Actual source code: plexorient.c
petsc-3.13.6 2020-09-29
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      1:  #include <petsc/private/dmpleximpl.h>
      2:  #include <petscsf.h>

      4: /*@
      5:   DMPlexCompareOrientations - Compare the cone of the given DAG point (cell) with the given reference cone (with the same cone points modulo order), and return relative orientation.

      7:   Not Collective

      9:   Input Parameters:
     10: + dm              - The DM (DMPLEX)
     11: . p               - The DAG point whose cone is compared
     12: . masterConeSize  - Number of the reference cone points passed (at least 2 and at most size of the cone of p)
     13: - masterCone      - The reference cone points

     15:   Output Parameters:
     16: + start           - The new starting point within the cone of p to make it conforming with the reference cone
     17: - reverse         - The flag whether the order of the cone points should be reversed

     19:   Level: advanced

     21: .seealso: DMPlexOrient(), DMPlexOrientCell()
     22: @*/
     23: PetscErrorCode DMPlexCompareOrientations(DM dm, PetscInt p, PetscInt masterConeSize, const PetscInt masterCone[], PetscInt *start, PetscBool *reverse)
     24: {
     25:   PetscInt        coneSize;
     26:   const PetscInt *cone;
     27:   PetscInt        i, start_;
     28:   PetscBool       reverse_;
     29:   PetscErrorCode  ierr;

     33:   DMPlexGetConeSize(dm, p, &coneSize);
     34:   if (coneSize < 2) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Point %D has no cone", p);
     35:   DMPlexGetCone(dm, p, &cone);
     36:   if (masterConeSize < 2) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Point %D: masterConeSize must be at least 2", p);
     37:   if (masterConeSize > coneSize) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Point %D: masterConeSize must be at most coneSize", p);
     38:   start_ = 0;
     39:   for (i=0; i<coneSize; i++) {
     40:     if (cone[i] == masterCone[0]) {
     41:       start_ = i;
     42:       break;
     43:     }
     44:   }
     45:   if (PetscUnlikely(i==coneSize)) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Point %D: starting point of reference cone not found in slave cone", p);
     46:   reverse_ = PETSC_FALSE;
     47:   for (i=0; i<masterConeSize; i++) {if (cone[(start_+i)%coneSize] != masterCone[i]) break;}
     48:   if (i != masterConeSize) {
     49:     reverse_ = PETSC_TRUE;
     50:     for (i=0; i<masterConeSize; i++) {if (cone[(coneSize+start_-i)%coneSize] != masterCone[i]) break;}
     51:     if (i < masterConeSize) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "Point %D: cone has non-conforming order of points with respect to reference cone", p);
     52:   }
     53:   if (start) *start = start_;
     54:   if (reverse) *reverse = reverse_;
     55:   if (PetscUnlikely(cone[start_] != masterCone[0])) SETERRQ4(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Point %D: cone[%d] = %d != %d = masterCone[0]", p, start_, cone[start_], masterCone[0]);
     56:   return(0);
     57: }

     59: /*@
     60:   DMPlexOrientCell - Set the desired order of cone points of this DAG point, and fix orientations accordingly.

     62:   Not Collective

     64:   Input Parameters:
     65: + dm              - The DM
     66: . p               - The DAG point (from interval given by DMPlexGetChart())
     67: . masterConeSize  - Number of specified cone points (at least 2)
     68: - masterCone      - Specified cone points, i.e. ordered subset of current cone in DAG numbering (not cone-local numbering)

     70:   Level: intermediate

     72: .seealso: DMPlexOrient(), DMPlexGetCone(), DMPlexGetConeOrientation(), DMPlexInterpolate(), DMPlexGetChart()
     73: @*/
     74: PetscErrorCode DMPlexOrientCell(DM dm, PetscInt p, PetscInt masterConeSize, const PetscInt masterCone[])
     75: {
     76:   PetscInt        coneSize;
     77:   PetscInt        start1=0;
     78:   PetscBool       reverse1=PETSC_FALSE;
     79:   PetscErrorCode  ierr;

