Пример #1
0
/*@ 
  DMNetworkAddNumVariables - Add number of variables associated with a given point.

  Not Collective

  Input Parameters:
+ dm   - The DMNetworkObject
. p    - the vertex/edge point
- nvar - number of additional variables

  Level: intermediate

.seealso: DMNetworkSetNumVariables
@*/
PetscErrorCode DMNetworkAddNumVariables(DM dm,PetscInt p,PetscInt nvar)
{
  PetscErrorCode ierr;
  DM_Network     *network = (DM_Network*)dm->data;

  PetscFunctionBegin;
  ierr = PetscSectionAddDof(network->DofSection,p,nvar);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
Пример #2
0
/*@
  DMNetworkAddComponent - Adds a network component at the given point (vertex/edge)

  Not Collective

  Input Parameters:
+ dm           - The DMNetwork object
. p            - vertex/edge point
. componentkey - component key returned while registering the component
- compvalue    - pointer to the data structure for the component

  Level: intermediate

.seealso: DMNetworkGetVertexRange, DMNetworkGetEdgeRange, DMNetworkRegisterComponent
@*/
PetscErrorCode DMNetworkAddComponent(DM dm, PetscInt p,PetscInt componentkey,void* compvalue)
{
  DM_Network     *network = (DM_Network*)dm->data;
  DMNetworkComponent component=network->component[componentkey];
  DMNetworkComponentHeader header=&network->header[p];
  DMNetworkComponentValue  cvalue=&network->cvalue[p];
  PetscErrorCode         ierr;
  
  PetscFunctionBegin;
  header->size[header->ndata] = component.size;
  ierr = PetscSectionAddDof(network->DataSection,p,component.size);CHKERRQ(ierr);
  header->key[header->ndata] = componentkey;
  if (header->ndata != 0) header->offset[header->ndata] = header->offset[header->ndata-1] + header->size[header->ndata-1]; 

  cvalue->data[header->ndata] = (void*)compvalue;
  header->ndata++;
  PetscFunctionReturn(0);
}
Пример #3
0
/*@
  DMNetworkLayoutSetUp - Sets up the bare layout (graph) for the network

  Collective on DM

  Input Parameters
. DM - the dmnetwork object

  Notes:
  This routine should be called after the network sizes and edgelists have been provided. It creates
  the bare layout of the network and sets up the network to begin insertion of components.

  All the components should be registered before calling this routine.

  Level: intermediate

.seealso: DMNetworkSetSizes, DMNetworkSetEdgeList
@*/
PetscErrorCode DMNetworkLayoutSetUp(DM dm)
{
  PetscErrorCode ierr;
  DM_Network     *network = (DM_Network*) dm->data;
  PetscInt       dim = 1; /* One dimensional network */
  PetscInt       numCorners=2;
  PetscInt       spacedim=2;
  double         *vertexcoords=NULL;
  PetscInt       i;
  PetscInt       ndata;

  PetscFunctionBegin;
  if (network->nNodes) {
    ierr = PetscMalloc1(numCorners*network->nNodes,&vertexcoords);CHKERRQ(ierr);
  }
  ierr = DMPlexCreateFromCellList(PetscObjectComm((PetscObject)dm),dim,network->nEdges,network->nNodes,numCorners,PETSC_FALSE,network->edges,spacedim,vertexcoords,&network->plex);CHKERRQ(ierr);
  if (network->nNodes) {
    ierr = PetscFree(vertexcoords);CHKERRQ(ierr);
  }
  ierr = DMPlexGetChart(network->plex,&network->pStart,&network->pEnd);CHKERRQ(ierr);
  ierr = DMPlexGetHeightStratum(network->plex,0,&network->eStart,&network->eEnd);CHKERRQ(ierr);
  ierr = DMPlexGetHeightStratum(network->plex,1,&network->vStart,&network->vEnd);CHKERRQ(ierr);

  ierr = PetscSectionCreate(PetscObjectComm((PetscObject)dm),&network->DataSection);CHKERRQ(ierr);
  ierr = PetscSectionCreate(PetscObjectComm((PetscObject)dm),&network->DofSection);CHKERRQ(ierr);
  ierr = PetscSectionSetChart(network->DataSection,network->pStart,network->pEnd);CHKERRQ(ierr);
  ierr = PetscSectionSetChart(network->DofSection,network->pStart,network->pEnd);CHKERRQ(ierr);

  network->dataheadersize = sizeof(struct _p_DMNetworkComponentHeader)/sizeof(DMNetworkComponentGenericDataType);
  ierr = PetscMalloc1(network->pEnd-network->pStart,&network->header);CHKERRQ(ierr);
  for (i = network->pStart; i < network->pEnd; i++) {
    network->header[i].ndata = 0;
    ndata = network->header[i].ndata;
    ierr = PetscSectionAddDof(network->DataSection,i,network->dataheadersize);CHKERRQ(ierr);
    network->header[i].offset[ndata] = 0;
  }
  ierr = PetscMalloc1(network->pEnd-network->pStart,&network->cvalue);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
Пример #4
0
/* get adjacencies due to point-to-point constraints that can't be found with DMPlexGetAdjacency() */
static PetscErrorCode DMPlexComputeAnchorAdjacencies(DM dm, PetscSection section, PetscSection sectionGlobal, PetscSection *anchorSectionAdj, PetscInt *anchorAdj[])
{
  PetscInt       pStart, pEnd;
  PetscSection   adjSec, aSec;
  IS             aIS;
  PetscErrorCode ierr;

  PetscFunctionBegin;

  ierr = PetscSectionCreate(PetscObjectComm((PetscObject)section),&adjSec);CHKERRQ(ierr);
  ierr = PetscSectionGetChart(section,&pStart,&pEnd);CHKERRQ(ierr);
  ierr = PetscSectionSetChart(adjSec,pStart,pEnd);CHKERRQ(ierr);

  ierr = DMPlexGetAnchors(dm,&aSec,&aIS);CHKERRQ(ierr);
  if (aSec) {
    const PetscInt *anchors;
    PetscInt       p, q, a, aSize, *offsets, aStart, aEnd, *inverse, iSize, *adj, adjSize;
    PetscInt       *tmpAdjP = NULL, *tmpAdjQ = NULL;
    PetscSection   inverseSec;

    /* invert the constraint-to-anchor map */
    ierr = PetscSectionCreate(PetscObjectComm((PetscObject)aSec),&inverseSec);CHKERRQ(ierr);
    ierr = PetscSectionSetChart(inverseSec,pStart,pEnd);CHKERRQ(ierr);
    ierr = ISGetLocalSize(aIS, &aSize);CHKERRQ(ierr);
    ierr = ISGetIndices(aIS, &anchors);CHKERRQ(ierr);

    for (p = 0; p < aSize; p++) {
      PetscInt a = anchors[p];

      ierr = PetscSectionAddDof(inverseSec,a,1);CHKERRQ(ierr);
    }
    ierr = PetscSectionSetUp(inverseSec);CHKERRQ(ierr);
    ierr = PetscSectionGetStorageSize(inverseSec,&iSize);CHKERRQ(ierr);
    ierr = PetscMalloc1(iSize,&inverse);CHKERRQ(ierr);
    ierr = PetscCalloc1(pEnd-pStart,&offsets);CHKERRQ(ierr);
    ierr = PetscSectionGetChart(aSec,&aStart,&aEnd);CHKERRQ(ierr);
    for (p = aStart; p < aEnd; p++) {
      PetscInt dof, off;

      ierr = PetscSectionGetDof(aSec, p, &dof);CHKERRQ(ierr);
      ierr = PetscSectionGetOffset(aSec, p, &off);CHKERRQ(ierr);

      for (q = 0; q < dof; q++) {
        PetscInt iOff;

        a = anchors[off + q];
        ierr = PetscSectionGetOffset(inverseSec, a, &iOff);CHKERRQ(ierr);
        inverse[iOff + offsets[a-pStart]++] = p;
      }
    }
    ierr = ISRestoreIndices(aIS, &anchors);CHKERRQ(ierr);
    ierr = PetscFree(offsets);CHKERRQ(ierr);

