Actual source code: plexsfc.c

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

  5: typedef uint64_t ZCode;

  7: PETSC_HASH_SET(ZSet, ZCode, PetscHash_UInt64, PetscHashEqual)

  9: typedef struct {
 10:   PetscInt i, j, k;
 11: } Ijk;

 13: typedef struct {
 14:   Ijk         eextent;
 15:   Ijk         vextent;
 16:   PetscMPIInt comm_size;
 17:   ZCode      *zstarts;
 18: } ZLayout;

 20: // ***** Overview of ZCode *******
 21: // The SFC uses integer indexing for each dimension and encodes them into a single integer by interleaving the bits of each index.
 22: // This is known as Morton encoding, and is refered to as ZCode in this code.
 23: // So for index i having bits [i2,i1,i0], and similar for indexes j and k, the ZCode (Morton number) would be:
 24: //    [k2,j2,i2,k1,j1,i1,k0,j0,i0]
 25: // This encoding allows for easier traversal of the SFC structure (see https://en.wikipedia.org/wiki/Z-order_curve and `ZStepOct()`).
 26: // `ZEncode()` is used to go from indices to ZCode, while `ZCodeSplit()` goes from ZCode back to indices.

 28: // Decodes the leading interleaved index from a ZCode
 29: // e.g. [k2,j2,i2,k1,j1,i1,k0,j0,i0] -> [i2,i1,i0]
 30: // Magic numbers taken from https://stackoverflow.com/a/18528775/7564988 (translated to octal)
 31: static unsigned ZCodeSplit1(ZCode z)
 32: {
 33:   z &= 0111111111111111111111;
 34:   z = (z | z >> 2) & 0103030303030303030303;
 35:   z = (z | z >> 4) & 0100170017001700170017;
 36:   z = (z | z >> 8) & 0370000037700000377;
 37:   z = (z | z >> 16) & 0370000000000177777;
 38:   z = (z | z >> 32) & 07777777;
 39:   return (unsigned)z;
 40: }

 42: // Encodes the leading interleaved index from a ZCode
 43: // e.g. [i2,i1,i0] -> [0,0,i2,0,0,i1,0,0,i0]
 44: static ZCode ZEncode1(unsigned t)
 45: {
 46:   ZCode z = t;
 47:   z &= 07777777;
 48:   z = (z | z << 32) & 0370000000000177777;
 49:   z = (z | z << 16) & 0370000037700000377;
 50:   z = (z | z << 8) & 0100170017001700170017;
 51:   z = (z | z << 4) & 0103030303030303030303;
 52:   z = (z | z << 2) & 0111111111111111111111;
 53:   return z;
 54: }

 56: // Decodes i j k indices from a ZCode.
 57: // Uses `ZCodeSplit1()` by shifting ZCode so that the leading index is the desired one to decode
 58: static Ijk ZCodeSplit(ZCode z)
 59: {
 60:   Ijk c;
 61:   c.i = ZCodeSplit1(z >> 2);
 62:   c.j = ZCodeSplit1(z >> 1);
 63:   c.k = ZCodeSplit1(z >> 0);
 64:   return c;
 65: }

 67: // Encodes i j k indices to a ZCode.
 68: // Uses `ZCodeEncode1()` by shifting resulting ZCode to the appropriate bit placement
 69: static ZCode ZEncode(Ijk c)
 70: {
 71:   ZCode z = (ZEncode1((unsigned int)c.i) << 2) | (ZEncode1((unsigned int)c.j) << 1) | ZEncode1((unsigned int)c.k);
 72:   return z;
 73: }

 75: static PetscBool IjkActive(Ijk extent, Ijk l)
 76: {
 77:   if (l.i < extent.i && l.j < extent.j && l.k < extent.k) return PETSC_TRUE;
 78:   return PETSC_FALSE;
 79: }

 81: // If z is not the base of an octet (last 3 bits 0), return 0.
 82: //
 83: // If z is the base of an octet, we recursively grow to the biggest structured octet. This is typically useful when a z
 84: // is outside the domain and we wish to skip a (possibly recursively large) octet to find our next interesting point.
 85: static ZCode ZStepOct(ZCode z)
 86: {
 87:   if (PetscUnlikely(z == 0)) return 0; // Infinite loop below if z == 0
 88:   ZCode step = 07;
 89:   for (; (z & step) == 0; step = (step << 3) | 07) { }
 90:   return step >> 3;
 91: }

 93: // Since element/vertex box extents are typically not equal powers of 2, Z codes that lie within the domain are not contiguous.
 94: static PetscErrorCode ZLayoutCreate(PetscMPIInt size, const PetscInt eextent[3], const PetscInt vextent[3], ZLayout *layout)
 95: {
 96:   PetscFunctionBegin;
 97:   layout->eextent.i = eextent[0];
 98:   layout->eextent.j = eextent[1];
 99:   layout->eextent.k = eextent[2];
100:   layout->vextent.i = vextent[0];
101:   layout->vextent.j = vextent[1];
102:   layout->vextent.k = vextent[2];
103:   layout->comm_size = size;
104:   layout->zstarts   = NULL;
105:   PetscCall(PetscMalloc1(size + 1, &layout->zstarts));

107:   PetscInt total_elems = eextent[0] * eextent[1] * eextent[2];
108:   ZCode    z           = 0;
109:   layout->zstarts[0]   = 0;
110:   // This loop traverses all vertices in the global domain, so is worth making fast. We use ZStepBound
111:   for (PetscMPIInt r = 0; r < size; r++) {
112:     PetscInt elems_needed = (total_elems / size) + (total_elems % size > r), count;
113:     for (count = 0; count < elems_needed; z++) {
114:       ZCode skip = ZStepOct(z); // optimistically attempt a longer step
115:       for (ZCode s = skip;; s >>= 3) {
116:         Ijk trial = ZCodeSplit(z + s);
117:         if (IjkActive(layout->eextent, trial)) {
118:           while (count + s + 1 > (ZCode)elems_needed) s >>= 3; // Shrink the octet
119:           count += s + 1;
120:           z += s;
121:           break;
122:         }
123:         if (s == 0) { // the whole skip octet is inactive
124:           z += skip;
125:           break;
126:         }
127:       }
128:     }
129:     // Pick up any extra vertices in the Z ordering before the next rank's first owned element.
130:     //
131:     // This leads to poorly balanced vertices when eextent is a power of 2, since all the fringe vertices end up
132:     // on the last rank. A possible solution is to balance the Z-order vertices independently from the cells, which will
133:     // result in a lot of element closures being remote. We could finish marking boundary conditions, then do a round of
134:     // vertex ownership smoothing (which would reorder and redistribute vertices without touching element distribution).
135:     // Another would be to have an analytic ownership criteria for vertices in the fringe veextent - eextent. This would
136:     // complicate the job of identifying an owner and its offset.
137:     //
138:     // The current recommended approach is to let `-dm_distribute 1` (default) resolve vertex ownership. This is
139:     // *mandatory* with isoperiodicity (except in special cases) to remove standed vertices from local spaces. Here's
140:     // the issue:
141:     //
142:     // Consider this partition on rank 0 (left) and rank 1.
143:     //
144:     //    4 --------  5 -- 14 --10 -- 21 --11
145:     //                |          |          |
146:     // 7 -- 16 --  8  |          |          |
147:     // |           |  3 -------  7 -------  9
148:     // |           |             |          |
149:     // 4 --------  6 ------ 10   |          |
150:     // |           |         |   6 -- 16 -- 8
151:     // |           |         |
152:     // 3 ---11---  5 --18--  9
153:     //
154:     // The periodic face SF looks like
155:     // [0] Number of roots=21, leaves=1, remote ranks=1
156:     // [0] 16 <- (0,11)
157:     // [1] Number of roots=22, leaves=2, remote ranks=2
158:     // [1] 14 <- (0,18)
159:     // [1] 21 <- (1,16)
160:     //
161:     // In handling face (0,16), rank 0 learns that (0,7) and (0,8) map to (0,3) and (0,5) respectively, thus we won't use
162:     // the point SF links to (1,4) and (1,5). Rank 1 learns about the periodic mapping of (1,5) while handling face
163:     // (1,14), but never learns that vertex (1,4) has been mapped to (0,3) by face (0,16).
164:     //
165:     // We can relatively easily inform vertex (1,4) of this mapping, but it stays in rank 1's local space despite not
166:     // being in the closure and thus not being contributed to. This would be mostly harmless except that some viewer
167:     // routines expect all local points to be somehow significant. It is not easy to analytically remove the (1,4)
168:     // vertex because the point SF and isoperiodic face SF would need to be updated to account for removal of the
169:     // stranded vertices.
170:     for (; z <= ZEncode(layout->vextent); z++) {
171:       Ijk loc = ZCodeSplit(z);
172:       if (IjkActive(layout->eextent, loc)) break;
173:       z += ZStepOct(z);
174:     }
175:     layout->zstarts[r + 1] = z;
176:   }
177:   layout->zstarts[size] = ZEncode(layout->vextent);
178:   PetscFunctionReturn(PETSC_SUCCESS);
179: }

181: static PetscInt ZLayoutElementsOnRank(const ZLayout *layout, PetscMPIInt rank)
182: {
183:   PetscInt remote_elem = 0;
184:   for (ZCode rz = layout->zstarts[rank]; rz < layout->zstarts[rank + 1]; rz++) {
185:     Ijk loc = ZCodeSplit(rz);
186:     if (IjkActive(layout->eextent, loc)) remote_elem++;
187:     else rz += ZStepOct(rz);
188:   }
189:   return remote_elem;
190: }

192: static PetscInt ZCodeFind(ZCode key, PetscInt n, const ZCode X[])
193: {
194:   PetscInt lo = 0, hi = n;

196:   if (n == 0) return -1;
197:   while (hi - lo > 1) {
198:     PetscInt mid = lo + (hi - lo) / 2;
199:     if (key < X[mid]) hi = mid;
200:     else lo = mid;
201:   }
202:   return key == X[lo] ? lo : -(lo + (key > X[lo]) + 1);
203: }

205: static inline PetscBool IsPointInsideStratum(PetscInt point, PetscInt pStart, PetscInt pEnd)
206: {
207:   return (point >= pStart && point < pEnd) ? PETSC_TRUE : PETSC_FALSE;
208: }

210: static PetscErrorCode DMPlexCreateBoxMesh_Tensor_SFC_Periodicity_Private(DM dm, const ZLayout *layout, const ZCode *vert_z, PetscSegBuffer per_faces[3], const PetscReal *lower, const PetscReal *upper, const DMBoundaryType *periodicity, PetscSegBuffer donor_face_closure[3], PetscSegBuffer my_donor_faces[3])
211: {
212:   MPI_Comm    comm;
213:   PetscInt    dim, vStart, vEnd;
214:   PetscMPIInt size;
215:   PetscSF     face_sfs[3];
216:   PetscScalar transforms[3][4][4] = {{{0}}};

