRank)
		highestRank = *itpart2;
	    }

	    if (insert)
	      rankOwnedDofs.push_back(it->first);

	    boundaryDofs[it->first] = highestRank;
	  }

	  isInRank = true;
	  break;
	}

      }

      if (!isInRank)
	vertexDof.erase(it->first);
    }

    sort(rankAllDofs.begin(), rankAllDofs.end(), cmpDofsByValue);
    sort(rankOwnedDofs.begin(), rankOwnedDofs.end(), cmpDofsByValue);
  }

  void ParallelDomainBase::createPeriodicMap()
  {
    FUNCNAME("ParallelDomainBase::createPeriodicMap()");

    if (periodicBoundary.boundary.size() == 0)
      return;

    // Clear all periodic dof mappings calculated before. We do it from scratch.
    periodicDof.clear();

    MPI::Request request[min(static_cast<int>(periodicBoundary.boundary.size() * 2), 4)];
    int requestCounter = 0;
    std::vector<int*> sendBuffers, recvBuffers;

    // === Each rank traverse its periodic boundaries and sends the dof indices ===
    // === to the rank "on the other side" of the periodic boundary.            ===

    for (RankToBoundMap::iterator it = periodicBoundary.boundary.begin();
	 it != periodicBoundary.boundary.end(); ++it) {

      TEST_EXIT_DBG(it->first != mpiRank)
	("Periodic interior boundary within the rank itself is not possible!\n");

      DofContainer dofs;

      // Create dof indices on the boundary. 

      for (std::vector<AtomicBoundary>::iterator boundIt = it->second.begin();
	   boundIt != it->second.end(); ++boundIt) {
	boundIt->rankObj.el->getVertexDofs(feSpace, boundIt->rankObj, dofs);
	boundIt->rankObj.el->getNonVertexDofs(feSpace, boundIt->rankObj, dofs);
      }

      // Send the global indices to the rank on the other side.

      int *sendbuf = new int[dofs.size()];
      for (int i = 0; i < static_cast<int>(dofs.size()); i++)
	sendbuf[i] = mapLocalGlobalDofs[*(dofs[i])];      
      
      request[requestCounter++] = 
	mpiComm.Isend(sendbuf, dofs.size(), MPI_INT, it->first, 0);
      
      sendBuffers.push_back(sendbuf);

      // Receive from this rank the same number of dofs.

      int *recvbuf = new int[dofs.size()];
      request[requestCounter++] = 
	mpiComm.Irecv(recvbuf, dofs.size(), MPI_INT, it->first, 0);

      recvBuffers.push_back(recvbuf);
    }


    MPI::Request::Waitall(requestCounter, request);    

    // === The rank has received the dofs from the rank on the other side of ===
    // === the boundary. Now it can use them to create the mapping between   ===
    // === the periodic dofs in this rank and the corresponding periodic     ===
    // === dofs from the other ranks.                                        ===


    std::map<DegreeOfFreedom, std::set<int> > dofFromRank;

    int i = 0;
    for (RankToBoundMap::iterator it = periodicBoundary.boundary.begin();
	 it != periodicBoundary.boundary.end(); ++it) {
      DofContainer dofs;
      
      // Create the dofs on the boundary in inverse order.
      for (std::vector<AtomicBoundary>::iterator boundIt = it->second.begin();
	   boundIt != it->second.end(); ++boundIt) {
	DofContainer tmpdofs;
	boundIt->rankObj.el->getNonVertexDofs(feSpace, boundIt->rankObj, tmpdofs);
	boundIt->rankObj.el->getVertexDofs(feSpace, boundIt->rankObj, tmpdofs);

	for (int j = static_cast<int>(tmpdofs.size()) - 1; j >= 0; j--)
	  dofs.push_back(tmpdofs[j]);	
      }

      // Added the received dofs to the mapping.
      for (int j = 0; j < static_cast<int>(dofs.size()); j++) {
	int globalDofIndex = mapLocalGlobalDofs[*(dofs[j])];
	periodicDof[globalDofIndex].insert(recvBuffers[i][j]);      
	dofFromRank[globalDofIndex].insert(it->first);
      }
      
      delete [] sendBuffers[i];
      delete [] recvBuffers[i];
      i++;
    }

    sendBuffers.clear();
    recvBuffers.clear();

    if (dofFromRank.size() > 0) 
      TEST_EXIT_DBG(mesh->getDim() == 2)
	("Periodic boundary corner problem must be generalized to 3d!\n");

