Actual source code: plexorient.c

  1: #include <petsc/private/dmpleximpl.h>
  2: #include <petscsf.h>

  4: /*@
  5:   DMPlexOrientPoint - Act with the given orientation on the cone points of this mesh point, and update its use in the mesh.

  7:   Not Collective

  9:   Input Parameters:
 10: + dm - The `DM`
 11: . p  - The mesh point
 12: - o  - The orientation

 14:   Level: intermediate

 16: .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMPlexOrient()`, `DMPlexGetCone()`, `DMPlexGetConeOrientation()`, `DMPlexInterpolate()`, `DMPlexGetChart()`
 17: @*/
 18: PetscErrorCode DMPlexOrientPoint(DM dm, PetscInt p, PetscInt o)
 19: {
 20:   DMPolytopeType  ct;
 21:   const PetscInt *arr, *cone, *ornt, *support;
 22:   PetscInt       *newcone, *newornt;
 23:   PetscInt        coneSize, c, supportSize, s;

 25:   PetscFunctionBegin;
 27:   PetscCall(DMPlexGetCellType(dm, p, &ct));
 28:   arr = DMPolytopeTypeGetArrangement(ct, o);
 29:   PetscCall(DMPlexGetConeSize(dm, p, &coneSize));
 30:   PetscCall(DMPlexGetCone(dm, p, &cone));
 31:   PetscCall(DMPlexGetConeOrientation(dm, p, &ornt));
 32:   PetscCall(DMGetWorkArray(dm, coneSize, MPIU_INT, &newcone));
 33:   PetscCall(DMGetWorkArray(dm, coneSize, MPIU_INT, &newornt));
 34:   for (c = 0; c < coneSize; ++c) {
 35:     DMPolytopeType ft;
 36:     PetscInt       nO;

 38:     PetscCall(DMPlexGetCellType(dm, cone[c], &ft));
 39:     nO         = DMPolytopeTypeGetNumArrangements(ft) / 2;
 40:     newcone[c] = cone[arr[c * 2 + 0]];
 41:     newornt[c] = DMPolytopeTypeComposeOrientation(ft, arr[c * 2 + 1], ornt[arr[c * 2 + 0]]);
 42:     PetscCheck(!newornt[c] || !(newornt[c] >= nO || newornt[c] < -nO), PETSC_COMM_SELF, PETSC_ERR_PLIB, "Invalid orientation %" PetscInt_FMT " not in [%" PetscInt_FMT ",%" PetscInt_FMT ") for %s %" PetscInt_FMT, newornt[c], -nO, nO, DMPolytopeTypes[ft], cone[c]);
 43:   }
 44:   PetscCall(DMPlexSetCone(dm, p, newcone));
 45:   PetscCall(DMPlexSetConeOrientation(dm, p, newornt));
 46:   PetscCall(DMRestoreWorkArray(dm, coneSize, MPIU_INT, &newcone));
 47:   PetscCall(DMRestoreWorkArray(dm, coneSize, MPIU_INT, &newornt));
 48:   /* Update orientation of this point in the support points */
 49:   PetscCall(DMPlexGetSupportSize(dm, p, &supportSize));
 50:   PetscCall(DMPlexGetSupport(dm, p, &support));
 51:   for (s = 0; s < supportSize; ++s) {
 52:     PetscCall(DMPlexGetConeSize(dm, support[s], &coneSize));
 53:     PetscCall(DMPlexGetCone(dm, support[s], &cone));
 54:     PetscCall(DMPlexGetConeOrientation(dm, support[s], &ornt));
 55:     for (c = 0; c < coneSize; ++c) {
 56:       PetscInt po;

 58:       if (cone[c] != p) continue;
 59:       /* ornt[c] * 0 = target = po * o so that po = ornt[c] * o^{-1} */
 60:       po = DMPolytopeTypeComposeOrientationInv(ct, ornt[c], o);
 61:       PetscCall(DMPlexInsertConeOrientation(dm, support[s], c, po));
 62:     }
 63:   }
 64:   PetscFunctionReturn(PETSC_SUCCESS);
 65: }

