AbstractTetrahedralMeshWriter.cpp

/*

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 * Redistributions of source code must retain the above copyright notice,
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   this list of conditions and the following disclaimer in the documentation
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   contributors may be used to endorse or promote products derived from this
   software without specific prior written permission.

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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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*/

// Disable PETSc logging of MPI calls (we don't use this, anyway) to fix
// "right-hand operand of comma has no effect" warnings when building with
// PETSc 2.2.1.
#define PETSC_HAVE_BROKEN_RECURSIVE_MACRO

#include "AbstractTetrahedralMeshWriter.hpp"
#include "AbstractTetrahedralMesh.hpp"
#include "DistributedTetrahedralMesh.hpp"
#include "MixedDimensionMesh.hpp"
#include "Version.hpp"
#include "Exception.hpp"

#include <mpi.h> // For MPI_Send, MPI_Recv

const char* MeshEventHandler::EventName[] = { "Tri write","BinTri write","VTK write","PVTK write", "node write", "ele write", "face write", "ncl write", "comm1","comm2","Total"};

template<unsigned ELEMENT_DIM, unsigned SPACE_DIM>
struct MeshWriterIterators
{
    typename AbstractMesh<ELEMENT_DIM,SPACE_DIM>::NodeIterator* pNodeIter;
    typename AbstractTetrahedralMesh<ELEMENT_DIM,SPACE_DIM>::ElementIterator* pElemIter;
    typename AbstractTetrahedralMesh<ELEMENT_DIM,SPACE_DIM>::BoundaryElementIterator* pBoundaryElemIter;
};

// Implementation

template<unsigned ELEMENT_DIM, unsigned SPACE_DIM>
AbstractTetrahedralMeshWriter<ELEMENT_DIM, SPACE_DIM>::AbstractTetrahedralMeshWriter(const std::string& rDirectory,
                   const std::string& rBaseName,
                   const bool clearOutputDir)
    : AbstractMeshWriter<ELEMENT_DIM, SPACE_DIM>(rDirectory, rBaseName, clearOutputDir),
      mpNodeMap(nullptr),
      mNodesPerElement(ELEMENT_DIM+1),
      mNodesPerBoundaryElement(ELEMENT_DIM),
      mpMesh(nullptr),
      mpDistributedMesh(nullptr),
      mpMixedMesh(nullptr),
      mpIters(new MeshWriterIterators<ELEMENT_DIM,SPACE_DIM>),
      mNodeCounterForParallelMesh(0),
      mElementCounterForParallelMesh(0),
      mBoundaryElementCounterForParallelMesh(0),
      mCableElementCounterForParallelMesh(0),
      mFilesAreBinary(false)
{
    mpIters->pNodeIter = nullptr;
    mpIters->pElemIter = nullptr;
    mpIters->pBoundaryElemIter = nullptr;
}

template<unsigned ELEMENT_DIM, unsigned SPACE_DIM>
AbstractTetrahedralMeshWriter<ELEMENT_DIM, SPACE_DIM>::~AbstractTetrahedralMeshWriter()
{
    if (mpIters->pNodeIter)
    {
        delete mpIters->pNodeIter;
    }
    if (mpIters->pElemIter)
    {
        delete mpIters->pElemIter;
    }
    if (mpIters->pBoundaryElemIter)
    {
        delete mpIters->pBoundaryElemIter;
    }

    delete mpIters;

    if (mpNodeMap)
    {
        delete mpNodeMap;
    }
}

template<unsigned ELEMENT_DIM, unsigned SPACE_DIM>
std::vector<double> AbstractTetrahedralMeshWriter<ELEMENT_DIM, SPACE_DIM>::GetNextNode()
{
    // if we are writing from a mesh..
    assert(PetscTools::AmMaster());
    if (mpMesh)
    {
        std::vector<double> coords(SPACE_DIM);

        //Iterate over the locally-owned nodes
        if ((*(mpIters->pNodeIter)) != mpMesh->GetNodeIteratorEnd())
        {
            // Either this is a sequential mesh (and we own it all)
            // or it's parallel (and the master owns the first chunk)
            for (unsigned j=0; j<SPACE_DIM; j++)
            {
                coords[j] = (*(mpIters->pNodeIter))->GetPoint()[j];
            }

            mNodeCounterForParallelMesh=(*(mpIters->pNodeIter))->GetIndex() + 1;//Ready for when we run out of local nodes