    /* construct anchorAdj and adjSec
     *
     * loop over anchors:
     *   construct anchor adjacency
     *   loop over constrained:
     *     construct constrained adjacency
     *     if not in anchor adjacency, add to dofs
     * setup adjSec, allocate anchorAdj
     * loop over anchors:
     *   construct anchor adjacency
     *   loop over constrained:
     *     construct constrained adjacency
     *     if not in anchor adjacency
     *       if not already in list, put in list
     *   sort, unique, reduce dof count
     * optional: compactify
     */
    for (p = pStart; p < pEnd; p++) {
      PetscInt iDof, iOff, i, r, s, numAdjP = PETSC_DETERMINE;

      ierr = PetscSectionGetDof(inverseSec,p,&iDof);CHKERRQ(ierr);
      if (!iDof) continue;
      ierr = PetscSectionGetOffset(inverseSec,p,&iOff);CHKERRQ(ierr);
      ierr = DMPlexGetAdjacency(dm,p,&numAdjP,&tmpAdjP);CHKERRQ(ierr);
      for (i = 0; i < iDof; i++) {
        PetscInt iNew = 0, qAdj, qAdjDof, qAdjCDof, numAdjQ = PETSC_DETERMINE;

        q = inverse[iOff + i];
        ierr = DMPlexGetAdjacency(dm,q,&numAdjQ,&tmpAdjQ);CHKERRQ(ierr);
        for (r = 0; r < numAdjQ; r++) {
          qAdj = tmpAdjQ[r];
          if ((qAdj < pStart) || (qAdj >= pEnd)) continue;
          for (s = 0; s < numAdjP; s++) {
            if (qAdj == tmpAdjP[s]) break;
          }
          if (s < numAdjP) continue;
          ierr  = PetscSectionGetDof(section,qAdj,&qAdjDof);CHKERRQ(ierr);
          ierr  = PetscSectionGetConstraintDof(section,qAdj,&qAdjCDof);CHKERRQ(ierr);
          iNew += qAdjDof - qAdjCDof;
        }
        ierr = PetscSectionAddDof(adjSec,p,iNew);CHKERRQ(ierr);
      }
    }

    ierr = PetscSectionSetUp(adjSec);CHKERRQ(ierr);
    ierr = PetscSectionGetStorageSize(adjSec,&adjSize);CHKERRQ(ierr);
    ierr = PetscMalloc1(adjSize,&adj);CHKERRQ(ierr);

    for (p = pStart; p < pEnd; p++) {
      PetscInt iDof, iOff, i, r, s, aOff, aOffOrig, aDof, numAdjP = PETSC_DETERMINE;

      ierr = PetscSectionGetDof(inverseSec,p,&iDof);CHKERRQ(ierr);
      if (!iDof) continue;
      ierr = PetscSectionGetOffset(inverseSec,p,&iOff);CHKERRQ(ierr);
      ierr = DMPlexGetAdjacency(dm,p,&numAdjP,&tmpAdjP);CHKERRQ(ierr);
      ierr = PetscSectionGetDof(adjSec,p,&aDof);CHKERRQ(ierr);
      ierr = PetscSectionGetOffset(adjSec,p,&aOff);CHKERRQ(ierr);
      aOffOrig = aOff;
      for (i = 0; i < iDof; i++) {
        PetscInt qAdj, qAdjDof, qAdjCDof, qAdjOff, nd, numAdjQ = PETSC_DETERMINE;

        q = inverse[iOff + i];
        ierr = DMPlexGetAdjacency(dm,q,&numAdjQ,&tmpAdjQ);CHKERRQ(ierr);
        for (r = 0; r < numAdjQ; r++) {
          qAdj = tmpAdjQ[r];
          if ((qAdj < pStart) || (qAdj >= pEnd)) continue;
          for (s = 0; s < numAdjP; s++) {
            if (qAdj == tmpAdjP[s]) break;
          }
          if (s < numAdjP) continue;
          ierr  = PetscSectionGetDof(section,qAdj,&qAdjDof);CHKERRQ(ierr);
          ierr  = PetscSectionGetConstraintDof(section,qAdj,&qAdjCDof);CHKERRQ(ierr);
          ierr  = PetscSectionGetOffset(sectionGlobal,qAdj,&qAdjOff);CHKERRQ(ierr);
          for (nd = 0; nd < qAdjDof-qAdjCDof; ++nd) {
            adj[aOff++] = (qAdjOff < 0 ? -(qAdjOff+1) : qAdjOff) + nd;
          }
        }
      }
      ierr = PetscSortRemoveDupsInt(&aDof,&adj[aOffOrig]);CHKERRQ(ierr);
      ierr = PetscSectionSetDof(adjSec,p,aDof);CHKERRQ(ierr);
    }
    *anchorAdj = adj;