 67: /*
 68:   - Checks face match
 69:     - Flips non-matching
 70:   - Inserts faces of support cells in FIFO
 71: */
 72: static PetscErrorCode DMPlexCheckFace_Internal(DM dm, PetscInt *faceFIFO, PetscInt *fTop, PetscInt *fBottom, PetscInt cStart, PetscInt fStart, PetscInt fEnd, PetscBT seenCells, PetscBT flippedCells, PetscBT seenFaces)
 73: {
 74:   const PetscInt *support, *coneA, *coneB, *coneOA, *coneOB;
 75:   PetscInt        supportSize, coneSizeA, coneSizeB, posA = -1, posB = -1;
 76:   PetscInt        face, dim, seenA, flippedA, seenB, flippedB, mismatch, c;

 78:   PetscFunctionBegin;
 79:   face = faceFIFO[(*fTop)++];
 80:   PetscCall(DMGetDimension(dm, &dim));
 81:   PetscCall(DMPlexGetSupportSize(dm, face, &supportSize));
 82:   PetscCall(DMPlexGetSupport(dm, face, &support));
 83:   if (supportSize < 2) PetscFunctionReturn(PETSC_SUCCESS);
 84:   PetscCheck(supportSize == 2, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Faces should separate only two cells, not %" PetscInt_FMT, supportSize);
 85:   seenA    = PetscBTLookup(seenCells, support[0] - cStart);
 86:   flippedA = PetscBTLookup(flippedCells, support[0] - cStart) ? 1 : 0;
 87:   seenB    = PetscBTLookup(seenCells, support[1] - cStart);
 88:   flippedB = PetscBTLookup(flippedCells, support[1] - cStart) ? 1 : 0;

 90:   PetscCall(DMPlexGetConeSize(dm, support[0], &coneSizeA));
 91:   PetscCall(DMPlexGetConeSize(dm, support[1], &coneSizeB));
 92:   PetscCall(DMPlexGetCone(dm, support[0], &coneA));
 93:   PetscCall(DMPlexGetCone(dm, support[1], &coneB));
 94:   PetscCall(DMPlexGetConeOrientation(dm, support[0], &coneOA));
 95:   PetscCall(DMPlexGetConeOrientation(dm, support[1], &coneOB));
 96:   for (c = 0; c < coneSizeA; ++c) {
 97:     if (!PetscBTLookup(seenFaces, coneA[c] - fStart)) {
 98:       faceFIFO[(*fBottom)++] = coneA[c];
 99:       PetscCall(PetscBTSet(seenFaces, coneA[c] - fStart));
100:     }
101:     if (coneA[c] == face) posA = c;
102:     PetscCheck(*fBottom <= fEnd - fStart, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Face %" PetscInt_FMT " was pushed exceeding capacity %" PetscInt_FMT " > %" PetscInt_FMT, coneA[c], *fBottom, fEnd - fStart);
103:   }
104:   PetscCheck(posA >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Face %" PetscInt_FMT " could not be located in cell %" PetscInt_FMT, face, support[0]);
105:   for (c = 0; c < coneSizeB; ++c) {
106:     if (!PetscBTLookup(seenFaces, coneB[c] - fStart)) {
107:       faceFIFO[(*fBottom)++] = coneB[c];
108:       PetscCall(PetscBTSet(seenFaces, coneB[c] - fStart));
109:     }
110:     if (coneB[c] == face) posB = c;
111:     PetscCheck(*fBottom <= fEnd - fStart, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Face %" PetscInt_FMT " was pushed exceeding capacity %" PetscInt_FMT " > %" PetscInt_FMT, coneA[c], *fBottom, fEnd - fStart);
112:   }
113:   PetscCheck(posB >= 0, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Face %" PetscInt_FMT " could not be located in cell %" PetscInt_FMT, face, support[1]);