            ++(*(mpIters->pNodeIter));
            return coords;
        }

        // If we didn't return then the iterator has reached the end of the local nodes.
        // It must be a parallel mesh and we are expecting messages...

        assert( mpDistributedMesh != nullptr );

        MPI_Status status;
        status.MPI_ERROR = MPI_SUCCESS; //For MPICH2
        // do receive, convert to std::vector on master
        boost::scoped_array<double> raw_coords(new double[SPACE_DIM]);
        MPI_Recv(raw_coords.get(), SPACE_DIM, MPI_DOUBLE, MPI_ANY_SOURCE, mNodeCounterForParallelMesh, PETSC_COMM_WORLD, &status);
        assert(status.MPI_ERROR == MPI_SUCCESS);
        for (unsigned j=0; j<coords.size(); j++)
        {
            coords[j] = raw_coords[j];
        }

        mNodeCounterForParallelMesh++;
        return coords;
    }
    else
    {
        return AbstractMeshWriter<ELEMENT_DIM,SPACE_DIM>::GetNextNode();
    }
}

template<unsigned ELEMENT_DIM, unsigned SPACE_DIM>
ElementData AbstractTetrahedralMeshWriter<ELEMENT_DIM, SPACE_DIM>::GetNextElement()
{
    assert(PetscTools::AmMaster());
    // if we are writing from a mesh..
    if (mpMesh)
    {
        ElementData elem_data;
        elem_data.NodeIndices.resize(mNodesPerElement);

        if (mpDistributedMesh == nullptr) // not using parallel mesh
        {
            // Use the iterator
            assert(this->mNumElements == mpMesh->GetNumElements());

            for (unsigned j=0; j<elem_data.NodeIndices.size(); j++)
            {
                unsigned old_index = (*(mpIters->pElemIter))->GetNodeGlobalIndex(j);
                elem_data.NodeIndices[j] = mpMesh->IsMeshChanging() ? mpNodeMap->GetNewIndex(old_index) : old_index;
            }
            // Set attribute
            elem_data.AttributeValue = (*(mpIters->pElemIter))->GetAttribute();

            ++(*(mpIters->pElemIter));

            return elem_data;
        }
        else // Parallel mesh
        {
            // Use the mElementCounterForParallelMesh variable to identify next element
            if (mpDistributedMesh->CalculateDesignatedOwnershipOfElement(mElementCounterForParallelMesh) == true)
            {
                // Master owns this element
                Element<ELEMENT_DIM, SPACE_DIM>* p_element = mpDistributedMesh->GetElement(mElementCounterForParallelMesh);
                assert(elem_data.NodeIndices.size() == mNodesPerElement);
                assert(!p_element->IsDeleted());
                // Master can use the local data to recover node indices & attribute
                for (unsigned j=0; j<mNodesPerElement; j++)
                {
                    elem_data.NodeIndices[j] = p_element->GetNodeGlobalIndex(j);
                }
                elem_data.AttributeValue = p_element->GetAttribute();
            }
            else
            {
                //Master doesn't own this element.
                UnpackElement(elem_data, mElementCounterForParallelMesh, mNodesPerElement, this->mNumNodes +  mElementCounterForParallelMesh);
            }
            // increment element counter
            mElementCounterForParallelMesh++;

            return elem_data; // non-master processors will return garbage here - but they should never write to file
        }
    }
    else // not writing from a mesh
    {
        return AbstractMeshWriter<ELEMENT_DIM,SPACE_DIM>::GetNextElement();
    }
}

template<unsigned ELEMENT_DIM, unsigned SPACE_DIM>
ElementData AbstractTetrahedralMeshWriter<ELEMENT_DIM, SPACE_DIM>::GetNextBoundaryElement()
{
    assert(PetscTools::AmMaster());
    // if we are writing from a mesh..
    if (mpMesh)
    {
        ElementData boundary_elem_data;
        boundary_elem_data.NodeIndices.resize(mNodesPerBoundaryElement);

        if (mpDistributedMesh == nullptr) // not using parallel mesh
        {
            // Use the iterator
            assert(this->mNumBoundaryElements==mpMesh->GetNumBoundaryElements());

            for (unsigned j=0; j<boundary_elem_data.NodeIndices.size(); j++)
            {
                unsigned old_index = (*(*(mpIters->pBoundaryElemIter)))->GetNodeGlobalIndex(j);
                boundary_elem_data.NodeIndices[j] = mpMesh->IsMeshChanging() ? mpNodeMap->GetNewIndex(old_index) : old_index;
            }
            boundary_elem_data.AttributeValue = (*(*(mpIters->pBoundaryElemIter)))->GetAttribute();