     84:   if (masterConeSize == 1) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "masterConeSize cannot be 1");
     85:   DMPlexGetConeSize(dm, p, &coneSize);
     86:   if (!coneSize) return(0); /* do nothing for points with no cone */
     87:   DMPlexCompareOrientations(dm, p, masterConeSize, masterCone, &start1, &reverse1);
     88:   DMPlexOrientCell_Internal(dm, p, start1, reverse1);
     89: #if defined(PETSC_USE_DEBUG)
     90:   {
     91:     PetscInt        c;
     92:     const PetscInt *cone;
     93:     DMPlexGetCone(dm, p, &cone);
     94:     for (c = 0; c < masterConeSize; c++) {
     95:       if (PetscUnlikely(cone[c] != masterCone[c])) SETERRQ4(PETSC_COMM_SELF, PETSC_ERR_PLIB, "The algorithm above is wrong as cone[%d] = %d != %d = masterCone[%d]", c, cone[c], masterCone[c], c);
     96:     }
     97:   }
     98: #endif
     99:   return(0);
    100: }

    102: PetscErrorCode DMPlexOrientCell_Internal(DM dm, PetscInt p, PetscInt start1, PetscBool reverse1)
    103: {
    104:   PetscInt        i, j, k, maxConeSize, coneSize, coneConeSize, supportSize, supportConeSize;
    105:   PetscInt        start0, start;
    106:   PetscBool       reverse0, reverse;
    107:   PetscInt        newornt;
    108:   const PetscInt *cone=NULL, *support=NULL, *supportCone=NULL, *ornts=NULL;
    109:   PetscInt       *newcone=NULL, *newornts=NULL;
    110:   PetscErrorCode  ierr;

    113:   if (!start1 && !reverse1) return(0);
    114:   DMPlexGetConeSize(dm, p, &coneSize);
    115:   if (!coneSize) return(0); /* do nothing for points with no cone */
    116:   DMPlexGetCone(dm, p, &cone);
    117:   DMPlexGetMaxSizes(dm, &maxConeSize, NULL);
    118:   /* permute p's cone and orientations */
    119:   DMPlexGetConeOrientation(dm, p, &ornts);
    120:   DMGetWorkArray(dm, maxConeSize, MPIU_INT, &newcone);
    121:   DMGetWorkArray(dm, maxConeSize, MPIU_INT, &newornts);
    122:   DMPlexFixFaceOrientations_Permute_Private(coneSize, cone, start1, reverse1, newcone);
    123:   DMPlexFixFaceOrientations_Permute_Private(coneSize, ornts, start1, reverse1, newornts);
    124:   /* if direction of p (face) is flipped, flip also p's cone points (edges) */
    125:   if (reverse1) {
    126:     for (i=0; i<coneSize; i++) {
    127:       DMPlexGetConeSize(dm, cone[i], &coneConeSize);
    128:       DMPlexFixFaceOrientations_Translate_Private(newornts[i], &start0, &reverse0);
    129:       DMPlexFixFaceOrientations_Combine_Private(coneConeSize, start0, reverse0, 1, PETSC_FALSE, &start, &reverse);
    130:       DMPlexFixFaceOrientations_TranslateBack_Private(coneConeSize, start, reverse, &newornts[i]);
    131:     }
    132:   }
    133:   DMPlexSetConeOrientation(dm, p, newornts);
    134:   /* fix oriention of p within cones of p's support points */
    135:   DMPlexGetSupport(dm, p, &support);
    136:   DMPlexGetSupportSize(dm, p, &supportSize);
    137:   for (j=0; j<supportSize; j++) {
    138:     DMPlexGetCone(dm, support[j], &supportCone);
    139:     DMPlexGetConeSize(dm, support[j], &supportConeSize);
    140:     DMPlexGetConeOrientation(dm, support[j], &ornts);
    141:     for (k=0; k<supportConeSize; k++) {
    142:       if (supportCone[k] != p) continue;
    143:       DMPlexFixFaceOrientations_Translate_Private(ornts[k], &start0, &reverse0);
    144:       DMPlexFixFaceOrientations_Combine_Private(coneSize, start0, reverse0, start1, reverse1, &start, &reverse);
    145:       DMPlexFixFaceOrientations_TranslateBack_Private(coneSize, start, reverse, &newornt);
    146:       DMPlexInsertConeOrientation(dm, support[j], k, newornt);
    147:     }
    148:   }
    149:   /* rewrite cone */
    150:   DMPlexSetCone(dm, p, newcone);
    151:   DMRestoreWorkArray(dm, maxConeSize, MPIU_INT, &newcone);
    152:   DMRestoreWorkArray(dm, maxConeSize, MPIU_INT, &newornts);
    153:   return(0);
    154: }

    156: /*@
    157:   DMPlexReverseCell - Give a mesh cell the opposite orientation

    159:   Input Parameters:
    160: + dm   - The DM
    161: - cell - The cell number

    163:   Note: The modification of the DM is done in-place.