115:   if (dim == 1) {
116:     mismatch = posA == posB;
117:   } else {
118:     mismatch = coneOA[posA] == coneOB[posB];
119:   }

121:   if (mismatch ^ (flippedA ^ flippedB)) {
122:     PetscCheck(!seenA || !seenB, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Previously seen cells %" PetscInt_FMT " and %" PetscInt_FMT " do not match: Fault mesh is non-orientable", support[0], support[1]);
123:     if (!seenA && !flippedA) {
124:       PetscCall(PetscBTSet(flippedCells, support[0] - cStart));
125:     } else if (!seenB && !flippedB) {
126:       PetscCall(PetscBTSet(flippedCells, support[1] - cStart));
127:     } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Inconsistent mesh orientation: Fault mesh is non-orientable");
128:   } else PetscCheck(!mismatch || !flippedA || !flippedB, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Attempt to flip already flipped cell: Fault mesh is non-orientable");
129:   PetscCall(PetscBTSet(seenCells, support[0] - cStart));
130:   PetscCall(PetscBTSet(seenCells, support[1] - cStart));
131:   PetscFunctionReturn(PETSC_SUCCESS);
132: }

134: /*@
135:   DMPlexOrient - Give a consistent orientation to the input mesh

137:   Input Parameter:
138: . dm - The `DM`

140:   Note:
141:   The orientation data for the `DM` are change in-place.

143:   This routine will fail for non-orientable surfaces, such as the Moebius strip.

145:   Level: advanced

147: .seealso: [](ch_unstructured), `DM`, `DMPLEX`, `DMCreate()`
148: @*/
149: PetscErrorCode DMPlexOrient(DM dm)
150: {
151:   MPI_Comm           comm;
152:   PetscSF            sf;
153:   const PetscInt    *lpoints;
154:   const PetscSFNode *rpoints;
155:   PetscSFNode       *rorntComp = NULL, *lorntComp = NULL;
156:   PetscInt          *numNeighbors, **neighbors, *locSupport = NULL;
157:   PetscSFNode       *nrankComp;
158:   PetscBool         *match, *flipped;
159:   PetscBT            seenCells, flippedCells, seenFaces;
160:   PetscInt          *faceFIFO, fTop, fBottom, *cellComp, *faceComp;
161:   PetscInt           numLeaves, numRoots, dim, h, cStart, cEnd, c, cell, fStart, fEnd, face, off, totNeighbors = 0;
162:   PetscMPIInt        rank, size, numComponents, comp = 0;
163:   PetscBool          flg, flg2;
164:   PetscViewer        viewer = NULL, selfviewer = NULL;

166:   PetscFunctionBegin;
167:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
168:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
169:   PetscCallMPI(MPI_Comm_size(comm, &size));
170:   PetscCall(PetscOptionsHasName(((PetscObject)dm)->options, ((PetscObject)dm)->prefix, "-orientation_view", &flg));
171:   PetscCall(PetscOptionsHasName(((PetscObject)dm)->options, ((PetscObject)dm)->prefix, "-orientation_view_synchronized", &flg2));
172:   PetscCall(DMGetPointSF(dm, &sf));
173:   PetscCall(PetscSFGetGraph(sf, &numRoots, &numLeaves, &lpoints, &rpoints));
174:   /* Truth Table
175:      mismatch    flips   do action   mismatch   flipA ^ flipB   action
176:          F       0 flips     no         F             F           F
177:          F       1 flip      yes        F             T           T
178:          F       2 flips     no         T             F           T
179:          T       0 flips     yes        T             T           F
180:          T       1 flip      no
181:          T       2 flips     yes
182:   */
183:   PetscCall(DMGetDimension(dm, &dim));
184:   PetscCall(DMPlexGetVTKCellHeight(dm, &h));
185:   PetscCall(DMPlexGetHeightStratum(dm, h, &cStart, &cEnd));
186:   PetscCall(DMPlexGetHeightStratum(dm, h + 1, &fStart, &fEnd));
187:   PetscCall(PetscBTCreate(cEnd - cStart, &seenCells));
188:   PetscCall(PetscBTMemzero(cEnd - cStart, seenCells));
189:   PetscCall(PetscBTCreate(cEnd - cStart, &flippedCells));
190:   PetscCall(PetscBTMemzero(cEnd - cStart, flippedCells));
191:   PetscCall(PetscBTCreate(fEnd - fStart, &seenFaces));
192:   PetscCall(PetscBTMemzero(fEnd - fStart, seenFaces));
193:   PetscCall(PetscCalloc3(fEnd - fStart, &faceFIFO, cEnd - cStart, &cellComp, fEnd - fStart, &faceComp));
194:   /*
195:    OLD STYLE
196:    - Add an integer array over cells and faces (component) for connected component number
197:    Foreach component
198:      - Mark the initial cell as seen
199:      - Process component as usual
200:      - Set component for all seenCells
201:      - Wipe seenCells and seenFaces (flippedCells can stay)
202:    - Generate parallel adjacency for component using SF and seenFaces
203:    - Collect numComponents adj data from each proc to 0
204:    - Build same serial graph
205:    - Use same solver
206:    - Use Scatterv to send back flipped flags for each component
207:    - Negate flippedCells by component