    /* clean up */
    ierr = PetscSectionDestroy(&inverseSec);CHKERRQ(ierr);
    ierr = PetscFree(inverse);CHKERRQ(ierr);
    ierr = PetscFree(tmpAdjP);CHKERRQ(ierr);
    ierr = PetscFree(tmpAdjQ);CHKERRQ(ierr);
  }
  else {
    *anchorAdj = NULL;
    ierr = PetscSectionSetUp(adjSec);CHKERRQ(ierr);
  }
  *anchorSectionAdj = adjSec;
  PetscFunctionReturn(0);
}
Пример #5
0
PetscErrorCode DMPlexPreallocateOperator(DM dm, PetscInt bs, PetscSection section, PetscSection sectionGlobal, PetscInt dnz[], PetscInt onz[], PetscInt dnzu[], PetscInt onzu[], Mat A, PetscBool fillMatrix)
{
  MPI_Comm           comm;
  MatType            mtype;
  PetscSF            sf, sfDof, sfAdj;
  PetscSection       leafSectionAdj, rootSectionAdj, sectionAdj, anchorSectionAdj;
  PetscInt           nroots, nleaves, l, p;
  const PetscInt    *leaves;
  const PetscSFNode *remotes;
  PetscInt           dim, pStart, pEnd, numDof, globalOffStart, globalOffEnd, numCols;
  PetscInt          *tmpAdj = NULL, *adj, *rootAdj, *anchorAdj = NULL, *cols, *remoteOffsets;
  PetscInt           adjSize;
  PetscLayout        rLayout;
  PetscInt           locRows, rStart, rEnd, r;
  PetscMPIInt        size;
  PetscBool          doCommLocal, doComm, debug = PETSC_FALSE, isSymBlock, isSymSeqBlock, isSymMPIBlock;
  PetscBool          useAnchors;
  PetscErrorCode     ierr;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
  PetscValidHeaderSpecific(section, PETSC_SECTION_CLASSID, 3);
  PetscValidHeaderSpecific(sectionGlobal, PETSC_SECTION_CLASSID, 4);
  PetscValidHeaderSpecific(A, MAT_CLASSID, 9);
  if (dnz)  PetscValidPointer(dnz,5);
  if (onz)  PetscValidPointer(onz,6);
  if (dnzu) PetscValidPointer(dnzu,7);
  if (onzu) PetscValidPointer(onzu,8);
  ierr = PetscLogEventBegin(DMPLEX_Preallocate,dm,0,0,0);CHKERRQ(ierr);
  ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
  ierr = PetscOptionsGetBool(NULL, "-dm_view_preallocation", &debug, NULL);CHKERRQ(ierr);
  ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
  ierr = DMGetDimension(dm, &dim);CHKERRQ(ierr);
  ierr = DMGetPointSF(dm, &sf);CHKERRQ(ierr);
  ierr = PetscSFGetGraph(sf, &nroots, NULL, NULL, NULL);CHKERRQ(ierr);
  doCommLocal = (size > 1) && (nroots >= 0) ? PETSC_TRUE : PETSC_FALSE;
  ierr = MPI_Allreduce(&doCommLocal, &doComm, 1, MPIU_BOOL, MPI_LAND, comm);CHKERRQ(ierr);
  /* Create dof SF based on point SF */
  if (debug) {
    ierr = PetscPrintf(comm, "Input Section for Preallocation:\n");CHKERRQ(ierr);
    ierr = PetscSectionView(section, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
    ierr = PetscPrintf(comm, "Input Global Section for Preallocation:\n");CHKERRQ(ierr);
    ierr = PetscSectionView(sectionGlobal, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
    ierr = PetscPrintf(comm, "Input SF for Preallocation:\n");CHKERRQ(ierr);
    ierr = PetscSFView(sf, NULL);CHKERRQ(ierr);
  }
  ierr = PetscSFCreateRemoteOffsets(sf, section, section, &remoteOffsets);CHKERRQ(ierr);
  ierr = PetscSFCreateSectionSF(sf, section, remoteOffsets, section, &sfDof);CHKERRQ(ierr);
  if (debug) {
    ierr = PetscPrintf(comm, "Dof SF for Preallocation:\n");CHKERRQ(ierr);
    ierr = PetscSFView(sfDof, NULL);CHKERRQ(ierr);
  }
  /* Create section for dof adjacency (dof ==> # adj dof) */
  ierr = PetscSectionGetChart(section, &pStart, &pEnd);CHKERRQ(ierr);
  ierr = PetscSectionGetStorageSize(section, &numDof);CHKERRQ(ierr);
  ierr = PetscSectionCreate(comm, &leafSectionAdj);CHKERRQ(ierr);
  ierr = PetscSectionSetChart(leafSectionAdj, 0, numDof);CHKERRQ(ierr);
  ierr = PetscSectionCreate(comm, &rootSectionAdj);CHKERRQ(ierr);
  ierr = PetscSectionSetChart(rootSectionAdj, 0, numDof);CHKERRQ(ierr);
  /*   Fill in the ghost dofs on the interface */
  ierr = PetscSFGetGraph(sf, NULL, &nleaves, &leaves, &remotes);CHKERRQ(ierr);
  /* use constraints in finding adjacency in this routine */
  ierr = DMPlexGetAdjacencyUseAnchors(dm,&useAnchors);CHKERRQ(ierr);
  ierr = DMPlexSetAdjacencyUseAnchors(dm,PETSC_TRUE);CHKERRQ(ierr);

  /*
   section        - maps points to (# dofs, local dofs)
   sectionGlobal  - maps points to (# dofs, global dofs)
   leafSectionAdj - maps unowned local dofs to # adj dofs
   rootSectionAdj - maps   owned local dofs to # adj dofs
   adj            - adj global dofs indexed by leafSectionAdj
   rootAdj        - adj global dofs indexed by rootSectionAdj
   sf    - describes shared points across procs
   sfDof - describes shared dofs across procs
   sfAdj - describes shared adjacent dofs across procs
   ** The bootstrapping process involves six rounds with similar structure of visiting neighbors of each point.
  (0). If there are point-to-point constraints, add the adjacencies of constrained points to anchors in anchorAdj
       (This is done in DMPlexComputeAnchorAdjacencies())
    1. Visit unowned points on interface, count adjacencies placing in leafSectionAdj
       Reduce those counts to rootSectionAdj (now redundantly counting some interface points)
    2. Visit owned points on interface, count adjacencies placing in rootSectionAdj
       Create sfAdj connecting rootSectionAdj and leafSectionAdj
    3. Visit unowned points on interface, write adjacencies to adj
       Gather adj to rootAdj (note that there is redundancy in rootAdj when multiple procs find the same adjacencies)
    4. Visit owned points on interface, write adjacencies to rootAdj
       Remove redundancy in rootAdj
   ** The last two traversals use transitive closure
    5. Visit all owned points in the subdomain, count dofs for each point (sectionAdj)
       Allocate memory addressed by sectionAdj (cols)
    6. Visit all owned points in the subdomain, insert dof adjacencies into cols
   ** Knowing all the column adjacencies, check ownership and sum into dnz and onz
  */

  ierr = DMPlexComputeAnchorAdjacencies(dm,section,sectionGlobal,&anchorSectionAdj,&anchorAdj);CHKERRQ(ierr);

  for (l = 0; l < nleaves; ++l) {
    PetscInt dof, off, d, q, anDof;
    PetscInt p = leaves[l], numAdj = PETSC_DETERMINE;

    if ((p < pStart) || (p >= pEnd)) continue;
    ierr = PetscSectionGetDof(section, p, &dof);CHKERRQ(ierr);
    ierr = PetscSectionGetOffset(section, p, &off);CHKERRQ(ierr);
    ierr = DMPlexGetAdjacency(dm, p, &numAdj, &tmpAdj);CHKERRQ(ierr);
    for (q = 0; q < numAdj; ++q) {
      const PetscInt padj = tmpAdj[q];
      PetscInt ndof, ncdof;

      if ((padj < pStart) || (padj >= pEnd)) continue;
      ierr = PetscSectionGetDof(section, padj, &ndof);CHKERRQ(ierr);
      ierr = PetscSectionGetConstraintDof(section, padj, &ncdof);CHKERRQ(ierr);
      for (d = off; d < off+dof; ++d) {
        ierr = PetscSectionAddDof(leafSectionAdj, d, ndof-ncdof);CHKERRQ(ierr);
      }
    }
    ierr = PetscSectionGetDof(anchorSectionAdj, p, &anDof);CHKERRQ(ierr);
    if (anDof) {
      for (d = off; d < off+dof; ++d) {
        ierr = PetscSectionAddDof(leafSectionAdj, d, anDof);CHKERRQ(ierr);
      }
    }
  }
  ierr = PetscSectionSetUp(leafSectionAdj);CHKERRQ(ierr);
  if (debug) {
    ierr = PetscPrintf(comm, "Adjacency Section for Preallocation on Leaves:\n");CHKERRQ(ierr);
    ierr = PetscSectionView(leafSectionAdj, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
  }
  /* Get maximum remote adjacency sizes for owned dofs on interface (roots) */
  if (doComm) {
    ierr = PetscSFReduceBegin(sfDof, MPIU_INT, leafSectionAdj->atlasDof, rootSectionAdj->atlasDof, MPI_SUM);CHKERRQ(ierr);
    ierr = PetscSFReduceEnd(sfDof, MPIU_INT, leafSectionAdj->atlasDof, rootSectionAdj->atlasDof, MPI_SUM);CHKERRQ(ierr);
  }
  if (debug) {
    ierr = PetscPrintf(comm, "Adjancency Section for Preallocation on Roots:\n");CHKERRQ(ierr);
    ierr = PetscSectionView(rootSectionAdj, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
  }
  /* Add in local adjacency sizes for owned dofs on interface (roots) */
  for (p = pStart; p < pEnd; ++p) {
    PetscInt numAdj = PETSC_DETERMINE, adof, dof, off, d, q, anDof;

