xref: /petsc/src/dm/impls/plex/plexdistribute.c (revision 70034214b4f51eb44fb6e1753b0a1c1f20e8240c)

#include <petsc-private/dmpleximpl.h>   /*I      "petscdmplex.h"   I*/
#include <petscsf.h>

#undef __FUNCT__
#define __FUNCT__ "DMPlexSetAdjacencyUseCone"
/*@
  DMPlexSetAdjacencyUseCone - Define adjacency in the mesh using either the cone or the support first

  Input Parameters:
+ dm      - The DM object
- useCone - Flag to use the cone first

  Level: intermediate

  Notes:
$     FEM:   Two points p and q are adjacent if q \in closure(star(p)), useCone = PETSC_FALSE, useClosure = PETSC_TRUE
$     FVM:   Two points p and q are adjacent if q \in star(cone(p)),    useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
$     FVM++: Two points p and q are adjacent if q \in star(closure(p)), useCone = PETSC_TRUE,  useClosure = PETSC_TRUE

.seealso: DMPlexGetAdjacencyUseCone(), DMPlexSetAdjacencyUseClosure(), DMPlexGetAdjacencyUseClosure(), DMPlexDistribute(), DMPlexPreallocateOperator()
@*/
PetscErrorCode DMPlexSetAdjacencyUseCone(DM dm, PetscBool useCone)
{
  DM_Plex *mesh = (DM_Plex *) dm->data;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
  mesh->useCone = useCone;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "DMPlexGetAdjacencyUseCone"
/*@
  DMPlexGetAdjacencyUseCone - Query whether adjacency in the mesh uses the cone or the support first

  Input Parameter:
. dm      - The DM object

  Output Parameter:
. useCone - Flag to use the cone first

  Level: intermediate

  Notes:
$     FEM:   Two points p and q are adjacent if q \in closure(star(p)), useCone = PETSC_FALSE, useClosure = PETSC_TRUE
$     FVM:   Two points p and q are adjacent if q \in star(cone(p)),    useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
$     FVM++: Two points p and q are adjacent if q \in star(closure(p)), useCone = PETSC_TRUE,  useClosure = PETSC_TRUE

.seealso: DMPlexSetAdjacencyUseCone(), DMPlexSetAdjacencyUseClosure(), DMPlexGetAdjacencyUseClosure(), DMPlexDistribute(), DMPlexPreallocateOperator()
@*/
PetscErrorCode DMPlexGetAdjacencyUseCone(DM dm, PetscBool *useCone)
{
  DM_Plex *mesh = (DM_Plex *) dm->data;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
  PetscValidIntPointer(useCone, 2);
  *useCone = mesh->useCone;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "DMPlexSetAdjacencyUseClosure"
/*@
  DMPlexSetAdjacencyUseClosure - Define adjacency in the mesh using the transitive closure

  Input Parameters:
+ dm      - The DM object
- useClosure - Flag to use the closure

  Level: intermediate

  Notes:
$     FEM:   Two points p and q are adjacent if q \in closure(star(p)), useCone = PETSC_FALSE, useClosure = PETSC_TRUE
$     FVM:   Two points p and q are adjacent if q \in star(cone(p)),    useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
$     FVM++: Two points p and q are adjacent if q \in star(closure(p)), useCone = PETSC_TRUE,  useClosure = PETSC_TRUE

.seealso: DMPlexGetAdjacencyUseClosure(), DMPlexSetAdjacencyUseCone(), DMPlexGetAdjacencyUseCone(), DMPlexDistribute(), DMPlexPreallocateOperator()
@*/
PetscErrorCode DMPlexSetAdjacencyUseClosure(DM dm, PetscBool useClosure)
{
  DM_Plex *mesh = (DM_Plex *) dm->data;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
  mesh->useClosure = useClosure;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "DMPlexGetAdjacencyUseClosure"
/*@
  DMPlexGetAdjacencyUseClosure - Query whether adjacency in the mesh uses the transitive closure

  Input Parameter:
. dm      - The DM object

  Output Parameter:
. useClosure - Flag to use the closure

  Level: intermediate

  Notes:
$     FEM:   Two points p and q are adjacent if q \in closure(star(p)), useCone = PETSC_FALSE, useClosure = PETSC_TRUE
$     FVM:   Two points p and q are adjacent if q \in star(cone(p)),    useCone = PETSC_TRUE,  useClosure = PETSC_FALSE
$     FVM++: Two points p and q are adjacent if q \in star(closure(p)), useCone = PETSC_TRUE,  useClosure = PETSC_TRUE