    requestCounter = 0;
    for (std::map<DegreeOfFreedom, std::set<int> >::iterator it = dofFromRank.begin();
	 it != dofFromRank.end(); ++it) {
      if (it->second.size() == 2) {
	TEST_EXIT_DBG(periodicDof[it->first].size() == 2)("Missing periodic dof!\n");
	
	int *sendbuf = new int[2];
	sendbuf[0] = *(periodicDof[it->first].begin());
	sendbuf[1] = *(++(periodicDof[it->first].begin()));
	
	request[requestCounter++] = 
	  mpiComm.Isend(sendbuf, 2, MPI_INT, *(it->second.begin()), 0);
	request[requestCounter++] = 
	  mpiComm.Isend(sendbuf, 2, MPI_INT, *(++(it->second.begin())), 0);
	
	sendBuffers.push_back(sendbuf);

	int *recvbuf1 = new int[2];
	int *recvbuf2 = new int[2];

	request[requestCounter++] = 
	  mpiComm.Irecv(recvbuf1, 2, MPI_INT, *(it->second.begin()), 0);
	request[requestCounter++] = 
	  mpiComm.Irecv(recvbuf2, 2, MPI_INT, *(++(it->second.begin())), 0);

	recvBuffers.push_back(recvbuf1);
	recvBuffers.push_back(recvbuf2);
      }
    }

    MPI::Request::Waitall(requestCounter, request);

    i = 0;
    for (std::map<DegreeOfFreedom, std::set<int> >::iterator it = dofFromRank.begin();
	 it != dofFromRank.end(); ++it) {
      if (it->second.size() == 2) {
	for (int k = 0; k < 2; k++)
	  for (int j = 0; j < 2; j++)
	    if (recvBuffers[i + k][j] != it->first)
	      periodicDof[it->first].insert(recvBuffers[i + k][j]);

	i++;
      }
    }
  }


  Flag ParallelDomainBase::oneIteration(AdaptInfo *adaptInfo, Flag toDo)
  {
    FUNCNAME("ParallelDomainBase::oneIteration()");

    Flag flag = buildAndAdapt(adaptInfo, toDo);

    if (toDo.isSet(SOLVE))
      solve();

    if (toDo.isSet(SOLVE_RHS))
      ERROR_EXIT("Not yet implemented!\n");

    if (toDo.isSet(ESTIMATE))
      iterationIF->getProblem()->estimate(adaptInfo);

    return flag;
  }


  Flag ParallelDomainBase::buildAndAdapt(AdaptInfo *adaptInfo, Flag toDo)
  {
        FUNCNAME("StandardProblemIteration::buildAndAdapt()");

    Flag flag = 0, markFlag = 0;
    ProblemStatBase *problem = iterationIF->getProblem();

    if (toDo.isSet(MARK))
      markFlag = problem->markElements(adaptInfo);
    else
      markFlag = 3;

    if (toDo.isSet(BUILD))
      problem->buildBeforeRefine(adaptInfo, markFlag);

    // refine
    if (toDo.isSet(ADAPT) && markFlag.isSet(MESH_REFINED))
      flag = problem->refineMesh(adaptInfo);

    if (toDo.isSet(BUILD))
      problem->buildBeforeCoarsen(adaptInfo, markFlag);

    // coarsen
    if (toDo.isSet(ADAPT) && markFlag.isSet(MESH_COARSENED))
      flag |= problem->coarsenMesh(adaptInfo);

    checkMeshChange();

    if (toDo.isSet(BUILD))
      problem->buildAfterCoarsen(adaptInfo, markFlag, true, true);

    if (toDo.isSet(BUILD_RHS))
      problem->buildAfterCoarsen(adaptInfo, markFlag, false, true);

    return flag;
  }


  void ParallelDomainBase::serialize(std::ostream &out)
  {
    SerUtil::serialize(out, elemWeights);
    SerUtil::serialize(out, initialPartitionMesh);
    SerUtil::serialize(out, partitionVec);
    SerUtil::serialize(out, oldPartitionVec);
    SerUtil::serialize(out, nRankDofs);
    
    myIntBoundary.serialize(out);
    otherIntBoundary.serialize(out);

    serialize(out, sendDofs);
    serialize(out, recvDofs);

    SerUtil::serialize(out, mapLocalGlobalDofs);
    SerUtil::serialize(out, mapLocalToDofIndex);
    SerUtil::serialize(out, isRankDof);

    serialize(out, vertexDof);
    serialize(out, periodicDof);