    ierr = PetscSectionGetDof(section, p, &dof);CHKERRQ(ierr);
    ierr = PetscSectionGetOffset(section, p, &off);CHKERRQ(ierr);
    if (!dof) continue;
    ierr = PetscSectionGetDof(rootSectionAdj, off, &adof);CHKERRQ(ierr);
    if (adof <= 0) continue;
    ierr = DMPlexGetAdjacency(dm, p, &numAdj, &tmpAdj);CHKERRQ(ierr);
    for (q = 0; q < numAdj; ++q) {
      const PetscInt padj = tmpAdj[q];
      PetscInt ndof, ncdof;

      if ((padj < pStart) || (padj >= pEnd)) continue;
      ierr = PetscSectionGetDof(section, padj, &ndof);CHKERRQ(ierr);
      ierr = PetscSectionGetConstraintDof(section, padj, &ncdof);CHKERRQ(ierr);
      for (d = off; d < off+dof; ++d) {
        ierr = PetscSectionAddDof(rootSectionAdj, d, ndof-ncdof);CHKERRQ(ierr);
      }
    }
    ierr = PetscSectionGetDof(anchorSectionAdj, p, &anDof);CHKERRQ(ierr);
    if (anDof) {
      for (d = off; d < off+dof; ++d) {
        ierr = PetscSectionAddDof(rootSectionAdj, d, anDof);CHKERRQ(ierr);
      }
    }
  }
  ierr = PetscSectionSetUp(rootSectionAdj);CHKERRQ(ierr);
  if (debug) {
    ierr = PetscPrintf(comm, "Adjancency Section for Preallocation on Roots after local additions:\n");CHKERRQ(ierr);
    ierr = PetscSectionView(rootSectionAdj, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
  }
  /* Create adj SF based on dof SF */
  ierr = PetscSFCreateRemoteOffsets(sfDof, rootSectionAdj, leafSectionAdj, &remoteOffsets);CHKERRQ(ierr);
  ierr = PetscSFCreateSectionSF(sfDof, rootSectionAdj, remoteOffsets, leafSectionAdj, &sfAdj);CHKERRQ(ierr);
  if (debug) {
    ierr = PetscPrintf(comm, "Adjacency SF for Preallocation:\n");CHKERRQ(ierr);
    ierr = PetscSFView(sfAdj, NULL);CHKERRQ(ierr);
  }
  ierr = PetscSFDestroy(&sfDof);CHKERRQ(ierr);
  /* Create leaf adjacency */
  ierr = PetscSectionSetUp(leafSectionAdj);CHKERRQ(ierr);
  ierr = PetscSectionGetStorageSize(leafSectionAdj, &adjSize);CHKERRQ(ierr);
  ierr = PetscCalloc1(adjSize, &adj);CHKERRQ(ierr);
  for (l = 0; l < nleaves; ++l) {
    PetscInt dof, off, d, q, anDof, anOff;
    PetscInt p = leaves[l], numAdj = PETSC_DETERMINE;

    if ((p < pStart) || (p >= pEnd)) continue;
    ierr = PetscSectionGetDof(section, p, &dof);CHKERRQ(ierr);
    ierr = PetscSectionGetOffset(section, p, &off);CHKERRQ(ierr);
    ierr = DMPlexGetAdjacency(dm, p, &numAdj, &tmpAdj);CHKERRQ(ierr);
    ierr = PetscSectionGetDof(anchorSectionAdj, p, &anDof);CHKERRQ(ierr);
    ierr = PetscSectionGetOffset(anchorSectionAdj, p, &anOff);CHKERRQ(ierr);
    for (d = off; d < off+dof; ++d) {
      PetscInt aoff, i = 0;

      ierr = PetscSectionGetOffset(leafSectionAdj, d, &aoff);CHKERRQ(ierr);
      for (q = 0; q < numAdj; ++q) {
        const PetscInt padj = tmpAdj[q];
        PetscInt ndof, ncdof, ngoff, nd;

        if ((padj < pStart) || (padj >= pEnd)) continue;
        ierr = PetscSectionGetDof(section, padj, &ndof);CHKERRQ(ierr);
        ierr = PetscSectionGetConstraintDof(section, padj, &ncdof);CHKERRQ(ierr);
        ierr = PetscSectionGetOffset(sectionGlobal, padj, &ngoff);CHKERRQ(ierr);
        for (nd = 0; nd < ndof-ncdof; ++nd) {
          adj[aoff+i] = (ngoff < 0 ? -(ngoff+1) : ngoff) + nd;
          ++i;
        }
      }
      for (q = 0; q < anDof; q++) {
        adj[aoff+i] = anchorAdj[anOff+q];
        ++i;
      }
    }
  }
  /* Debugging */
  if (debug) {
    IS tmp;
    ierr = PetscPrintf(comm, "Leaf adjacency indices\n");CHKERRQ(ierr);
    ierr = ISCreateGeneral(comm, adjSize, adj, PETSC_USE_POINTER, &tmp);CHKERRQ(ierr);
    ierr = ISView(tmp, NULL);CHKERRQ(ierr);
    ierr = ISDestroy(&tmp);CHKERRQ(ierr);
  }
  /* Gather adjacenct indices to root */
  ierr = PetscSectionGetStorageSize(rootSectionAdj, &adjSize);CHKERRQ(ierr);
  ierr = PetscMalloc1(adjSize, &rootAdj);CHKERRQ(ierr);
  for (r = 0; r < adjSize; ++r) rootAdj[r] = -1;
  if (doComm) {
    ierr = PetscSFGatherBegin(sfAdj, MPIU_INT, adj, rootAdj);CHKERRQ(ierr);
    ierr = PetscSFGatherEnd(sfAdj, MPIU_INT, adj, rootAdj);CHKERRQ(ierr);
  }
  ierr = PetscSFDestroy(&sfAdj);CHKERRQ(ierr);
  ierr = PetscFree(adj);CHKERRQ(ierr);
  /* Debugging */
  if (debug) {
    IS tmp;
    ierr = PetscPrintf(comm, "Root adjacency indices after gather\n");CHKERRQ(ierr);
    ierr = ISCreateGeneral(comm, adjSize, rootAdj, PETSC_USE_POINTER, &tmp);CHKERRQ(ierr);
    ierr = ISView(tmp, NULL);CHKERRQ(ierr);
    ierr = ISDestroy(&tmp);CHKERRQ(ierr);
  }
  /* Add in local adjacency indices for owned dofs on interface (roots) */
  for (p = pStart; p < pEnd; ++p) {
    PetscInt numAdj = PETSC_DETERMINE, adof, dof, off, d, q, anDof, anOff;