    165:   Level: advanced

    167: .seealso: DMPlexOrient(), DMCreate(), DMPLEX
    168: @*/
    169: PetscErrorCode DMPlexReverseCell(DM dm, PetscInt cell)
    170: {
    171:   /* Note that the reverse orientation ro of a face with orientation o is:

    173:        ro = o >= 0 ? -(faceSize - o) : faceSize + o

    175:      where faceSize is the size of the cone for the face.
    176:   */
    177:   const PetscInt *cone,    *coneO, *support;
    178:   PetscInt       *revcone, *revconeO;
    179:   PetscInt        maxConeSize, coneSize, supportSize, faceSize, cp, sp;
    180:   PetscErrorCode  ierr;

    183:   DMPlexGetMaxSizes(dm, &maxConeSize, NULL);
    184:   DMGetWorkArray(dm, maxConeSize, MPIU_INT, &revcone);
    185:   DMGetWorkArray(dm, maxConeSize, MPIU_INT, &revconeO);
    186:   /* Reverse cone, and reverse orientations of faces */
    187:   DMPlexGetConeSize(dm, cell, &coneSize);
    188:   DMPlexGetCone(dm, cell, &cone);
    189:   DMPlexGetConeOrientation(dm, cell, &coneO);
    190:   for (cp = 0; cp < coneSize; ++cp) {
    191:     const PetscInt rcp = coneSize-cp-1;

    193:     DMPlexGetConeSize(dm, cone[rcp], &faceSize);
    194:     revcone[cp]  = cone[rcp];
    195:     revconeO[cp] = coneO[rcp] >= 0 ? -(faceSize-coneO[rcp]) : faceSize+coneO[rcp];
    196:   }
    197:   DMPlexSetCone(dm, cell, revcone);
    198:   DMPlexSetConeOrientation(dm, cell, revconeO);
    199:   /* Reverse orientation of this cell in the support hypercells */
    200:   faceSize = coneSize;
    201:   DMPlexGetSupportSize(dm, cell, &supportSize);
    202:   DMPlexGetSupport(dm, cell, &support);
    203:   for (sp = 0; sp < supportSize; ++sp) {
    204:     DMPlexGetConeSize(dm, support[sp], &coneSize);
    205:     DMPlexGetCone(dm, support[sp], &cone);
    206:     DMPlexGetConeOrientation(dm, support[sp], &coneO);
    207:     for (cp = 0; cp < coneSize; ++cp) {
    208:       if (cone[cp] != cell) continue;
    209:       DMPlexInsertConeOrientation(dm, support[sp], cp, coneO[cp] >= 0 ? -(faceSize-coneO[cp]) : faceSize+coneO[cp]);
    210:     }
    211:   }
    212:   DMRestoreWorkArray(dm, maxConeSize, MPIU_INT, &revcone);
    213:   DMRestoreWorkArray(dm, maxConeSize, MPIU_INT, &revconeO);
    214:   return(0);
    215: }

    217: /*
    218:   - Checks face match
    219:     - Flips non-matching
    220:   - Inserts faces of support cells in FIFO
    221: */
    222: static PetscErrorCode DMPlexCheckFace_Internal(DM dm, PetscInt *faceFIFO, PetscInt *fTop, PetscInt *fBottom, PetscInt cStart, PetscInt fStart, PetscInt fEnd, PetscBT seenCells, PetscBT flippedCells, PetscBT seenFaces)
    223: {
    224:   const PetscInt *support, *coneA, *coneB, *coneOA, *coneOB;
    225:   PetscInt        supportSize, coneSizeA, coneSizeB, posA = -1, posB = -1;
    226:   PetscInt        face, dim, seenA, flippedA, seenB, flippedB, mismatch, c;
    227:   PetscErrorCode  ierr;

    230:   face = faceFIFO[(*fTop)++];
    231:   DMGetDimension(dm, &dim);
    232:   DMPlexGetSupportSize(dm, face, &supportSize);
    233:   DMPlexGetSupport(dm, face, &support);
    234:   if (supportSize < 2) return(0);
    235:   if (supportSize != 2) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Faces should separate only two cells, not %d", supportSize);
    236:   seenA    = PetscBTLookup(seenCells,    support[0]-cStart);
    237:   flippedA = PetscBTLookup(flippedCells, support[0]-cStart) ? 1 : 0;
    238:   seenB    = PetscBTLookup(seenCells,    support[1]-cStart);
    239:   flippedB = PetscBTLookup(flippedCells, support[1]-cStart) ? 1 : 0;

