コード例 #1
0
ファイル: zsf.c プロジェクト: tom-klotz/petsc
PETSC_EXTERN void PETSC_STDCALL petscsfview_(PetscSF *sf, PetscViewer *vin, PetscErrorCode *ierr)
{
  PetscViewer v;

  PetscPatchDefaultViewers_Fortran(vin, v);
  *ierr = PetscSFView(*sf, v);
}
コード例 #2
0
PetscErrorCode DMMeshConvertOverlapToSF(DM dm, PetscSF *sf)
{
    ALE::Obj<PETSC_MESH_TYPE> mesh;
    PetscInt                  *local;
    PetscSFNode               *remote;
    PetscInt                  numPoints;
    PetscErrorCode            ierr;

    PetscFunctionBegin;
    ierr = PetscSFCreate(((PetscObject) dm)->comm, sf);
    CHKERRQ(ierr);
    ierr = DMMeshGetMesh(dm, mesh);
    CHKERRQ(ierr);
    {
        /* The local points have degree 1
             We use the recv overlap
        */
        ALE::Obj<PETSC_MESH_TYPE::recv_overlap_type> overlap = mesh->getRecvOverlap();

        numPoints = overlap->getNumPoints();
        ierr      = PetscMalloc(numPoints * sizeof(PetscInt), &local);
        CHKERRQ(ierr);
        ierr      = PetscMalloc(numPoints * sizeof(PetscSFNode), &remote);
        CHKERRQ(ierr);
        for (PetscInt r = 0, i = 0; r < overlap->getNumRanks(); ++r) {
            const PetscInt                                                      rank   = overlap->getRank(r);
            const PETSC_MESH_TYPE::recv_overlap_type::supportSequence::iterator cBegin = overlap->supportBegin(rank);
            const PETSC_MESH_TYPE::recv_overlap_type::supportSequence::iterator cEnd   = overlap->supportEnd(rank);

            for (PETSC_MESH_TYPE::recv_overlap_type::supportSequence::iterator c_iter = cBegin; c_iter != cEnd; ++c_iter, ++i) {
                local[i]        = *c_iter;
                remote[i].rank  = rank;
                remote[i].index = c_iter.color();
            }
        }
        ierr = PetscSFSetGraph(*sf, numPoints, numPoints, local, PETSC_OWN_POINTER, remote, PETSC_OWN_POINTER);
        CHKERRQ(ierr);
        ierr = PetscSFView(*sf, NULL);
        CHKERRQ(ierr);
    }
    PetscFunctionReturn(0);
}
コード例 #3
0
ファイル: ex2.c プロジェクト: tom-klotz/petsc
int main(int argc, char **argv)
{
  PetscInt    ierr;
  PetscSF     sf;
  Vec         A,Aout;
  Vec         B,Bout;
  PetscScalar *bufA;
  PetscScalar *bufAout;
  PetscScalar *bufB;
  PetscScalar *bufBout;
  PetscMPIInt rank, size;
  PetscInt    nroots, nleaves;
  PetscInt    i;
  PetscInt    *ilocal;
  PetscSFNode *iremote;

  ierr = PetscInitialize(&argc,&argv,NULL,help);if (ierr) return ierr;
  ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
  ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);

  if (size != 2) SETERRQ(PETSC_COMM_WORLD, PETSC_ERR_USER, "Only coded for two MPI processes\n");

  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);

  nleaves = 2;
  nroots = 1;
  ierr = PetscMalloc1(nleaves,&ilocal);CHKERRQ(ierr);

  for (i = 0; i<nleaves; i++) {
    ilocal[i] = i;
  }

  ierr = PetscMalloc1(nleaves,&iremote);CHKERRQ(ierr);
  if (rank == 0) {
    iremote[0].rank = 0;
    iremote[0].index = 0;
    iremote[1].rank = 1;
    iremote[1].index = 0;
  } else {
    iremote[0].rank = 1;
    iremote[0].index = 0;
    iremote[1].rank = 0;
    iremote[1].index = 0;
  }
  ierr = PetscSFSetGraph(sf,nroots,nleaves,ilocal,PETSC_OWN_POINTER,iremote,PETSC_OWN_POINTER);CHKERRQ(ierr);
  ierr = PetscSFSetUp(sf);CHKERRQ(ierr);
  ierr = PetscSFView(sf,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
  ierr = VecCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr);
  ierr = VecSetSizes(A,2,PETSC_DETERMINE);CHKERRQ(ierr);
  ierr = VecSetFromOptions(A);CHKERRQ(ierr);
  ierr = VecSetUp(A);CHKERRQ(ierr);