.seealso: DMPlexSetAdjacencyUseClosure(), DMPlexSetAdjacencyUseCone(), DMPlexGetAdjacencyUseCone(), DMPlexDistribute(), DMPlexPreallocateOperator()
@*/
PetscErrorCode DMPlexGetAdjacencyUseClosure(DM dm, PetscBool *useClosure)
{
  DM_Plex *mesh = (DM_Plex *) dm->data;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
  PetscValidIntPointer(useClosure, 2);
  *useClosure = mesh->useClosure;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "DMPlexGetAdjacency_Cone_Internal"
static PetscErrorCode DMPlexGetAdjacency_Cone_Internal(DM dm, PetscInt p, PetscInt *adjSize, PetscInt adj[])
{
  const PetscInt *cone = NULL;
  PetscInt        numAdj = 0, maxAdjSize = *adjSize, coneSize, c;
  PetscErrorCode  ierr;

  PetscFunctionBeginHot;
  ierr = DMPlexGetConeSize(dm, p, &coneSize);CHKERRQ(ierr);
  ierr = DMPlexGetCone(dm, p, &cone);CHKERRQ(ierr);
  for (c = 0; c < coneSize; ++c) {
    const PetscInt *support = NULL;
    PetscInt        supportSize, s, q;

    ierr = DMPlexGetSupportSize(dm, cone[c], &supportSize);CHKERRQ(ierr);
    ierr = DMPlexGetSupport(dm, cone[c], &support);CHKERRQ(ierr);
    for (s = 0; s < supportSize; ++s) {
      for (q = 0; q < numAdj || (adj[numAdj++] = support[s],0); ++q) {
        if (support[s] == adj[q]) break;
      }
      if (numAdj > maxAdjSize) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid mesh exceeded adjacency allocation (%D)", maxAdjSize);
    }
  }
  *adjSize = numAdj;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "DMPlexGetAdjacency_Support_Internal"
static PetscErrorCode DMPlexGetAdjacency_Support_Internal(DM dm, PetscInt p, PetscInt *adjSize, PetscInt adj[])
{
  const PetscInt *support = NULL;
  PetscInt        numAdj   = 0, maxAdjSize = *adjSize, supportSize, s;
  PetscErrorCode  ierr;

  PetscFunctionBeginHot;
  ierr = DMPlexGetSupportSize(dm, p, &supportSize);CHKERRQ(ierr);
  ierr = DMPlexGetSupport(dm, p, &support);CHKERRQ(ierr);
  for (s = 0; s < supportSize; ++s) {
    const PetscInt *cone = NULL;
    PetscInt        coneSize, c, q;

    ierr = DMPlexGetConeSize(dm, support[s], &coneSize);CHKERRQ(ierr);
    ierr = DMPlexGetCone(dm, support[s], &cone);CHKERRQ(ierr);
    for (c = 0; c < coneSize; ++c) {
      for (q = 0; q < numAdj || (adj[numAdj++] = cone[c],0); ++q) {
        if (cone[c] == adj[q]) break;
      }
      if (numAdj > maxAdjSize) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid mesh exceeded adjacency allocation (%D)", maxAdjSize);
    }
  }
  *adjSize = numAdj;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "DMPlexGetAdjacency_Transitive_Internal"
static PetscErrorCode DMPlexGetAdjacency_Transitive_Internal(DM dm, PetscInt p, PetscBool useClosure, PetscInt *adjSize, PetscInt adj[])
{
  PetscInt      *star = NULL;
  PetscInt       numAdj = 0, maxAdjSize = *adjSize, starSize, s;
  PetscErrorCode ierr;

  PetscFunctionBeginHot;
  ierr = DMPlexGetTransitiveClosure(dm, p, useClosure, &starSize, &star);CHKERRQ(ierr);
  for (s = 0; s < starSize*2; s += 2) {
    const PetscInt *closure = NULL;
    PetscInt        closureSize, c, q;

    ierr = DMPlexGetTransitiveClosure(dm, star[s], (PetscBool)!useClosure, &closureSize, (PetscInt**) &closure);CHKERRQ(ierr);
    for (c = 0; c < closureSize*2; c += 2) {
      for (q = 0; q < numAdj || (adj[numAdj++] = closure[c],0); ++q) {
        if (closure[c] == adj[q]) break;
      }
      if (numAdj > maxAdjSize) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid mesh exceeded adjacency allocation (%D)", maxAdjSize);
    }
    ierr = DMPlexRestoreTransitiveClosure(dm, star[s], (PetscBool)!useClosure, &closureSize, (PetscInt**) &closure);CHKERRQ(ierr);
  }
  ierr = DMPlexRestoreTransitiveClosure(dm, p, useClosure, &starSize, &star);CHKERRQ(ierr);
  *adjSize = numAdj;
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "DMPlexGetAdjacency_Internal"
PetscErrorCode DMPlexGetAdjacency_Internal(DM dm, PetscInt p, PetscBool useCone, PetscBool useTransitiveClosure, PetscInt *adjSize, PetscInt adj[])
{
  PetscErrorCode  ierr;