    SerUtil::serialize(out, rstart);
    SerUtil::serialize(out, nRankRows);
    SerUtil::serialize(out, nOverallRows);
  }


  void ParallelDomainBase::deserialize(std::istream &in)
  {
    SerUtil::deserialize(in, elemWeights);
    SerUtil::deserialize(in, initialPartitionMesh);
    SerUtil::deserialize(in, partitionVec);
    SerUtil::deserialize(in, oldPartitionVec);
    SerUtil::deserialize(in, nRankDofs);    

    // Create two maps: one from from element indices to the corresponding element 
    // pointers, and one map from Dof indices to the corresponding dof pointers.
    std::map<int, Element*> elIndexMap;
    std::map<int, const DegreeOfFreedom*> dofMap;
    ElementDofIterator elDofIter(feSpace);
    TraverseStack stack;
    ElInfo *elInfo = stack.traverseFirst(mesh, -1, Mesh::CALL_LEAF_EL);
    while (elInfo) {
      Element *el = elInfo->getElement();
      elIndexMap[el->getIndex()] = el;
      elInfo = stack.traverseNext(elInfo);

      elDofIter.reset(el);
      do {
	dofMap[elDofIter.getDof()] = elDofIter.getDofPtr();
      } while(elDofIter.next());      
    }

    myIntBoundary.deserialize(in, elIndexMap);
    otherIntBoundary.deserialize(in, elIndexMap);

    deserialize(in, sendDofs, dofMap);
    deserialize(in, recvDofs, dofMap);

    SerUtil::deserialize(in, mapLocalGlobalDofs);
    SerUtil::deserialize(in, mapLocalToDofIndex);
    SerUtil::deserialize(in, isRankDof);

    deserialize(in, vertexDof, dofMap);

    SerUtil::deserialize(in, rstart);
    SerUtil::deserialize(in, nRankRows);
    SerUtil::deserialize(in, nOverallRows);

    deserialized = true;
  }

  void ParallelDomainBase::serialize(std::ostream &out, PeriodicDofMap &data)
  {
    int mapSize = data.size();
    SerUtil::serialize(out, mapSize);

    for (PeriodicDofMap::iterator it = data.begin(); it != data.end(); ++it) {
      DegreeOfFreedom dof = it->first;
      std::set<DegreeOfFreedom> dofSet = it->second;
      SerUtil::serialize(out, dof);
      SerUtil::serialize(out, dofSet);
    }
  }

  void ParallelDomainBase::deserialize(std::istream &in, PeriodicDofMap &data)
  {
    data.clear();

    int mapSize = 0;
    SerUtil::deserialize(in, mapSize);
    for (int i = 0; i < mapSize; i++) {
      DegreeOfFreedom dof = 0;
      std::set<DegreeOfFreedom> dofSet;

      SerUtil::deserialize(in, dof);
      SerUtil::deserialize(in, dofSet);

      data[dof] = dofSet;
    }    
  }
  
  void ParallelDomainBase::dbgCreateElementMap(ElementIdxToDofs &elMap)
  {
    FUNCNAME("ParallelDomainBase::dbgCreateElementMap()");

    int dim = mesh->getDim();
    elMap.clear();
       
    TraverseStack stack;
    ElInfo *elInfo = stack.traverseFirst(mesh, -1, Mesh::CALL_LEAF_EL);
    while (elInfo) {
      Element *el = elInfo->getElement();
      switch (dim) {
      case 2:
	orderDofs(el->getDOF(0), el->getDOF(1), el->getDOF(2), elMap[el->getIndex()]);
	break;
      case 3:
	orderDofs(el->getDOF(0), el->getDOF(1), el->getDOF(2), el->getDOF(3), elMap[el->getIndex()]);
	break;
      default:
	ERROR_EXIT("What is this?\n");
      }
      elInfo = stack.traverseNext(elInfo);
    }
  }

  void ParallelDomainBase::dbgTestElementMap(ElementIdxToDofs &elMap)
  {
    FUNCNAME("ParallelDomainbase::dbgTestElementMap()");

    int dim = mesh->getDim();
    int nVertex = Global::getGeo(VERTEX, dim);
    DofContainer vec(nVertex);