209:    NEW STYLE
210:    - Create the adj on each process
211:    - Bootstrap to complete graph on proc 0
212:   */
213:   /* Loop over components */
214:   for (cell = cStart; cell < cEnd; ++cell) cellComp[cell - cStart] = -1;
215:   do {
216:     /* Look for first unmarked cell */
217:     for (cell = cStart; cell < cEnd; ++cell)
218:       if (cellComp[cell - cStart] < 0) break;
219:     if (cell >= cEnd) break;
220:     /* Initialize FIFO with first cell in component */
221:     {
222:       const PetscInt *cone;
223:       PetscInt        coneSize;

225:       fTop = fBottom = 0;
226:       PetscCall(DMPlexGetConeSize(dm, cell, &coneSize));
227:       PetscCall(DMPlexGetCone(dm, cell, &cone));
228:       for (c = 0; c < coneSize; ++c) {
229:         faceFIFO[fBottom++] = cone[c];
230:         PetscCall(PetscBTSet(seenFaces, cone[c] - fStart));
231:       }
232:       PetscCall(PetscBTSet(seenCells, cell - cStart));
233:     }
234:     /* Consider each face in FIFO */
235:     while (fTop < fBottom) PetscCall(DMPlexCheckFace_Internal(dm, faceFIFO, &fTop, &fBottom, cStart, fStart, fEnd, seenCells, flippedCells, seenFaces));
236:     /* Set component for cells and faces */
237:     for (cell = 0; cell < cEnd - cStart; ++cell) {
238:       if (PetscBTLookup(seenCells, cell)) cellComp[cell] = comp;
239:     }
240:     for (face = 0; face < fEnd - fStart; ++face) {
241:       if (PetscBTLookup(seenFaces, face)) faceComp[face] = comp;
242:     }
243:     /* Wipe seenCells and seenFaces for next component */
244:     PetscCall(PetscBTMemzero(fEnd - fStart, seenFaces));
245:     PetscCall(PetscBTMemzero(cEnd - cStart, seenCells));
246:     ++comp;
247:   } while (1);
248:   numComponents = comp;
249:   if (flg) {
250:     PetscViewer v;

252:     PetscCall(PetscViewerASCIIGetStdout(comm, &v));
253:     PetscCall(PetscViewerASCIIPushSynchronized(v));
254:     PetscCall(PetscViewerASCIISynchronizedPrintf(v, "[%d]BT for serial flipped cells:\n", rank));
255:     PetscCall(PetscBTView(cEnd - cStart, flippedCells, v));
256:     PetscCall(PetscViewerFlush(v));
257:     PetscCall(PetscViewerASCIIPopSynchronized(v));
258:   }
259:   /* Now all subdomains are oriented, but we need a consistent parallel orientation */
260:   if (numLeaves >= 0) {
261:     PetscInt maxSupportSize, neighbor;