  PetscFunctionBeginHot;
  if (useTransitiveClosure) {
    ierr = DMPlexGetAdjacency_Transitive_Internal(dm, p, useCone, adjSize, adj);CHKERRQ(ierr);
  } else if (useCone) {
    ierr = DMPlexGetAdjacency_Cone_Internal(dm, p, adjSize, adj);CHKERRQ(ierr);
  } else {
    ierr = DMPlexGetAdjacency_Support_Internal(dm, p, adjSize, adj);CHKERRQ(ierr);
  }
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "DMPlexGetAdjacency"
/*@
  DMPlexGetAdjacency - Return all points adjacent to the given point

  Input Parameters:
+ dm - The DM object
. p  - The point
. adjSize - The maximum size of adj if it is non-NULL, or PETSC_DETERMINE
- adj - Either NULL so that the array is allocated, or an existing array with size adjSize

  Output Parameters:
+ adjSize - The number of adjacent points
- adj - The adjacent points

  Level: advanced

  Notes: The user must PetscFree the adj array if it was not passed in.

.seealso: DMPlexSetAdjacencyUseCone(), DMPlexSetAdjacencyUseClosure(), DMPlexDistribute(), DMCreateMatrix(), DMPlexPreallocateOperator()
@*/
PetscErrorCode DMPlexGetAdjacency(DM dm, PetscInt p, PetscInt *adjSize, PetscInt *adj[])
{
  DM_Plex        *mesh = (DM_Plex *) dm->data;
  static PetscInt asiz = 0;
  PetscErrorCode  ierr;

  PetscFunctionBeginHot;
  PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
  PetscValidPointer(adjSize,3);
  PetscValidPointer(adj,4);
  if (!*adj) {
    PetscInt depth, maxConeSize, maxSupportSize;

    ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
    ierr = DMPlexGetMaxSizes(dm, &maxConeSize, &maxSupportSize);CHKERRQ(ierr);
    asiz = PetscPowInt(maxConeSize, depth+1) * PetscPowInt(maxSupportSize, depth+1) + 1;
    ierr = PetscMalloc1(asiz,adj);CHKERRQ(ierr);
  }
  if (*adjSize < 0) *adjSize = asiz;
  ierr = DMPlexGetAdjacency_Internal(dm, p, mesh->useCone, mesh->useClosure, adjSize, *adj);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "DMPlexDistributeField"
/*@
  DMPlexDistributeField - Distribute field data to match a given PetscSF, usually the SF from mesh distribution

  Collective on DM

  Input Parameters:
+ dm - The DMPlex object
. pointSF - The PetscSF describing the communication pattern
. originalSection - The PetscSection for existing data layout
- originalVec - The existing data

  Output Parameters:
+ newSection - The PetscSF describing the new data layout
- newVec - The new data

  Level: developer

.seealso: DMPlexDistribute(), DMPlexDistributeData()
@*/
PetscErrorCode DMPlexDistributeField(DM dm, PetscSF pointSF, PetscSection originalSection, Vec originalVec, PetscSection newSection, Vec newVec)
{
  PetscSF        fieldSF;
  PetscInt      *remoteOffsets, fieldSize;
  PetscScalar   *originalValues, *newValues;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  ierr = PetscLogEventBegin(DMPLEX_DistributeField,dm,0,0,0);CHKERRQ(ierr);
  ierr = PetscSFDistributeSection(pointSF, originalSection, &remoteOffsets, newSection);CHKERRQ(ierr);

  ierr = PetscSectionGetStorageSize(newSection, &fieldSize);CHKERRQ(ierr);
  ierr = VecSetSizes(newVec, fieldSize, PETSC_DETERMINE);CHKERRQ(ierr);
  ierr = VecSetType(newVec,dm->vectype);CHKERRQ(ierr);