218:   PetscFunctionBegin;
219:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
220:   PetscCallMPI(MPI_Comm_size(comm, &size));
221:   PetscCall(DMGetDimension(dm, &dim));
222:   const PetscInt csize = PetscPowInt(2, dim - 1);
223:   PetscCall(DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd));

225:   PetscInt num_directions = 0;
226:   for (PetscInt direction = 0; direction < dim; direction++) {
227:     PetscCount   num_faces;
228:     PetscInt    *faces;
229:     ZCode       *donor_verts, *donor_minz;
230:     PetscSFNode *leaf;
231:     PetscCount   num_multiroots = 0;
232:     PetscInt     pStart, pEnd;
233:     PetscBool    sorted;
234:     PetscInt     inum_faces;

236:     if (periodicity[direction] != DM_BOUNDARY_PERIODIC) continue;
237:     PetscCall(PetscSegBufferGetSize(per_faces[direction], &num_faces));
238:     PetscCall(PetscSegBufferExtractInPlace(per_faces[direction], &faces));
239:     PetscCall(PetscSegBufferExtractInPlace(donor_face_closure[direction], &donor_verts));
240:     PetscCall(PetscMalloc1(num_faces, &donor_minz));
241:     PetscCall(PetscMalloc1(num_faces, &leaf));
242:     for (PetscCount i = 0; i < num_faces; i++) {
243:       ZCode minz = donor_verts[i * csize];

245:       for (PetscInt j = 1; j < csize; j++) minz = PetscMin(minz, donor_verts[i * csize + j]);
246:       donor_minz[i] = minz;
247:     }
248:     PetscCall(PetscIntCast(num_faces, &inum_faces));
249:     PetscCall(PetscSortedInt64(inum_faces, (const PetscInt64 *)donor_minz, &sorted));
250:     // If a donor vertex were chosen to broker multiple faces, we would have a logic error.
251:     // Checking for sorting is a cheap check that there are no duplicates.
252:     PetscCheck(sorted, PETSC_COMM_SELF, PETSC_ERR_PLIB, "minz not sorted; possible duplicates not checked");
253:     for (PetscCount i = 0; i < num_faces;) {
254:       ZCode       z = donor_minz[i];
255:       PetscMPIInt remote_rank, remote_count = 0;

257:       PetscCall(PetscMPIIntCast(ZCodeFind(z, size + 1, layout->zstarts), &remote_rank));
258:       if (remote_rank < 0) remote_rank = -(remote_rank + 1) - 1;
259:       // Process all the vertices on this rank
260:       for (ZCode rz = layout->zstarts[remote_rank]; rz < layout->zstarts[remote_rank + 1]; rz++) {
261:         Ijk loc = ZCodeSplit(rz);

263:         if (rz == z) {
264:           leaf[i].rank  = remote_rank;
265:           leaf[i].index = remote_count;
266:           i++;
267:           if (i == num_faces) break;
268:           z = donor_minz[i];
269:         }
270:         if (IjkActive(layout->vextent, loc)) remote_count++;
271:       }
272:     }
273:     PetscCall(PetscFree(donor_minz));
274:     PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), &face_sfs[num_directions]));
275:     PetscCall(PetscSFSetGraph(face_sfs[num_directions], vEnd - vStart, inum_faces, NULL, PETSC_USE_POINTER, leaf, PETSC_USE_POINTER));
276:     const PetscInt *my_donor_degree;
277:     PetscCall(PetscSFComputeDegreeBegin(face_sfs[num_directions], &my_donor_degree));
278:     PetscCall(PetscSFComputeDegreeEnd(face_sfs[num_directions], &my_donor_degree));

280:     for (PetscInt i = 0; i < vEnd - vStart; i++) {
281:       num_multiroots += my_donor_degree[i];
282:       if (my_donor_degree[i] == 0) continue;
283:       PetscAssert(my_donor_degree[i] == 1, PETSC_COMM_SELF, PETSC_ERR_SUP, "Local vertex has multiple faces");
284:     }
285:     PetscInt  *my_donors, *donor_indices, *my_donor_indices;
286:     PetscCount num_my_donors;

288:     PetscCall(PetscSegBufferGetSize(my_donor_faces[direction], &num_my_donors));
289:     PetscCheck(num_my_donors == num_multiroots, PETSC_COMM_SELF, PETSC_ERR_SUP, "Donor request (%" PetscCount_FMT ") does not match expected donors (%" PetscCount_FMT ")", num_my_donors, num_multiroots);
290:     PetscCall(PetscSegBufferExtractInPlace(my_donor_faces[direction], &my_donors));
291:     PetscCall(PetscMalloc1(vEnd - vStart, &my_donor_indices));
292:     for (PetscCount i = 0; i < num_my_donors; i++) {
293:       PetscInt f = my_donors[i];
294:       PetscInt num_points, *points = NULL, minv = PETSC_INT_MAX;

296:       PetscCall(DMPlexGetTransitiveClosure(dm, f, PETSC_TRUE, &num_points, &points));
297:       for (PetscInt j = 0; j < num_points; j++) {
298:         PetscInt p = points[2 * j];
299:         if (!IsPointInsideStratum(p, vStart, vEnd)) continue;
300:         minv = PetscMin(minv, p);
301:       }
302:       PetscCall(DMPlexRestoreTransitiveClosure(dm, f, PETSC_TRUE, &num_points, &points));
303:       PetscAssert(my_donor_degree[minv - vStart] == 1, PETSC_COMM_SELF, PETSC_ERR_SUP, "Local vertex not requested");
304:       my_donor_indices[minv - vStart] = f;
305:     }
306:     PetscCall(PetscMalloc1(num_faces, &donor_indices));
307:     PetscCall(PetscSFBcastBegin(face_sfs[num_directions], MPIU_INT, my_donor_indices, donor_indices, MPI_REPLACE));
308:     PetscCall(PetscSFBcastEnd(face_sfs[num_directions], MPIU_INT, my_donor_indices, donor_indices, MPI_REPLACE));
309:     PetscCall(PetscFree(my_donor_indices));
310:     // Modify our leafs so they point to donor faces instead of donor minz. Additionally, give them indices as faces.
311:     for (PetscCount i = 0; i < num_faces; i++) leaf[i].index = donor_indices[i];
312:     PetscCall(PetscFree(donor_indices));
313:     PetscCall(DMPlexGetChart(dm, &pStart, &pEnd));
314:     PetscCall(PetscSFSetGraph(face_sfs[num_directions], pEnd - pStart, inum_faces, faces, PETSC_COPY_VALUES, leaf, PETSC_OWN_POINTER));
315:     {
316:       char face_sf_name[PETSC_MAX_PATH_LEN];
317:       PetscCall(PetscSNPrintf(face_sf_name, sizeof face_sf_name, "Z-order Isoperiodic Faces #%" PetscInt_FMT, num_directions));
318:       PetscCall(PetscObjectSetName((PetscObject)face_sfs[num_directions], face_sf_name));
319:     }

321:     transforms[num_directions][0][0]         = 1;
322:     transforms[num_directions][1][1]         = 1;
323:     transforms[num_directions][2][2]         = 1;
324:     transforms[num_directions][3][3]         = 1;
325:     transforms[num_directions][direction][3] = upper[direction] - lower[direction];
326:     num_directions++;
327:   }

329:   PetscCall(DMPlexSetIsoperiodicFaceSF(dm, num_directions, face_sfs));
330:   PetscCall(DMPlexSetIsoperiodicFaceTransform(dm, num_directions, (PetscScalar *)transforms));

332:   for (PetscInt i = 0; i < num_directions; i++) PetscCall(PetscSFDestroy(&face_sfs[i]));
333:   PetscFunctionReturn(PETSC_SUCCESS);
334: }

336: // This is a DMGlobalToLocalHook that applies the affine offsets. When extended for rotated periodicity, it'll need to
337: // apply a rotatonal transform and similar operations will be needed for fields (e.g., to rotate a velocity vector).
338: // We use this crude approach here so we don't have to write new GPU kernels yet.
339: static PetscErrorCode DMCoordAddPeriodicOffsets_Private(DM dm, Vec g, InsertMode mode, Vec l, void *ctx)
340: {
341:   PetscFunctionBegin;
342:   // These `VecScatter`s should be merged to improve efficiency; the scatters cannot be overlapped.
343:   for (PetscInt i = 0; i < dm->periodic.num_affines; i++) {
344:     PetscCall(VecScatterBegin(dm->periodic.affine_to_local[i], dm->periodic.affine[i], l, ADD_VALUES, SCATTER_FORWARD));
345:     PetscCall(VecScatterEnd(dm->periodic.affine_to_local[i], dm->periodic.affine[i], l, ADD_VALUES, SCATTER_FORWARD));
346:   }
347:   PetscFunctionReturn(PETSC_SUCCESS);
348: }

350: // Modify Vec based on the transformation of `point` for the given section and field
351: static PetscErrorCode DMPlexOrientFieldPointVec(DM dm, PetscSection section, PetscInt field, Vec V, PetscInt point, PetscInt orientation)
352: {
353:   PetscScalar        *copy, *V_arr;
354:   PetscInt            dof, off, point_ornt[2] = {point, orientation};
355:   const PetscInt    **perms;
356:   const PetscScalar **rots;

358:   PetscFunctionBeginUser;
359:   PetscCall(PetscSectionGetDof(section, point, &dof));
360:   PetscCall(PetscSectionGetOffset(section, point, &off));
361:   PetscCall(VecGetArray(V, &V_arr));
362:   PetscCall(DMGetWorkArray(dm, dof, MPIU_SCALAR, &copy));
363:   PetscArraycpy(copy, &V_arr[off], dof);

365:   PetscCall(PetscSectionGetFieldPointSyms(section, field, 1, point_ornt, &perms, &rots));
366:   for (PetscInt i = 0; i < dof; i++) {
367:     if (perms[0]) V_arr[off + perms[0][i]] = copy[i];
368:     if (rots[0]) V_arr[off + perms[0][i]] *= rots[0][i];
369:   }

371:   PetscCall(PetscSectionRestoreFieldPointSyms(section, field, 1, point_ornt, &perms, &rots));
372:   PetscCall(DMRestoreWorkArray(dm, dof, MPIU_SCALAR, &copy));
373:   PetscCall(VecRestoreArray(V, &V_arr));
374:   PetscFunctionReturn(PETSC_SUCCESS);
375: }

377: // Reorient the point in the DMPlex while also applying necessary corrections to other structures (e.g. coordinates)
378: static PetscErrorCode DMPlexOrientPointWithCorrections(DM dm, PetscInt point, PetscInt ornt)
379: {
380:   // TODO: Potential speed up if we early exit for ornt == 0 (i.e. if ornt is identity, we don't need to do anything)
381:   PetscFunctionBeginUser;
382:   PetscCall(DMPlexOrientPoint(dm, point, ornt));