263:     /* Store orientations of boundary faces*/
264:     PetscCall(DMPlexGetMaxSizes(dm, NULL, &maxSupportSize));
265:     PetscCall(PetscCalloc3(numRoots, &rorntComp, numRoots, &lorntComp, maxSupportSize, &locSupport));
266:     for (face = fStart; face < fEnd; ++face) {
267:       const PetscInt *cone, *support, *ornt;
268:       PetscInt        coneSize, supportSize, Ns = 0, s, l;

270:       PetscCall(DMPlexGetSupportSize(dm, face, &supportSize));
271:       /* Ignore overlapping cells */
272:       PetscCall(DMPlexGetSupport(dm, face, &support));
273:       for (s = 0; s < supportSize; ++s) {
274:         PetscCall(PetscFindInt(support[s], numLeaves, lpoints, &l));
275:         if (l >= 0) continue;
276:         locSupport[Ns++] = support[s];
277:       }
278:       if (Ns != 1) continue;
279:       neighbor = locSupport[0];
280:       PetscCall(DMPlexGetCone(dm, neighbor, &cone));
281:       PetscCall(DMPlexGetConeSize(dm, neighbor, &coneSize));
282:       PetscCall(DMPlexGetConeOrientation(dm, neighbor, &ornt));
283:       for (c = 0; c < coneSize; ++c)
284:         if (cone[c] == face) break;
285:       if (dim == 1) {
286:         /* Use cone position instead, shifted to -1 or 1 */
287:         if (PetscBTLookup(flippedCells, neighbor - cStart)) rorntComp[face].rank = 1 - c * 2;
288:         else rorntComp[face].rank = c * 2 - 1;
289:       } else {
290:         if (PetscBTLookup(flippedCells, neighbor - cStart)) rorntComp[face].rank = ornt[c] < 0 ? -1 : 1;
291:         else rorntComp[face].rank = ornt[c] < 0 ? 1 : -1;
292:       }
293:       rorntComp[face].index = faceComp[face - fStart];
294:     }
295:     /* Communicate boundary edge orientations */
296:     PetscCall(PetscSFBcastBegin(sf, MPIU_2INT, rorntComp, lorntComp, MPI_REPLACE));
297:     PetscCall(PetscSFBcastEnd(sf, MPIU_2INT, rorntComp, lorntComp, MPI_REPLACE));
298:   }
299:   /* Get process adjacency */
300:   PetscCall(PetscMalloc2(numComponents, &numNeighbors, numComponents, &neighbors));
301:   viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)dm));
302:   if (flg2) PetscCall(PetscViewerASCIIPushSynchronized(viewer));
303:   PetscCall(PetscViewerGetSubViewer(viewer, PETSC_COMM_SELF, &selfviewer));
304:   for (comp = 0; comp < numComponents; ++comp) {
305:     PetscInt l, n;

307:     numNeighbors[comp] = 0;
308:     PetscCall(PetscMalloc1(PetscMax(numLeaves, 0), &neighbors[comp]));
309:     /* I know this is p^2 time in general, but for bounded degree its alright */
310:     for (l = 0; l < numLeaves; ++l) {
311:       const PetscInt face = lpoints[l];

313:       /* Find a representative face (edge) separating pairs of procs */
314:       if ((face >= fStart) && (face < fEnd) && (faceComp[face - fStart] == comp) && rorntComp[face].rank) {
315:         const PetscInt rrank = rpoints[l].rank;
316:         const PetscInt rcomp = lorntComp[face].index;

318:         for (n = 0; n < numNeighbors[comp]; ++n)
319:           if ((rrank == rpoints[neighbors[comp][n]].rank) && (rcomp == lorntComp[lpoints[neighbors[comp][n]]].index)) break;
320:         if (n >= numNeighbors[comp]) {
321:           PetscInt supportSize;