  ierr = VecGetArray(originalVec, &originalValues);CHKERRQ(ierr);
  ierr = VecGetArray(newVec, &newValues);CHKERRQ(ierr);
  ierr = PetscSFCreateSectionSF(pointSF, originalSection, remoteOffsets, newSection, &fieldSF);CHKERRQ(ierr);
  ierr = PetscSFBcastBegin(fieldSF, MPIU_SCALAR, originalValues, newValues);CHKERRQ(ierr);
  ierr = PetscSFBcastEnd(fieldSF, MPIU_SCALAR, originalValues, newValues);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&fieldSF);CHKERRQ(ierr);
  ierr = VecRestoreArray(newVec, &newValues);CHKERRQ(ierr);
  ierr = VecRestoreArray(originalVec, &originalValues);CHKERRQ(ierr);
  ierr = PetscLogEventEnd(DMPLEX_DistributeField,dm,0,0,0);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "DMPlexDistributeData"
/*@
  DMPlexDistributeData - Distribute field data to match a given PetscSF, usually the SF from mesh distribution

  Collective on DM

  Input Parameters:
+ dm - The DMPlex object
. pointSF - The PetscSF describing the communication pattern
. originalSection - The PetscSection for existing data layout
. datatype - The type of data
- originalData - The existing data

  Output Parameters:
+ newSection - The PetscSF describing the new data layout
- newData - The new data

  Level: developer

.seealso: DMPlexDistribute(), DMPlexDistributeField()
@*/
PetscErrorCode DMPlexDistributeData(DM dm, PetscSF pointSF, PetscSection originalSection, MPI_Datatype datatype, void *originalData, PetscSection newSection, void **newData)
{
  PetscSF        fieldSF;
  PetscInt      *remoteOffsets, fieldSize;
  PetscMPIInt    dataSize;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  ierr = PetscLogEventBegin(DMPLEX_DistributeData,dm,0,0,0);CHKERRQ(ierr);
  ierr = PetscSFDistributeSection(pointSF, originalSection, &remoteOffsets, newSection);CHKERRQ(ierr);

  ierr = PetscSectionGetStorageSize(newSection, &fieldSize);CHKERRQ(ierr);
  ierr = MPI_Type_size(datatype, &dataSize);CHKERRQ(ierr);
  ierr = PetscMalloc(fieldSize * dataSize, newData);CHKERRQ(ierr);

  ierr = PetscSFCreateSectionSF(pointSF, originalSection, remoteOffsets, newSection, &fieldSF);CHKERRQ(ierr);
  ierr = PetscSFBcastBegin(fieldSF, datatype, originalData, *newData);CHKERRQ(ierr);
  ierr = PetscSFBcastEnd(fieldSF, datatype, originalData, *newData);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&fieldSF);CHKERRQ(ierr);
  ierr = PetscLogEventEnd(DMPLEX_DistributeData,dm,0,0,0);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}

#undef __FUNCT__
#define __FUNCT__ "DMPlexDistribute"
/*@C
  DMPlexDistribute - Distributes the mesh and any associated sections.

  Not Collective

  Input Parameter:
+ dm  - The original DMPlex object
. partitioner - The partitioning package, or NULL for the default
- overlap - The overlap of partitions, 0 is the default

  Output Parameter:
+ sf - The PetscSF used for point distribution
- parallelMesh - The distributed DMPlex object, or NULL

  Note: If the mesh was not distributed, the return value is NULL

  Level: intermediate

.keywords: mesh, elements
.seealso: DMPlexCreate(), DMPlexDistributeByFace()
@*/
PetscErrorCode DMPlexDistribute(DM dm, const char partitioner[], PetscInt overlap, PetscSF *sf, DM *dmParallel)
{
  DM_Plex               *mesh   = (DM_Plex*) dm->data, *pmesh;
  MPI_Comm               comm;
  const PetscInt         height = 0;
  PetscInt               dim, numRemoteRanks;
  IS                     origCellPart,        origPart,        cellPart,        part;
  PetscSection           origCellPartSection, origPartSection, cellPartSection, partSection;
  PetscSFNode           *remoteRanks;
  PetscSF                partSF, pointSF, coneSF;
  ISLocalToGlobalMapping renumbering;
  PetscSection           originalConeSection, newConeSection;
  PetscInt              *remoteOffsets;
  PetscInt              *cones, *newCones, newConesSize;
  PetscBool              flg;
  PetscMPIInt            rank, numProcs, p;
  PetscErrorCode         ierr;