            ++(*(mpIters->pBoundaryElemIter));
            return boundary_elem_data;
        }
        else // Parallel mesh
        {
            // Use the mElementCounterForParallelMesh variable to identify next element
            if (mpDistributedMesh->CalculateDesignatedOwnershipOfBoundaryElement(mBoundaryElementCounterForParallelMesh) == true)
            {
                // Master owns this boundary element
                BoundaryElement<ELEMENT_DIM-1, SPACE_DIM>* p_boundary_element = mpDistributedMesh->GetBoundaryElement(mBoundaryElementCounterForParallelMesh);
                assert(boundary_elem_data.NodeIndices.size() == ELEMENT_DIM);
                assert(!p_boundary_element->IsDeleted());

                // Master can use the local data to recover node indices & attribute
                for (unsigned j=0; j<ELEMENT_DIM; j++)
                {
                    boundary_elem_data.NodeIndices[j] = p_boundary_element->GetNodeGlobalIndex(j);
                }
                boundary_elem_data.AttributeValue = p_boundary_element->GetAttribute();
            }
            else
            {
                //Master doesn't own this boundary element.
                UnpackElement(boundary_elem_data, mBoundaryElementCounterForParallelMesh, ELEMENT_DIM, this->mNumNodes + this->mNumElements + mBoundaryElementCounterForParallelMesh);
            }
            // increment element counter
            mBoundaryElementCounterForParallelMesh++;

            return boundary_elem_data; // non-master processors will return garbage here - but they should never write to file
        }
    }
    else // not writing from a mesh
    {
        return AbstractMeshWriter<ELEMENT_DIM,SPACE_DIM>::GetNextBoundaryElement();
    }
}

template<unsigned ELEMENT_DIM, unsigned SPACE_DIM>
ElementData AbstractTetrahedralMeshWriter<ELEMENT_DIM, SPACE_DIM>::GetNextCableElement()
{
    assert(PetscTools::AmMaster());

    // if we are writing from a mesh..
    if (mpMesh)
    {
        // Need to be using a MixedDimensionMesh or there will be no cable data
        assert(mpMixedMesh);

        ElementData elem_data;
        elem_data.NodeIndices.resize(2);

        // Use the mCableElementCounterForParallelMesh variable to identify next element
        if (mpMixedMesh->CalculateDesignatedOwnershipOfCableElement(mCableElementCounterForParallelMesh) == true)
        {
            // Master owns this element
            Element<1, SPACE_DIM>* p_element = mpMixedMesh->GetCableElement(mCableElementCounterForParallelMesh);
            assert(!p_element->IsDeleted());

            // Master can use the local data to recover node indices & attribute
            for (unsigned j=0; j<2; j++)
            {
                elem_data.NodeIndices[j] = p_element->GetNodeGlobalIndex(j);
            }
            elem_data.AttributeValue = p_element->GetAttribute();
        }
        else
        {
            // Master doesn't own this element
            UnpackElement(elem_data, mCableElementCounterForParallelMesh, 2, this->mNumNodes + this->mNumElements + this->mNumBoundaryElements + mCableElementCounterForParallelMesh);
        }
        // Increment element counter
        mCableElementCounterForParallelMesh++;

        return elem_data; // non-master processors will return garbage here - but they should never write to file
    }
    else // not writing from a mesh
    {
        return AbstractMeshWriter<ELEMENT_DIM,SPACE_DIM>::GetNextCableElement();
    }
}