    ierr = PetscSectionGetDof(section, p, &dof);CHKERRQ(ierr);
    ierr = PetscSectionGetOffset(section, p, &off);CHKERRQ(ierr);
    if (!dof) continue;
    ierr = PetscSectionGetDof(rootSectionAdj, off, &adof);CHKERRQ(ierr);
    if (adof <= 0) continue;
    ierr = DMPlexGetAdjacency(dm, p, &numAdj, &tmpAdj);CHKERRQ(ierr);
    ierr = PetscSectionGetDof(anchorSectionAdj, p, &anDof);CHKERRQ(ierr);
    ierr = PetscSectionGetOffset(anchorSectionAdj, p, &anOff);CHKERRQ(ierr);
    for (d = off; d < off+dof; ++d) {
      PetscInt adof, aoff, i;

      ierr = PetscSectionGetDof(rootSectionAdj, d, &adof);CHKERRQ(ierr);
      ierr = PetscSectionGetOffset(rootSectionAdj, d, &aoff);CHKERRQ(ierr);
      i    = adof-1;
      for (q = 0; q < anDof; q++) {
        rootAdj[aoff+i] = anchorAdj[anOff+q];
        --i;
      }
      for (q = 0; q < numAdj; ++q) {
        const PetscInt padj = tmpAdj[q];
        PetscInt ndof, ncdof, ngoff, nd;

        if ((padj < pStart) || (padj >= pEnd)) continue;
        ierr = PetscSectionGetDof(section, padj, &ndof);CHKERRQ(ierr);
        ierr = PetscSectionGetConstraintDof(section, padj, &ncdof);CHKERRQ(ierr);
        ierr = PetscSectionGetOffset(sectionGlobal, padj, &ngoff);CHKERRQ(ierr);
        for (nd = 0; nd < ndof-ncdof; ++nd) {
          rootAdj[aoff+i] = ngoff < 0 ? -(ngoff+1)+nd : ngoff+nd;
          --i;
        }
      }
    }
  }
  /* Debugging */
  if (debug) {
    IS tmp;
    ierr = PetscPrintf(comm, "Root adjacency indices\n");CHKERRQ(ierr);
    ierr = ISCreateGeneral(comm, adjSize, rootAdj, PETSC_USE_POINTER, &tmp);CHKERRQ(ierr);
    ierr = ISView(tmp, NULL);CHKERRQ(ierr);
    ierr = ISDestroy(&tmp);CHKERRQ(ierr);
  }
  /* Compress indices */
  ierr = PetscSectionSetUp(rootSectionAdj);CHKERRQ(ierr);
  for (p = pStart; p < pEnd; ++p) {
    PetscInt dof, cdof, off, d;
    PetscInt adof, aoff;

    ierr = PetscSectionGetDof(section, p, &dof);CHKERRQ(ierr);
    ierr = PetscSectionGetConstraintDof(section, p, &cdof);CHKERRQ(ierr);
    ierr = PetscSectionGetOffset(section, p, &off);CHKERRQ(ierr);
    if (!dof) continue;
    ierr = PetscSectionGetDof(rootSectionAdj, off, &adof);CHKERRQ(ierr);
    if (adof <= 0) continue;
    for (d = off; d < off+dof-cdof; ++d) {
      ierr = PetscSectionGetDof(rootSectionAdj, d, &adof);CHKERRQ(ierr);
      ierr = PetscSectionGetOffset(rootSectionAdj, d, &aoff);CHKERRQ(ierr);
      ierr = PetscSortRemoveDupsInt(&adof, &rootAdj[aoff]);CHKERRQ(ierr);
      ierr = PetscSectionSetDof(rootSectionAdj, d, adof);CHKERRQ(ierr);
    }
  }
  /* Debugging */
  if (debug) {
    IS tmp;
    ierr = PetscPrintf(comm, "Adjancency Section for Preallocation on Roots after compression:\n");CHKERRQ(ierr);
    ierr = PetscSectionView(rootSectionAdj, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
    ierr = PetscPrintf(comm, "Root adjacency indices after compression\n");CHKERRQ(ierr);
    ierr = ISCreateGeneral(comm, adjSize, rootAdj, PETSC_USE_POINTER, &tmp);CHKERRQ(ierr);
    ierr = ISView(tmp, NULL);CHKERRQ(ierr);
    ierr = ISDestroy(&tmp);CHKERRQ(ierr);
  }
  /* Build adjacency section: Maps global indices to sets of adjacent global indices */
  ierr = PetscSectionGetOffsetRange(sectionGlobal, &globalOffStart, &globalOffEnd);CHKERRQ(ierr);
  ierr = PetscSectionCreate(comm, &sectionAdj);CHKERRQ(ierr);
  ierr = PetscSectionSetChart(sectionAdj, globalOffStart, globalOffEnd);CHKERRQ(ierr);
  for (p = pStart; p < pEnd; ++p) {
    PetscInt  numAdj = PETSC_DETERMINE, dof, cdof, off, goff, d, q, anDof;
    PetscBool found  = PETSC_TRUE;

    ierr = PetscSectionGetDof(section, p, &dof);CHKERRQ(ierr);
    ierr = PetscSectionGetConstraintDof(section, p, &cdof);CHKERRQ(ierr);
    ierr = PetscSectionGetOffset(section, p, &off);CHKERRQ(ierr);
    ierr = PetscSectionGetOffset(sectionGlobal, p, &goff);CHKERRQ(ierr);
    for (d = 0; d < dof-cdof; ++d) {
      PetscInt ldof, rdof;

      ierr = PetscSectionGetDof(leafSectionAdj, off+d, &ldof);CHKERRQ(ierr);
      ierr = PetscSectionGetDof(rootSectionAdj, off+d, &rdof);CHKERRQ(ierr);
      if (ldof > 0) {
        /* We do not own this point */
      } else if (rdof > 0) {
        ierr = PetscSectionSetDof(sectionAdj, goff+d, rdof);CHKERRQ(ierr);
      } else {
        found = PETSC_FALSE;
      }
    }
    if (found) continue;
    ierr = PetscSectionGetDof(section, p, &dof);CHKERRQ(ierr);
    ierr = PetscSectionGetOffset(sectionGlobal, p, &goff);CHKERRQ(ierr);
    ierr = DMPlexGetAdjacency(dm, p, &numAdj, &tmpAdj);CHKERRQ(ierr);
    for (q = 0; q < numAdj; ++q) {
      const PetscInt padj = tmpAdj[q];
      PetscInt ndof, ncdof, noff;

      if ((padj < pStart) || (padj >= pEnd)) continue;
      ierr = PetscSectionGetDof(section, padj, &ndof);CHKERRQ(ierr);
      ierr = PetscSectionGetConstraintDof(section, padj, &ncdof);CHKERRQ(ierr);
      ierr = PetscSectionGetOffset(section, padj, &noff);CHKERRQ(ierr);
      for (d = goff; d < goff+dof-cdof; ++d) {
        ierr = PetscSectionAddDof(sectionAdj, d, ndof-ncdof);CHKERRQ(ierr);
      }
    }
    ierr = PetscSectionGetDof(anchorSectionAdj, p, &anDof);CHKERRQ(ierr);
    if (anDof) {
      for (d = goff; d < goff+dof-cdof; ++d) {
        ierr = PetscSectionAddDof(sectionAdj, d, anDof);CHKERRQ(ierr);
      }
    }
  }
  ierr = PetscSectionSetUp(sectionAdj);CHKERRQ(ierr);
  if (debug) {
    ierr = PetscPrintf(comm, "Adjacency Section for Preallocation:\n");CHKERRQ(ierr);
    ierr = PetscSectionView(sectionAdj, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
  }
  /* Get adjacent indices */
  ierr = PetscSectionGetStorageSize(sectionAdj, &numCols);CHKERRQ(ierr);
  ierr = PetscMalloc1(numCols, &cols);CHKERRQ(ierr);
  for (p = pStart; p < pEnd; ++p) {
    PetscInt  numAdj = PETSC_DETERMINE, dof, cdof, off, goff, d, q, anDof, anOff;
    PetscBool found  = PETSC_TRUE;