384:   { // Correct coordinates based on new cone ordering
385:     DM           cdm;
386:     PetscSection csection;
387:     Vec          coordinates;
388:     PetscInt     pStart, pEnd;

390:     PetscCall(DMGetCoordinatesLocal(dm, &coordinates));
391:     PetscCall(DMGetCoordinateDM(dm, &cdm));
392:     PetscCall(DMGetLocalSection(cdm, &csection));
393:     PetscCall(PetscSectionGetChart(csection, &pStart, &pEnd));
394:     if (IsPointInsideStratum(point, pStart, pEnd)) PetscCall(DMPlexOrientFieldPointVec(cdm, csection, 0, coordinates, point, ornt));
395:   }
396:   // TODO: Correct sfNatural
397:   PetscFunctionReturn(PETSC_SUCCESS);
398: }

400: // Creates SF to communicate data from donor to periodic faces. The data can be different sizes per donor-periodic pair and is given in `point_sizes[]`
401: static PetscErrorCode CreateDonorToPeriodicSF(DM dm, PetscSF face_sf, PetscInt pStart, PetscInt pEnd, const PetscInt point_sizes[], PetscInt *rootbuffersize, PetscInt *leafbuffersize, PetscBT *rootbt, PetscSF *sf_closure)
402: {
403:   MPI_Comm           comm;
404:   PetscMPIInt        rank;
405:   PetscInt           nroots, nleaves;
406:   PetscInt          *rootdata, *leafdata;
407:   const PetscInt    *filocal;
408:   const PetscSFNode *firemote;

410:   PetscFunctionBeginUser;
411:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
412:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

414:   PetscCall(PetscSFGetGraph(face_sf, &nroots, &nleaves, &filocal, &firemote));
415:   PetscCall(PetscCalloc2(2 * nroots, &rootdata, 2 * nroots, &leafdata));
416:   for (PetscInt i = 0; i < nleaves; i++) {
417:     PetscInt point = filocal[i];
418:     PetscCheck(IsPointInsideStratum(point, pStart, pEnd), PETSC_COMM_SELF, PETSC_ERR_PLIB, "Point %" PetscInt_FMT " in leaves exists outside of stratum [%" PetscInt_FMT ", %" PetscInt_FMT ")", point, pStart, pEnd);
419:     leafdata[point] = point_sizes[point - pStart];
420:   }
421:   PetscCall(PetscSFReduceBegin(face_sf, MPIU_INT, leafdata, rootdata + nroots, MPIU_SUM));
422:   PetscCall(PetscSFReduceEnd(face_sf, MPIU_INT, leafdata, rootdata + nroots, MPIU_SUM));

424:   PetscInt root_offset = 0;
425:   PetscCall(PetscBTCreate(nroots, rootbt));
426:   for (PetscInt p = 0; p < nroots; p++) {
427:     const PetscInt *donor_dof = rootdata + nroots;
428:     if (donor_dof[p] == 0) {
429:       rootdata[2 * p]     = -1;
430:       rootdata[2 * p + 1] = -1;
431:       continue;
432:     }
433:     PetscCall(PetscBTSet(*rootbt, p));
434:     PetscCheck(IsPointInsideStratum(p, pStart, pEnd), PETSC_COMM_SELF, PETSC_ERR_PLIB, "Point %" PetscInt_FMT " in roots exists outside of stratum [%" PetscInt_FMT ", %" PetscInt_FMT ")", p, pStart, pEnd);
435:     PetscInt p_size = point_sizes[p - pStart];
436:     PetscCheck(donor_dof[p] == p_size, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Reduced leaf data size (%" PetscInt_FMT ") does not match root data size (%" PetscInt_FMT ")", donor_dof[p], p_size);
437:     rootdata[2 * p]     = root_offset;
438:     rootdata[2 * p + 1] = p_size;
439:     root_offset += p_size;
440:   }
441:   PetscCall(PetscSFBcastBegin(face_sf, MPIU_2INT, rootdata, leafdata, MPI_REPLACE));
442:   PetscCall(PetscSFBcastEnd(face_sf, MPIU_2INT, rootdata, leafdata, MPI_REPLACE));
443:   // Count how many leaves we need to communicate the closures
444:   PetscInt leaf_offset = 0;
445:   for (PetscInt i = 0; i < nleaves; i++) {
446:     PetscInt point = filocal[i];
447:     if (leafdata[2 * point + 1] < 0) continue;
448:     leaf_offset += leafdata[2 * point + 1];
449:   }

451:   PetscSFNode *closure_leaf;
452:   PetscCall(PetscMalloc1(leaf_offset, &closure_leaf));
453:   leaf_offset = 0;
454:   for (PetscInt i = 0; i < nleaves; i++) {
455:     PetscInt point   = filocal[i];
456:     PetscInt cl_size = leafdata[2 * point + 1];
457:     if (cl_size < 0) continue;
458:     for (PetscInt j = 0; j < cl_size; j++) {
459:       closure_leaf[leaf_offset].rank  = firemote[i].rank;
460:       closure_leaf[leaf_offset].index = leafdata[2 * point] + j;
461:       leaf_offset++;
462:     }
463:   }

465:   PetscCall(PetscSFCreate(comm, sf_closure));
466:   PetscCall(PetscSFSetGraph(*sf_closure, root_offset, leaf_offset, NULL, PETSC_USE_POINTER, closure_leaf, PETSC_OWN_POINTER));
467:   *rootbuffersize = root_offset;
468:   *leafbuffersize = leaf_offset;
469:   PetscCall(PetscFree2(rootdata, leafdata));
470:   PetscFunctionReturn(PETSC_SUCCESS);
471: }

473: // Determine if `key` is in `array`. `array` does NOT need to be sorted
474: static inline PetscBool SearchIntArray(PetscInt key, PetscInt array_size, const PetscInt array[])
475: {
476:   for (PetscInt i = 0; i < array_size; i++)
477:     if (array[i] == key) return PETSC_TRUE;
478:   return PETSC_FALSE;
479: }

481: // Translate a cone in periodic points to the cone in donor points based on the `periodic2donor` array
482: static inline PetscErrorCode TranslateConeP2D(const PetscInt periodic_cone[], PetscInt cone_size, const PetscInt periodic2donor[], PetscInt p2d_count, PetscInt p2d_cone[])
483: {
484:   PetscFunctionBeginUser;
485:   for (PetscInt p = 0; p < cone_size; p++) {
486:     PetscInt p2d_index = -1;
487:     for (PetscInt p2d = 0; p2d < p2d_count; p2d++) {
488:       if (periodic2donor[p2d * 2] == periodic_cone[p]) p2d_index = p2d;
489:     }
490:     PetscCheck(p2d_index >= 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Could not find periodic point in periodic-to-donor array");
491:     p2d_cone[p] = periodic2donor[2 * p2d_index + 1];
492:   }
493:   PetscFunctionReturn(PETSC_SUCCESS);
494: }

496: // Corrects the cone order of periodic faces (and their transitive closure's cones) to match their donor face pair.
497: //
498: // This is done by:
499: // 1. Communicating the donor's vertex coordinates and recursive cones (i.e. its own cone and those of it's constituent edges) to it's periodic pairs
500: //    - The donor vertices have the isoperiodic transform applied to them such that they should match exactly
501: // 2. Translating the periodic vertices into the donor vertices point IDs
502: // 3. Translating the cone of each periodic point into the donor point IDs
503: // 4. Comparing the periodic-to-donor cone to the donor cone for each point
504: // 5. Apply the necessary transformation to the periodic cone to make it match the donor cone
505: static PetscErrorCode DMPlexCorrectOrientationForIsoperiodic(DM dm)
506: {
507:   MPI_Comm        comm;
508:   DM_Plex        *plex = (DM_Plex *)dm->data;
509:   PetscInt        nroots, nleaves;
510:   const PetscInt *filocal;
511:   DM              cdm;
512:   PetscSection    csection;
513:   Vec             coordinates;
514:   PetscInt        coords_field_id = 0;
515:   PetscBool       debug_printing  = PETSC_FALSE;

517:   PetscFunctionBeginUser;
518:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
519:   PetscCall(DMGetCoordinatesLocal(dm, &coordinates));
520:   PetscCheck(coordinates, comm, PETSC_ERR_ARG_WRONGSTATE, "DM must have coordinates to setup isoperiodic");
521:   PetscCall(DMGetCoordinateDM(dm, &cdm));
522:   PetscCall(DMGetLocalSection(cdm, &csection));

524:   for (PetscInt f = 0; f < plex->periodic.num_face_sfs; f++) {
525:     PetscSF face_sf                  = plex->periodic.face_sfs[f];
526:     const PetscScalar(*transform)[4] = (const PetscScalar(*)[4])plex->periodic.transform[f];
527:     PetscInt *face_vertices_size, *face_cones_size;
528:     PetscInt  fStart, fEnd, vStart, vEnd, rootnumvert, leafnumvert, rootconesize, leafconesize, dim;
529:     PetscSF   sf_vert_coords, sf_face_cones;
530:     PetscBT   rootbt;

532:     PetscCall(DMGetCoordinateDim(dm, &dim));
533:     PetscCall(DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd));
534:     PetscCall(DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd));
535:     PetscCall(PetscCalloc2(fEnd - fStart, &face_vertices_size, fEnd - fStart, &face_cones_size));

537:     // Create SFs to communicate donor vertices and donor cones to periodic faces
538:     for (PetscInt f = fStart, index = 0; f < fEnd; f++, index++) {
539:       PetscInt cl_size, *closure = NULL, num_vertices = 0;
540:       PetscCall(DMPlexGetTransitiveClosure(dm, f, PETSC_TRUE, &cl_size, &closure));
541:       for (PetscInt p = 0; p < cl_size; p++) {
542:         PetscInt cl_point = closure[2 * p];
543:         if (IsPointInsideStratum(cl_point, vStart, vEnd)) num_vertices++;
544:         else {
545:           PetscInt cone_size;
546:           PetscCall(DMPlexGetConeSize(dm, cl_point, &cone_size));
547:           face_cones_size[index] += cone_size + 2;
548:         }
549:       }
550:       face_vertices_size[index] = num_vertices;
551:       face_cones_size[index] += num_vertices;
552:       PetscCall(DMPlexRestoreTransitiveClosure(dm, f, PETSC_TRUE, &cl_size, &closure));
553:     }
554:     PetscCall(CreateDonorToPeriodicSF(dm, face_sf, fStart, fEnd, face_vertices_size, &rootnumvert, &leafnumvert, &rootbt, &sf_vert_coords));
555:     PetscCall(PetscBTDestroy(&rootbt));
556:     PetscCall(CreateDonorToPeriodicSF(dm, face_sf, fStart, fEnd, face_cones_size, &rootconesize, &leafconesize, &rootbt, &sf_face_cones));

558:     PetscCall(PetscSFGetGraph(face_sf, &nroots, &nleaves, &filocal, NULL));