template<unsigned ELEMENT_DIM, unsigned SPACE_DIM>
void AbstractTetrahedralMeshWriter<ELEMENT_DIM, SPACE_DIM>::WriteNclFile(
        AbstractTetrahedralMesh<ELEMENT_DIM, SPACE_DIM>& rMesh,
        bool invertMeshPermutation)
{
    MeshEventHandler::BeginEvent(MeshEventHandler::NCL);
    unsigned max_elements_all;
    if (PetscTools::IsSequential())
    {
        max_elements_all = rMesh.CalculateMaximumContainingElementsPerProcess();
    }
    else
    {
        unsigned max_elements_per_process = rMesh.CalculateMaximumContainingElementsPerProcess();
        MPI_Allreduce(&max_elements_per_process, &max_elements_all, 1, MPI_UNSIGNED, MPI_MAX, PETSC_COMM_WORLD);
    }

    std::string node_connect_list_file_name = this->mBaseName + ".ncl";
    if (invertMeshPermutation && !rMesh.rGetNodePermutation().empty())
    {
        node_connect_list_file_name += "-tmp";
    }

    PetscTools::BeginRoundRobin();
    {
        out_stream p_ncl_file = out_stream(nullptr);

        if (PetscTools::AmMaster())
        {
            //Open the file for the first time
            p_ncl_file = this->mpOutputFileHandler->OpenOutputFile(node_connect_list_file_name, std::ios::binary | std::ios::trunc);

            // Write the ncl header
            *p_ncl_file << rMesh.GetNumNodes() << "\t";
            *p_ncl_file << max_elements_all << "\t";
            *p_ncl_file << "\tBIN\n";
        }
        else
        {
            // Append to the existing file
            p_ncl_file = this->mpOutputFileHandler->OpenOutputFile(node_connect_list_file_name, std::ios::binary | std::ios::app);
        }

        // Write each node's data
        unsigned default_marker = UINT_MAX;

        typedef typename AbstractMesh<ELEMENT_DIM,SPACE_DIM>::NodeIterator NodeIterType;
        for (NodeIterType iter = rMesh.GetNodeIteratorBegin();
             iter != rMesh.GetNodeIteratorEnd();
             ++iter)
        {
            // Get the containing element indices from the node's set and sort them
            std::set<unsigned>& r_elem_set = iter->rGetContainingElementIndices();
            std::vector<unsigned> elem_vector(r_elem_set.begin(), r_elem_set.end());
            std::sort(elem_vector.begin(), elem_vector.end());
            // Pad the vector with unsigned markers
            for (unsigned elem_index=elem_vector.size();  elem_index<max_elements_all; elem_index++)
            {
                elem_vector.push_back(default_marker);
            }
            assert(elem_vector.size() == max_elements_all);
            // Write raw data out of std::vector into the file
            if (max_elements_all > 0u)
            {
                p_ncl_file->write((char*)&elem_vector[0], elem_vector.size()*sizeof(unsigned));
            }
        }

        if (PetscTools::AmTopMost())
        {
            *p_ncl_file << "#\n# " + ChasteBuildInfo::GetProvenanceString();
        }

        p_ncl_file->close();
    }
    PetscTools::EndRoundRobin();

    if (invertMeshPermutation && PetscTools::AmMaster() && !rMesh.rGetNodePermutation().empty() && max_elements_all > 0u)
    {
        // Open files
        const std::string real_node_connect_list_file_name = this->mBaseName + ".ncl";
        out_stream p_ncl_file = this->mpOutputFileHandler->OpenOutputFile(real_node_connect_list_file_name, std::ios::binary | std::ios::trunc);
        FileFinder temp_ncl_path = this->mpOutputFileHandler->FindFile(node_connect_list_file_name);
        std::ifstream temp_ncl_file(temp_ncl_path.GetAbsolutePath().c_str(), std::ios::binary);
        // Copy the header
        std::string header_line;
        getline(temp_ncl_file, header_line, '\n');
        (*p_ncl_file) << header_line << "\n";
        const std::streampos data_start = temp_ncl_file.tellg();
        const std::streamoff item_width = max_elements_all * sizeof(unsigned);
        // Copy the binary data, permuted
        std::vector<unsigned> elem_vector(max_elements_all);
        for (unsigned node_index=0; node_index<rMesh.GetNumAllNodes(); node_index++)
        {
            unsigned permuted_index = rMesh.rGetNodePermutation()[node_index];
            temp_ncl_file.seekg(data_start + item_width * permuted_index, std::ios_base::beg);
            temp_ncl_file.read((char*)&elem_vector[0], max_elements_all*sizeof(unsigned));
            p_ncl_file->write((char*)&elem_vector[0], max_elements_all*sizeof(unsigned));
        }
        // Footer
        *p_ncl_file << "#\n# " + ChasteBuildInfo::GetProvenanceString();
        p_ncl_file->close();
        // Remove temp file
        remove(temp_ncl_path.GetAbsolutePath().c_str());
    }
    PetscTools::Barrier("AbstractTetrahedralMeshWriter::WriteNclFile");
    MeshEventHandler::EndEvent(MeshEventHandler::NCL);
}