  ierr = VecDuplicate(A,&B);CHKERRQ(ierr);
  ierr = VecDuplicate(A,&Aout);CHKERRQ(ierr);
  ierr = VecDuplicate(A,&Bout);CHKERRQ(ierr);
  ierr = VecGetArray(A,&bufA);CHKERRQ(ierr);
  ierr = VecGetArray(B,&bufB);CHKERRQ(ierr);
  for (i=0; i<2; i++) {
    bufA[i] = (PetscScalar)rank;
    bufB[i] = (PetscScalar)(rank) + 10.0;
  }
  ierr = VecRestoreArray(A,&bufA);CHKERRQ(ierr);
  ierr = VecRestoreArray(B,&bufB);CHKERRQ(ierr);

  ierr = VecGetArrayRead(A,(const PetscScalar**)&bufA);CHKERRQ(ierr);
  ierr = VecGetArrayRead(B,(const PetscScalar**)&bufB);CHKERRQ(ierr);
  ierr = VecGetArray(Aout,&bufAout);CHKERRQ(ierr);
  ierr = VecGetArray(Bout,&bufBout);CHKERRQ(ierr);
  ierr = PetscSFBcastBegin(sf,MPIU_SCALAR,(const void*)bufA,(void *)bufAout);CHKERRQ(ierr);
  ierr = PetscSFBcastBegin(sf,MPIU_SCALAR,(const void*)bufB,(void *)bufBout);CHKERRQ(ierr);
  ierr = PetscSFBcastEnd(sf,MPIU_SCALAR,(const void*)bufA,(void *)bufAout);CHKERRQ(ierr);
  ierr = PetscSFBcastEnd(sf,MPIU_SCALAR,(const void*)bufB,(void *)bufBout);CHKERRQ(ierr);
  ierr = VecRestoreArrayRead(A,(const PetscScalar**)&bufA);CHKERRQ(ierr);
  ierr = VecRestoreArrayRead(B,(const PetscScalar**)&bufB);CHKERRQ(ierr);
  ierr = VecRestoreArray(Aout,&bufAout);CHKERRQ(ierr);
  ierr = VecRestoreArray(Bout,&bufBout);CHKERRQ(ierr);

  ierr = VecView(Aout,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
  ierr = VecView(Bout,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
  ierr = VecDestroy(&A);CHKERRQ(ierr);
  ierr = VecDestroy(&B);CHKERRQ(ierr);
  ierr = VecDestroy(&Aout);CHKERRQ(ierr);
  ierr = VecDestroy(&Bout);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  ierr = PetscFinalize();
  return ierr;
}
コード例 #4
0
ファイル: plexpreallocate.c プロジェクト: jgoldfar/petsc
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);
}
コード例 #5
0
/*@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.

  The user can control the definition of adjacency for the mesh using DMPlexGetAdjacencyUseCone() and
  DMPlexSetAdjacencyUseClosure(). They should choose the combination appropriate for the function
  representation on the mesh.

  Level: intermediate

.keywords: mesh, elements
.seealso: DMPlexCreate(), DMPlexDistributeByFace(), DMPlexSetAdjacencyUseCone(), DMPlexSetAdjacencyUseClosure()
@*/
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 = ISGlobalToLocalMappingApplyBlock(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;
    PetscInt     bs;
    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 = VecGetBlockSize(originalCoordinates, &bs);CHKERRQ(ierr);
    ierr = VecSetBlockSize(newCoordinates, bs);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);
  }
  pmesh->useCone    = mesh->useCone;
  pmesh->useClosure = mesh->useClosure;
  ierr = PetscLogEventEnd(DMPLEX_DistributeSF,dm,0,0,0);CHKERRQ(ierr);
  /* Copy BC */
  ierr = DMPlexCopyBoundary(dm, *dmParallel);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);
}
コード例 #6
0
ファイル: ex3.c プロジェクト: masa-ito/PETScToPoisson
int main(int argc, char **argv)
{
  PetscInt    ierr;
  PetscSF     sf;
  Vec         A,Aout;
  PetscScalar *bufA;
  PetscScalar *bufAout;
  PetscMPIInt rank, size;
  PetscInt    nroots, nleaves;
  PetscInt    i;
  PetscInt    *ilocal;
  PetscSFNode *iremote;
  PetscBool   test_dupped_type;
  MPI_Datatype contig;

  ierr = PetscInitialize(&argc,&argv,NULL,help);if (ierr) return ierr;
  ierr = MPI_Comm_rank(PETSC_COMM_WORLD,&rank);CHKERRQ(ierr);
  ierr = MPI_Comm_size(PETSC_COMM_WORLD,&size);CHKERRQ(ierr);

  if (size != 1) SETERRQ(PETSC_COMM_WORLD, PETSC_ERR_USER, "Only coded for one MPI process");

  ierr             = PetscOptionsBegin(PETSC_COMM_WORLD,"","PetscSF type freeing options","none");CHKERRQ(ierr);
  test_dupped_type = PETSC_FALSE;
  ierr             = PetscOptionsBool("-test_dupped_type", "Test dupped input type","",test_dupped_type,&test_dupped_type,NULL);CHKERRQ(ierr);
  ierr             = PetscOptionsEnd();CHKERRQ(ierr);