    ierr = PetscSectionGetDof(section, p, &dof);CHKERRQ(ierr);
    ierr = PetscSectionGetConstraintDof(section, p, &cdof);CHKERRQ(ierr);
    ierr = PetscSectionGetOffset(section, p, &off);CHKERRQ(ierr);
    ierr = PetscSectionGetOffset(sectionGlobal, p, &goff);CHKERRQ(ierr);
    for (d = 0; d < dof-cdof; ++d) {
      PetscInt ldof, rdof;

      ierr = PetscSectionGetDof(leafSectionAdj, off+d, &ldof);CHKERRQ(ierr);
      ierr = PetscSectionGetDof(rootSectionAdj, off+d, &rdof);CHKERRQ(ierr);
      if (ldof > 0) {
        /* We do not own this point */
      } else if (rdof > 0) {
        PetscInt aoff, roff;

        ierr = PetscSectionGetOffset(sectionAdj, goff+d, &aoff);CHKERRQ(ierr);
        ierr = PetscSectionGetOffset(rootSectionAdj, off+d, &roff);CHKERRQ(ierr);
        ierr = PetscMemcpy(&cols[aoff], &rootAdj[roff], rdof * sizeof(PetscInt));CHKERRQ(ierr);
      } else {
        found = PETSC_FALSE;
      }
    }
    if (found) continue;
    ierr = DMPlexGetAdjacency(dm, p, &numAdj, &tmpAdj);CHKERRQ(ierr);
    ierr = PetscSectionGetDof(anchorSectionAdj, p, &anDof);CHKERRQ(ierr);
    ierr = PetscSectionGetOffset(anchorSectionAdj, p, &anOff);CHKERRQ(ierr);
    for (d = goff; d < goff+dof-cdof; ++d) {
      PetscInt adof, aoff, i = 0;

      ierr = PetscSectionGetDof(sectionAdj, d, &adof);CHKERRQ(ierr);
      ierr = PetscSectionGetOffset(sectionAdj, d, &aoff);CHKERRQ(ierr);
      for (q = 0; q < numAdj; ++q) {
        const PetscInt  padj = tmpAdj[q];
        PetscInt        ndof, ncdof, ngoff, nd;
        const PetscInt *ncind;

        /* Adjacent points may not be in the section chart */
        if ((padj < pStart) || (padj >= pEnd)) continue;
        ierr = PetscSectionGetDof(section, padj, &ndof);CHKERRQ(ierr);
        ierr = PetscSectionGetConstraintDof(section, padj, &ncdof);CHKERRQ(ierr);
        ierr = PetscSectionGetConstraintIndices(section, padj, &ncind);CHKERRQ(ierr);
        ierr = PetscSectionGetOffset(sectionGlobal, padj, &ngoff);CHKERRQ(ierr);
        for (nd = 0; nd < ndof-ncdof; ++nd, ++i) {
          cols[aoff+i] = ngoff < 0 ? -(ngoff+1)+nd : ngoff+nd;
        }
      }
      for (q = 0; q < anDof; q++, i++) {
        cols[aoff+i] = anchorAdj[anOff + q];
      }
      if (i != adof) SETERRQ4(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid number of entries %D != %D for dof %D (point %D)", i, adof, d, p);
    }
  }
  ierr = PetscSectionDestroy(&anchorSectionAdj);CHKERRQ(ierr);
  ierr = PetscSectionDestroy(&leafSectionAdj);CHKERRQ(ierr);
  ierr = PetscSectionDestroy(&rootSectionAdj);CHKERRQ(ierr);
  ierr = PetscFree(anchorAdj);CHKERRQ(ierr);
  ierr = PetscFree(rootAdj);CHKERRQ(ierr);
  ierr = PetscFree(tmpAdj);CHKERRQ(ierr);
  /* Debugging */
  if (debug) {
    IS tmp;
    ierr = PetscPrintf(comm, "Column indices\n");CHKERRQ(ierr);
    ierr = ISCreateGeneral(comm, numCols, cols, PETSC_USE_POINTER, &tmp);CHKERRQ(ierr);
    ierr = ISView(tmp, NULL);CHKERRQ(ierr);
    ierr = ISDestroy(&tmp);CHKERRQ(ierr);
  }
  /* Create allocation vectors from adjacency graph */
  ierr = MatGetLocalSize(A, &locRows, NULL);CHKERRQ(ierr);
  ierr = PetscLayoutCreate(PetscObjectComm((PetscObject)A), &rLayout);CHKERRQ(ierr);
  ierr = PetscLayoutSetLocalSize(rLayout, locRows);CHKERRQ(ierr);
  ierr = PetscLayoutSetBlockSize(rLayout, 1);CHKERRQ(ierr);
  ierr = PetscLayoutSetUp(rLayout);CHKERRQ(ierr);
  ierr = PetscLayoutGetRange(rLayout, &rStart, &rEnd);CHKERRQ(ierr);
  ierr = PetscLayoutDestroy(&rLayout);CHKERRQ(ierr);
  /* Only loop over blocks of rows */
  if (rStart%bs || rEnd%bs) SETERRQ3(PetscObjectComm((PetscObject)A), PETSC_ERR_ARG_WRONG, "Invalid layout [%d, %d) for matrix, must be divisible by block size %d", rStart, rEnd, bs);
  for (r = rStart/bs; r < rEnd/bs; ++r) {
    const PetscInt row = r*bs;
    PetscInt       numCols, cStart, c;

    ierr = PetscSectionGetDof(sectionAdj, row, &numCols);CHKERRQ(ierr);
    ierr = PetscSectionGetOffset(sectionAdj, row, &cStart);CHKERRQ(ierr);
    for (c = cStart; c < cStart+numCols; ++c) {
      if ((cols[c] >= rStart*bs) && (cols[c] < rEnd*bs)) {
        ++dnz[r-rStart];
        if (cols[c] >= row) ++dnzu[r-rStart];
      } else {
        ++onz[r-rStart];
        if (cols[c] >= row) ++onzu[r-rStart];
      }
    }
  }
  if (bs > 1) {
    for (r = 0; r < locRows/bs; ++r) {
      dnz[r]  /= bs;
      onz[r]  /= bs;
      dnzu[r] /= bs;
      onzu[r] /= bs;
    }
  }
  /* Set matrix pattern */
  ierr = MatXAIJSetPreallocation(A, bs, dnz, onz, dnzu, onzu);CHKERRQ(ierr);
  ierr = MatSetOption(A, MAT_NEW_NONZERO_ALLOCATION_ERR,PETSC_TRUE);CHKERRQ(ierr);
  /* Check for symmetric storage */
  ierr = MatGetType(A, &mtype);CHKERRQ(ierr);
  ierr = PetscStrcmp(mtype, MATSBAIJ, &isSymBlock);CHKERRQ(ierr);
  ierr = PetscStrcmp(mtype, MATSEQSBAIJ, &isSymSeqBlock);CHKERRQ(ierr);
  ierr = PetscStrcmp(mtype, MATMPISBAIJ, &isSymMPIBlock);CHKERRQ(ierr);
  if (isSymBlock || isSymSeqBlock || isSymMPIBlock) {ierr = MatSetOption(A, MAT_IGNORE_LOWER_TRIANGULAR, PETSC_TRUE);CHKERRQ(ierr);}
  /* Fill matrix with zeros */
  if (fillMatrix) {
    PetscScalar *values;
    PetscInt     maxRowLen = 0;