template<unsigned ELEMENT_DIM, unsigned SPACE_DIM>
void AbstractTetrahedralMeshWriter<ELEMENT_DIM, SPACE_DIM>::WriteFilesUsingMesh(
      AbstractTetrahedralMesh<ELEMENT_DIM,SPACE_DIM>& rMesh,
      bool keepOriginalElementIndexing)
{
    this->mpMeshReader = nullptr;
    mpMesh = &rMesh;

    this->mNumNodes = mpMesh->GetNumNodes();
    this->mNumElements = mpMesh->GetNumElements();
    this->mNumBoundaryElements = mpMesh->GetNumBoundaryElements();
    this->mNumCableElements = mpMesh->GetNumCableElements();

    typedef typename AbstractMesh<ELEMENT_DIM,SPACE_DIM>::NodeIterator NodeIterType;
    mpIters->pNodeIter = new NodeIterType(mpMesh->GetNodeIteratorBegin());

    typedef typename AbstractTetrahedralMesh<ELEMENT_DIM,SPACE_DIM>::ElementIterator ElemIterType;
    mpIters->pElemIter = new ElemIterType(mpMesh->GetElementIteratorBegin());

    typedef typename AbstractTetrahedralMesh<ELEMENT_DIM,SPACE_DIM>::BoundaryElementIterator BoundaryElemIterType;
    mpIters->pBoundaryElemIter = new BoundaryElemIterType(mpMesh->GetBoundaryElementIteratorBegin());

    // Use this process's first element to gauge the size of all the elements
    if ((*(mpIters->pElemIter)) != mpMesh->GetElementIteratorEnd())
    {
        mNodesPerElement = (*(mpIters->pElemIter))->GetNumNodes();
    }

    // Use this process's first boundary element to gauge the size of all the boundary elements
    if ((*(mpIters->pBoundaryElemIter)) != mpMesh->GetBoundaryElementIteratorEnd())
    {
        mNodesPerBoundaryElement = (*(*(mpIters->pBoundaryElemIter)))->GetNumNodes();
    }

    //Connectivity file is written when we write to a binary file (only available for TrianglesMeshWriter) and if we are preserving the element order
    if (this->mFilesAreBinary && keepOriginalElementIndexing)
    {
        WriteNclFile(*mpMesh);
    }

    // Have we got a parallel mesh?
    mpDistributedMesh = dynamic_cast<DistributedTetrahedralMesh<ELEMENT_DIM,SPACE_DIM>* >(&rMesh);

    // Have we got a MixedDimensionMesh?
    mpMixedMesh = dynamic_cast<MixedDimensionMesh<ELEMENT_DIM,SPACE_DIM>* >(this->mpMesh);

    if (mpDistributedMesh != nullptr)
    {
        // It's a parallel mesh
        WriteFilesUsingParallelMesh(keepOriginalElementIndexing);
        return;
    }

    if (!PetscTools::AmMaster())
    {
        PetscTools::Barrier("AbstractTetrahedralMeshWriter::WriteFilesUsingMesh"); //Paired with Master process writing files
        return;
    }