560:     PetscReal *leaf_donor_coords;
561:     PetscInt  *leaf_donor_cones;

563:     { // Communicate donor coords and cones to the periodic faces
564:       PetscReal         *mydonor_vertices;
565:       PetscInt          *mydonor_cones;
566:       const PetscScalar *coords_arr;

568:       PetscCall(PetscCalloc2(rootnumvert * dim, &mydonor_vertices, rootconesize, &mydonor_cones));
569:       PetscCall(VecGetArrayRead(coordinates, &coords_arr));
570:       for (PetscInt donor_face = 0, donor_vert_offset = 0, donor_cone_offset = 0; donor_face < nroots; donor_face++) {
571:         if (!PetscBTLookup(rootbt, donor_face)) continue;
572:         PetscInt cl_size, *closure = NULL;

574:         PetscCall(DMPlexGetTransitiveClosure(dm, donor_face, PETSC_TRUE, &cl_size, &closure));
575:         // Pack vertex coordinates
576:         for (PetscInt p = 0; p < cl_size; p++) {
577:           PetscInt cl_point = closure[2 * p], dof, offset;
578:           if (!IsPointInsideStratum(cl_point, vStart, vEnd)) continue;
579:           mydonor_cones[donor_cone_offset++] = cl_point;
580:           PetscCall(PetscSectionGetFieldDof(csection, cl_point, coords_field_id, &dof));
581:           PetscCall(PetscSectionGetFieldOffset(csection, cl_point, coords_field_id, &offset));
582:           PetscAssert(dof == dim, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Point %" PetscInt_FMT " has dof size %" PetscInt_FMT ", but should match dimension size %" PetscInt_FMT, cl_point, dof, dim);
583:           // Apply isoperiodic transform to donor vertices such that corresponding periodic vertices should match exactly
584:           for (PetscInt d = 0; d < dof; d++) mydonor_vertices[donor_vert_offset * dim + d] = PetscRealPart(coords_arr[offset + d]) + PetscRealPart(transform[d][3]);
585:           donor_vert_offset++;
586:         }
587:         // Pack cones of face points (including face itself)
588:         for (PetscInt p = 0; p < cl_size; p++) {
589:           PetscInt        cl_point = closure[2 * p], cone_size, depth;
590:           const PetscInt *cone;

592:           PetscCall(DMPlexGetConeSize(dm, cl_point, &cone_size));
593:           PetscCall(DMPlexGetCone(dm, cl_point, &cone));
594:           PetscCall(DMPlexGetPointDepth(dm, cl_point, &depth));
595:           if (depth == 0) continue; // don't include vertex depth
596:           mydonor_cones[donor_cone_offset++] = cone_size;
597:           mydonor_cones[donor_cone_offset++] = cl_point;
598:           PetscArraycpy(&mydonor_cones[donor_cone_offset], cone, cone_size);
599:           donor_cone_offset += cone_size;
600:         }
601:         PetscCall(DMPlexRestoreTransitiveClosure(dm, donor_face, PETSC_TRUE, &cl_size, &closure));
602:       }
603:       PetscCall(VecRestoreArrayRead(coordinates, &coords_arr));
604:       PetscCall(PetscBTDestroy(&rootbt));

606:       MPI_Datatype vertex_unit;
607:       PetscMPIInt  n;
608:       PetscCall(PetscMPIIntCast(dim, &n));
609:       PetscCallMPI(MPI_Type_contiguous(n, MPIU_REAL, &vertex_unit));
610:       PetscCallMPI(MPI_Type_commit(&vertex_unit));
611:       PetscCall(PetscMalloc2(leafnumvert * 3, &leaf_donor_coords, leafconesize, &leaf_donor_cones));
612:       PetscCall(PetscSFBcastBegin(sf_vert_coords, vertex_unit, mydonor_vertices, leaf_donor_coords, MPI_REPLACE));
613:       PetscCall(PetscSFBcastBegin(sf_face_cones, MPIU_INT, mydonor_cones, leaf_donor_cones, MPI_REPLACE));
614:       PetscCall(PetscSFBcastEnd(sf_vert_coords, vertex_unit, mydonor_vertices, leaf_donor_coords, MPI_REPLACE));
615:       PetscCall(PetscSFBcastEnd(sf_face_cones, MPIU_INT, mydonor_cones, leaf_donor_cones, MPI_REPLACE));
616:       PetscCall(PetscSFDestroy(&sf_vert_coords));
617:       PetscCall(PetscSFDestroy(&sf_face_cones));
618:       PetscCallMPI(MPI_Type_free(&vertex_unit));
619:       PetscCall(PetscFree2(mydonor_vertices, mydonor_cones));
620:     }

622:     { // Determine periodic orientation w/rt donor vertices and reorient
623:       PetscReal tol = PetscSqr(PETSC_MACHINE_EPSILON * 1e3);
624:       PetscInt *periodic2donor, dm_depth, maxConeSize;
625:       PetscInt  coords_offset = 0, cones_offset = 0;

627:       PetscCall(DMPlexGetDepth(dm, &dm_depth));
628:       PetscCall(DMPlexGetMaxSizes(dm, &maxConeSize, NULL));
629:       PetscCall(DMGetWorkArray(dm, 2 * PetscPowInt(maxConeSize, dm_depth - 1), MPIU_INT, &periodic2donor));

631:       // Translate the periodic face vertices into the donor vertices
632:       // Translation stored in periodic2donor
633:       for (PetscInt i = 0; i < nleaves; i++) {
634:         PetscInt  periodic_face = filocal[i], cl_size, num_verts = face_vertices_size[periodic_face - fStart];
635:         PetscInt  cones_size = face_cones_size[periodic_face - fStart], p2d_count = 0;
636:         PetscInt *closure = NULL;

638:         PetscCall(DMPlexGetTransitiveClosure(dm, periodic_face, PETSC_TRUE, &cl_size, &closure));
639:         for (PetscInt p = 0; p < cl_size; p++) {
640:           PetscInt     cl_point = closure[2 * p], coords_size, donor_vertex = -1;
641:           PetscScalar *coords = NULL;

643:           if (!IsPointInsideStratum(cl_point, vStart, vEnd)) continue;
644:           PetscCall(DMPlexVecGetClosure(dm, csection, coordinates, cl_point, &coords_size, &coords));
645:           PetscAssert(coords_size == dim, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Point %" PetscInt_FMT " has dof size %" PetscInt_FMT ", but should match dimension size %" PetscInt_FMT, cl_point, coords_size, dim);

647:           for (PetscInt v = 0; v < num_verts; v++) {
648:             PetscReal dist_sqr = 0;
649:             for (PetscInt d = 0; d < coords_size; d++) dist_sqr += PetscSqr(PetscRealPart(coords[d]) - leaf_donor_coords[(v + coords_offset) * dim + d]);
650:             if (dist_sqr < tol) {
651:               donor_vertex = leaf_donor_cones[cones_offset + v];
652:               break;
653:             }
654:           }
655:           PetscCheck(donor_vertex >= 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Periodic face %" PetscInt_FMT " could not find matching donor vertex for vertex %" PetscInt_FMT, periodic_face, cl_point);
656:           if (PetscDefined(USE_DEBUG)) {
657:             for (PetscInt c = 0; c < p2d_count; c++) PetscCheck(periodic2donor[2 * c + 1] != donor_vertex, comm, PETSC_ERR_PLIB, "Found repeated cone_point in periodic_ordering");
658:           }

660:           periodic2donor[2 * p2d_count + 0] = cl_point;
661:           periodic2donor[2 * p2d_count + 1] = donor_vertex;
662:           p2d_count++;
663:           PetscCall(DMPlexVecRestoreClosure(dm, csection, coordinates, cl_point, &coords_size, &coords));
664:         }
665:         coords_offset += num_verts;
666:         PetscCall(DMPlexRestoreTransitiveClosure(dm, periodic_face, PETSC_TRUE, &cl_size, &closure));

668:         { // Determine periodic orientation w/rt donor vertices and reorient
669:           PetscInt      depth, *p2d_cone, face_is_array[1] = {periodic_face};
670:           IS           *is_arrays, face_is;
671:           PetscSection *section_arrays;
672:           PetscInt     *donor_cone_array = &leaf_donor_cones[cones_offset + num_verts];

674:           PetscCall(ISCreateGeneral(PETSC_COMM_SELF, 1, face_is_array, PETSC_USE_POINTER, &face_is));
675:           PetscCall(DMPlexGetConeRecursive(dm, face_is, &depth, &is_arrays, &section_arrays));
676:           PetscCall(ISDestroy(&face_is));
677:           PetscCall(DMGetWorkArray(dm, maxConeSize, MPIU_INT, &p2d_cone));
678:           for (PetscInt d = 0; d < depth - 1; d++) {
679:             PetscInt        pStart, pEnd;
680:             PetscSection    section = section_arrays[d];
681:             const PetscInt *periodic_cone_arrays, *periodic_point_arrays;

683:             PetscCall(ISGetIndices(is_arrays[d], &periodic_cone_arrays));
684:             PetscCall(ISGetIndices(is_arrays[d + 1], &periodic_point_arrays)); // Points at d+1 correspond to the cones at d
685:             PetscCall(PetscSectionGetChart(section_arrays[d], &pStart, &pEnd));
686:             for (PetscInt p = pStart; p < pEnd; p++) {
687:               PetscInt periodic_cone_size, periodic_cone_offset, periodic_point = periodic_point_arrays[p];

689:               PetscCall(PetscSectionGetDof(section, p, &periodic_cone_size));
690:               PetscCall(PetscSectionGetOffset(section, p, &periodic_cone_offset));
691:               const PetscInt *periodic_cone = &periodic_cone_arrays[periodic_cone_offset];
692:               PetscCall(TranslateConeP2D(periodic_cone, periodic_cone_size, periodic2donor, p2d_count, p2d_cone));

694:               // Find the donor cone that matches the periodic point's cone
695:               PetscInt  donor_cone_offset = 0, donor_point = -1, *donor_cone = NULL;
696:               PetscBool cone_matches = PETSC_FALSE;
697:               while (donor_cone_offset < cones_size - num_verts) {
698:                 PetscInt donor_cone_size = donor_cone_array[donor_cone_offset];
699:                 donor_point              = donor_cone_array[donor_cone_offset + 1];
700:                 donor_cone               = &donor_cone_array[donor_cone_offset + 2];

702:                 if (donor_cone_size != periodic_cone_size) goto next_cone;
703:                 for (PetscInt c = 0; c < periodic_cone_size; c++) {
704:                   cone_matches = SearchIntArray(donor_cone[c], periodic_cone_size, p2d_cone);
705:                   if (!cone_matches) goto next_cone;
706:                 }
707:                 // Save the found donor cone's point to the translation array. These will be used for higher depth points.
708:                 // i.e. we save the edge translations for when we look for face cones
709:                 periodic2donor[2 * p2d_count + 0] = periodic_point;
710:                 periodic2donor[2 * p2d_count + 1] = donor_point;
711:                 p2d_count++;
712:                 break;

