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 referred 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 index array based on the transformation of `point` for the given section and field
351: // Used for correcting the sfNatural based on point reorientation
352: static PetscErrorCode DMPlexOrientFieldPointIndex(DM dm, PetscSection section, PetscInt field, PetscInt array_size, PetscInt array[], PetscInt point, PetscInt orientation)
353: {
354:   PetscInt        *copy;
355:   PetscInt         dof, off, point_ornt[2] = {point, orientation};
356:   const PetscInt **perms;

358:   PetscFunctionBeginUser;
359:   PetscCall(PetscSectionGetFieldPointSyms(section, field, 1, point_ornt, &perms, NULL));
360:   if (!perms) PetscFunctionReturn(PETSC_SUCCESS); // section may not have symmetries, such as Q2 finite elements
361:   PetscCall(PetscSectionGetDof(section, point, &dof));
362:   PetscCall(PetscSectionGetOffset(section, point, &off));
363:   PetscCheck(off + dof <= array_size, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Section indices exceed index array bounds");
364:   PetscCall(DMGetWorkArray(dm, dof, MPIU_INT, &copy));
365:   PetscArraycpy(copy, &array[off], dof);

367:   for (PetscInt i = 0; i < dof; i++) {
368:     if (perms[0]) array[off + perms[0][i]] = copy[i];
369:   }

371:   PetscCall(PetscSectionRestoreFieldPointSyms(section, field, 1, point_ornt, &perms, NULL));
372:   PetscCall(DMRestoreWorkArray(dm, dof, MPIU_INT, &copy));
373:   PetscFunctionReturn(PETSC_SUCCESS);
374: }

376: // Modify Vec based on the transformation of `point` for the given section and field
377: static PetscErrorCode DMPlexOrientFieldPointVec(DM dm, PetscSection section, PetscInt field, Vec V, PetscInt point, PetscInt orientation)
378: {
379:   PetscScalar        *copy, *V_arr;
380:   PetscInt            dof, off, point_ornt[2] = {point, orientation};
381:   const PetscInt    **perms;
382:   const PetscScalar **rots;

384:   PetscFunctionBeginUser;
385:   PetscCall(PetscSectionGetFieldPointSyms(section, field, 1, point_ornt, &perms, &rots));
386:   if (!perms) PetscFunctionReturn(PETSC_SUCCESS); // section may not have symmetries, such as Q2 finite elements
387:   PetscCall(PetscSectionGetDof(section, point, &dof));
388:   PetscCall(PetscSectionGetOffset(section, point, &off));
389:   PetscCall(VecGetArray(V, &V_arr));
390:   PetscCall(DMGetWorkArray(dm, dof, MPIU_SCALAR, &copy));
391:   PetscArraycpy(copy, &V_arr[off], dof);

393:   for (PetscInt i = 0; i < dof; i++) {
394:     if (perms[0]) V_arr[off + perms[0][i]] = copy[i];
395:     if (rots[0]) V_arr[off + perms[0][i]] *= rots[0][i];
396:   }

398:   PetscCall(PetscSectionRestoreFieldPointSyms(section, field, 1, point_ornt, &perms, &rots));
399:   PetscCall(DMRestoreWorkArray(dm, dof, MPIU_SCALAR, &copy));
400:   PetscCall(VecRestoreArray(V, &V_arr));
401:   PetscFunctionReturn(PETSC_SUCCESS);
402: }

404: // Reorient the point in the DMPlex while also applying necessary corrections to other structures (e.g. coordinates)
405: static PetscErrorCode DMPlexOrientPointWithCorrections(DM dm, PetscInt point, PetscInt ornt, PetscSection perm_section, PetscInt perm_length, PetscInt perm[])
406: {
407:   // TODO: Potential speed up if we early exit for ornt == 0 (i.e. if ornt is identity, we don't need to do anything)
408:   PetscFunctionBeginUser;
409:   PetscCall(DMPlexOrientPoint(dm, point, ornt));