323:           PetscCall(DMPlexGetSupportSize(dm, face, &supportSize));
324:           PetscCheck(supportSize == 1, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Boundary faces should see one cell, not %" PetscInt_FMT, supportSize);
325:           if (flg)
326:             PetscCall(PetscViewerASCIIPrintf(selfviewer, "[%d]: component %d, Found representative leaf %" PetscInt_FMT " (face %" PetscInt_FMT ") connecting to face %" PetscInt_FMT " on (%" PetscInt_FMT ", %" PetscInt_FMT ") with orientation %" PetscInt_FMT "\n", rank, comp, l, face,
327:                                              rpoints[l].index, rrank, rcomp, lorntComp[face].rank));
328:           neighbors[comp][numNeighbors[comp]++] = l;
329:         }
330:       }
331:     }
332:     totNeighbors += numNeighbors[comp];
333:   }
334:   PetscCall(PetscViewerRestoreSubViewer(viewer, PETSC_COMM_SELF, &selfviewer));
335:   if (flg2) PetscCall(PetscViewerASCIIPopSynchronized(viewer));
336:   PetscCall(PetscMalloc2(totNeighbors, &nrankComp, totNeighbors, &match));
337:   for (comp = 0, off = 0; comp < numComponents; ++comp) {
338:     PetscInt n;

340:     for (n = 0; n < numNeighbors[comp]; ++n, ++off) {
341:       const PetscInt face = lpoints[neighbors[comp][n]];
342:       const PetscInt o    = rorntComp[face].rank * lorntComp[face].rank;

344:       if (o < 0) match[off] = PETSC_TRUE;
345:       else if (o > 0) match[off] = PETSC_FALSE;
346:       else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid face %" PetscInt_FMT " (%" PetscInt_FMT ", %" PetscInt_FMT ") neighbor: %" PetscInt_FMT " comp: %d", face, rorntComp[face].rank, lorntComp[face].rank, neighbors[comp][n], comp);
347:       nrankComp[off].rank  = rpoints[neighbors[comp][n]].rank;
348:       nrankComp[off].index = lorntComp[lpoints[neighbors[comp][n]]].index;
349:     }
350:     PetscCall(PetscFree(neighbors[comp]));
351:   }
352:   /* Collect the graph on 0 */
353:   if (numLeaves >= 0) {
354:     Mat          G;
355:     PetscBT      seenProcs, flippedProcs;
356:     PetscInt    *procFIFO, pTop, pBottom;
357:     PetscInt    *N          = NULL, *Noff;
358:     PetscSFNode *adj        = NULL;
359:     PetscBool   *val        = NULL;
360:     PetscMPIInt *recvcounts = NULL, *displs = NULL, *Nc, p, o;
361:     PetscMPIInt  size = 0;

363:     PetscCall(PetscCalloc1(numComponents, &flipped));
364:     if (rank == 0) PetscCallMPI(MPI_Comm_size(comm, &size));
365:     PetscCall(PetscCalloc4(size, &recvcounts, size + 1, &displs, size, &Nc, size + 1, &Noff));
366:     PetscCallMPI(MPI_Gather(&numComponents, 1, MPI_INT, Nc, 1, MPI_INT, 0, comm));
367:     for (p = 0; p < size; ++p) displs[p + 1] = displs[p] + Nc[p];
368:     if (rank == 0) PetscCall(PetscMalloc1(displs[size], &N));
369:     PetscCallMPI(MPI_Gatherv(numNeighbors, numComponents, MPIU_INT, N, Nc, displs, MPIU_INT, 0, comm));
370:     for (p = 0, o = 0; p < size; ++p) {
371:       recvcounts[p] = 0;
372:       for (c = 0; c < Nc[p]; ++c, ++o) recvcounts[p] += N[o];
373:       displs[p + 1] = displs[p] + recvcounts[p];
374:     }
375:     if (rank == 0) PetscCall(PetscMalloc2(displs[size], &adj, displs[size], &val));
376:     PetscCallMPI(MPI_Gatherv(nrankComp, totNeighbors, MPIU_2INT, adj, recvcounts, displs, MPIU_2INT, 0, comm));
377:     PetscCallMPI(MPI_Gatherv(match, totNeighbors, MPIU_BOOL, val, recvcounts, displs, MPIU_BOOL, 0, comm));
378:     PetscCall(PetscFree2(numNeighbors, neighbors));
379:     if (rank == 0) {
380:       for (p = 1; p <= size; ++p) Noff[p] = Noff[p - 1] + Nc[p - 1];
381:       if (flg) {
382:         PetscInt n;