    241:   DMPlexGetConeSize(dm, support[0], &coneSizeA);
    242:   DMPlexGetConeSize(dm, support[1], &coneSizeB);
    243:   DMPlexGetCone(dm, support[0], &coneA);
    244:   DMPlexGetCone(dm, support[1], &coneB);
    245:   DMPlexGetConeOrientation(dm, support[0], &coneOA);
    246:   DMPlexGetConeOrientation(dm, support[1], &coneOB);
    247:   for (c = 0; c < coneSizeA; ++c) {
    248:     if (!PetscBTLookup(seenFaces, coneA[c]-fStart)) {
    249:       faceFIFO[(*fBottom)++] = coneA[c];
    250:       PetscBTSet(seenFaces, coneA[c]-fStart);
    251:     }
    252:     if (coneA[c] == face) posA = c;
    253:     if (*fBottom > fEnd-fStart) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Face %d was pushed exceeding capacity %d > %d", coneA[c], *fBottom, fEnd-fStart);
    254:   }
    255:   if (posA < 0) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Face %d could not be located in cell %d", face, support[0]);
    256:   for (c = 0; c < coneSizeB; ++c) {
    257:     if (!PetscBTLookup(seenFaces, coneB[c]-fStart)) {
    258:       faceFIFO[(*fBottom)++] = coneB[c];
    259:       PetscBTSet(seenFaces, coneB[c]-fStart);
    260:     }
    261:     if (coneB[c] == face) posB = c;
    262:     if (*fBottom > fEnd-fStart) SETERRQ3(PETSC_COMM_SELF, PETSC_ERR_PLIB, "Face %d was pushed exceeding capacity %d > %d", coneA[c], *fBottom, fEnd-fStart);
    263:   }
    264:   if (posB < 0) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Face %d could not be located in cell %d", face, support[1]);

    266:   if (dim == 1) {
    267:     mismatch = posA == posB;
    268:   } else {
    269:     mismatch = coneOA[posA] == coneOB[posB];
    270:   }

    272:   if (mismatch ^ (flippedA ^ flippedB)) {
    273:     if (seenA && seenB) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Previously seen cells %d and %d do not match: Fault mesh is non-orientable", support[0], support[1]);
    274:     if (!seenA && !flippedA) {
    275:       PetscBTSet(flippedCells, support[0]-cStart);
    276:     } else if (!seenB && !flippedB) {
    277:       PetscBTSet(flippedCells, support[1]-cStart);
    278:     } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Inconsistent mesh orientation: Fault mesh is non-orientable");
    279:   } else if (mismatch && flippedA && flippedB) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Attempt to flip already flipped cell: Fault mesh is non-orientable");
    280:   PetscBTSet(seenCells, support[0]-cStart);
    281:   PetscBTSet(seenCells, support[1]-cStart);
    282:   return(0);
    283: }

    285: /*@
    286:   DMPlexOrient - Give a consistent orientation to the input mesh

    288:   Input Parameters:
    289: . dm - The DM

    291:   Note: The orientation data for the DM are change in-place.
    292: $ This routine will fail for non-orientable surfaces, such as the Moebius strip.

    294:   Level: advanced

    296: .seealso: DMCreate(), DMPLEX
    297: @*/
    298: PetscErrorCode DMPlexOrient(DM dm)
    299: {
    300:   MPI_Comm           comm;
    301:   PetscSF            sf;
    302:   const PetscInt    *lpoints;
    303:   const PetscSFNode *rpoints;
    304:   PetscSFNode       *rorntComp = NULL, *lorntComp = NULL;
    305:   PetscInt          *numNeighbors, **neighbors;
    306:   PetscSFNode       *nrankComp;
    307:   PetscBool         *match, *flipped;
    308:   PetscBT            seenCells, flippedCells, seenFaces;
    309:   PetscInt          *faceFIFO, fTop, fBottom, *cellComp, *faceComp;
    310:   PetscInt           numLeaves, numRoots, dim, h, cStart, cEnd, c, cell, fStart, fEnd, face, off, totNeighbors = 0;
    311:   PetscMPIInt        rank, size, numComponents, comp = 0;
    312:   PetscBool          flg, flg2;
    313:   PetscViewer        viewer = NULL, selfviewer = NULL;
    314:   PetscErrorCode     ierr;