  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);

  nleaves = 1;
  nroots = 1;
  ierr = PetscMalloc1(nleaves,&ilocal);CHKERRQ(ierr);

  for (i = 0; i<nleaves; i++) {
    ilocal[i] = i;
  }

  ierr = PetscMalloc1(nleaves,&iremote);CHKERRQ(ierr);
  iremote[0].rank = 0;
  iremote[0].index = 0;
  ierr = PetscSFSetGraph(sf,nroots,nleaves,ilocal,PETSC_OWN_POINTER,iremote,PETSC_OWN_POINTER);CHKERRQ(ierr);
  ierr = PetscSFSetUp(sf);CHKERRQ(ierr);
  ierr = PetscSFView(sf,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
  ierr = VecCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr);
  ierr = VecSetSizes(A,4,PETSC_DETERMINE);CHKERRQ(ierr);
  ierr = VecSetFromOptions(A);CHKERRQ(ierr);
  ierr = VecSetUp(A);CHKERRQ(ierr);

  ierr = VecDuplicate(A,&Aout);CHKERRQ(ierr);
  ierr = VecGetArray(A,&bufA);CHKERRQ(ierr);
  for (i=0; i<4; i++) {
    bufA[i] = (PetscScalar)i;
  }
  ierr = VecRestoreArray(A,&bufA);CHKERRQ(ierr);

  ierr = VecGetArrayRead(A,(const PetscScalar**)&bufA);CHKERRQ(ierr);
  ierr = VecGetArray(Aout,&bufAout);CHKERRQ(ierr);

  ierr = MPI_Type_contiguous(4, MPIU_SCALAR, &contig);CHKERRQ(ierr);
  ierr = MPI_Type_commit(&contig);CHKERRQ(ierr);

  if (test_dupped_type) {
    MPI_Datatype tmp;
    ierr = MPI_Type_dup(contig, &tmp);CHKERRQ(ierr);
    ierr = MPI_Type_free(&contig);CHKERRQ(ierr);
    contig = tmp;
  }
  for (i=0;i<10000;i++) {
    ierr = PetscSFBcastBegin(sf,contig,bufA,bufAout);CHKERRQ(ierr);
    ierr = PetscSFBcastEnd(sf,contig,bufA,bufAout);CHKERRQ(ierr);
  }
  ierr = VecRestoreArrayRead(A,(const PetscScalar**)&bufA);CHKERRQ(ierr);
  ierr = VecRestoreArray(Aout,&bufAout);CHKERRQ(ierr);

  ierr = VecView(Aout,PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
  ierr = VecDestroy(&A);CHKERRQ(ierr);
  ierr = VecDestroy(&Aout);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
  ierr = MPI_Type_free(&contig);CHKERRQ(ierr);
  ierr = PetscFinalize();
  return ierr;
}
コード例 #7
0
ファイル: patch.c プロジェクト: firedrakeproject/petsc
PetscErrorCode DMPatchSolve(DM dm)
{
  MPI_Comm       comm;
  MPI_Comm       commz;
  DM             dmc;
  PetscSF        sfz, sfzr;
  Vec            XC;
  MatStencil     patchSize, commSize, gridRank, lower, upper;
  PetscInt       M, N, P, i, j, k, l, m, n, p = 0;
  PetscMPIInt    rank, size;
  PetscInt       debug = 0;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  ierr = PetscObjectGetComm((PetscObject)dm,&comm);CHKERRQ(ierr);  
  ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
  ierr = MPI_Comm_size(comm, &size);CHKERRQ(ierr);
  ierr = DMPatchGetCoarse(dm, &dmc);CHKERRQ(ierr);
  ierr = DMPatchGetPatchSize(dm, &patchSize);CHKERRQ(ierr);
  ierr = DMPatchGetCommSize(dm, &commSize);CHKERRQ(ierr);
  ierr = DMPatchGetCommSize(dm, &commSize);CHKERRQ(ierr);
  ierr = DMGetGlobalVector(dmc, &XC);CHKERRQ(ierr);
  ierr = DMDAGetInfo(dmc, 0, &M, &N, &P, &l, &m, &n, 0,0,0,0,0,0);CHKERRQ(ierr);
  M    = PetscMax(M, 1); l = PetscMax(l, 1);
  N    = PetscMax(N, 1); m = PetscMax(m, 1);
  P    = PetscMax(P, 1); n = PetscMax(n, 1);

  gridRank.i = rank       % l;
  gridRank.j = rank/l     % m;
  gridRank.k = rank/(l*m) % n;

  if (commSize.i*commSize.j*commSize.k == size || commSize.i*commSize.j*commSize.k == 0) {
    commSize.i = l; commSize.j = m; commSize.k = n;
    commz      = comm;
  } else if (commSize.i*commSize.j*commSize.k == 1) {
    commz = PETSC_COMM_SELF;
  } else {
    const PetscMPIInt newComm = ((gridRank.k/commSize.k)*(m/commSize.j) + gridRank.j/commSize.j)*(l/commSize.i) + (gridRank.i/commSize.i);
    const PetscMPIInt newRank = ((gridRank.k%commSize.k)*commSize.j     + gridRank.j%commSize.j)*commSize.i     + (gridRank.i%commSize.i);