  PetscFunctionBegin;
  PetscValidHeaderSpecific(dm, DM_CLASSID, 1);
  if (sf) PetscValidPointer(sf,4);
  PetscValidPointer(dmParallel,5);

  ierr = PetscLogEventBegin(DMPLEX_Distribute,dm,0,0,0);CHKERRQ(ierr);
  ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);
  ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
  ierr = MPI_Comm_size(comm, &numProcs);CHKERRQ(ierr);

  *dmParallel = NULL;
  if (numProcs == 1) PetscFunctionReturn(0);

  ierr = DMPlexGetDimension(dm, &dim);CHKERRQ(ierr);
  /* Create cell partition - We need to rewrite to use IS, use the MatPartition stuff */
  ierr = PetscLogEventBegin(DMPLEX_Partition,dm,0,0,0);CHKERRQ(ierr);
  if (overlap > 1) SETERRQ(PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Overlap > 1 not yet implemented");
  ierr = DMPlexCreatePartition(dm, partitioner, height, overlap > 0 ? PETSC_TRUE : PETSC_FALSE, &cellPartSection, &cellPart, &origCellPartSection, &origCellPart);CHKERRQ(ierr);
  /* Create SF assuming a serial partition for all processes: Could check for IS length here */
  if (!rank) numRemoteRanks = numProcs;
  else       numRemoteRanks = 0;
  ierr = PetscMalloc1(numRemoteRanks, &remoteRanks);CHKERRQ(ierr);
  for (p = 0; p < numRemoteRanks; ++p) {
    remoteRanks[p].rank  = p;
    remoteRanks[p].index = 0;
  }
  ierr = PetscSFCreate(comm, &partSF);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(partSF, 1, numRemoteRanks, NULL, PETSC_OWN_POINTER, remoteRanks, PETSC_OWN_POINTER);CHKERRQ(ierr);
  ierr = PetscOptionsHasName(((PetscObject) dm)->prefix, "-partition_view", &flg);CHKERRQ(ierr);
  if (flg) {
    ierr = PetscPrintf(comm, "Cell Partition:\n");CHKERRQ(ierr);
    ierr = PetscSectionView(cellPartSection, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
    ierr = ISView(cellPart, NULL);CHKERRQ(ierr);
    if (origCellPart) {
      ierr = PetscPrintf(comm, "Original Cell Partition:\n");CHKERRQ(ierr);
      ierr = PetscSectionView(origCellPartSection, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
      ierr = ISView(origCellPart, NULL);CHKERRQ(ierr);
    }
    ierr = PetscSFView(partSF, NULL);CHKERRQ(ierr);
  }
  /* Close the partition over the mesh */
  ierr = DMPlexCreatePartitionClosure(dm, cellPartSection, cellPart, &partSection, &part);CHKERRQ(ierr);
  ierr = ISDestroy(&cellPart);CHKERRQ(ierr);
  ierr = PetscSectionDestroy(&cellPartSection);CHKERRQ(ierr);
  /* Create new mesh */
  ierr  = DMPlexCreate(comm, dmParallel);CHKERRQ(ierr);
  ierr  = DMPlexSetDimension(*dmParallel, dim);CHKERRQ(ierr);
  ierr  = PetscObjectSetName((PetscObject) *dmParallel, "Parallel Mesh");CHKERRQ(ierr);
  pmesh = (DM_Plex*) (*dmParallel)->data;
  /* Distribute sieve points and the global point numbering (replaces creating remote bases) */
  ierr = PetscSFConvertPartition(partSF, partSection, part, &renumbering, &pointSF);CHKERRQ(ierr);
  if (flg) {
    ierr = PetscPrintf(comm, "Point Partition:\n");CHKERRQ(ierr);
    ierr = PetscSectionView(partSection, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
    ierr = ISView(part, NULL);CHKERRQ(ierr);
    ierr = PetscSFView(pointSF, NULL);CHKERRQ(ierr);
    ierr = PetscPrintf(comm, "Point Renumbering after partition:\n");CHKERRQ(ierr);
    ierr = ISLocalToGlobalMappingView(renumbering, NULL);CHKERRQ(ierr);
  }
  ierr = PetscLogEventEnd(DMPLEX_Partition,dm,0,0,0);CHKERRQ(ierr);
  ierr = PetscLogEventBegin(DMPLEX_DistributeCones,dm,0,0,0);CHKERRQ(ierr);
  /* Distribute cone section */
  ierr = DMPlexGetConeSection(dm, &originalConeSection);CHKERRQ(ierr);
  ierr = DMPlexGetConeSection(*dmParallel, &newConeSection);CHKERRQ(ierr);
  ierr = PetscSFDistributeSection(pointSF, originalConeSection, &remoteOffsets, newConeSection);CHKERRQ(ierr);
  ierr = DMSetUp(*dmParallel);CHKERRQ(ierr);
  {
    PetscInt pStart, pEnd, p;