    317:   PetscObjectGetComm((PetscObject) dm, &comm);
    318:   MPI_Comm_rank(comm, &rank);
    319:   MPI_Comm_size(comm, &size);
    320:   PetscOptionsHasName(((PetscObject) dm)->options,((PetscObject) dm)->prefix, "-orientation_view", &flg);
    321:   PetscOptionsHasName(((PetscObject) dm)->options,((PetscObject) dm)->prefix, "-orientation_view_synchronized", &flg2);
    322:   DMGetPointSF(dm, &sf);
    323:   PetscSFGetGraph(sf, &numRoots, &numLeaves, &lpoints, &rpoints);
    324:   /* Truth Table
    325:      mismatch    flips   do action   mismatch   flipA ^ flipB   action
    326:          F       0 flips     no         F             F           F
    327:          F       1 flip      yes        F             T           T
    328:          F       2 flips     no         T             F           T
    329:          T       0 flips     yes        T             T           F
    330:          T       1 flip      no
    331:          T       2 flips     yes
    332:   */
    333:   DMGetDimension(dm, &dim);
    334:   DMPlexGetVTKCellHeight(dm, &h);
    335:   DMPlexGetHeightStratum(dm, h,   &cStart, &cEnd);
    336:   DMPlexGetHeightStratum(dm, h+1, &fStart, &fEnd);
    337:   PetscBTCreate(cEnd - cStart, &seenCells);
    338:   PetscBTMemzero(cEnd - cStart, seenCells);
    339:   PetscBTCreate(cEnd - cStart, &flippedCells);
    340:   PetscBTMemzero(cEnd - cStart, flippedCells);
    341:   PetscBTCreate(fEnd - fStart, &seenFaces);
    342:   PetscBTMemzero(fEnd - fStart, seenFaces);
    343:   PetscCalloc3(fEnd - fStart, &faceFIFO, cEnd-cStart, &cellComp, fEnd-fStart, &faceComp);
    344:   /*
    345:    OLD STYLE
    346:    - Add an integer array over cells and faces (component) for connected component number
    347:    Foreach component
    348:      - Mark the initial cell as seen
    349:      - Process component as usual
    350:      - Set component for all seenCells
    351:      - Wipe seenCells and seenFaces (flippedCells can stay)
    352:    - Generate parallel adjacency for component using SF and seenFaces
    353:    - Collect numComponents adj data from each proc to 0
    354:    - Build same serial graph
    355:    - Use same solver
    356:    - Use Scatterv to to send back flipped flags for each component
    357:    - Negate flippedCells by component

    359:    NEW STYLE
    360:    - Create the adj on each process
    361:    - Bootstrap to complete graph on proc 0
    362:   */
    363:   /* Loop over components */
    364:   for (cell = cStart; cell < cEnd; ++cell) cellComp[cell-cStart] = -1;
    365:   do {
    366:     /* Look for first unmarked cell */
    367:     for (cell = cStart; cell < cEnd; ++cell) if (cellComp[cell-cStart] < 0) break;
    368:     if (cell >= cEnd) break;
    369:     /* Initialize FIFO with first cell in component */
    370:     {
    371:       const PetscInt *cone;
    372:       PetscInt        coneSize;

    374:       fTop = fBottom = 0;
    375:       DMPlexGetConeSize(dm, cell, &coneSize);
    376:       DMPlexGetCone(dm, cell, &cone);
    377:       for (c = 0; c < coneSize; ++c) {
    378:         faceFIFO[fBottom++] = cone[c];
    379:         PetscBTSet(seenFaces, cone[c]-fStart);
    380:       }
    381:       PetscBTSet(seenCells, cell-cStart);
    382:     }
    383:     /* Consider each face in FIFO */
    384:     while (fTop < fBottom) {
    385:       DMPlexCheckFace_Internal(dm, faceFIFO, &fTop, &fBottom, cStart, fStart, fEnd, seenCells, flippedCells, seenFaces);
    386:     }
    387:     /* Set component for cells and faces */
    388:     for (cell = 0; cell < cEnd-cStart; ++cell) {
    389:       if (PetscBTLookup(seenCells, cell)) cellComp[cell] = comp;
    390:     }
    391:     for (face = 0; face < fEnd-fStart; ++face) {
    392:       if (PetscBTLookup(seenFaces, face)) faceComp[face] = comp;
    393:     }
    394:     /* Wipe seenCells and seenFaces for next component */
    395:     PetscBTMemzero(fEnd - fStart, seenFaces);
    396:     PetscBTMemzero(cEnd - cStart, seenCells);
    397:     ++comp;
    398:   } while (1);
    399:   numComponents = comp;
    400:   if (flg) {
    401:     PetscViewer v;