    ierr = MPI_Comm_split(comm, newComm, newRank, &commz);CHKERRQ(ierr);
    if (debug) {ierr = PetscPrintf(PETSC_COMM_SELF, "Rank %d color %d key %d commz %d\n", rank, newComm, newRank, *((PetscMPIInt*) &commz));CHKERRQ(ierr);}
  }
  /*
   Assumptions:
     - patchSize divides gridSize
     - commSize divides gridSize
     - commSize divides l,m,n
   Ignore multiple patches per rank for now

   Multiple ranks per patch:
     - l,m,n divides patchSize
     - commSize divides patchSize
   */
  for (k = 0; k < P; k += PetscMax(patchSize.k, 1)) {
    for (j = 0; j < N; j += PetscMax(patchSize.j, 1)) {
      for (i = 0; i < M; i += PetscMax(patchSize.i, 1), ++p) {
        MPI_Comm commp = MPI_COMM_NULL;
        DM       dmz   = NULL;
#if 0
        DM  dmf     = NULL;
        Mat interpz = NULL;
#endif
        Vec         XZ       = NULL;
        PetscScalar *xcarray = NULL;
        PetscScalar *xzarray = NULL;

        if ((gridRank.k/commSize.k == p/(l/commSize.i * m/commSize.j) % n/commSize.k) &&
            (gridRank.j/commSize.j == p/(l/commSize.i)                % m/commSize.j) &&
            (gridRank.i/commSize.i == p                               % l/commSize.i)) {
          if (debug) {ierr = PetscPrintf(PETSC_COMM_SELF, "Rank %d is accepting Patch %d\n", rank, p);CHKERRQ(ierr);}
          commp = commz;
        }
        /* Zoom to coarse patch */
        lower.i = i; lower.j = j; lower.k = k;
        upper.i = i + patchSize.i; upper.j = j + patchSize.j; upper.k = k + patchSize.k;
        ierr    = DMPatchZoom(dmc, XC, lower, upper, commp, &dmz, &sfz, &sfzr);CHKERRQ(ierr);
        lower.c = 0; /* initialize member, otherwise compiler issues warnings */
        upper.c = 0; /* initialize member, otherwise compiler issues warnings */
        /* Debug */
        ierr = PetscPrintf(comm, "Patch %d: (%d, %d, %d)--(%d, %d, %d)\n", p, lower.i, lower.j, lower.k, upper.i, upper.j, upper.k);CHKERRQ(ierr);
        if (dmz) {ierr = DMView(dmz, PETSC_VIEWER_STDOUT_(commz));CHKERRQ(ierr);}
        ierr = PetscSFView(sfz,  PETSC_VIEWER_STDOUT_(comm));CHKERRQ(ierr);
        ierr = PetscSFView(sfzr, PETSC_VIEWER_STDOUT_(comm));CHKERRQ(ierr);
        /* Scatter Xcoarse -> Xzoom */
        if (dmz) {ierr = DMGetGlobalVector(dmz, &XZ);CHKERRQ(ierr);}
        if (XZ)  {ierr = VecGetArray(XZ, &xzarray);CHKERRQ(ierr);}
        ierr = VecGetArray(XC, &xcarray);CHKERRQ(ierr);
        ierr = PetscSFBcastBegin(sfz, MPIU_SCALAR, xcarray, xzarray);CHKERRQ(ierr);
        ierr = PetscSFBcastEnd(sfz, MPIU_SCALAR, xcarray, xzarray);CHKERRQ(ierr);
        ierr = VecRestoreArray(XC, &xcarray);CHKERRQ(ierr);
        if (XZ)  {ierr = VecRestoreArray(XZ, &xzarray);CHKERRQ(ierr);}
#if 0
        /* Interpolate Xzoom -> Xfine, note that this may be on subcomms */
        ierr = DMRefine(dmz, MPI_COMM_NULL, &dmf);CHKERRQ(ierr);
        ierr = DMCreateInterpolation(dmz, dmf, &interpz, NULL);CHKERRQ(ierr);
        ierr = DMInterpolate(dmz, interpz, dmf);CHKERRQ(ierr);
        /* Smooth Xfine using two-step smoother, normal smoother plus Kaczmarz---moves back and forth from dmzoom to dmfine */
        /* Compute residual Rfine */
        /* Restrict Rfine to Rzoom_restricted */
#endif
        /* Scatter Rzoom_restricted -> Rcoarse_restricted */
        if (XZ)  {ierr = VecGetArray(XZ, &xzarray);CHKERRQ(ierr);}
        ierr = VecGetArray(XC, &xcarray);CHKERRQ(ierr);
        ierr = PetscSFReduceBegin(sfzr, MPIU_SCALAR, xzarray, xcarray, MPIU_SUM);CHKERRQ(ierr);
        ierr = PetscSFReduceEnd(sfzr, MPIU_SCALAR, xzarray, xcarray, MPIU_SUM);CHKERRQ(ierr);
        ierr = VecRestoreArray(XC, &xcarray);CHKERRQ(ierr);
        if (XZ)  {ierr = VecRestoreArray(XZ, &xzarray);CHKERRQ(ierr);}
        if (dmz) {ierr = DMRestoreGlobalVector(dmz, &XZ);CHKERRQ(ierr);}
        /* Compute global residual Rcoarse */
        /* TauCoarse = Rcoarse - Rcoarse_restricted */