714:               next_cone:
715:                 donor_cone_offset += donor_cone_size + 2;
716:               }
717:               PetscCheck(donor_cone_offset < cones_size - num_verts, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Could not find donor cone equivalent to cone of periodic point %" PetscInt_FMT, periodic_point);

719:               { // Compare the donor cone with the translated periodic cone and reorient
720:                 PetscInt       ornt;
721:                 DMPolytopeType cell_type;
722:                 PetscBool      found;
723:                 PetscCall(DMPlexGetCellType(dm, periodic_point, &cell_type));
724:                 PetscCall(DMPolytopeMatchOrientation(cell_type, donor_cone, p2d_cone, &ornt, &found));
725:                 PetscCheck(found, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONG, "Could not find transformation between donor (%" PetscInt_FMT ") and periodic (%" PetscInt_FMT ") cone's", periodic_point, donor_point);
726:                 if (debug_printing) PetscCall(PetscPrintf(PETSC_COMM_SELF, "Reorienting point %" PetscInt_FMT " by %" PetscInt_FMT "\n", periodic_point, ornt));
727:                 PetscCall(DMPlexOrientPointWithCorrections(dm, periodic_point, ornt));
728:               }
729:             }
730:             PetscCall(ISRestoreIndices(is_arrays[d], &periodic_cone_arrays));
731:             PetscCall(ISRestoreIndices(is_arrays[d + 1], &periodic_point_arrays));
732:           }
733:           PetscCall(DMRestoreWorkArray(dm, maxConeSize, MPIU_INT, &p2d_cone));
734:           PetscCall(DMPlexRestoreConeRecursive(dm, face_is, &depth, &is_arrays, &section_arrays));
735:         }

737:         PetscCall(DMPlexRestoreTransitiveClosure(dm, periodic_face, PETSC_TRUE, &cl_size, &closure));
738:         cones_offset += cones_size;
739:       }
740:       PetscCall(DMRestoreWorkArray(dm, 2 * PetscPowInt(maxConeSize, dm_depth - 1), MPIU_INT, &periodic2donor));
741:     }

743:     PetscCall(PetscFree2(leaf_donor_coords, leaf_donor_cones));
744:     PetscCall(PetscFree2(face_vertices_size, face_cones_size));
745:   }
746:   PetscFunctionReturn(PETSC_SUCCESS);
747: }

749: // Start with an SF for a positive depth (e.g., faces) and create a new SF for matched closure.
750: //
751: // Output Arguments:
752: //
753: // + closure_sf - augmented point SF (see `DMGetPointSF()`) that includes the faces and all points in its closure. This
754: //   can be used to create a global section and section SF.
755: // - is_points - array of index sets for just the points in the closure of `face_sf`. These may be used to apply an affine
756: //   transformation to periodic dofs; see DMPeriodicCoordinateSetUp_Internal().
757: //
758: static PetscErrorCode DMPlexCreateIsoperiodicPointSF_Private(DM dm, PetscInt num_face_sfs, PetscSF *face_sfs, PetscSF *closure_sf, IS **is_points)
759: {
760:   MPI_Comm           comm;
761:   PetscMPIInt        rank;
762:   PetscSF            point_sf;
763:   PetscInt           nroots, nleaves;
764:   const PetscInt    *filocal;
765:   const PetscSFNode *firemote;

767:   PetscFunctionBegin;
768:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
769:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
770:   PetscCall(DMGetPointSF(dm, &point_sf)); // Point SF has remote points
771:   PetscCall(PetscMalloc1(num_face_sfs, is_points));

773:   PetscCall(DMPlexCorrectOrientationForIsoperiodic(dm));

775:   for (PetscInt f = 0; f < num_face_sfs; f++) {
776:     PetscSF   face_sf = face_sfs[f];
777:     PetscInt *cl_sizes;
778:     PetscInt  fStart, fEnd, rootbuffersize, leafbuffersize;
779:     PetscSF   sf_closure;
780:     PetscBT   rootbt;

782:     PetscCall(DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd));
783:     PetscCall(PetscMalloc1(fEnd - fStart, &cl_sizes));
784:     for (PetscInt f = fStart, index = 0; f < fEnd; f++, index++) {
785:       PetscInt cl_size, *closure = NULL;
786:       PetscCall(DMPlexGetTransitiveClosure(dm, f, PETSC_TRUE, &cl_size, &closure));
787:       cl_sizes[index] = cl_size - 1;
788:       PetscCall(DMPlexRestoreTransitiveClosure(dm, f, PETSC_TRUE, &cl_size, &closure));
789:     }

791:     PetscCall(CreateDonorToPeriodicSF(dm, face_sf, fStart, fEnd, cl_sizes, &rootbuffersize, &leafbuffersize, &rootbt, &sf_closure));
792:     PetscCall(PetscFree(cl_sizes));
793:     PetscCall(PetscSFGetGraph(face_sf, &nroots, &nleaves, &filocal, &firemote));

795:     PetscSFNode *leaf_donor_closure;
796:     { // Pack root buffer with owner for every point in the root cones
797:       PetscSFNode       *donor_closure;
798:       const PetscInt    *pilocal;
799:       const PetscSFNode *piremote;
800:       PetscInt           npoints;

802:       PetscCall(PetscSFGetGraph(point_sf, NULL, &npoints, &pilocal, &piremote));
803:       PetscCall(PetscCalloc1(rootbuffersize, &donor_closure));
804:       for (PetscInt p = 0, root_offset = 0; p < nroots; p++) {
805:         if (!PetscBTLookup(rootbt, p)) continue;
806:         PetscInt cl_size, *closure = NULL;
807:         PetscCall(DMPlexGetTransitiveClosure(dm, p, PETSC_TRUE, &cl_size, &closure));
808:         for (PetscInt j = 1; j < cl_size; j++) {
809:           PetscInt c = closure[2 * j];
810:           if (pilocal) {
811:             PetscInt found = -1;
812:             if (npoints > 0) PetscCall(PetscFindInt(c, npoints, pilocal, &found));
813:             if (found >= 0) {
814:               donor_closure[root_offset++] = piremote[found];
815:               continue;
816:             }
817:           }
818:           // we own c
819:           donor_closure[root_offset].rank  = rank;
820:           donor_closure[root_offset].index = c;
821:           root_offset++;
822:         }
823:         PetscCall(DMPlexRestoreTransitiveClosure(dm, p, PETSC_TRUE, &cl_size, &closure));
824:       }

826:       PetscCall(PetscMalloc1(leafbuffersize, &leaf_donor_closure));
827:       PetscCall(PetscSFBcastBegin(sf_closure, MPIU_SF_NODE, donor_closure, leaf_donor_closure, MPI_REPLACE));
828:       PetscCall(PetscSFBcastEnd(sf_closure, MPIU_SF_NODE, donor_closure, leaf_donor_closure, MPI_REPLACE));
829:       PetscCall(PetscSFDestroy(&sf_closure));
830:       PetscCall(PetscFree(donor_closure));
831:     }

833:     PetscSFNode *new_iremote;
834:     PetscCall(PetscCalloc1(nroots, &new_iremote));
835:     for (PetscInt i = 0; i < nroots; i++) new_iremote[i].rank = -1;
836:     // Walk leaves and match vertices
837:     for (PetscInt i = 0, leaf_offset = 0; i < nleaves; i++) {
838:       PetscInt  point   = filocal[i], cl_size;
839:       PetscInt *closure = NULL;
840:       PetscCall(DMPlexGetTransitiveClosure(dm, point, PETSC_TRUE, &cl_size, &closure));
841:       for (PetscInt j = 1; j < cl_size; j++) {
842:         PetscInt    c  = closure[2 * j];
843:         PetscSFNode lc = leaf_donor_closure[leaf_offset];
844:         // printf("[%d] face %d.%d: %d ?-- (%d,%d)\n", rank, point, j, c, lc.rank, lc.index);
845:         if (new_iremote[c].rank == -1) {
846:           new_iremote[c] = lc;
847:         } else PetscCheck(new_iremote[c].rank == lc.rank && new_iremote[c].index == lc.index, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Mismatched cone ordering between faces");
848:         leaf_offset++;
849:       }
850:       PetscCall(DMPlexRestoreTransitiveClosure(dm, point, PETSC_TRUE, &cl_size, &closure));
851:     }
852:     PetscCall(PetscFree(leaf_donor_closure));

854:     // Include face points in closure SF
855:     for (PetscInt i = 0; i < nleaves; i++) new_iremote[filocal[i]] = firemote[i];
856:     // consolidate leaves
857:     PetscInt *leafdata;
858:     PetscCall(PetscMalloc1(nroots, &leafdata));
859:     PetscInt num_new_leaves = 0;
860:     for (PetscInt i = 0; i < nroots; i++) {
861:       if (new_iremote[i].rank == -1) continue;
862:       new_iremote[num_new_leaves] = new_iremote[i];
863:       leafdata[num_new_leaves]    = i;
864:       num_new_leaves++;
865:     }
866:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, num_new_leaves, leafdata, PETSC_COPY_VALUES, &(*is_points)[f]));

868:     PetscSF csf;
869:     PetscCall(PetscSFCreate(comm, &csf));
870:     PetscCall(PetscSFSetGraph(csf, nroots, num_new_leaves, leafdata, PETSC_COPY_VALUES, new_iremote, PETSC_COPY_VALUES));
871:     PetscCall(PetscFree(new_iremote)); // copy and delete because new_iremote is longer than it needs to be
872:     PetscCall(PetscFree(leafdata));
873:     PetscCall(PetscBTDestroy(&rootbt));

875:     PetscInt npoints;
876:     PetscCall(PetscSFGetGraph(point_sf, NULL, &npoints, NULL, NULL));
877:     if (npoints < 0) { // empty point_sf
878:       *closure_sf = csf;
879:     } else {
880:       PetscCall(PetscSFMerge(point_sf, csf, closure_sf));
881:       PetscCall(PetscSFDestroy(&csf));
882:     }
883:     if (f > 0) PetscCall(PetscSFDestroy(&point_sf)); // Only destroy if point_sf is from previous calls to PetscSFMerge
884:     point_sf = *closure_sf;                          // Use combined point + isoperiodic SF to define point ownership for further face_sf
885:   }
886:   PetscCall(PetscObjectSetName((PetscObject)*closure_sf, "Composed Periodic Points"));
887:   PetscFunctionReturn(PETSC_SUCCESS);
888: }

890: static PetscErrorCode DMGetIsoperiodicPointSF_Plex(DM dm, PetscSF *sf)
891: {
892:   DM_Plex *plex = (DM_Plex *)dm->data;