    ierr = PetscSectionGetChart(newConeSection, &pStart, &pEnd);CHKERRQ(ierr);
    for (p = pStart; p < pEnd; ++p) {
      PetscInt coneSize;
      ierr               = PetscSectionGetDof(newConeSection, p, &coneSize);CHKERRQ(ierr);
      pmesh->maxConeSize = PetscMax(pmesh->maxConeSize, coneSize);
    }
  }
  /* Communicate and renumber cones */
  ierr = PetscSFCreateSectionSF(pointSF, originalConeSection, remoteOffsets, newConeSection, &coneSF);CHKERRQ(ierr);
  ierr = DMPlexGetCones(dm, &cones);CHKERRQ(ierr);
  ierr = DMPlexGetCones(*dmParallel, &newCones);CHKERRQ(ierr);
  ierr = PetscSFBcastBegin(coneSF, MPIU_INT, cones, newCones);CHKERRQ(ierr);
  ierr = PetscSFBcastEnd(coneSF, MPIU_INT, cones, newCones);CHKERRQ(ierr);
  ierr = PetscSectionGetStorageSize(newConeSection, &newConesSize);CHKERRQ(ierr);
  ierr = ISGlobalToLocalMappingApply(renumbering, IS_GTOLM_MASK, newConesSize, newCones, NULL, newCones);CHKERRQ(ierr);
  ierr = PetscOptionsHasName(((PetscObject) dm)->prefix, "-cones_view", &flg);CHKERRQ(ierr);
  if (flg) {
    ierr = PetscPrintf(comm, "Serial Cone Section:\n");CHKERRQ(ierr);
    ierr = PetscSectionView(originalConeSection, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
    ierr = PetscPrintf(comm, "Parallel Cone Section:\n");CHKERRQ(ierr);
    ierr = PetscSectionView(newConeSection, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
    ierr = PetscSFView(coneSF, NULL);CHKERRQ(ierr);
  }
  ierr = DMPlexGetConeOrientations(dm, &cones);CHKERRQ(ierr);
  ierr = DMPlexGetConeOrientations(*dmParallel, &newCones);CHKERRQ(ierr);
  ierr = PetscSFBcastBegin(coneSF, MPIU_INT, cones, newCones);CHKERRQ(ierr);
  ierr = PetscSFBcastEnd(coneSF, MPIU_INT, cones, newCones);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&coneSF);CHKERRQ(ierr);
  ierr = PetscLogEventEnd(DMPLEX_DistributeCones,dm,0,0,0);CHKERRQ(ierr);
  /* Create supports and stratify sieve */
  {
    PetscInt pStart, pEnd;

    ierr = PetscSectionGetChart(pmesh->coneSection, &pStart, &pEnd);CHKERRQ(ierr);
    ierr = PetscSectionSetChart(pmesh->supportSection, pStart, pEnd);CHKERRQ(ierr);
  }
  ierr = DMPlexSymmetrize(*dmParallel);CHKERRQ(ierr);
  ierr = DMPlexStratify(*dmParallel);CHKERRQ(ierr);
  /* Distribute Coordinates */
  {
    PetscSection originalCoordSection, newCoordSection;
    Vec          originalCoordinates, newCoordinates;
    const char  *name;

    ierr = DMGetCoordinateSection(dm, &originalCoordSection);CHKERRQ(ierr);
    ierr = DMGetCoordinateSection(*dmParallel, &newCoordSection);CHKERRQ(ierr);
    ierr = DMGetCoordinatesLocal(dm, &originalCoordinates);CHKERRQ(ierr);
    ierr = VecCreate(comm, &newCoordinates);CHKERRQ(ierr);
    ierr = PetscObjectGetName((PetscObject) originalCoordinates, &name);CHKERRQ(ierr);
    ierr = PetscObjectSetName((PetscObject) newCoordinates, name);CHKERRQ(ierr);

    ierr = DMPlexDistributeField(dm, pointSF, originalCoordSection, originalCoordinates, newCoordSection, newCoordinates);CHKERRQ(ierr);
    ierr = DMSetCoordinatesLocal(*dmParallel, newCoordinates);CHKERRQ(ierr);
    ierr = VecDestroy(&newCoordinates);CHKERRQ(ierr);
  }
  /* Distribute labels */
  ierr = PetscLogEventBegin(DMPLEX_DistributeLabels,dm,0,0,0);CHKERRQ(ierr);
  {
    DMLabel  next      = mesh->labels, newNext = pmesh->labels;
    PetscInt numLabels = 0, l;