        ierr = PetscSFDestroy(&sfz);CHKERRQ(ierr);
        ierr = PetscSFDestroy(&sfzr);CHKERRQ(ierr);
        ierr = DMDestroy(&dmz);CHKERRQ(ierr);
      }
    }
  }
  ierr = DMRestoreGlobalVector(dmc, &XC);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
コード例 #8
0
PetscErrorCode PetscSFCreateSectionSF(PetscSF sf, PetscSection section, PetscSF *sectionSF)
{
    PetscInt          numRanks;
    const PetscInt    *ranks, *rankOffsets;
    const PetscMPIInt *localPoints, *remotePoints;
    PetscInt          numPoints, numIndices = 0;
    PetscInt          *remoteOffsets;
    PetscInt          *localIndices;
    PetscSFNode       *remoteIndices;
    PetscInt          i, r, ind;
    PetscErrorCode    ierr;

    PetscFunctionBegin;
    ierr      = PetscSFGetRanks(sf, &numRanks, &ranks, &rankOffsets, &localPoints, &remotePoints);
    CHKERRQ(ierr);
    numPoints = rankOffsets[numRanks];
    for (i = 0; i < numPoints; ++i) {
        PetscInt dof;

        ierr        = PetscSectionGetDof(section, localPoints[i], &dof);
        CHKERRQ(ierr);
        numIndices += dof;
    }
    /* Communicate offsets for ghosted points */
#if 0
    PetscInt *localOffsets;
    ierr = PetscMalloc2(numPoints,PetscInt,&localOffsets,numPoints,PetscInt,&remoteOffsets);
    CHKERRQ(ierr);
    for (i = 0; i < numPoints; ++i) {
        ierr = PetscSectionGetOffset(section, localPoints[i], &localOffsets[i]);
        CHKERRQ(ierr);
    }
    ierr = PetscSFBcastBegin(sf, MPIU_INT, localOffsets, remoteOffsets);
    CHKERRQ(ierr);
    ierr = PetscSFBcastEnd(sf, MPIU_INT, localOffsets, remoteOffsets);
    CHKERRQ(ierr);
    for (i = 0; i < numPoints; ++i) {
        ierr = PetscSynchronizedPrintf(((PetscObject) sf)->comm, "remoteOffsets[%d]: %d\n", i, remoteOffsets[i]);
        CHKERRQ(ierr);
    }
#else
    ierr = PetscMalloc((section->atlasLayout.pEnd - section->atlasLayout.pStart) * sizeof(PetscInt), &remoteOffsets);
    CHKERRQ(ierr);
    ierr = PetscSFBcastBegin(sf, MPIU_INT, &section->atlasOff[-section->atlasLayout.pStart], &remoteOffsets[-section->atlasLayout.pStart]);
    CHKERRQ(ierr);
    ierr = PetscSFBcastEnd(sf, MPIU_INT, &section->atlasOff[-section->atlasLayout.pStart], &remoteOffsets[-section->atlasLayout.pStart]);
    CHKERRQ(ierr);
    for (i = section->atlasLayout.pStart; i < section->atlasLayout.pEnd; ++i) {
        ierr = PetscSynchronizedPrintf(((PetscObject) sf)->comm, "remoteOffsets[%d]: %d\n", i, remoteOffsets[i-section->atlasLayout.pStart]);
        CHKERRQ(ierr);
    }
#endif
    ierr = PetscSynchronizedFlush(((PetscObject) sf)->comm);
    CHKERRQ(ierr);
    ierr = PetscMalloc(numIndices * sizeof(PetscInt), &localIndices);
    CHKERRQ(ierr);
    ierr = PetscMalloc(numIndices * sizeof(PetscSFNode), &remoteIndices);
    CHKERRQ(ierr);
    /* Create new index graph */
    for (r = 0, ind = 0; r < numRanks; ++r) {
        PetscInt rank = ranks[r];

        for (i = rankOffsets[r]; i < rankOffsets[r+1]; ++i) {
            PetscInt localPoint   = localPoints[i];
            PetscInt remoteOffset = remoteOffsets[localPoint-section->atlasLayout.pStart];
            PetscInt localOffset, dof, d;