    403:     PetscViewerASCIIGetStdout(comm, &v);
    404:     PetscViewerASCIIPushSynchronized(v);
    405:     PetscViewerASCIISynchronizedPrintf(v, "[%d]BT for serial flipped cells:\n", rank);
    406:     PetscBTView(cEnd-cStart, flippedCells, v);
    407:     PetscViewerFlush(v);
    408:     PetscViewerASCIIPopSynchronized(v);
    409:   }
    410:   /* Now all subdomains are oriented, but we need a consistent parallel orientation */
    411:   if (numLeaves >= 0) {
    412:     /* Store orientations of boundary faces*/
    413:     PetscCalloc2(numRoots,&rorntComp,numRoots,&lorntComp);
    414:     for (face = fStart; face < fEnd; ++face) {
    415:       const PetscInt *cone, *support, *ornt;
    416:       PetscInt        coneSize, supportSize;

    418:       DMPlexGetSupportSize(dm, face, &supportSize);
    419:       if (supportSize != 1) continue;
    420:       DMPlexGetSupport(dm, face, &support);

    422:       DMPlexGetCone(dm, support[0], &cone);
    423:       DMPlexGetConeSize(dm, support[0], &coneSize);
    424:       DMPlexGetConeOrientation(dm, support[0], &ornt);
    425:       for (c = 0; c < coneSize; ++c) if (cone[c] == face) break;
    426:       if (dim == 1) {
    427:         /* Use cone position instead, shifted to -1 or 1 */
    428:         if (PetscBTLookup(flippedCells, support[0]-cStart)) rorntComp[face].rank = 1-c*2;
    429:         else                                                rorntComp[face].rank = c*2-1;
    430:       } else {
    431:         if (PetscBTLookup(flippedCells, support[0]-cStart)) rorntComp[face].rank = ornt[c] < 0 ? -1 :  1;
    432:         else                                                rorntComp[face].rank = ornt[c] < 0 ?  1 : -1;
    433:       }
    434:       rorntComp[face].index = faceComp[face-fStart];
    435:     }
    436:     /* Communicate boundary edge orientations */
    437:     PetscSFBcastBegin(sf, MPIU_2INT, rorntComp, lorntComp);
    438:     PetscSFBcastEnd(sf, MPIU_2INT, rorntComp, lorntComp);
    439:   }
    440:   /* Get process adjacency */
    441:   PetscMalloc2(numComponents, &numNeighbors, numComponents, &neighbors);
    442:   viewer = PETSC_VIEWER_STDOUT_(PetscObjectComm((PetscObject)dm));
    443:   if (flg2) {PetscViewerASCIIPushSynchronized(viewer);}
    444:   PetscViewerGetSubViewer(viewer,PETSC_COMM_SELF,&selfviewer);
    445:   for (comp = 0; comp < numComponents; ++comp) {
    446:     PetscInt  l, n;

    448:     numNeighbors[comp] = 0;
    449:     PetscMalloc1(PetscMax(numLeaves, 0), &neighbors[comp]);
    450:     /* I know this is p^2 time in general, but for bounded degree its alright */
    451:     for (l = 0; l < numLeaves; ++l) {
    452:       const PetscInt face = lpoints[l];

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

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

    463:           DMPlexGetSupportSize(dm, face, &supportSize);
    464:           if (supportSize != 1) SETERRQ1(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Boundary faces should see one cell, not %d", supportSize);
    465:           if (flg) {PetscViewerASCIIPrintf(selfviewer, "[%d]: component %d, Found representative leaf %d (face %d) connecting to face %d on (%d, %d) with orientation %d\n", rank, comp, l, face, rpoints[l].index, rrank, rcomp, lorntComp[face].rank);}
    466:           neighbors[comp][numNeighbors[comp]++] = l;
    467:         }
    468:       }
    469:     }
    470:     totNeighbors += numNeighbors[comp];
    471:   }
    472:   PetscViewerRestoreSubViewer(viewer,PETSC_COMM_SELF,&selfviewer);
    473:   PetscViewerFlush(viewer);
    474:   if (flg2) {PetscViewerASCIIPopSynchronized(viewer);}
    475:   PetscMalloc2(totNeighbors, &nrankComp, totNeighbors, &match);
    476:   for (comp = 0, off = 0; comp < numComponents; ++comp) {
    477:     PetscInt n;