411:   { // Correct coordinates based on new cone ordering
412:     DM           cdm;
413:     PetscSection csection;
414:     Vec          coordinates;
415:     PetscInt     pStart, pEnd;

417:     PetscCall(DMGetCoordinatesLocal(dm, &coordinates));
418:     PetscCall(DMGetCoordinateDM(dm, &cdm));
419:     PetscCall(DMGetLocalSection(cdm, &csection));
420:     PetscCall(PetscSectionGetChart(csection, &pStart, &pEnd));
421:     if (IsPointInsideStratum(point, pStart, pEnd)) PetscCall(DMPlexOrientFieldPointVec(cdm, csection, 0, coordinates, point, ornt));
422:   }

424:   if (perm_section) {
425:     PetscInt num_fields;
426:     PetscCall(PetscSectionGetNumFields(perm_section, &num_fields));
427:     for (PetscInt f = 0; f < num_fields; f++) PetscCall(DMPlexOrientFieldPointIndex(dm, perm_section, f, perm_length, perm, point, ornt));
428:   }
429:   PetscFunctionReturn(PETSC_SUCCESS);
430: }

432: // 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[]`
433: 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)
434: {
435:   MPI_Comm           comm;
436:   PetscMPIInt        rank;
437:   PetscInt           nroots, nleaves;
438:   PetscInt          *rootdata, *leafdata;
439:   const PetscInt    *filocal;
440:   const PetscSFNode *firemote;

442:   PetscFunctionBeginUser;
443:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
444:   PetscCallMPI(MPI_Comm_rank(comm, &rank));

446:   PetscCall(PetscSFGetGraph(face_sf, &nroots, &nleaves, &filocal, &firemote));
447:   PetscCall(PetscCalloc2(2 * nroots, &rootdata, 2 * nroots, &leafdata));
448:   for (PetscInt i = 0; i < nleaves; i++) {
449:     PetscInt point = filocal[i];
450:     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);
451:     leafdata[point] = point_sizes[point - pStart];
452:   }
453:   PetscCall(PetscSFReduceBegin(face_sf, MPIU_INT, leafdata, rootdata + nroots, MPIU_SUM));
454:   PetscCall(PetscSFReduceEnd(face_sf, MPIU_INT, leafdata, rootdata + nroots, MPIU_SUM));

456:   PetscInt root_offset = 0;
457:   PetscCall(PetscBTCreate(nroots, rootbt));
458:   for (PetscInt p = 0; p < nroots; p++) {
459:     const PetscInt *donor_dof = rootdata + nroots;
460:     if (donor_dof[p] == 0) {
461:       rootdata[2 * p]     = -1;
462:       rootdata[2 * p + 1] = -1;
463:       continue;
464:     }
465:     PetscCall(PetscBTSet(*rootbt, p));
466:     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);
467:     PetscInt p_size = point_sizes[p - pStart];
468:     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);
469:     rootdata[2 * p]     = root_offset;
470:     rootdata[2 * p + 1] = p_size;
471:     root_offset += p_size;
472:   }
473:   PetscCall(PetscSFBcastBegin(face_sf, MPIU_2INT, rootdata, leafdata, MPI_REPLACE));
474:   PetscCall(PetscSFBcastEnd(face_sf, MPIU_2INT, rootdata, leafdata, MPI_REPLACE));
475:   // Count how many leaves we need to communicate the closures
476:   PetscInt leaf_offset = 0;
477:   for (PetscInt i = 0; i < nleaves; i++) {
478:     PetscInt point = filocal[i];
479:     if (leafdata[2 * point + 1] < 0) continue;
480:     leaf_offset += leafdata[2 * point + 1];
481:   }