    // Set up node map if we might have deleted nodes
    unsigned node_map_index = 0;
    if (mpMesh->IsMeshChanging())
    {
        mpNodeMap = new NodeMap(1 + mpMesh->GetMaximumNodeIndex());
        for (NodeIterType it = mpMesh->GetNodeIteratorBegin(); it != mpMesh->GetNodeIteratorEnd(); ++it)
        {
            mpNodeMap->SetNewIndex(it->GetIndex(), node_map_index++);
        }
    }

    this->WriteFiles();
    PetscTools::Barrier("AbstractTetrahedralMeshWriter::WriteFilesUsingMesh"); // Paired with waiting Slave processes
    delete mpIters->pNodeIter;
    mpIters->pNodeIter = nullptr;
    delete mpIters->pElemIter;
    mpIters->pElemIter = nullptr;
    delete mpIters->pBoundaryElemIter;
    mpIters->pBoundaryElemIter = nullptr;
}

template<unsigned ELEMENT_DIM, unsigned SPACE_DIM>
void AbstractTetrahedralMeshWriter<ELEMENT_DIM, SPACE_DIM>::WriteFilesUsingMeshReaderAndMesh(
        AbstractMeshReader<ELEMENT_DIM, SPACE_DIM>& rMeshReader,
        AbstractTetrahedralMesh<ELEMENT_DIM, SPACE_DIM>& rMesh)
{
    WriteNclFile(rMesh, true);
    this->WriteFilesUsingMeshReader(rMeshReader);
}

template<unsigned ELEMENT_DIM, unsigned SPACE_DIM>
void AbstractTetrahedralMeshWriter<ELEMENT_DIM, SPACE_DIM>::WriteFilesUsingParallelMesh(bool keepOriginalElementIndexing)
{
    if (keepOriginalElementIndexing)
    {
        // Master goes on to write as usual
        if (PetscTools::AmMaster())
        {
            this->WriteFiles();
        }
        else
        {
//            PetscTools::Barrier("DodgyBarrierBeforeNODE");
            MeshEventHandler::BeginEvent(MeshEventHandler::NODE);
            boost::scoped_array<double> raw_coords(new double[SPACE_DIM]);
            // Slaves concentrate the Nodes
            typedef typename AbstractMesh<ELEMENT_DIM,SPACE_DIM>::NodeIterator NodeIterType;
            for (NodeIterType it = mpMesh->GetNodeIteratorBegin(); it != mpMesh->GetNodeIteratorEnd(); ++it)
            {
                for (unsigned j=0; j<SPACE_DIM; j++)
                {
                    raw_coords[j] = it->GetPoint()[j];
                }
                MPI_Ssend(raw_coords.get(), SPACE_DIM, MPI_DOUBLE, 0, it->GetIndex(), PETSC_COMM_WORLD);//Nodes sent with positive tags
            }
//            PetscTools::Barrier("DodgyBarrierAfterNODE");
            MeshEventHandler::EndEvent(MeshEventHandler::NODE);

            MeshEventHandler::BeginEvent(MeshEventHandler::ELE);
            // Slaves concentrate the Elements for which they are owners
            boost::scoped_array<unsigned> raw_indices(new unsigned[mNodesPerElement]); // Assuming that we don't have parallel quadratic elements
            typedef typename AbstractTetrahedralMesh<ELEMENT_DIM,SPACE_DIM>::ElementIterator ElementIterType;
            for (ElementIterType it = mpMesh->GetElementIteratorBegin(); it != mpMesh->GetElementIteratorEnd(); ++it)
            {
                unsigned index = it->GetIndex();
                if (mpDistributedMesh->CalculateDesignatedOwnershipOfElement(index) == true)
                {
                    for (unsigned j=0; j<mNodesPerElement; j++)
                    {
                        raw_indices[j] = it->GetNodeGlobalIndex(j);
                    }
                    PostElement(index, raw_indices.get(), mNodesPerElement, this->mNumNodes + index, it->GetAttribute());
                }
            }
//            PetscTools::Barrier("DodgyBarrierAfterELE");
            MeshEventHandler::EndEvent(MeshEventHandler::ELE);
            MeshEventHandler::BeginEvent(MeshEventHandler::FACE);
            // Slaves concentrate the Faces for which they are owners (not in 1-d)
            if (ELEMENT_DIM != 1)  
            {
                boost::scoped_array<unsigned> raw_face_indices(new unsigned[ELEMENT_DIM]); // Assuming that we don't have parallel quadratic meshes
                typedef typename AbstractTetrahedralMesh<ELEMENT_DIM,SPACE_DIM>::BoundaryElementIterator BoundaryElementIterType;
                for (BoundaryElementIterType it = mpMesh->GetBoundaryElementIteratorBegin(); it != mpMesh->GetBoundaryElementIteratorEnd(); ++it)
                {
                    unsigned index = (*it)->GetIndex();
                    if (mpDistributedMesh->CalculateDesignatedOwnershipOfBoundaryElement(index) == true)
                    {
                        for (unsigned j=0; j<ELEMENT_DIM; j++)
                        {
                            raw_face_indices[j] = (*it)->GetNodeGlobalIndex(j);
                        }
                        PostElement(index, raw_face_indices.get(), ELEMENT_DIM, this->mNumNodes + this->mNumElements + index, (*it)->GetAttribute());
                    }
                }
            }
//            PetscTools::Barrier("DodgyBarrierAfterFACE");
            MeshEventHandler::EndEvent(MeshEventHandler::FACE);