            ierr = PetscSectionGetOffset(section, localPoint, &localOffset);
            CHKERRQ(ierr);
            ierr = PetscSectionGetDof(section, localPoint, &dof);
            CHKERRQ(ierr);
            for (d = 0; d < dof; ++d, ++ind) {
                localIndices[ind]        = localOffset+d;
                remoteIndices[ind].rank  = rank;
                remoteIndices[ind].index = remoteOffset+d;
            }
        }
    }
    ierr = PetscFree(remoteOffsets);
    CHKERRQ(ierr);
    if (numIndices != ind) SETERRQ2(((PetscObject) sf)->comm, PETSC_ERR_PLIB, "Inconsistency in indices, %d should be %d", ind, numIndices);
    ierr = PetscSFCreate(((PetscObject) sf)->comm, sectionSF);
    CHKERRQ(ierr);
    ierr = PetscSFSetGraph(*sectionSF, numIndices, numIndices, localIndices, PETSC_OWN_POINTER, remoteIndices, PETSC_OWN_POINTER);
    CHKERRQ(ierr);
    ierr = PetscSFView(*sectionSF, NULL);
    CHKERRQ(ierr);
    PetscFunctionReturn(0);
}
コード例 #9
0
ファイル: ex3.c プロジェクト: erdc-cm/petsc-dev
/* Distribute cones
   - Partitioning:         input partition point map and naive sf, output sf with inverse of map, distribute points
   - Distribute section:   input current sf, communicate sizes and offsets, output local section and offsets (only use for new sf)
   - Create SF for values: input current sf and offsets, output new sf
   - Distribute values:    input new sf, communicate values
 */
PetscErrorCode DistributeMesh(DM dm, AppCtx *user, PetscSF *pointSF, DM *parallelDM)
{
  MPI_Comm       comm   = ((PetscObject) dm)->comm;
  const PetscInt height = 0;
  PetscInt       dim, numRemoteRanks;
  IS             cellPart,        part;
  PetscSection   cellPartSection, partSection;
  PetscSFNode   *remoteRanks;
  PetscSF        partSF;
  ISLocalToGlobalMapping renumbering;
  PetscSF        coneSF;
  PetscSection   originalConeSection, newConeSection;
  PetscInt      *remoteOffsets, newConesSize;
  PetscInt      *cones, *newCones;
  PetscMPIInt    numProcs, rank, p;
  PetscErrorCode ierr;

  PetscFunctionBegin;
  ierr = MPI_Comm_size(comm, &numProcs);CHKERRQ(ierr);
  ierr = MPI_Comm_rank(comm, &rank);CHKERRQ(ierr);
  ierr = DMMeshGetDimension(dm, &dim);CHKERRQ(ierr);
  /* Create cell partition - We need to rewrite to use IS, use the MatPartition stuff */
  ierr = DMMeshCreatePartition(dm, &cellPartSection, &cellPart, height);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 = PetscMalloc(numRemoteRanks * sizeof(PetscSFNode), &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, PETSC_NULL, PETSC_OWN_POINTER, remoteRanks, PETSC_OWN_POINTER);CHKERRQ(ierr);
  /* Debugging */
  ierr = PetscPrintf(comm, "Cell Partition:\n");CHKERRQ(ierr);
  ierr = PetscSectionView(cellPartSection, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
  ierr = ISView(cellPart, PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscSFView(partSF, PETSC_NULL);CHKERRQ(ierr);
  /* Close the partition over the mesh */
  ierr = DMMeshCreatePartitionClosure(dm, cellPartSection, cellPart, &partSection, &part);CHKERRQ(ierr);
  ierr = ISDestroy(&cellPart);CHKERRQ(ierr);
  ierr = PetscSectionDestroy(&cellPartSection);CHKERRQ(ierr);
  /* Create new mesh */
  ierr = DMMeshCreate(comm, parallelDM);CHKERRQ(ierr);
  ierr = DMMeshSetDimension(*parallelDM, dim);CHKERRQ(ierr);
  ierr = PetscObjectSetName((PetscObject) *parallelDM, "Parallel Mesh");CHKERRQ(ierr);
  /* Distribute sieve points and the global point numbering (replaces creating remote bases) */
  ierr = PetscSFConvertPartition(partSF, partSection, part, &renumbering, pointSF);CHKERRQ(ierr);
  /* Debugging */
  ierr = PetscPrintf(comm, "Point Partition:\n");CHKERRQ(ierr);
  ierr = PetscSectionView(partSection, PETSC_VIEWER_STDOUT_WORLD);CHKERRQ(ierr);
  ierr = ISView(part, PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscSFView(*pointSF, PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscPrintf(comm, "Point Renumbering after partition:\n");CHKERRQ(ierr);
  ierr = ISLocalToGlobalMappingView(renumbering, PETSC_NULL);CHKERRQ(ierr);
  /* Cleanup */
  ierr = PetscSFDestroy(&partSF);CHKERRQ(ierr);
  ierr = PetscSectionDestroy(&partSection);CHKERRQ(ierr);
  ierr = ISDestroy(&part);CHKERRQ(ierr);
  /* Distribute cone section */
  ierr = DMMeshGetConeSection(dm, &originalConeSection);CHKERRQ(ierr);
  ierr = DMMeshGetConeSection(*parallelDM, &newConeSection);CHKERRQ(ierr);
  ierr = PetscSFDistributeSection(*pointSF, originalConeSection, &remoteOffsets, newConeSection);CHKERRQ(ierr);
  ierr = DMMeshSetUp(*parallelDM);CHKERRQ(ierr);
  /* Communicate and renumber cones */
  ierr = PetscSFCreateSectionSF(*pointSF, originalConeSection, remoteOffsets, newConeSection, &coneSF);CHKERRQ(ierr);
  ierr = DMMeshGetCones(dm, &cones);CHKERRQ(ierr);
  ierr = DMMeshGetCones(*parallelDM, &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, PETSC_NULL, newCones);CHKERRQ(ierr);
  ierr = ISLocalToGlobalMappingDestroy(&renumbering);CHKERRQ(ierr);
  /* Debugging */
  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, PETSC_NULL);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&coneSF);CHKERRQ(ierr);
  /* Create supports and stratify sieve */
  ierr = DMMeshSymmetrize(*parallelDM);CHKERRQ(ierr);
  ierr = DMMeshStratify(*parallelDM);CHKERRQ(ierr);
  PetscFunctionReturn(0);
}
コード例 #10
0
ファイル: ex1.c プロジェクト: firedrakeproject/petsc
int main(int argc,char **argv)
{
  PetscSF        sf,sfDup,sfInv,sfEmbed,sfA,sfB,sfBA;
  const PetscInt *degree;
  PetscErrorCode ierr;