483:   PetscSFNode *closure_leaf;
484:   PetscCall(PetscMalloc1(leaf_offset, &closure_leaf));
485:   leaf_offset = 0;
486:   for (PetscInt i = 0; i < nleaves; i++) {
487:     PetscInt point   = filocal[i];
488:     PetscInt cl_size = leafdata[2 * point + 1];
489:     if (cl_size < 0) continue;
490:     for (PetscInt j = 0; j < cl_size; j++) {
491:       closure_leaf[leaf_offset].rank  = firemote[i].rank;
492:       closure_leaf[leaf_offset].index = leafdata[2 * point] + j;
493:       leaf_offset++;
494:     }
495:   }

497:   PetscCall(PetscSFCreate(comm, sf_closure));
498:   PetscCall(PetscSFSetGraph(*sf_closure, root_offset, leaf_offset, NULL, PETSC_USE_POINTER, closure_leaf, PETSC_OWN_POINTER));
499:   *rootbuffersize = root_offset;
500:   *leafbuffersize = leaf_offset;
501:   PetscCall(PetscFree2(rootdata, leafdata));
502:   PetscFunctionReturn(PETSC_SUCCESS);
503: }

505: // Determine if `key` is in `array`. `array` does NOT need to be sorted
506: static inline PetscBool SearchIntArray(PetscInt key, PetscInt array_size, const PetscInt array[])
507: {
508:   for (PetscInt i = 0; i < array_size; i++)
509:     if (array[i] == key) return PETSC_TRUE;
510:   return PETSC_FALSE;
511: }

513: // Translate a cone in periodic points to the cone in donor points based on the `periodic2donor` array
514: static inline PetscErrorCode TranslateConeP2D(const PetscInt periodic_cone[], PetscInt cone_size, const PetscInt periodic2donor[], PetscInt p2d_count, PetscInt p2d_cone[])
515: {
516:   PetscFunctionBeginUser;
517:   for (PetscInt p = 0; p < cone_size; p++) {
518:     PetscInt p2d_index = -1;
519:     for (PetscInt p2d = 0; p2d < p2d_count; p2d++) {
520:       if (periodic2donor[p2d * 2] == periodic_cone[p]) p2d_index = p2d;
521:     }
522:     PetscCheck(p2d_index >= 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Could not find periodic point in periodic-to-donor array");
523:     p2d_cone[p] = periodic2donor[2 * p2d_index + 1];
524:   }
525:   PetscFunctionReturn(PETSC_SUCCESS);
526: }

528: // Corrects the cone order of periodic faces (and their transitive closure's cones) to match their donor face pair.
529: //
530: // This is done by:
531: // 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
532: //    - The donor vertices have the isoperiodic transform applied to them such that they should match exactly
533: // 2. Translating the periodic vertices into the donor vertices point IDs
534: // 3. Translating the cone of each periodic point into the donor point IDs
535: // 4. Comparing the periodic-to-donor cone to the donor cone for each point
536: // 5. Apply the necessary transformation to the periodic cone to make it match the donor cone
537: static PetscErrorCode DMPlexCorrectOrientationForIsoperiodic(DM dm)
538: {
539:   MPI_Comm        comm;
540:   DM_Plex        *plex = (DM_Plex *)dm->data;
541:   PetscInt        nroots, nleaves;
542:   PetscInt       *local_vec_perm = NULL, local_vec_length = 0, *global_vec_perm = NULL, global_vec_length = 0;
543:   const PetscInt *filocal, coords_field_id = 0;
544:   DM              cdm;
545:   PetscSection    csection, localSection = NULL;
546:   PetscSF         sfNatural_old = NULL;
547:   Vec             coordinates;
548:   PetscMPIInt     myrank;
549:   PetscBool       debug_printing = PETSC_FALSE;

551:   PetscFunctionBeginUser;
552:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
553:   PetscCallMPI(MPI_Comm_rank(comm, &myrank));
554:   PetscCall(DMGetCoordinatesLocal(dm, &coordinates));
555:   PetscCheck(coordinates, comm, PETSC_ERR_ARG_WRONGSTATE, "DM must have coordinates to setup isoperiodic");
556:   PetscCall(DMGetCoordinateDM(dm, &cdm));
557:   PetscCall(DMGetLocalSection(cdm, &csection));