    TraverseStack stack;
    ElInfo *elInfo = stack.traverseFirst(mesh, -1, Mesh::CALL_LEAF_EL);
    while (elInfo) {
      Element *el = elInfo->getElement();

      switch (dim) {
      case 2:
	orderDofs(el->getDOF(0), el->getDOF(1), el->getDOF(2), vec);
	break;
      case 3:
	orderDofs(el->getDOF(0), el->getDOF(1), el->getDOF(2), el->getDOF(3), vec);
	break;
      default:
	ERROR_EXIT("What is this?\n");
      }

      for (int i = 0; i < nVertex; i++) {
	if (elMap[el->getIndex()][i] != vec[i]) {
	  std::cout << "[DBG " << mpiRank 
		    << "]: Wrong new dof numeration in element = " 
		    << el->getIndex() << std::endl;
	  std::cout << "[DBG " << mpiRank << "]: Old numeration was: ";
	  for (int j = 0; j < nVertex; j++)
	    std::cout << elMap[el->getIndex()][j] << " = " 
		      << *(elMap[el->getIndex()][j]) << "  ";
	  std::cout << std::endl;
	  std::cout << "[DBG " << mpiRank << "]: New numeration is:  ";
	  for (int j = 0; j < nVertex; j++)
	    std::cout << vec[j] << " = "  << *(vec[j]) << "  ";
	  std::cout << std::endl;
	  ERROR_EXIT("WRONG NEW DOF NUMERATION!\n");
	}
      }
      elInfo = stack.traverseNext(elInfo);
    }
  }

  void ParallelDomainBase::dbgTestInteriorBoundary()
  {
    FUNCNAME("ParallelDomainBase::dbgTestInteriorBoundary()");

    std::vector<int*> sendBuffers, recvBuffers;

    MPI::Request request[myIntBoundary.boundary.size() + 
			 otherIntBoundary.boundary.size()];
    int requestCounter = 0;

    for (RankToBoundMap::iterator rankIt = myIntBoundary.boundary.begin();
	 rankIt != myIntBoundary.boundary.end(); ++rankIt) {

      int nSendInt = rankIt->second.size();
      int* buffer = new int[nSendInt];
      for (int i = 0; i < nSendInt; i++)
	buffer[i] = (rankIt->second)[i].rankObj.elIndex;
      
      sendBuffers.push_back(buffer);
      
      request[requestCounter++] =
	mpiComm.Isend(buffer, nSendInt, MPI_INT, rankIt->first, 0);
    }

    for (RankToBoundMap::iterator rankIt = otherIntBoundary.boundary.begin();
	 rankIt != otherIntBoundary.boundary.end(); ++rankIt) {
      int nRecvInt = rankIt->second.size();
      int *buffer = new int[nRecvInt];
      recvBuffers.push_back(buffer);

      request[requestCounter++] = 
	mpiComm.Irecv(buffer, nRecvInt, MPI_INT, rankIt->first, 0);
    }

    MPI::Request::Waitall(requestCounter, request);

    for (int i = 0; i < static_cast<int>(sendBuffers.size()); i++)
      delete [] sendBuffers[i];

    int bufCounter = 0;
    for (RankToBoundMap::iterator rankIt = otherIntBoundary.boundary.begin();
	 rankIt != otherIntBoundary.boundary.end(); ++rankIt) {

      TEST_EXIT(rankIt->second.size() == otherIntBoundary.boundary[rankIt->first].size())
	("Boundaries does not fit together!\n");      

      for (int i = 0; i < static_cast<int>(rankIt->second.size()); i++) {
	int elIndex1 = recvBuffers[bufCounter][i];
	int elIndex2 = otherIntBoundary.boundary[rankIt->first][i].neighObj.elIndex;

	TEST_EXIT(elIndex1 == elIndex2)("Wrong element index at interior boundary!\n");
      }

      delete [] recvBuffers[bufCounter++];
    }
  }
  

  void ParallelDomainBase::dbgTestCommonDofs(bool printCoords)
  {
    FUNCNAME("ParallelDomainBase::dbgTestCommonDofs()");

    clock_t first = clock();

    int testCommonDofs = 1;
    GET_PARAMETER(0, "dbg->test common dofs", "%d", &testCommonDofs);
    if (testCommonDofs == 0) {
      MSG("Skip test common dofs!\n");
      return;
    }

    // Maps to each neighbour rank an array of WorldVectors. This array contains the 
    // coordinates of all dofs this rank shares on the interior boundary with the 
    // neighbour rank. A rank sends the coordinates to another rank, if it owns the
    // boundarys dof.
    RankToCoords sendCoords;

    // A rank receives all boundary dofs that are at its interior boundaries but are
    // not owned by the rank. This map stores for each rank the coordinates of dofs
    // this rank expectes to receive from.
    RankToCoords recvCoords;