    for (r = rStart; r < rEnd; ++r) {
      PetscInt len;

      ierr      = PetscSectionGetDof(sectionAdj, r, &len);CHKERRQ(ierr);
      maxRowLen = PetscMax(maxRowLen, len);
    }
    ierr = PetscCalloc1(maxRowLen, &values);CHKERRQ(ierr);
    for (r = rStart; r < rEnd; ++r) {
      PetscInt numCols, cStart;

      ierr = PetscSectionGetDof(sectionAdj, r, &numCols);CHKERRQ(ierr);
      ierr = PetscSectionGetOffset(sectionAdj, r, &cStart);CHKERRQ(ierr);
      ierr = MatSetValues(A, 1, &r, numCols, &cols[cStart], values, INSERT_VALUES);CHKERRQ(ierr);
    }
    ierr = PetscFree(values);CHKERRQ(ierr);
    ierr = MatAssemblyBegin(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
    ierr = MatAssemblyEnd(A, MAT_FINAL_ASSEMBLY);CHKERRQ(ierr);
  }
  /* restore original useAnchors */
  ierr = DMPlexSetAdjacencyUseAnchors(dm,useAnchors);CHKERRQ(ierr);
  ierr = PetscSectionDestroy(&sectionAdj);CHKERRQ(ierr);
  ierr = PetscFree(cols);CHKERRQ(ierr);
  ierr = PetscLogEventEnd(DMPLEX_Preallocate,dm,0,0,0);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
Пример #6
0
/* This interpolates the PointSF in parallel following local interpolation */
static PetscErrorCode DMPlexInterpolatePointSF(DM dm, PetscSF pointSF, PetscInt depth)
{
  PetscMPIInt        numProcs, rank;
  PetscInt           p, c, d, dof, offset;
  PetscInt           numLeaves, numRoots, candidatesSize, candidatesRemoteSize;
  const PetscInt    *localPoints;
  const PetscSFNode *remotePoints;
  PetscSFNode       *candidates, *candidatesRemote, *claims;
  PetscSection       candidateSection, candidateSectionRemote, claimSection;
  PetscHashI         leafhash;
  PetscHashIJ        roothash;
  PetscHashIJKey     key;
  PetscErrorCode     ierr;