  ierr = PetscInitialize(&argc,&argv,NULL,help);if (ierr) return ierr;

  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = CheckGraphNotSet(sf);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = CheckGraphNotSet(sf);CHKERRQ(ierr);
  ierr = PetscSFReset(sf);CHKERRQ(ierr);
  ierr = CheckGraphNotSet(sf);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = CheckGraphNotSet(sf);CHKERRQ(ierr);
  ierr = PetscSFSetType(sf,PETSCSFBASIC);CHKERRQ(ierr);
  ierr = CheckGraphNotSet(sf);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = CheckGraphNotSet(sf);CHKERRQ(ierr);
  ierr = PetscSFSetType(sf,PETSCSFBASIC);CHKERRQ(ierr);
  ierr = CheckGraphNotSet(sf);CHKERRQ(ierr);
  ierr = PetscSFReset(sf);CHKERRQ(ierr);
  ierr = CheckGraphNotSet(sf);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sf,0,0,NULL,PETSC_COPY_VALUES,NULL,PETSC_COPY_VALUES);CHKERRQ(ierr);
  ierr = CheckGraphEmpty(sf);CHKERRQ(ierr);
  ierr = PetscSFReset(sf);CHKERRQ(ierr);
  ierr = CheckGraphNotSet(sf);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetType(sf,PETSCSFBASIC);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sf,0,0,NULL,PETSC_COPY_VALUES,NULL,PETSC_COPY_VALUES);CHKERRQ(ierr);
  ierr = CheckGraphEmpty(sf);CHKERRQ(ierr);
  ierr = PetscSFReset(sf);CHKERRQ(ierr);
  ierr = CheckGraphNotSet(sf);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test setup */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = CheckRanksNotSet(sf);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sf,0,0,NULL,PETSC_COPY_VALUES,NULL,PETSC_COPY_VALUES);CHKERRQ(ierr);
  ierr = CheckRanksNotSet(sf);CHKERRQ(ierr);
  ierr = PetscSFSetUp(sf);CHKERRQ(ierr);
  ierr = CheckRanksEmpty(sf);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test setup then reset */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sf,0,0,NULL,PETSC_COPY_VALUES,NULL,PETSC_COPY_VALUES);CHKERRQ(ierr);
  ierr = PetscSFSetUp(sf);CHKERRQ(ierr);
  ierr = PetscSFReset(sf);CHKERRQ(ierr);
  ierr = CheckRanksNotSet(sf);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test view (no graph set, no type set) */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFView(sf,NULL);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test set graph then view (no type set) */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sf,0,0,NULL,PETSC_COPY_VALUES,NULL,PETSC_COPY_VALUES);CHKERRQ(ierr);
  ierr = PetscSFView(sf,NULL);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test set type then view (no graph set) */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetType(sf,PETSCSFBASIC);CHKERRQ(ierr);
  ierr = PetscSFView(sf,NULL);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test set type then graph then view */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetType(sf,PETSCSFBASIC);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sf,0,0,NULL,PETSC_COPY_VALUES,NULL,PETSC_COPY_VALUES);CHKERRQ(ierr);
  ierr = PetscSFView(sf,NULL);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test set graph then type */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sf,0,0,NULL,PETSC_COPY_VALUES,NULL,PETSC_COPY_VALUES);CHKERRQ(ierr);
  ierr = PetscSFSetType(sf,PETSCSFBASIC);CHKERRQ(ierr);
  ierr = CheckGraphEmpty(sf);CHKERRQ(ierr);
  ierr = PetscSFReset(sf);CHKERRQ(ierr);
  ierr = CheckGraphNotSet(sf);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test Bcast */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sf,0,0,NULL,PETSC_COPY_VALUES,NULL,PETSC_COPY_VALUES);CHKERRQ(ierr);