    /* Bcast number of labels */
    while (next) {++numLabels; next = next->next;}
    ierr = MPI_Bcast(&numLabels, 1, MPIU_INT, 0, comm);CHKERRQ(ierr);
    next = mesh->labels;
    for (l = 0; l < numLabels; ++l) {
      DMLabel   labelNew;
      PetscBool isdepth;

      /* Skip "depth" because it is recreated */
      if (!rank) {ierr = PetscStrcmp(next->name, "depth", &isdepth);CHKERRQ(ierr);}
      ierr = MPI_Bcast(&isdepth, 1, MPIU_BOOL, 0, comm);CHKERRQ(ierr);
      if (isdepth) {if (!rank) next = next->next; continue;}
      ierr = DMLabelDistribute(next, partSection, part, renumbering, &labelNew);CHKERRQ(ierr);
      /* Insert into list */
      if (newNext) newNext->next = labelNew;
      else         pmesh->labels = labelNew;
      newNext = labelNew;
      if (!rank) next = next->next;
    }
  }
  ierr = PetscLogEventEnd(DMPLEX_DistributeLabels,dm,0,0,0);CHKERRQ(ierr);
  /* Setup hybrid structure */
  {
    const PetscInt *gpoints;
    PetscInt        depth, n, d;

    for (d = 0; d <= dim; ++d) {pmesh->hybridPointMax[d] = mesh->hybridPointMax[d];}
    ierr = MPI_Bcast(pmesh->hybridPointMax, dim+1, MPIU_INT, 0, comm);CHKERRQ(ierr);
    ierr = ISLocalToGlobalMappingGetSize(renumbering, &n);CHKERRQ(ierr);
    ierr = ISLocalToGlobalMappingGetIndices(renumbering, &gpoints);CHKERRQ(ierr);
    ierr = DMPlexGetDepth(dm, &depth);CHKERRQ(ierr);
    for (d = 0; d <= dim; ++d) {
      PetscInt pmax = pmesh->hybridPointMax[d], newmax = 0, pEnd, stratum[2], p;

      if (pmax < 0) continue;
      ierr = DMPlexGetDepthStratum(dm, d > depth ? depth : d, &stratum[0], &stratum[1]);CHKERRQ(ierr);
      ierr = DMPlexGetDepthStratum(*dmParallel, d, NULL, &pEnd);CHKERRQ(ierr);
      ierr = MPI_Bcast(stratum, 2, MPIU_INT, 0, comm);CHKERRQ(ierr);
      for (p = 0; p < n; ++p) {
        const PetscInt point = gpoints[p];

        if ((point >= stratum[0]) && (point < stratum[1]) && (point >= pmax)) ++newmax;
      }
      if (newmax > 0) pmesh->hybridPointMax[d] = pEnd - newmax;
      else            pmesh->hybridPointMax[d] = -1;
    }
    ierr = ISLocalToGlobalMappingRestoreIndices(renumbering, &gpoints);CHKERRQ(ierr);
  }
  /* Cleanup Partition */
  ierr = ISLocalToGlobalMappingDestroy(&renumbering);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&partSF);CHKERRQ(ierr);
  ierr = PetscSectionDestroy(&partSection);CHKERRQ(ierr);
  ierr = ISDestroy(&part);CHKERRQ(ierr);
  /* Create point SF for parallel mesh */
  ierr = PetscLogEventBegin(DMPLEX_DistributeSF,dm,0,0,0);CHKERRQ(ierr);
  {
    const PetscInt *leaves;
    PetscSFNode    *remotePoints, *rowners, *lowners;
    PetscInt        numRoots, numLeaves, numGhostPoints = 0, p, gp, *ghostPoints;
    PetscInt        pStart, pEnd;

    ierr = DMPlexGetChart(*dmParallel, &pStart, &pEnd);CHKERRQ(ierr);
    ierr = PetscSFGetGraph(pointSF, &numRoots, &numLeaves, &leaves, NULL);CHKERRQ(ierr);
    ierr = PetscMalloc2(numRoots,&rowners,numLeaves,&lowners);CHKERRQ(ierr);
    for (p=0; p<numRoots; p++) {
      rowners[p].rank  = -1;
      rowners[p].index = -1;
    }
    if (origCellPart) {
      /* Make sure points in the original partition are not assigned to other procs */
      const PetscInt *origPoints;