  PetscFunctionBegin;
  ierr = MPI_Comm_size(PetscObjectComm((PetscObject) dm), &numProcs);CHKERRQ(ierr);
  ierr = MPI_Comm_rank(PetscObjectComm((PetscObject) dm), &rank);CHKERRQ(ierr);
  ierr = PetscSFGetGraph(pointSF, &numRoots, &numLeaves, &localPoints, &remotePoints);CHKERRQ(ierr);
  if (numProcs < 2 || numRoots < 0) PetscFunctionReturn(0);
  /* Build hashes of points in the SF for efficient lookup */
  PetscHashICreate(leafhash);
  PetscHashIJCreate(&roothash);
  ierr = PetscHashIJSetMultivalued(roothash, PETSC_FALSE);CHKERRQ(ierr);
  for (p = 0; p < numLeaves; ++p) {
    PetscHashIAdd(leafhash, localPoints[p], p);
    key.i = remotePoints[p].index; key.j = remotePoints[p].rank;
    PetscHashIJAdd(roothash, key, p);
  }
  /* Build a section / SFNode array of candidate points in the single-level adjacency of leaves,
     where each candidate is defined by the root entry for the other vertex that defines the edge. */
  ierr = PetscSectionCreate(PetscObjectComm((PetscObject) dm), &candidateSection);CHKERRQ(ierr);
  ierr = PetscSectionSetChart(candidateSection, 0, numRoots);CHKERRQ(ierr);
  {
    PetscInt leaf, root, idx, a, *adj = NULL;
    for (p = 0; p < numLeaves; ++p) {
      PetscInt adjSize = PETSC_DETERMINE;
      ierr = DMPlexGetAdjacency_Internal(dm, localPoints[p], PETSC_FALSE, PETSC_FALSE, PETSC_FALSE, &adjSize, &adj);CHKERRQ(ierr);
      for (a = 0; a < adjSize; ++a) {
        PetscHashIMap(leafhash, adj[a], leaf);
        if (leaf >= 0) {ierr = PetscSectionAddDof(candidateSection, localPoints[p], 1);CHKERRQ(ierr);}
      }
    }
    ierr = PetscSectionSetUp(candidateSection);CHKERRQ(ierr);
    ierr = PetscSectionGetStorageSize(candidateSection, &candidatesSize);CHKERRQ(ierr);
    ierr = PetscMalloc1(candidatesSize, &candidates);CHKERRQ(ierr);
    for (p = 0; p < numLeaves; ++p) {
      PetscInt adjSize = PETSC_DETERMINE;
      ierr = PetscSectionGetOffset(candidateSection, localPoints[p], &offset);CHKERRQ(ierr);
      ierr = DMPlexGetAdjacency_Internal(dm, localPoints[p], PETSC_FALSE, PETSC_FALSE, PETSC_FALSE, &adjSize, &adj);CHKERRQ(ierr);
      for (idx = 0, a = 0; a < adjSize; ++a) {
        PetscHashIMap(leafhash, adj[a], root);
        if (root >= 0) candidates[offset+idx++] = remotePoints[root];
      }
    }
    ierr = PetscFree(adj);CHKERRQ(ierr);
  }
  /* Gather candidate section / array pair into the root partition via inverse(multi(pointSF)). */
  {
    PetscSF   sfMulti, sfInverse, sfCandidates;
    PetscInt *remoteOffsets;
    ierr = PetscSFGetMultiSF(pointSF, &sfMulti);CHKERRQ(ierr);
    ierr = PetscSFCreateInverseSF(sfMulti, &sfInverse);CHKERRQ(ierr);
    ierr = PetscSectionCreate(PetscObjectComm((PetscObject) dm), &candidateSectionRemote);CHKERRQ(ierr);
    ierr = PetscSFDistributeSection(sfInverse, candidateSection, &remoteOffsets, candidateSectionRemote);CHKERRQ(ierr);
    ierr = PetscSFCreateSectionSF(sfInverse, candidateSection, remoteOffsets, candidateSectionRemote, &sfCandidates);CHKERRQ(ierr);
    ierr = PetscSectionGetStorageSize(candidateSectionRemote, &candidatesRemoteSize);CHKERRQ(ierr);
    ierr = PetscMalloc1(candidatesRemoteSize, &candidatesRemote);CHKERRQ(ierr);
    ierr = PetscSFBcastBegin(sfCandidates, MPIU_2INT, candidates, candidatesRemote);CHKERRQ(ierr);
    ierr = PetscSFBcastEnd(sfCandidates, MPIU_2INT, candidates, candidatesRemote);CHKERRQ(ierr);
    ierr = PetscSFDestroy(&sfInverse);CHKERRQ(ierr);
    ierr = PetscSFDestroy(&sfCandidates);CHKERRQ(ierr);
    ierr = PetscFree(remoteOffsets);CHKERRQ(ierr);
  }
  /* Walk local roots and check for each remote candidate whether we know all required points,
     either from owning it or having a root entry in the point SF. If we do we place a claim
     by replacing the vertex number with our edge ID. */
  {
    PetscInt        idx, root, joinSize, vertices[2];
    const PetscInt *rootdegree, *join = NULL;
    ierr = PetscSFComputeDegreeBegin(pointSF, &rootdegree);CHKERRQ(ierr);
    ierr = PetscSFComputeDegreeEnd(pointSF, &rootdegree);CHKERRQ(ierr);
    /* Loop remote edge connections and put in a claim if both vertices are known */
    for (idx = 0, p = 0; p < numRoots; ++p) {
      for (d = 0; d < rootdegree[p]; ++d) {
        ierr = PetscSectionGetDof(candidateSectionRemote, idx, &dof);CHKERRQ(ierr);
        ierr = PetscSectionGetOffset(candidateSectionRemote, idx, &offset);CHKERRQ(ierr);
        for (c = 0; c < dof; ++c) {
          /* We own both vertices, so we claim the edge by replacing vertex with edge */
          if (candidatesRemote[offset+c].rank == rank) {
            vertices[0] = p; vertices[1] = candidatesRemote[offset+c].index;
            ierr = DMPlexGetJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
            if (joinSize == 1) candidatesRemote[offset+c].index = join[0];
            ierr = DMPlexRestoreJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
            continue;
          }
          /* If we own one vertex and share a root with the other, we claim it */
          key.i = candidatesRemote[offset+c].index; key.j = candidatesRemote[offset+c].rank;
          PetscHashIJGet(roothash, key, &root);
          if (root >= 0) {
            vertices[0] = p; vertices[1] = localPoints[root];
            ierr = DMPlexGetJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
            if (joinSize == 1) {
              candidatesRemote[offset+c].index = join[0];
              candidatesRemote[offset+c].rank = rank;
            }
            ierr = DMPlexRestoreJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
          }
        }
        idx++;
      }
    }
  }
  /* Push claims back to receiver via the MultiSF and derive new pointSF mapping on receiver */
  {
    PetscSF         sfMulti, sfClaims, sfPointNew;
    PetscHashI      claimshash;
    PetscInt        size, pStart, pEnd, root, joinSize, numLocalNew;
    PetscInt       *remoteOffsets, *localPointsNew, vertices[2];
    const PetscInt *join = NULL;
    PetscSFNode    *remotePointsNew;
    ierr = PetscSFGetMultiSF(pointSF, &sfMulti);CHKERRQ(ierr);
    ierr = PetscSectionCreate(PetscObjectComm((PetscObject) dm), &claimSection);CHKERRQ(ierr);
    ierr = PetscSFDistributeSection(sfMulti, candidateSectionRemote, &remoteOffsets, claimSection);CHKERRQ(ierr);
    ierr = PetscSFCreateSectionSF(sfMulti, candidateSectionRemote, remoteOffsets, claimSection, &sfClaims);CHKERRQ(ierr);
    ierr = PetscSectionGetStorageSize(claimSection, &size);CHKERRQ(ierr);
    ierr = PetscMalloc1(size, &claims);CHKERRQ(ierr);
    ierr = PetscSFBcastBegin(sfClaims, MPIU_2INT, candidatesRemote, claims);CHKERRQ(ierr);
    ierr = PetscSFBcastEnd(sfClaims, MPIU_2INT, candidatesRemote, claims);CHKERRQ(ierr);
    ierr = PetscSFDestroy(&sfClaims);CHKERRQ(ierr);
    ierr = PetscFree(remoteOffsets);CHKERRQ(ierr);
    /* Walk the original section of local supports and add an SF entry for each updated item */
    PetscHashICreate(claimshash);
    for (p = 0; p < numRoots; ++p) {
      ierr = PetscSectionGetDof(candidateSection, p, &dof);CHKERRQ(ierr);
      ierr = PetscSectionGetOffset(candidateSection, p, &offset);CHKERRQ(ierr);
      for (d = 0; d < dof; ++d) {
        if (candidates[offset+d].index != claims[offset+d].index) {
          key.i = candidates[offset+d].index; key.j = candidates[offset+d].rank;
          PetscHashIJGet(roothash, key, &root);
          if (root >= 0) {
            vertices[0] = p; vertices[1] = localPoints[root];
            ierr = DMPlexGetJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
            if (joinSize == 1) PetscHashIAdd(claimshash, join[0], offset+d);
            ierr = DMPlexRestoreJoin(dm, 2, vertices, &joinSize, &join);CHKERRQ(ierr);
          }
        }
      }
    }
    /* Create new pointSF from hashed claims */
    PetscHashISize(claimshash, numLocalNew);
    ierr = DMPlexGetChart(dm, &pStart, &pEnd);CHKERRQ(ierr);
    ierr = PetscMalloc1(numLeaves + numLocalNew, &localPointsNew);CHKERRQ(ierr);
    ierr = PetscMalloc1(numLeaves + numLocalNew, &remotePointsNew);CHKERRQ(ierr);
    for (p = 0; p < numLeaves; ++p) {
      localPointsNew[p] = localPoints[p];
      remotePointsNew[p].index = remotePoints[p].index;
      remotePointsNew[p].rank = remotePoints[p].rank;
    }
    p = numLeaves; ierr = PetscHashIGetKeys(claimshash, &p, localPointsNew);CHKERRQ(ierr);
    for (p = numLeaves; p < numLeaves + numLocalNew; ++p) {
      PetscHashIMap(claimshash, localPointsNew[p], offset);
      remotePointsNew[p] = claims[offset];
    }
    ierr = PetscSFCreate(PetscObjectComm((PetscObject) dm), &sfPointNew);CHKERRQ(ierr);
    ierr = PetscSFSetGraph(sfPointNew, pEnd-pStart, numLeaves+numLocalNew, localPointsNew, PETSC_OWN_POINTER, remotePointsNew, PETSC_OWN_POINTER);CHKERRQ(ierr);
    ierr = DMSetPointSF(dm, sfPointNew);CHKERRQ(ierr);
    ierr = PetscSFDestroy(&sfPointNew);CHKERRQ(ierr);
    PetscHashIDestroy(claimshash);
  }
  PetscHashIDestroy(leafhash);
  ierr = PetscHashIJDestroy(&roothash);CHKERRQ(ierr);
  ierr = PetscSectionDestroy(&candidateSection);CHKERRQ(ierr);
  ierr = PetscSectionDestroy(&candidateSectionRemote);CHKERRQ(ierr);
  ierr = PetscSectionDestroy(&claimSection);CHKERRQ(ierr);
  ierr = PetscFree(candidates);CHKERRQ(ierr);
  ierr = PetscFree(candidatesRemote);CHKERRQ(ierr);
  ierr = PetscFree(claims);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}