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

    483:       if      (o < 0) match[off] = PETSC_TRUE;
    484:       else if (o > 0) match[off] = PETSC_FALSE;
    485:       else SETERRQ5(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Invalid face %d (%d, %d) neighbor: %d comp: %d", face, rorntComp[face], lorntComp[face], neighbors[comp][n], comp);
    486:       nrankComp[off].rank  = rpoints[neighbors[comp][n]].rank;
    487:       nrankComp[off].index = lorntComp[lpoints[neighbors[comp][n]]].index;
    488:     }
    489:     PetscFree(neighbors[comp]);
    490:   }
    491:   /* Collect the graph on 0 */
    492:   if (numLeaves >= 0) {
    493:     Mat          G;
    494:     PetscBT      seenProcs, flippedProcs;
    495:     PetscInt    *procFIFO, pTop, pBottom;
    496:     PetscInt    *N   = NULL, *Noff;
    497:     PetscSFNode *adj = NULL;
    498:     PetscBool   *val = NULL;
    499:     PetscMPIInt *recvcounts = NULL, *displs = NULL, *Nc, p, o;
    500:     PetscMPIInt  size = 0;

    502:     PetscCalloc1(numComponents, &flipped);
    503:     if (!rank) {MPI_Comm_size(comm, &size);}
    504:     PetscCalloc4(size, &recvcounts, size+1, &displs, size, &Nc, size+1, &Noff);
    505:     MPI_Gather(&numComponents, 1, MPI_INT, Nc, 1, MPI_INT, 0, comm);
    506:     for (p = 0; p < size; ++p) {
    507:       displs[p+1] = displs[p] + Nc[p];
    508:     }
    509:     if (!rank) {PetscMalloc1(displs[size],&N);}
    510:     MPI_Gatherv(numNeighbors, numComponents, MPIU_INT, N, Nc, displs, MPIU_INT, 0, comm);
    511:     for (p = 0, o = 0; p < size; ++p) {
    512:       recvcounts[p] = 0;
    513:       for (c = 0; c < Nc[p]; ++c, ++o) recvcounts[p] += N[o];
    514:       displs[p+1] = displs[p] + recvcounts[p];
    515:     }
    516:     if (!rank) {PetscMalloc2(displs[size], &adj, displs[size], &val);}
    517:     MPI_Gatherv(nrankComp, totNeighbors, MPIU_2INT, adj, recvcounts, displs, MPIU_2INT, 0, comm);
    518:     MPI_Gatherv(match, totNeighbors, MPIU_BOOL, val, recvcounts, displs, MPIU_BOOL, 0, comm);
    519:     PetscFree2(numNeighbors, neighbors);
    520:     if (!rank) {
    521:       for (p = 1; p <= size; ++p) {Noff[p] = Noff[p-1] + Nc[p-1];}
    522:       if (flg) {
    523:         PetscInt n;

    525:         for (p = 0, off = 0; p < size; ++p) {
    526:           for (c = 0; c < Nc[p]; ++c) {
    527:             PetscPrintf(PETSC_COMM_SELF, "Proc %d Comp %d:\n", p, c);
    528:             for (n = 0; n < N[Noff[p]+c]; ++n, ++off) {
    529:               PetscPrintf(PETSC_COMM_SELF, "  edge (%d, %d) (%d):\n", adj[off].rank, adj[off].index, val[off]);
    530:             }
    531:           }
    532:         }
    533:       }
    534:       /* Symmetrize the graph */
    535:       MatCreate(PETSC_COMM_SELF, &G);
    536:       MatSetSizes(G, Noff[size], Noff[size], Noff[size], Noff[size]);
    537:       MatSetUp(G);
    538:       for (p = 0, off = 0; p < size; ++p) {
    539:         for (c = 0; c < Nc[p]; ++c) {
    540:           const PetscInt r = Noff[p]+c;
    541:           PetscInt       n;

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

    547:             MatSetValues(G, 1, &r, 1, &q, &o, INSERT_VALUES);
    548:             MatSetValues(G, 1, &q, 1, &r, &o, INSERT_VALUES);
    549:           }
    550:         }
    551:       }
    552:       MatAssemblyBegin(G, MAT_FINAL_ASSEMBLY);
    553:       MatAssemblyEnd(G, MAT_FINAL_ASSEMBLY);

    555:       PetscBTCreate(Noff[size], &seenProcs);
    556:       PetscBTMemzero(Noff[size], seenProcs);
    557:       PetscBTCreate(Noff[size], &flippedProcs);
    558:       PetscBTMemzero(Noff[size], flippedProcs);
    559:       PetscMalloc1(Noff[size], &procFIFO);
    560:       pTop = pBottom = 0;
    561:       for (p = 0; p < Noff[size]; ++p) {
    562:         if (PetscBTLookup(seenProcs, p)) continue;
    563:         /* Initialize FIFO with next proc */
    564:         procFIFO[pBottom++] = p;
    565:         PetscBTSet(seenProcs, p);
    566:         /* Consider each proc in FIFO */
    567:         while (pTop < pBottom) {
    568:           const PetscScalar *ornt;
    569:           const PetscInt    *neighbors;
    570:           PetscInt           proc, nproc, seen, flippedA, flippedB, mismatch, numNeighbors, n;