    DOFVector<WorldVector<double> > coords(feSpace, "dofCorrds");
    mesh->getDofIndexCoords(feSpace, coords);
  
    for (RankToDofContainer::iterator it = sendDofs.begin();
	 it != sendDofs.end(); ++it)
      for (DofContainer::iterator dofIt = it->second.begin(); 
	   dofIt != it->second.end(); ++dofIt)
	sendCoords[it->first].push_back(coords[**dofIt]);

    for (RankToDofContainer::iterator it = recvDofs.begin();
	 it != recvDofs.end(); ++it)
      for (DofContainer::iterator dofIt = it->second.begin();
	   dofIt != it->second.end(); ++dofIt)
	recvCoords[it->first].push_back(coords[**dofIt]);

    std::vector<int> sendSize(mpiSize, 0);
    std::vector<int> recvSize(mpiSize, 0);
    std::vector<int> recvSizeBuffer(mpiSize, 0);
    MPI::Request request[(mpiSize - 1) * 2];
    int requestCounter = 0;

    for (RankToCoords::iterator it = sendCoords.begin(); it != sendCoords.end(); ++it)
      sendSize[it->first] = it->second.size();

    for (RankToCoords::iterator it = recvCoords.begin(); it != recvCoords.end(); ++it)
      recvSize[it->first] = it->second.size();

    for (int i = 0; i < mpiSize; i++) {
      if (i == mpiRank)
	continue;

      request[requestCounter++] = mpiComm.Isend(&(sendSize[i]), 1, MPI_INT, i, 0);
    }   

    for (int i = 0; i < mpiSize; i++) {
      if (i == mpiRank)
	continue;

      request[requestCounter++] = mpiComm.Irecv(&(recvSizeBuffer[i]), 1, MPI_INT, i, 0);
    }

    MPI::Request::Waitall(requestCounter, request);


    for (int i = 0; i < mpiSize; i++) {
      if (i == mpiRank)
	continue;

      if (recvSize[i] != recvSizeBuffer[i]) {
	std::cout << "Error: MPI rank " << mpiRank << " expectes to receive " 
		  << recvSize[i] << " DOFs from rank " << i << ". But this rank sends "
		  << recvSizeBuffer[i] << " DOFs!" << std::endl;

	ERROR_EXIT("Should not happen!\n");
      }
    }

    // === Now we know that the number of send and received DOFs fits together. ===
    // === So we can check if also the coordinates of the communicated DOFs are ===
    // === the same on both corresponding ranks.                                ===

    typedef std::vector<WorldVector<double> > CoordsVec;
    StdMpi<CoordsVec, CoordsVec> stdMpi(mpiComm, true);
    stdMpi.send(sendCoords);
    stdMpi.recv(recvCoords);   
    stdMpi.startCommunication<double>(MPI_DOUBLE);

    double eps = 1e-13;
    int dimOfWorld = Global::getGeo(WORLD);

    // === Compare the received with the expected coordinates. ===

    for (RankToCoords::iterator it = stdMpi.getRecvData().begin(); 
	 it != stdMpi.getRecvData().end(); ++it) {
      for (int i = 0; i < static_cast<int>(it->second.size()); i++) {
	for (int j = 0; j < dimOfWorld; j++) {
	  bool c = fabs((it->second)[i][j] - recvCoords[it->first][i][j]) < eps;
	  
	  // === Print error message if the coordinates are not the same. ===

	  if (printCoords && !c) {
	    std::cout.precision(5);
	    std::cout << "[DBG] i = " << i << std::endl;    
	    std::cout << "[DBG] Rank " << mpiRank << " from rank " << it->first
		      << " expect coords (";
	    for (int k = 0; k < dimOfWorld; k++) {
	      std::cout << recvCoords[it->first][i][k];
	      if (k + 1 < dimOfWorld)
		std::cout << " / ";
	    }
	    std::cout << ")  received coords (";
	    for (int k = 0; k < dimOfWorld; k++) {
	      std::cout << (it->second)[i][k];
	      if (k + 1 < dimOfWorld)
		std::cout << " / ";
	    }
	    std::cout << ")" << std::endl;

	    debug::printInfoByDof(feSpace, *(recvDofs[it->first][i]));
	  }

	  TEST_EXIT(c)("Wrong DOFs in rank %d!\n", mpiRank);
	}
      } 
    }

    INFO(info, 8)("Test common dofs needed %.5f seconds\n", TIME_USED(first, clock()));
  }