      ierr = DMPlexCreatePartitionClosure(dm, origCellPartSection, origCellPart, &origPartSection, &origPart);CHKERRQ(ierr);
      ierr = ISGetIndices(origPart, &origPoints);CHKERRQ(ierr);
      for (p = 0; p < numProcs; ++p) {
        PetscInt dof, off, d;

        ierr = PetscSectionGetDof(origPartSection, p, &dof);CHKERRQ(ierr);
        ierr = PetscSectionGetOffset(origPartSection, p, &off);CHKERRQ(ierr);
        for (d = off; d < off+dof; ++d) {
          rowners[origPoints[d]].rank = p;
        }
      }
      ierr = ISRestoreIndices(origPart, &origPoints);CHKERRQ(ierr);
      ierr = ISDestroy(&origPart);CHKERRQ(ierr);
      ierr = PetscSectionDestroy(&origPartSection);CHKERRQ(ierr);
    }
    ierr = ISDestroy(&origCellPart);CHKERRQ(ierr);
    ierr = PetscSectionDestroy(&origCellPartSection);CHKERRQ(ierr);

    ierr = PetscSFBcastBegin(pointSF, MPIU_2INT, rowners, lowners);CHKERRQ(ierr);
    ierr = PetscSFBcastEnd(pointSF, MPIU_2INT, rowners, lowners);CHKERRQ(ierr);
    for (p = 0; p < numLeaves; ++p) {
      if (lowners[p].rank < 0 || lowners[p].rank == rank) { /* Either put in a bid or we know we own it */
        lowners[p].rank  = rank;
        lowners[p].index = leaves ? leaves[p] : p;
      } else if (lowners[p].rank >= 0) { /* Point already claimed so flag so that MAXLOC does not listen to us */
        lowners[p].rank  = -2;
        lowners[p].index = -2;
      }
    }
    for (p=0; p<numRoots; p++) { /* Root must not participate in the rediction, flag so that MAXLOC does not use */
      rowners[p].rank  = -3;
      rowners[p].index = -3;
    }
    ierr = PetscSFReduceBegin(pointSF, MPIU_2INT, lowners, rowners, MPI_MAXLOC);CHKERRQ(ierr);
    ierr = PetscSFReduceEnd(pointSF, MPIU_2INT, lowners, rowners, MPI_MAXLOC);CHKERRQ(ierr);
    ierr = PetscSFBcastBegin(pointSF, MPIU_2INT, rowners, lowners);CHKERRQ(ierr);
    ierr = PetscSFBcastEnd(pointSF, MPIU_2INT, rowners, lowners);CHKERRQ(ierr);
    for (p = 0; p < numLeaves; ++p) {
      if (lowners[p].rank < 0 || lowners[p].index < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Cell partition corrupt: point not claimed");
      if (lowners[p].rank != rank) ++numGhostPoints;
    }
    ierr = PetscMalloc1(numGhostPoints,    &ghostPoints);CHKERRQ(ierr);
    ierr = PetscMalloc1(numGhostPoints, &remotePoints);CHKERRQ(ierr);
    for (p = 0, gp = 0; p < numLeaves; ++p) {
      if (lowners[p].rank != rank) {
        ghostPoints[gp]        = leaves ? leaves[p] : p;
        remotePoints[gp].rank  = lowners[p].rank;
        remotePoints[gp].index = lowners[p].index;
        ++gp;
      }
    }
    ierr = PetscFree2(rowners,lowners);CHKERRQ(ierr);
    ierr = PetscSFSetGraph((*dmParallel)->sf, pEnd - pStart, numGhostPoints, ghostPoints, PETSC_OWN_POINTER, remotePoints, PETSC_OWN_POINTER);CHKERRQ(ierr);
    ierr = PetscSFSetFromOptions((*dmParallel)->sf);CHKERRQ(ierr);
  }
  ierr = PetscLogEventEnd(DMPLEX_DistributeSF,dm,0,0,0);CHKERRQ(ierr);
  /* Cleanup */
  if (sf) {*sf = pointSF;}
  else    {ierr = PetscSFDestroy(&pointSF);CHKERRQ(ierr);}
  ierr = DMSetFromOptions(*dmParallel);CHKERRQ(ierr);
  ierr = PetscLogEventEnd(DMPLEX_Distribute,dm,0,0,0);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}