894:   PetscFunctionBegin;
895:   if (!plex->periodic.composed_sf) PetscCall(DMPlexCreateIsoperiodicPointSF_Private(dm, plex->periodic.num_face_sfs, plex->periodic.face_sfs, &plex->periodic.composed_sf, &plex->periodic.periodic_points));
896:   if (sf) *sf = plex->periodic.composed_sf;
897:   PetscFunctionReturn(PETSC_SUCCESS);
898: }

900: PetscErrorCode DMPlexMigrateIsoperiodicFaceSF_Internal(DM old_dm, DM dm, PetscSF sf_migration)
901: {
902:   DM_Plex    *plex = (DM_Plex *)old_dm->data;
903:   PetscSF     sf_point, *new_face_sfs;
904:   PetscMPIInt rank;

906:   PetscFunctionBegin;
907:   if (!plex->periodic.face_sfs) PetscFunctionReturn(PETSC_SUCCESS);
908:   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank));
909:   PetscCall(DMGetPointSF(dm, &sf_point));
910:   PetscCall(PetscMalloc1(plex->periodic.num_face_sfs, &new_face_sfs));

912:   for (PetscInt f = 0; f < plex->periodic.num_face_sfs; f++) {
913:     PetscInt           old_npoints, new_npoints, old_nleaf, new_nleaf, point_nleaf;
914:     PetscSFNode       *new_leafdata, *rootdata, *leafdata;
915:     const PetscInt    *old_local, *point_local;
916:     const PetscSFNode *old_remote, *point_remote;

918:     PetscCall(PetscSFGetGraph(plex->periodic.face_sfs[f], &old_npoints, &old_nleaf, &old_local, &old_remote));
919:     PetscCall(PetscSFGetGraph(sf_migration, NULL, &new_nleaf, NULL, NULL));
920:     PetscCall(PetscSFGetGraph(sf_point, &new_npoints, &point_nleaf, &point_local, &point_remote));
921:     PetscAssert(new_nleaf == new_npoints, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Expected migration leaf space to match new point root space");
922:     PetscCall(PetscMalloc3(old_npoints, &rootdata, old_npoints, &leafdata, new_npoints, &new_leafdata));

924:     // Fill new_leafdata with new owners of all points
925:     for (PetscInt i = 0; i < new_npoints; i++) {
926:       new_leafdata[i].rank  = rank;
927:       new_leafdata[i].index = i;
928:     }
929:     for (PetscInt i = 0; i < point_nleaf; i++) {
930:       PetscInt j      = point_local[i];
931:       new_leafdata[j] = point_remote[i];
932:     }
933:     // REPLACE is okay because every leaf agrees about the new owners
934:     PetscCall(PetscSFReduceBegin(sf_migration, MPIU_SF_NODE, new_leafdata, rootdata, MPI_REPLACE));
935:     PetscCall(PetscSFReduceEnd(sf_migration, MPIU_SF_NODE, new_leafdata, rootdata, MPI_REPLACE));
936:     // rootdata now contains the new owners

938:     // Send to leaves of old space
939:     for (PetscInt i = 0; i < old_npoints; i++) {
940:       leafdata[i].rank  = -1;
941:       leafdata[i].index = -1;
942:     }
943:     PetscCall(PetscSFBcastBegin(plex->periodic.face_sfs[f], MPIU_SF_NODE, rootdata, leafdata, MPI_REPLACE));
944:     PetscCall(PetscSFBcastEnd(plex->periodic.face_sfs[f], MPIU_SF_NODE, rootdata, leafdata, MPI_REPLACE));

946:     // Send to new leaf space
947:     PetscCall(PetscSFBcastBegin(sf_migration, MPIU_SF_NODE, leafdata, new_leafdata, MPI_REPLACE));
948:     PetscCall(PetscSFBcastEnd(sf_migration, MPIU_SF_NODE, leafdata, new_leafdata, MPI_REPLACE));

950:     PetscInt     nface = 0, *new_local;
951:     PetscSFNode *new_remote;
952:     for (PetscInt i = 0; i < new_npoints; i++) nface += (new_leafdata[i].rank >= 0);
953:     PetscCall(PetscMalloc1(nface, &new_local));
954:     PetscCall(PetscMalloc1(nface, &new_remote));
955:     nface = 0;
956:     for (PetscInt i = 0; i < new_npoints; i++) {
957:       if (new_leafdata[i].rank == -1) continue;
958:       new_local[nface]  = i;
959:       new_remote[nface] = new_leafdata[i];
960:       nface++;
961:     }
962:     PetscCall(PetscFree3(rootdata, leafdata, new_leafdata));
963:     PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), &new_face_sfs[f]));
964:     PetscCall(PetscSFSetGraph(new_face_sfs[f], new_npoints, nface, new_local, PETSC_OWN_POINTER, new_remote, PETSC_OWN_POINTER));
965:     {
966:       char new_face_sf_name[PETSC_MAX_PATH_LEN];
967:       PetscCall(PetscSNPrintf(new_face_sf_name, sizeof new_face_sf_name, "Migrated Isoperiodic Faces #%" PetscInt_FMT, f));
968:       PetscCall(PetscObjectSetName((PetscObject)new_face_sfs[f], new_face_sf_name));
969:     }
970:   }

972:   PetscCall(DMPlexSetIsoperiodicFaceSF(dm, plex->periodic.num_face_sfs, new_face_sfs));
973:   PetscCall(DMPlexSetIsoperiodicFaceTransform(dm, plex->periodic.num_face_sfs, (PetscScalar *)plex->periodic.transform));
974:   for (PetscInt f = 0; f < plex->periodic.num_face_sfs; f++) PetscCall(PetscSFDestroy(&new_face_sfs[f]));
975:   PetscCall(PetscFree(new_face_sfs));
976:   PetscFunctionReturn(PETSC_SUCCESS);
977: }

979: PetscErrorCode DMPeriodicCoordinateSetUp_Internal(DM dm)
980: {
981:   DM_Plex   *plex = (DM_Plex *)dm->data;
982:   PetscCount count;
983:   IS         isdof;
984:   PetscInt   dim;

986:   PetscFunctionBegin;
987:   if (!plex->periodic.face_sfs) PetscFunctionReturn(PETSC_SUCCESS);
988:   PetscCheck(plex->periodic.periodic_points, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Isoperiodic PointSF must be created before this function is called");

990:   PetscCall(DMGetCoordinateDim(dm, &dim));
991:   dm->periodic.num_affines = plex->periodic.num_face_sfs;
992:   PetscCall(PetscFree2(dm->periodic.affine_to_local, dm->periodic.affine));
993:   PetscCall(PetscMalloc2(dm->periodic.num_affines, &dm->periodic.affine_to_local, dm->periodic.num_affines, &dm->periodic.affine));

995:   for (PetscInt f = 0; f < plex->periodic.num_face_sfs; f++) {
996:     PetscInt        npoints, vsize, isize;
997:     const PetscInt *points;
998:     IS              is = plex->periodic.periodic_points[f];
999:     PetscSegBuffer  seg;
1000:     PetscSection    section;
1001:     PetscInt       *ind;
1002:     Vec             L, P;
1003:     VecType         vec_type;
1004:     VecScatter      scatter;
1005:     PetscScalar    *x;

1007:     PetscCall(DMGetLocalSection(dm, &section));
1008:     PetscCall(PetscSegBufferCreate(sizeof(PetscInt), 32, &seg));
1009:     PetscCall(ISGetSize(is, &npoints));
1010:     PetscCall(ISGetIndices(is, &points));
1011:     for (PetscInt i = 0; i < npoints; i++) {
1012:       PetscInt point = points[i], off, dof;

1014:       PetscCall(PetscSectionGetOffset(section, point, &off));
1015:       PetscCall(PetscSectionGetDof(section, point, &dof));
1016:       PetscAssert(dof % dim == 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Unexpected dof %" PetscInt_FMT " not divisible by dimension %" PetscInt_FMT, dof, dim);
1017:       for (PetscInt j = 0; j < dof / dim; j++) {
1018:         PetscInt *slot;

1020:         PetscCall(PetscSegBufferGetInts(seg, 1, &slot));
1021:         *slot = off / dim + j;
1022:       }
1023:     }
1024:     PetscCall(PetscSegBufferGetSize(seg, &count));
1025:     PetscCall(PetscSegBufferExtractAlloc(seg, &ind));
1026:     PetscCall(PetscSegBufferDestroy(&seg));
1027:     PetscCall(PetscIntCast(count, &isize));
1028:     PetscCall(ISCreateBlock(PETSC_COMM_SELF, dim, isize, ind, PETSC_OWN_POINTER, &isdof));

1030:     PetscCall(PetscIntCast(count * dim, &vsize));
1031:     PetscCall(DMGetLocalVector(dm, &L));
1032:     PetscCall(VecCreate(PETSC_COMM_SELF, &P));
1033:     PetscCall(VecSetSizes(P, vsize, vsize));
1034:     PetscCall(VecGetType(L, &vec_type));
1035:     PetscCall(VecSetType(P, vec_type));
1036:     PetscCall(VecScatterCreate(P, NULL, L, isdof, &scatter));
1037:     PetscCall(DMRestoreLocalVector(dm, &L));
1038:     PetscCall(ISDestroy(&isdof));

1040:     PetscCall(VecGetArrayWrite(P, &x));
1041:     for (PetscCount i = 0; i < count; i++) {
1042:       for (PetscInt j = 0; j < dim; j++) x[i * dim + j] = plex->periodic.transform[f][j][3];
1043:     }
1044:     PetscCall(VecRestoreArrayWrite(P, &x));

1046:     dm->periodic.affine_to_local[f] = scatter;
1047:     dm->periodic.affine[f]          = P;
1048:   }
1049:   PetscCall(DMGlobalToLocalHookAdd(dm, NULL, DMCoordAddPeriodicOffsets_Private, NULL));
1050:   PetscFunctionReturn(PETSC_SUCCESS);
1051: }