559:   PetscCall(DMGetNaturalSF(dm, &sfNatural_old));
560:   // Prep data for naturalSF correction
561:   if (plex->periodic.num_face_sfs > 0 && sfNatural_old) {
562:     PetscSection       globalSection;
563:     PetscSF            pointSF, sectionSF;
564:     PetscInt           nleaves;
565:     const PetscInt    *ilocal;
566:     const PetscSFNode *iremote;

568:     // Create global section with just pointSF and including constraints
569:     PetscCall(DMGetLocalSection(dm, &localSection));
570:     PetscCall(DMGetPointSF(dm, &pointSF));
571:     PetscCall(PetscSectionCreateGlobalSection(localSection, pointSF, PETSC_TRUE, PETSC_TRUE, PETSC_FALSE, &globalSection));

573:     // Set local_vec_perm to be negative values when that dof is not owned by the current rank
574:     // Dofs that are owned are set to their corresponding global Vec index
575:     PetscCall(PetscSectionGetStorageSize(globalSection, &global_vec_length));
576:     PetscCall(PetscSectionGetStorageSize(localSection, &local_vec_length));
577:     PetscCall(PetscMalloc2(global_vec_length, &global_vec_perm, local_vec_length, &local_vec_perm));
578:     for (PetscInt i = 0; i < global_vec_length; i++) global_vec_perm[i] = i;
579:     for (PetscInt i = 0; i < local_vec_length; i++) local_vec_perm[i] = -(i + 1);

581:     PetscCall(PetscSFCreate(comm, &sectionSF));
582:     PetscCall(PetscSFSetGraphSection(sectionSF, localSection, globalSection));
583:     PetscCall(PetscSFGetGraph(sectionSF, NULL, &nleaves, &ilocal, &iremote));
584:     for (PetscInt l = 0; l < nleaves; l++) {
585:       if (iremote[l].rank != myrank) continue;
586:       PetscInt local_index        = ilocal ? ilocal[l] : l;
587:       local_vec_perm[local_index] = global_vec_perm[iremote[l].index];
588:     }
589:     PetscCall(PetscSectionDestroy(&globalSection));
590:     PetscCall(PetscSFDestroy(&sectionSF));
591:   }

593:   // Create sf_vert_coords and sf_face_cones for communicating donor vertices and cones to periodic faces, respectively
594:   for (PetscInt f = 0; f < plex->periodic.num_face_sfs; f++) {
595:     PetscSF face_sf                   = plex->periodic.face_sfs[f];
596:     const PetscScalar (*transform)[4] = (const PetscScalar (*)[4])plex->periodic.transform[f];
597:     PetscInt *face_vertices_size, *face_cones_size;
598:     PetscInt  fStart, fEnd, vStart, vEnd, rootnumvert, leafnumvert, rootconesize, leafconesize, dim;
599:     PetscSF   sf_vert_coords, sf_face_cones;
600:     PetscBT   rootbt;

602:     PetscCall(DMGetCoordinateDim(dm, &dim));
603:     PetscCall(DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd));
604:     PetscCall(DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd));
605:     PetscCall(PetscCalloc2(fEnd - fStart, &face_vertices_size, fEnd - fStart, &face_cones_size));