  ierr = PetscSFBcastBegin(sf,MPI_INT,NULL,NULL);CHKERRQ(ierr);
  ierr = PetscSFBcastEnd  (sf,MPI_INT,NULL,NULL);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test Reduce */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sf,0,0,NULL,PETSC_COPY_VALUES,NULL,PETSC_COPY_VALUES);CHKERRQ(ierr);
  ierr = PetscSFReduceBegin(sf,MPI_INT,NULL,NULL,MPIU_REPLACE);CHKERRQ(ierr);
  ierr = PetscSFReduceEnd  (sf,MPI_INT,NULL,NULL,MPIU_REPLACE);CHKERRQ(ierr);
  ierr = PetscSFReduceBegin(sf,MPI_INT,NULL,NULL,MPI_SUM);CHKERRQ(ierr);
  ierr = PetscSFReduceEnd  (sf,MPI_INT,NULL,NULL,MPI_SUM);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test FetchAndOp */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sf,0,0,NULL,PETSC_COPY_VALUES,NULL,PETSC_COPY_VALUES);CHKERRQ(ierr);
  ierr = PetscSFFetchAndOpBegin(sf,MPI_INT,NULL,NULL,NULL,MPI_SUM);CHKERRQ(ierr);
  ierr = PetscSFFetchAndOpEnd  (sf,MPI_INT,NULL,NULL,NULL,MPI_SUM);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test ComputeDegree */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sf,0,0,NULL,PETSC_COPY_VALUES,NULL,PETSC_COPY_VALUES);CHKERRQ(ierr);
  ierr = PetscSFComputeDegreeBegin(sf,&degree);CHKERRQ(ierr);
  ierr = PetscSFComputeDegreeEnd(sf,&degree);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test PetscSFDuplicate() */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sf,0,0,NULL,PETSC_USE_POINTER,NULL,PETSC_USE_POINTER);CHKERRQ(ierr);
  ierr = PetscSFDuplicate(sf,PETSCSF_DUPLICATE_GRAPH,&sfDup);CHKERRQ(ierr);
  ierr = CheckGraphEmpty(sfDup);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sfDup);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test PetscSFCreateInverseSF() */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sf,0,0,NULL,PETSC_USE_POINTER,NULL,PETSC_USE_POINTER);CHKERRQ(ierr);
  ierr = PetscSFCreateInverseSF(sf,&sfInv);CHKERRQ(ierr);
  ierr = CheckGraphEmpty(sfInv);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sfInv);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test PetscSFCreateEmbeddedSF() */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sf,0,0,NULL,PETSC_USE_POINTER,NULL,PETSC_USE_POINTER);CHKERRQ(ierr);
  ierr = PetscSFCreateEmbeddedSF(sf,0,NULL,&sfEmbed);CHKERRQ(ierr);
  ierr = CheckGraphEmpty(sfEmbed);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sfEmbed);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test PetscSFCreateEmbeddedLeafSF() */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sf);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sf,0,0,NULL,PETSC_USE_POINTER,NULL,PETSC_USE_POINTER);CHKERRQ(ierr);
  ierr = PetscSFCreateEmbeddedLeafSF(sf,0,NULL,&sfEmbed);CHKERRQ(ierr);
  ierr = CheckGraphEmpty(sfEmbed);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sfEmbed);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);

  /* Test PetscSFCompose() */
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sfA);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sfA,0,0,NULL,PETSC_USE_POINTER,NULL,PETSC_USE_POINTER);CHKERRQ(ierr);
  ierr = PetscSFCreate(PETSC_COMM_WORLD,&sfB);CHKERRQ(ierr);
  ierr = PetscSFSetGraph(sfB,0,0,NULL,PETSC_USE_POINTER,NULL,PETSC_USE_POINTER);CHKERRQ(ierr);
  ierr = PetscSFCompose(sfA,sfB,&sfBA);CHKERRQ(ierr);
  ierr = CheckGraphEmpty(sfBA);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sfBA);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sfA);CHKERRQ(ierr);
  ierr = PetscSFDestroy(&sfB);CHKERRQ(ierr);

  ierr = PetscFinalize();
  return ierr;
}