1053: PetscErrorCode DMPlexCreateBoxMesh_Tensor_SFC_Internal(DM dm, PetscInt dim, const PetscInt faces[], const PetscReal lower[], const PetscReal upper[], const DMBoundaryType periodicity[], PetscBool interpolate)
1054: {
1055:   PetscInt  eextent[3] = {1, 1, 1}, vextent[3] = {1, 1, 1};
1056:   const Ijk closure_1[] = {
1057:     {0, 0, 0},
1058:     {1, 0, 0},
1059:   };
1060:   const Ijk closure_2[] = {
1061:     {0, 0, 0},
1062:     {1, 0, 0},
1063:     {1, 1, 0},
1064:     {0, 1, 0},
1065:   };
1066:   const Ijk closure_3[] = {
1067:     {0, 0, 0},
1068:     {0, 1, 0},
1069:     {1, 1, 0},
1070:     {1, 0, 0},
1071:     {0, 0, 1},
1072:     {1, 0, 1},
1073:     {1, 1, 1},
1074:     {0, 1, 1},
1075:   };
1076:   const Ijk *const closure_dim[] = {NULL, closure_1, closure_2, closure_3};
1077:   // This must be kept consistent with DMPlexCreateCubeMesh_Internal
1078:   const PetscInt        face_marker_1[]   = {1, 2};
1079:   const PetscInt        face_marker_2[]   = {4, 2, 1, 3};
1080:   const PetscInt        face_marker_3[]   = {6, 5, 3, 4, 1, 2};
1081:   const PetscInt *const face_marker_dim[] = {NULL, face_marker_1, face_marker_2, face_marker_3};
1082:   // Orient faces so the normal is in the positive axis and the first vertex is the one closest to zero.
1083:   // These orientations can be determined by examining cones of a reference quad and hex element.
1084:   const PetscInt        face_orient_1[]   = {0, 0};
1085:   const PetscInt        face_orient_2[]   = {-1, 0, 0, -1};
1086:   const PetscInt        face_orient_3[]   = {-2, 0, -2, 1, -2, 0};
1087:   const PetscInt *const face_orient_dim[] = {NULL, face_orient_1, face_orient_2, face_orient_3};

1089:   PetscFunctionBegin;
1090:   PetscCall(PetscLogEventBegin(DMPLEX_CreateBoxSFC, dm, 0, 0, 0));
1091:   PetscAssertPointer(dm, 1);
1093:   PetscCall(DMSetDimension(dm, dim));
1094:   PetscMPIInt rank, size;
1095:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)dm), &size));
1096:   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank));
1097:   for (PetscInt i = 0; i < dim; i++) {
1098:     eextent[i] = faces[i];
1099:     vextent[i] = faces[i] + 1;
1100:   }
1101:   ZLayout layout;
1102:   PetscCall(ZLayoutCreate(size, eextent, vextent, &layout));
1103:   PetscZSet vset; // set of all vertices in the closure of the owned elements
1104:   PetscCall(PetscZSetCreate(&vset));
1105:   PetscInt local_elems = 0;
1106:   for (ZCode z = layout.zstarts[rank]; z < layout.zstarts[rank + 1]; z++) {
1107:     Ijk loc = ZCodeSplit(z);
1108:     if (IjkActive(layout.vextent, loc)) PetscCall(PetscZSetAdd(vset, z));
1109:     else {
1110:       z += ZStepOct(z);
1111:       continue;
1112:     }
1113:     if (IjkActive(layout.eextent, loc)) {
1114:       local_elems++;
1115:       // Add all neighboring vertices to set
1116:       for (PetscInt n = 0; n < PetscPowInt(2, dim); n++) {
1117:         Ijk   inc  = closure_dim[dim][n];
1118:         Ijk   nloc = {loc.i + inc.i, loc.j + inc.j, loc.k + inc.k};
1119:         ZCode v    = ZEncode(nloc);
1120:         PetscCall(PetscZSetAdd(vset, v));
1121:       }
1122:     }
1123:   }
1124:   PetscInt local_verts, off = 0;
1125:   ZCode   *vert_z;
1126:   PetscCall(PetscZSetGetSize(vset, &local_verts));
1127:   PetscCall(PetscMalloc1(local_verts, &vert_z));
1128:   PetscCall(PetscZSetGetElems(vset, &off, vert_z));
1129:   PetscCall(PetscZSetDestroy(&vset));
1130:   // ZCode is unsigned for bitwise convenience, but highest bit should never be set, so can interpret as signed
1131:   PetscCall(PetscSortInt64(local_verts, (PetscInt64 *)vert_z));

1133:   PetscCall(DMPlexSetChart(dm, 0, local_elems + local_verts));
1134:   for (PetscInt e = 0; e < local_elems; e++) PetscCall(DMPlexSetConeSize(dm, e, PetscPowInt(2, dim)));
1135:   PetscCall(DMSetUp(dm));
1136:   {
1137:     PetscInt e = 0;
1138:     for (ZCode z = layout.zstarts[rank]; z < layout.zstarts[rank + 1]; z++) {
1139:       Ijk loc = ZCodeSplit(z);
1140:       if (!IjkActive(layout.eextent, loc)) {
1141:         z += ZStepOct(z);
1142:         continue;
1143:       }
1144:       PetscInt cone[8], orient[8] = {0};
1145:       for (PetscInt n = 0; n < PetscPowInt(2, dim); n++) {
1146:         Ijk      inc  = closure_dim[dim][n];
1147:         Ijk      nloc = {loc.i + inc.i, loc.j + inc.j, loc.k + inc.k};
1148:         ZCode    v    = ZEncode(nloc);
1149:         PetscInt ci   = ZCodeFind(v, local_verts, vert_z);
1150:         PetscAssert(ci >= 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Did not find neighbor vertex in set");
1151:         cone[n] = local_elems + ci;
1152:       }
1153:       PetscCall(DMPlexSetCone(dm, e, cone));
1154:       PetscCall(DMPlexSetConeOrientation(dm, e, orient));
1155:       e++;
1156:     }
1157:   }

1159:   PetscCall(DMPlexSymmetrize(dm));
1160:   PetscCall(DMPlexStratify(dm));

1162:   { // Create point SF
1163:     PetscSF sf;
1164:     PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), &sf));
1165:     PetscInt owned_verts = ZCodeFind(layout.zstarts[rank + 1], local_verts, vert_z);
1166:     if (owned_verts < 0) owned_verts = -(owned_verts + 1); // We don't care whether the key was found
1167:     PetscInt     num_ghosts = local_verts - owned_verts;   // Due to sorting, owned vertices always come first
1168:     PetscInt    *local_ghosts;
1169:     PetscSFNode *ghosts;
1170:     PetscCall(PetscMalloc1(num_ghosts, &local_ghosts));
1171:     PetscCall(PetscMalloc1(num_ghosts, &ghosts));
1172:     for (PetscInt i = 0; i < num_ghosts;) {
1173:       ZCode       z = vert_z[owned_verts + i];
1174:       PetscMPIInt remote_rank, remote_count = 0;

1176:       PetscCall(PetscMPIIntCast(ZCodeFind(z, size + 1, layout.zstarts), &remote_rank));
1177:       if (remote_rank < 0) remote_rank = -(remote_rank + 1) - 1;
1178:       // We have a new remote rank; find all the ghost indices (which are contiguous in vert_z)

1180:       // Count the elements on remote_rank
1181:       PetscInt remote_elem = ZLayoutElementsOnRank(&layout, remote_rank);

1183:       // Traverse vertices and make ghost links
1184:       for (ZCode rz = layout.zstarts[remote_rank]; rz < layout.zstarts[remote_rank + 1]; rz++) {
1185:         Ijk loc = ZCodeSplit(rz);
1186:         if (rz == z) {
1187:           local_ghosts[i] = local_elems + owned_verts + i;
1188:           ghosts[i].rank  = remote_rank;
1189:           ghosts[i].index = remote_elem + remote_count;
1190:           i++;
1191:           if (i == num_ghosts) break;
1192:           z = vert_z[owned_verts + i];
1193:         }
1194:         if (IjkActive(layout.vextent, loc)) remote_count++;
1195:         else rz += ZStepOct(rz);
1196:       }
1197:     }
1198:     PetscCall(PetscSFSetGraph(sf, local_elems + local_verts, num_ghosts, local_ghosts, PETSC_OWN_POINTER, ghosts, PETSC_OWN_POINTER));
1199:     PetscCall(PetscObjectSetName((PetscObject)sf, "SFC Point SF"));
1200:     PetscCall(DMSetPointSF(dm, sf));
1201:     PetscCall(PetscSFDestroy(&sf));
1202:   }
1203:   {
1204:     Vec          coordinates;
1205:     PetscScalar *coords;
1206:     PetscSection coord_section;
1207:     PetscInt     coord_size;
1208:     PetscCall(DMGetCoordinateSection(dm, &coord_section));
1209:     PetscCall(PetscSectionSetNumFields(coord_section, 1));
1210:     PetscCall(PetscSectionSetFieldComponents(coord_section, 0, dim));
1211:     PetscCall(PetscSectionSetChart(coord_section, local_elems, local_elems + local_verts));
1212:     for (PetscInt v = 0; v < local_verts; v++) {
1213:       PetscInt point = local_elems + v;
1214:       PetscCall(PetscSectionSetDof(coord_section, point, dim));
1215:       PetscCall(PetscSectionSetFieldDof(coord_section, point, 0, dim));
1216:     }
1217:     PetscCall(PetscSectionSetUp(coord_section));
1218:     PetscCall(PetscSectionGetStorageSize(coord_section, &coord_size));
1219:     PetscCall(VecCreate(PETSC_COMM_SELF, &coordinates));
1220:     PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
1221:     PetscCall(VecSetSizes(coordinates, coord_size, PETSC_DETERMINE));
1222:     PetscCall(VecSetBlockSize(coordinates, dim));
1223:     PetscCall(VecSetType(coordinates, VECSTANDARD));
1224:     PetscCall(VecGetArray(coordinates, &coords));
1225:     for (PetscInt v = 0; v < local_verts; v++) {
1226:       Ijk loc             = ZCodeSplit(vert_z[v]);
1227:       coords[v * dim + 0] = lower[0] + loc.i * (upper[0] - lower[0]) / layout.eextent.i;
1228:       if (dim > 1) coords[v * dim + 1] = lower[1] + loc.j * (upper[1] - lower[1]) / layout.eextent.j;
1229:       if (dim > 2) coords[v * dim + 2] = lower[2] + loc.k * (upper[2] - lower[2]) / layout.eextent.k;
1230:     }
1231:     PetscCall(VecRestoreArray(coordinates, &coords));
1232:     PetscCall(DMSetCoordinatesLocal(dm, coordinates));
1233:     PetscCall(VecDestroy(&coordinates));
1234:   }
1235:   if (interpolate) {
1236:     PetscCall(DMPlexInterpolateInPlace_Internal(dm));