607:     // Create SFs to communicate donor vertices and donor cones to periodic faces
608:     for (PetscInt f = fStart, index = 0; f < fEnd; f++, index++) {
609:       PetscInt cl_size, *closure = NULL, num_vertices = 0;
610:       PetscCall(DMPlexGetTransitiveClosure(dm, f, PETSC_TRUE, &cl_size, &closure));
611:       for (PetscInt p = 0; p < cl_size; p++) {
612:         PetscInt cl_point = closure[2 * p];
613:         if (IsPointInsideStratum(cl_point, vStart, vEnd)) num_vertices++;
614:         else {
615:           PetscInt cone_size;
616:           PetscCall(DMPlexGetConeSize(dm, cl_point, &cone_size));
617:           face_cones_size[index] += cone_size + 2;
618:         }
619:       }
620:       face_vertices_size[index] = num_vertices;
621:       face_cones_size[index] += num_vertices;
622:       PetscCall(DMPlexRestoreTransitiveClosure(dm, f, PETSC_TRUE, &cl_size, &closure));
623:     }
624:     PetscCall(CreateDonorToPeriodicSF(dm, face_sf, fStart, fEnd, face_vertices_size, &rootnumvert, &leafnumvert, &rootbt, &sf_vert_coords));
625:     PetscCall(PetscBTDestroy(&rootbt));
626:     PetscCall(CreateDonorToPeriodicSF(dm, face_sf, fStart, fEnd, face_cones_size, &rootconesize, &leafconesize, &rootbt, &sf_face_cones));

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

630:     PetscReal *leaf_donor_coords;
631:     PetscInt  *leaf_donor_cones;

633:     { // Communicate donor coords and cones to the periodic faces
634:       PetscReal         *mydonor_vertices;
635:       PetscInt          *mydonor_cones;
636:       const PetscScalar *coords_arr;

638:       PetscCall(PetscCalloc2(rootnumvert * dim, &mydonor_vertices, rootconesize, &mydonor_cones));
639:       PetscCall(VecGetArrayRead(coordinates, &coords_arr));
640:       for (PetscInt donor_face = 0, donor_vert_offset = 0, donor_cone_offset = 0; donor_face < nroots; donor_face++) {
641:         if (!PetscBTLookup(rootbt, donor_face)) continue;
642:         PetscInt cl_size, *closure = NULL;

644:         PetscCall(DMPlexGetTransitiveClosure(dm, donor_face, PETSC_TRUE, &cl_size, &closure));
645:         // Pack vertex coordinates
646:         for (PetscInt p = 0; p < cl_size; p++) {
647:           PetscInt cl_point = closure[2 * p], dof, offset;
648:           if (!IsPointInsideStratum(cl_point, vStart, vEnd)) continue;
649:           mydonor_cones[donor_cone_offset++] = cl_point;
650:           PetscCall(PetscSectionGetFieldDof(csection, cl_point, coords_field_id, &dof));
651:           PetscCall(PetscSectionGetFieldOffset(csection, cl_point, coords_field_id, &offset));
652:           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);
653:           // Apply isoperiodic transform to donor vertices such that corresponding periodic vertices should match exactly
654:           for (PetscInt d = 0; d < dof; d++) mydonor_vertices[donor_vert_offset * dim + d] = PetscRealPart(coords_arr[offset + d]) + PetscRealPart(transform[d][3]);
655:           donor_vert_offset++;
656:         }
657:         // Pack cones of face points (including face itself)
658:         for (PetscInt p = 0; p < cl_size; p++) {
659:           PetscInt        cl_point = closure[2 * p], cone_size, depth;
660:           const PetscInt *cone;

662:           PetscCall(DMPlexGetConeSize(dm, cl_point, &cone_size));
663:           PetscCall(DMPlexGetCone(dm, cl_point, &cone));
664:           PetscCall(DMPlexGetPointDepth(dm, cl_point, &depth));
665:           if (depth == 0) continue; // don't include vertex depth
666:           mydonor_cones[donor_cone_offset++] = cone_size;
667:           mydonor_cones[donor_cone_offset++] = cl_point;
668:           PetscArraycpy(&mydonor_cones[donor_cone_offset], cone, cone_size);
669:           donor_cone_offset += cone_size;
670:         }
671:         PetscCall(DMPlexRestoreTransitiveClosure(dm, donor_face, PETSC_TRUE, &cl_size, &closure));
672:       }
673:       PetscCall(VecRestoreArrayRead(coordinates, &coords_arr));
674:       PetscCall(PetscBTDestroy(&rootbt));