384:         for (p = 0, off = 0; p < size; ++p) {
385:           for (c = 0; c < Nc[p]; ++c) {
386:             PetscCall(PetscPrintf(PETSC_COMM_SELF, "Proc %d Comp %" PetscInt_FMT ":\n", p, c));
387:             for (n = 0; n < N[Noff[p] + c]; ++n, ++off) PetscCall(PetscPrintf(PETSC_COMM_SELF, "  edge (%" PetscInt_FMT ", %" PetscInt_FMT ") (%s):\n", adj[off].rank, adj[off].index, PetscBools[val[off]]));
388:           }
389:         }
390:       }
391:       /* Symmetrize the graph */
392:       PetscCall(MatCreate(PETSC_COMM_SELF, &G));
393:       PetscCall(MatSetSizes(G, Noff[size], Noff[size], Noff[size], Noff[size]));
394:       PetscCall(MatSetUp(G));
395:       for (p = 0, off = 0; p < size; ++p) {
396:         for (c = 0; c < Nc[p]; ++c) {
397:           const PetscInt r = Noff[p] + c;
398:           PetscInt       n;

400:           for (n = 0; n < N[r]; ++n, ++off) {
401:             const PetscInt    q = Noff[adj[off].rank] + adj[off].index;
402:             const PetscScalar o = val[off] ? 1.0 : 0.0;

404:             PetscCall(MatSetValues(G, 1, &r, 1, &q, &o, INSERT_VALUES));
405:             PetscCall(MatSetValues(G, 1, &q, 1, &r, &o, INSERT_VALUES));
406:           }
407:         }
408:       }
409:       PetscCall(MatAssemblyBegin(G, MAT_FINAL_ASSEMBLY));
410:       PetscCall(MatAssemblyEnd(G, MAT_FINAL_ASSEMBLY));

412:       PetscCall(PetscBTCreate(Noff[size], &seenProcs));
413:       PetscCall(PetscBTMemzero(Noff[size], seenProcs));
414:       PetscCall(PetscBTCreate(Noff[size], &flippedProcs));
415:       PetscCall(PetscBTMemzero(Noff[size], flippedProcs));
416:       PetscCall(PetscMalloc1(Noff[size], &procFIFO));
417:       pTop = pBottom = 0;
418:       for (p = 0; p < Noff[size]; ++p) {
419:         if (PetscBTLookup(seenProcs, p)) continue;
420:         /* Initialize FIFO with next proc */
421:         procFIFO[pBottom++] = p;
422:         PetscCall(PetscBTSet(seenProcs, p));
423:         /* Consider each proc in FIFO */
424:         while (pTop < pBottom) {
425:           const PetscScalar *ornt;
426:           const PetscInt    *neighbors;
427:           PetscInt           proc, nproc, seen, flippedA, flippedB, mismatch, numNeighbors, n;

429:           proc     = procFIFO[pTop++];
430:           flippedA = PetscBTLookup(flippedProcs, proc) ? 1 : 0;
431:           PetscCall(MatGetRow(G, proc, &numNeighbors, &neighbors, &ornt));
432:           /* Loop over neighboring procs */
433:           for (n = 0; n < numNeighbors; ++n) {
434:             nproc    = neighbors[n];
435:             mismatch = PetscRealPart(ornt[n]) > 0.5 ? 0 : 1;
436:             seen     = PetscBTLookup(seenProcs, nproc);
437:             flippedB = PetscBTLookup(flippedProcs, nproc) ? 1 : 0;

