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