  void ParallelDomainBase::printMapLocalGlobal(int rank)
  {    
    if (rank == -1 || mpiRank == rank) {
      std::cout << "====== DOF MAP LOCAL -> GLOBAL ====== " << std::endl;
      
      for (DofMapping::iterator it = mapLocalGlobalDofs.begin();
	   it != mapLocalGlobalDofs.end(); it++) {
	DegreeOfFreedom localdof = -1;
	if (mapLocalToDofIndex.count(it->first) > 0)
	  localdof = mapLocalToDofIndex[it->first];
	
	std::cout << "DOF " << it->first << " " 
		  << it->second << " " 
		  << localdof << std::endl;
	WorldVector<double> coords;
	mesh->getDofIndexCoords(it->first, feSpace, coords);
	coords.print();
	for (RankToDofContainer::iterator rankit = sendDofs.begin();
	     rankit != sendDofs.end(); ++rankit) {
	  for (DofContainer::iterator dofit = rankit->second.begin();
	       dofit != rankit->second.end(); ++dofit)
	    if (**dofit == it->first)
	      std::cout << "SEND DOF TO " << rankit->first << std::endl;	  
	}
	for (RankToDofContainer::iterator rankit = recvDofs.begin();
	     rankit != recvDofs.end(); ++rankit) {
	  for (DofContainer::iterator dofit = rankit->second.begin();
	       dofit != rankit->second.end(); ++dofit)
	    if (**dofit == it->first)
	      std::cout << "RECV DOF FROM " << rankit->first << std::endl;	  
	}
	std::cout << "------" << std::endl;
      }
    }
  }


  void ParallelDomainBase::printMapPeriodic(int rank)
  {
    FUNCNAME("ParallelDomainBase::printMapPeriodic()");

    if (rank == -1 || mpiRank == rank) {
      std::cout << "====== DOF MAP PERIODIC ====== " << std::endl;

      for (PeriodicDofMap::iterator it = periodicDof.begin();
	   it != periodicDof.end(); ++it) {
	std::cout << "DOF MAP " << it->first << ": ";
	for (std::set<DegreeOfFreedom>::iterator dofit = it->second.begin();
	     dofit != it->second.end(); ++dofit)
	  std::cout << *dofit << " ";
	std::cout << std::endl;

	DegreeOfFreedom localdof = -1;
	for (DofMapping::iterator dofIt = mapLocalGlobalDofs.begin();
	     dofIt != mapLocalGlobalDofs.end(); ++dofIt)
	  if (dofIt->second == it->first)
	    localdof = dofIt->first;

	TEST_EXIT(localdof != -1)("There is something wrong!\n");

	WorldVector<double> coords;
	mesh->getDofIndexCoords(localdof, feSpace, coords);
	coords.print();
      }
    }
  }

  
  void ParallelDomainBase::printRankDofs(int rank, DofContainer& rankDofs,
					 DofContainer& rankAllDofs)
  {
    if (rank == -1 || mpiRank == rank) {
      std::cout << "====== RANK DOF INFORMATION ====== " << std::endl;

      std::cout << "  RANK OWNED DOFS: " << std::endl;
      for (DofContainer::iterator dofit = rankDofs.begin();
	   dofit != rankDofs.end(); ++dofit) {
	std::cout << "    " << **dofit << std::endl;
	WorldVector<double> coords;
	mesh->getDofIndexCoords(*dofit, feSpace, coords);
	coords.print();
      }

      std::cout << "  RANK ALL DOFS: " << std::endl;
      for (DofContainer::iterator dofit = rankAllDofs.begin();
	   dofit != rankAllDofs.end(); ++dofit) {
	std::cout << "    " << **dofit << std::endl;
	WorldVector<double> coords;
	mesh->getDofIndexCoords(*dofit, feSpace, coords);
	coords.print();
      }      
    }
  }


  void ParallelDomainBase::writePartitioningMesh(std::string filename)
  {
    FUNCNAME("ParallelDomainBase::writePartitioningMesh()");

    std::map<int, double> vec;    
    TraverseStack stack;
    ElInfo *elInfo = stack.traverseFirst(mesh, -1, 
					 Mesh::CALL_LEAF_EL | Mesh::FILL_COORDS);
    
    while (elInfo) {		  
      int index = elInfo->getElement()->getIndex();
      vec[index] = partitionVec[index];
      elInfo = stack.traverseNext(elInfo);
    }

    ElementFileWriter::writeFile(vec, feSpace, filename);
  }

}