439:             if (mismatch ^ (flippedA ^ flippedB)) {
440:               PetscCheck(!seen, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Previously seen procs %" PetscInt_FMT " and %" PetscInt_FMT " do not match: Fault mesh is non-orientable", proc, nproc);
441:               if (!flippedB) {
442:                 PetscCall(PetscBTSet(flippedProcs, nproc));
443:               } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Inconsistent mesh orientation: Fault mesh is non-orientable");
444:             } else PetscCheck(!mismatch || !flippedA || !flippedB, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Attempt to flip already flipped cell: Fault mesh is non-orientable");
445:             if (!seen) {
446:               procFIFO[pBottom++] = nproc;
447:               PetscCall(PetscBTSet(seenProcs, nproc));
448:             }
449:           }
450:         }
451:       }
452:       PetscCall(PetscFree(procFIFO));
453:       PetscCall(MatDestroy(&G));
454:       PetscCall(PetscFree2(adj, val));
455:       PetscCall(PetscBTDestroy(&seenProcs));
456:     }
457:     /* Scatter flip flags */
458:     {
459:       PetscBool *flips = NULL;

461:       if (rank == 0) {
462:         PetscCall(PetscMalloc1(Noff[size], &flips));
463:         for (p = 0; p < Noff[size]; ++p) {
464:           flips[p] = PetscBTLookup(flippedProcs, p) ? PETSC_TRUE : PETSC_FALSE;
465:           if (flg && flips[p]) PetscCall(PetscPrintf(comm, "Flipping Proc+Comp %d:\n", p));
466:         }
467:         for (p = 0; p < size; ++p) displs[p + 1] = displs[p] + Nc[p];
468:       }
469:       PetscCallMPI(MPI_Scatterv(flips, Nc, displs, MPIU_BOOL, flipped, numComponents, MPIU_BOOL, 0, comm));
470:       PetscCall(PetscFree(flips));
471:     }
472:     if (rank == 0) PetscCall(PetscBTDestroy(&flippedProcs));
473:     PetscCall(PetscFree(N));
474:     PetscCall(PetscFree4(recvcounts, displs, Nc, Noff));
475:     PetscCall(PetscFree2(nrankComp, match));

477:     /* Decide whether to flip cells in each component */
478:     for (c = 0; c < cEnd - cStart; ++c) {
479:       if (flipped[cellComp[c]]) PetscCall(PetscBTNegate(flippedCells, c));
480:     }
481:     PetscCall(PetscFree(flipped));
482:   }
483:   if (flg) {
484:     PetscViewer v;

486:     PetscCall(PetscViewerASCIIGetStdout(comm, &v));
487:     PetscCall(PetscViewerASCIIPushSynchronized(v));
488:     PetscCall(PetscViewerASCIISynchronizedPrintf(v, "[%d]BT for parallel flipped cells:\n", rank));
489:     PetscCall(PetscBTView(cEnd - cStart, flippedCells, v));
490:     PetscCall(PetscViewerFlush(v));
491:     PetscCall(PetscViewerASCIIPopSynchronized(v));
492:   }
493:   /* Reverse flipped cells in the mesh */
494:   for (c = cStart; c < cEnd; ++c) {
495:     if (PetscBTLookup(flippedCells, c - cStart)) PetscCall(DMPlexOrientPoint(dm, c, -1));
496:   }
497:   PetscCall(PetscBTDestroy(&seenCells));
498:   PetscCall(PetscBTDestroy(&flippedCells));
499:   PetscCall(PetscBTDestroy(&seenFaces));
500:   PetscCall(PetscFree2(numNeighbors, neighbors));
501:   PetscCall(PetscFree3(rorntComp, lorntComp, locSupport));
502:   PetscCall(PetscFree3(faceFIFO, cellComp, faceComp));
503:   PetscFunctionReturn(PETSC_SUCCESS);
504: }