            // Slaves concentrate the cable elements for which they are owners
            if (mpMixedMesh)
            {
                typedef typename MixedDimensionMesh<ELEMENT_DIM,SPACE_DIM>::CableElementIterator CableElementIterType;
                for (CableElementIterType it = mpMixedMesh->GetCableElementIteratorBegin(); it != mpMixedMesh->GetCableElementIteratorEnd(); ++it)
                {
                    unsigned index =(*it)->GetIndex();
                    if (mpMixedMesh->CalculateDesignatedOwnershipOfCableElement(index) == true)
                    {
                        unsigned raw_cable_element_indices[2];
                        for (unsigned j=0; j<2; j++)
                        {
                            raw_cable_element_indices[j] = (*it)->GetNodeGlobalIndex(j);
                        }
                        PostElement(index, raw_cable_element_indices, 2, this->mNumNodes + this->mNumElements + this->mNumBoundaryElements + index, (*it)->GetAttribute());
                    }
                }
            }
        }
        PetscTools::Barrier("AbstractTetrahedralMeshWriter::WriteFilesUsingParallelMesh");
    }
    else
    {
        PetscTools::BeginRoundRobin();

        if (PetscTools::AmMaster())
        {
            // Make sure headers are written first
            assert(PetscTools::GetMyRank() == 0);
            CreateFilesWithHeaders();
        }

        AppendLocalDataToFiles();

        if (PetscTools::AmTopMost())
        {
            // Make sure footers are written last
            assert(PetscTools::GetMyRank() == PetscTools::GetNumProcs()-1);
            WriteFilesFooter();
        }

        PetscTools::EndRoundRobin();
    }
}

// LCOV_EXCL_START
template<unsigned ELEMENT_DIM, unsigned SPACE_DIM>
void AbstractTetrahedralMeshWriter<ELEMENT_DIM, SPACE_DIM>::CreateFilesWithHeaders()
{
    // If control reaches this line you haven't implemented the optimised
    // parallel write for whichever visualiser you are writing for.
    NEVER_REACHED;
}
// LCOV_EXCL_STOP


// LCOV_EXCL_START
template<unsigned ELEMENT_DIM, unsigned SPACE_DIM>
void AbstractTetrahedralMeshWriter<ELEMENT_DIM, SPACE_DIM>::AppendLocalDataToFiles()
{
    // If control reaches this line you haven't implemented the optimised
    // parallel write for whichever visualiser you are writing for.
    NEVER_REACHED;
}
// LCOV_EXCL_STOP


// LCOV_EXCL_START
template<unsigned ELEMENT_DIM, unsigned SPACE_DIM>
void AbstractTetrahedralMeshWriter<ELEMENT_DIM, SPACE_DIM>::WriteFilesFooter()
{
    // If control reaches this line you haven't implemented the optimised
    // parallel write for whichever visualiser you are writing for.
    NEVER_REACHED;
}
// LCOV_EXCL_STOP

// Explicit instantiation
template class AbstractTetrahedralMeshWriter<1,1>;
template class AbstractTetrahedralMeshWriter<1,2>;
template class AbstractTetrahedralMeshWriter<1,3>;
template class AbstractTetrahedralMeshWriter<2,2>;
template class AbstractTetrahedralMeshWriter<2,3>;
template class AbstractTetrahedralMeshWriter<3,3>;