    572:           proc     = procFIFO[pTop++];
    573:           flippedA = PetscBTLookup(flippedProcs, proc) ? 1 : 0;
    574:           MatGetRow(G, proc, &numNeighbors, &neighbors, &ornt);
    575:           /* Loop over neighboring procs */
    576:           for (n = 0; n < numNeighbors; ++n) {
    577:             nproc    = neighbors[n];
    578:             mismatch = PetscRealPart(ornt[n]) > 0.5 ? 0 : 1;
    579:             seen     = PetscBTLookup(seenProcs, nproc);
    580:             flippedB = PetscBTLookup(flippedProcs, nproc) ? 1 : 0;

    582:             if (mismatch ^ (flippedA ^ flippedB)) {
    583:               if (seen) SETERRQ2(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Previously seen procs %d and %d do not match: Fault mesh is non-orientable", proc, nproc);
    584:               if (!flippedB) {
    585:                 PetscBTSet(flippedProcs, nproc);
    586:               } else SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Inconsistent mesh orientation: Fault mesh is non-orientable");
    587:             } else if (mismatch && flippedA && flippedB) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Attempt to flip already flipped cell: Fault mesh is non-orientable");
    588:             if (!seen) {
    589:               procFIFO[pBottom++] = nproc;
    590:               PetscBTSet(seenProcs, nproc);
    591:             }
    592:           }
    593:         }
    594:       }
    595:       PetscFree(procFIFO);
    596:       MatDestroy(&G);
    597:       PetscFree2(adj, val);
    598:       PetscBTDestroy(&seenProcs);
    599:     }
    600:     /* Scatter flip flags */
    601:     {
    602:       PetscBool *flips = NULL;

    604:       if (!rank) {
    605:         PetscMalloc1(Noff[size], &flips);
    606:         for (p = 0; p < Noff[size]; ++p) {
    607:           flips[p] = PetscBTLookup(flippedProcs, p) ? PETSC_TRUE : PETSC_FALSE;
    608:           if (flg && flips[p]) {PetscPrintf(comm, "Flipping Proc+Comp %d:\n", p);}
    609:         }
    610:         for (p = 0; p < size; ++p) {
    611:           displs[p+1] = displs[p] + Nc[p];
    612:         }
    613:       }
    614:       MPI_Scatterv(flips, Nc, displs, MPIU_BOOL, flipped, numComponents, MPIU_BOOL, 0, comm);
    615:       PetscFree(flips);
    616:     }
    617:     if (!rank) {PetscBTDestroy(&flippedProcs);}
    618:     PetscFree(N);
    619:     PetscFree4(recvcounts, displs, Nc, Noff);
    620:     PetscFree2(nrankComp, match);

    622:     /* Decide whether to flip cells in each component */
    623:     for (c = 0; c < cEnd-cStart; ++c) {if (flipped[cellComp[c]]) {PetscBTNegate(flippedCells, c);}}
    624:     PetscFree(flipped);
    625:   }
    626:   if (flg) {
    627:     PetscViewer v;

    629:     PetscViewerASCIIGetStdout(comm, &v);
    630:     PetscViewerASCIIPushSynchronized(v);
    631:     PetscViewerASCIISynchronizedPrintf(v, "[%d]BT for parallel flipped cells:\n", rank);
    632:     PetscBTView(cEnd-cStart, flippedCells, v);
    633:     PetscViewerFlush(v);
    634:     PetscViewerASCIIPopSynchronized(v);
    635:   }
    636:   /* Reverse flipped cells in the mesh */
    637:   for (c = cStart; c < cEnd; ++c) {
    638:     if (PetscBTLookup(flippedCells, c-cStart)) {
    639:       DMPlexReverseCell(dm, c);
    640:     }
    641:   }
    642:   PetscBTDestroy(&seenCells);
    643:   PetscBTDestroy(&flippedCells);
    644:   PetscBTDestroy(&seenFaces);
    645:   PetscFree2(numNeighbors, neighbors);
    646:   PetscFree2(rorntComp, lorntComp);
    647:   PetscFree3(faceFIFO, cellComp, faceComp);
    648:   return(0);
    649: }