1238:     DMLabel label;
1239:     PetscCall(DMCreateLabel(dm, "Face Sets"));
1240:     PetscCall(DMGetLabel(dm, "Face Sets", &label));
1241:     PetscSegBuffer per_faces[3], donor_face_closure[3], my_donor_faces[3];
1242:     for (PetscInt i = 0; i < 3; i++) {
1243:       PetscCall(PetscSegBufferCreate(sizeof(PetscInt), 64, &per_faces[i]));
1244:       PetscCall(PetscSegBufferCreate(sizeof(PetscInt), 64, &my_donor_faces[i]));
1245:       PetscCall(PetscSegBufferCreate(sizeof(ZCode), 64 * PetscPowInt(2, dim), &donor_face_closure[i]));
1246:     }
1247:     PetscInt fStart, fEnd, vStart, vEnd;
1248:     PetscCall(DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd));
1249:     PetscCall(DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd));
1250:     for (PetscInt f = fStart; f < fEnd; f++) {
1251:       PetscInt npoints, *points = NULL, num_fverts = 0, fverts[8];
1252:       PetscCall(DMPlexGetTransitiveClosure(dm, f, PETSC_TRUE, &npoints, &points));
1253:       PetscInt bc_count[6] = {0};
1254:       for (PetscInt i = 0; i < npoints; i++) {
1255:         PetscInt p = points[2 * i];
1256:         if (!IsPointInsideStratum(p, vStart, vEnd)) continue;
1257:         fverts[num_fverts++] = p;
1258:         Ijk loc              = ZCodeSplit(vert_z[p - vStart]);
1259:         // Convention here matches DMPlexCreateCubeMesh_Internal
1260:         bc_count[0] += loc.i == 0;
1261:         bc_count[1] += loc.i == layout.vextent.i - 1;
1262:         bc_count[2] += loc.j == 0;
1263:         bc_count[3] += loc.j == layout.vextent.j - 1;
1264:         bc_count[4] += loc.k == 0;
1265:         bc_count[5] += loc.k == layout.vextent.k - 1;
1266:       }
1267:       PetscCall(DMPlexRestoreTransitiveClosure(dm, f, PETSC_TRUE, &npoints, &points));
1268:       for (PetscInt bc = 0, bc_match = 0; bc < 2 * dim; bc++) {
1269:         if (bc_count[bc] == PetscPowInt(2, dim - 1)) {
1270:           PetscCall(DMPlexOrientPoint(dm, f, face_orient_dim[dim][bc]));
1271:           if (periodicity[bc / 2] == DM_BOUNDARY_PERIODIC) {
1272:             PetscInt *put;
1273:             if (bc % 2 == 0) { // donor face; no label
1274:               PetscCall(PetscSegBufferGet(my_donor_faces[bc / 2], 1, &put));
1275:               *put = f;
1276:             } else { // periodic face
1277:               PetscCall(PetscSegBufferGet(per_faces[bc / 2], 1, &put));
1278:               *put = f;
1279:               ZCode *zput;
1280:               PetscCall(PetscSegBufferGet(donor_face_closure[bc / 2], num_fverts, &zput));
1281:               for (PetscInt i = 0; i < num_fverts; i++) {
1282:                 Ijk loc = ZCodeSplit(vert_z[fverts[i] - vStart]);
1283:                 switch (bc / 2) {
1284:                 case 0:
1285:                   loc.i = 0;
1286:                   break;
1287:                 case 1:
1288:                   loc.j = 0;
1289:                   break;
1290:                 case 2:
1291:                   loc.k = 0;
1292:                   break;
1293:                 }
1294:                 *zput++ = ZEncode(loc);
1295:               }
1296:             }
1297:             continue;
1298:           }
1299:           PetscAssert(bc_match == 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Face matches multiple face sets");
1300:           PetscCall(DMLabelSetValue(label, f, face_marker_dim[dim][bc]));
1301:           bc_match++;
1302:         }
1303:       }
1304:     }
1305:     // Ensure that the Coordinate DM has our new boundary labels
1306:     DM cdm;
1307:     PetscCall(DMGetCoordinateDM(dm, &cdm));
1308:     PetscCall(DMCopyLabels(dm, cdm, PETSC_COPY_VALUES, PETSC_FALSE, DM_COPY_LABELS_FAIL));
1309:     if (periodicity[0] == DM_BOUNDARY_PERIODIC || (dim > 1 && periodicity[1] == DM_BOUNDARY_PERIODIC) || (dim > 2 && periodicity[2] == DM_BOUNDARY_PERIODIC)) {
1310:       PetscCall(DMPlexCreateBoxMesh_Tensor_SFC_Periodicity_Private(dm, &layout, vert_z, per_faces, lower, upper, periodicity, donor_face_closure, my_donor_faces));
1311:     }
1312:     for (PetscInt i = 0; i < 3; i++) {
1313:       PetscCall(PetscSegBufferDestroy(&per_faces[i]));
1314:       PetscCall(PetscSegBufferDestroy(&donor_face_closure[i]));
1315:       PetscCall(PetscSegBufferDestroy(&my_donor_faces[i]));
1316:     }
1317:   }
1318:   PetscCall(PetscFree(layout.zstarts));
1319:   PetscCall(PetscFree(vert_z));
1320:   PetscCall(PetscLogEventEnd(DMPLEX_CreateBoxSFC, dm, 0, 0, 0));
1321:   PetscFunctionReturn(PETSC_SUCCESS);
1322: }

1324: /*@
1325:   DMPlexSetIsoperiodicFaceSF - Express periodicity from an existing mesh

1327:   Logically Collective

1329:   Input Parameters:
1330: + dm           - The `DMPLEX` on which to set periodicity
1331: . num_face_sfs - Number of `PetscSF`s in `face_sfs`
1332: - face_sfs     - Array of `PetscSF` in which roots are (owned) donor faces and leaves are faces that must be matched to a (possibly remote) donor face.

1334:   Level: advanced

1336:   Note:
1337:   One can use `-dm_plex_shape zbox` to use this mode of periodicity, wherein the periodic points are distinct both globally
1338:   and locally, but are paired when creating a global dof space.

1340: .seealso: [](ch_unstructured), `DMPLEX`, `DMGetGlobalSection()`, `DMPlexGetIsoperiodicFaceSF()`
1341: @*/
1342: PetscErrorCode DMPlexSetIsoperiodicFaceSF(DM dm, PetscInt num_face_sfs, PetscSF *face_sfs)
1343: {
1344:   DM_Plex *plex = (DM_Plex *)dm->data;

1346:   PetscFunctionBegin;
1348:   if (num_face_sfs) PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMGetIsoperiodicPointSF_C", DMGetIsoperiodicPointSF_Plex));
1349:   else PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMGetIsoperiodicPointSF_C", NULL));
1350:   if (num_face_sfs == plex->periodic.num_face_sfs && (num_face_sfs == 0 || face_sfs == plex->periodic.face_sfs)) PetscFunctionReturn(PETSC_SUCCESS);
1351:   PetscCall(DMSetGlobalSection(dm, NULL));

1353:   for (PetscInt i = 0; i < num_face_sfs; i++) PetscCall(PetscObjectReference((PetscObject)face_sfs[i]));

1355:   if (plex->periodic.num_face_sfs > 0) {
1356:     for (PetscInt i = 0; i < plex->periodic.num_face_sfs; i++) PetscCall(PetscSFDestroy(&plex->periodic.face_sfs[i]));
1357:     PetscCall(PetscFree(plex->periodic.face_sfs));
1358:   }

1360:   plex->periodic.num_face_sfs = num_face_sfs;
1361:   PetscCall(PetscCalloc1(num_face_sfs, &plex->periodic.face_sfs));
1362:   for (PetscInt i = 0; i < num_face_sfs; i++) plex->periodic.face_sfs[i] = face_sfs[i];

1364:   DM cdm = dm->coordinates[0].dm; // Can't DMGetCoordinateDM because it automatically creates one
1365:   if (cdm) {
1366:     PetscCall(DMPlexSetIsoperiodicFaceSF(cdm, num_face_sfs, face_sfs));
1367:     if (face_sfs) cdm->periodic.setup = DMPeriodicCoordinateSetUp_Internal;
1368:   }
1369:   PetscFunctionReturn(PETSC_SUCCESS);
1370: }

1372: /*@C
1373:   DMPlexGetIsoperiodicFaceSF - Obtain periodicity for a mesh

1375:   Logically Collective

1377:   Input Parameter:
1378: . dm - The `DMPLEX` for which to obtain periodic relation

1380:   Output Parameters:
1381: + num_face_sfs - Number of `PetscSF`s in the array
1382: - face_sfs     - Array of `PetscSF` in which roots are (owned) donor faces and leaves are faces that must be matched to a (possibly remote) donor face.

1384:   Level: advanced

1386: .seealso: [](ch_unstructured), `DMPLEX`, `DMGetGlobalSection()`, `DMPlexSetIsoperiodicFaceSF()`
1387: @*/
1388: PetscErrorCode DMPlexGetIsoperiodicFaceSF(DM dm, PetscInt *num_face_sfs, const PetscSF **face_sfs)
1389: {
1390:   DM_Plex *plex = (DM_Plex *)dm->data;

1392:   PetscFunctionBegin;
1394:   *face_sfs     = plex->periodic.face_sfs;
1395:   *num_face_sfs = plex->periodic.num_face_sfs;
1396:   PetscFunctionReturn(PETSC_SUCCESS);
1397: }

1399: /*@C
1400:   DMPlexSetIsoperiodicFaceTransform - set geometric transform from donor to periodic points

1402:   Logically Collective

1404:   Input Parameters:
1405: + dm - `DMPLEX` that has been configured with `DMPlexSetIsoperiodicFaceSF()`
1406: . n  - Number of transforms in array
1407: - t  - Array of 4x4 affine transformation basis.

1409:   Level: advanced

1411:   Notes:
1412:   Affine transforms are 4x4 matrices in which the leading 3x3 block expresses a rotation (or identity for no rotation),
1413:   the last column contains a translation vector, and the bottom row is all zero except the last entry, which must always
1414:   be 1. This representation is common in geometric modeling and allows affine transformations to be composed using
1415:   simple matrix multiplication.

1417:   Although the interface accepts a general affine transform, only affine translation is supported at present.

1419:   Developer Notes:
1420:   This interface should be replaced by making BasisTransform public, expanding it to support affine representations, and
1421:   adding GPU implementations to apply the G2L/L2G transforms.

1423: .seealso: [](ch_unstructured), `DMPLEX`, `DMGetGlobalSection()`, `DMPlexSetIsoperiodicFaceSF()`
1424: @*/
1425: PetscErrorCode DMPlexSetIsoperiodicFaceTransform(DM dm, PetscInt n, const PetscScalar t[])
1426: {
1427:   DM_Plex *plex = (DM_Plex *)dm->data;

1429:   PetscFunctionBegin;
1431:   PetscCheck(n == plex->periodic.num_face_sfs, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_OUTOFRANGE, "Number of transforms (%" PetscInt_FMT ") must equal number of isoperiodc face SFs (%" PetscInt_FMT ")", n, plex->periodic.num_face_sfs);

1433:   PetscCall(PetscFree(plex->periodic.transform));
1434:   PetscCall(PetscMalloc1(n, &plex->periodic.transform));
1435:   for (PetscInt i = 0; i < n; i++) {
1436:     for (PetscInt j = 0; j < 4; j++) {
1437:       for (PetscInt k = 0; k < 4; k++) {
1438:         PetscCheck(j != k || t[i * 16 + j * 4 + k] == 1., PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Rotated transforms not supported");
1439:         plex->periodic.transform[i][j][k] = t[i * 16 + j * 4 + k];
1440:       }
1441:     }
1442:   }
1443:   PetscFunctionReturn(PETSC_SUCCESS);
1444: }