676:       MPI_Datatype vertex_unit;
677:       PetscMPIInt  n;
678:       PetscCall(PetscMPIIntCast(dim, &n));
679:       PetscCallMPI(MPI_Type_contiguous(n, MPIU_REAL, &vertex_unit));
680:       PetscCallMPI(MPI_Type_commit(&vertex_unit));
681:       PetscCall(PetscMalloc2(leafnumvert * 3, &leaf_donor_coords, leafconesize, &leaf_donor_cones));
682:       PetscCall(PetscSFBcastBegin(sf_vert_coords, vertex_unit, mydonor_vertices, leaf_donor_coords, MPI_REPLACE));
683:       PetscCall(PetscSFBcastBegin(sf_face_cones, MPIU_INT, mydonor_cones, leaf_donor_cones, MPI_REPLACE));
684:       PetscCall(PetscSFBcastEnd(sf_vert_coords, vertex_unit, mydonor_vertices, leaf_donor_coords, MPI_REPLACE));
685:       PetscCall(PetscSFBcastEnd(sf_face_cones, MPIU_INT, mydonor_cones, leaf_donor_cones, MPI_REPLACE));
686:       PetscCall(PetscSFDestroy(&sf_vert_coords));
687:       PetscCall(PetscSFDestroy(&sf_face_cones));
688:       PetscCallMPI(MPI_Type_free(&vertex_unit));
689:       PetscCall(PetscFree2(mydonor_vertices, mydonor_cones));
690:     }

692:     { // Determine periodic orientation w/rt donor vertices and reorient
693:       PetscReal tol = PetscSqr(PETSC_MACHINE_EPSILON * 1e3);
694:       PetscInt *periodic2donor, dm_depth, maxConeSize;
695:       PetscInt  coords_offset = 0, cones_offset = 0;

697:       PetscCall(DMPlexGetDepth(dm, &dm_depth));
698:       PetscCall(DMPlexGetMaxSizes(dm, &maxConeSize, NULL));
699:       PetscCall(DMGetWorkArray(dm, 2 * PetscPowInt(maxConeSize, dm_depth - 1), MPIU_INT, &periodic2donor));

701:       // Translate the periodic face vertices into the donor vertices
702:       // Translation stored in periodic2donor
703:       for (PetscInt i = 0; i < nleaves; i++) {
704:         PetscInt  periodic_face = filocal[i], cl_size, num_verts = face_vertices_size[periodic_face - fStart];
705:         PetscInt  cones_size = face_cones_size[periodic_face - fStart], p2d_count = 0;
706:         PetscInt *closure = NULL;

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

713:           if (!IsPointInsideStratum(cl_point, vStart, vEnd)) continue;
714:           PetscCall(DMPlexVecGetClosure(dm, csection, coordinates, cl_point, &coords_size, &coords));
715:           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);

717:           for (PetscInt v = 0; v < num_verts; v++) {
718:             PetscReal dist_sqr = 0;
719:             for (PetscInt d = 0; d < coords_size; d++) dist_sqr += PetscSqr(PetscRealPart(coords[d]) - leaf_donor_coords[(v + coords_offset) * dim + d]);
720:             if (dist_sqr < tol) {
721:               donor_vertex = leaf_donor_cones[cones_offset + v];
722:               break;
723:             }
724:           }
725:           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);
726:           if (PetscDefined(USE_DEBUG)) {
727:             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");
728:           }

730:           periodic2donor[2 * p2d_count + 0] = cl_point;
731:           periodic2donor[2 * p2d_count + 1] = donor_vertex;
732:           p2d_count++;
733:           PetscCall(DMPlexVecRestoreClosure(dm, csection, coordinates, cl_point, &coords_size, &coords));
734:         }
735:         coords_offset += num_verts;
736:         PetscCall(DMPlexRestoreTransitiveClosure(dm, periodic_face, PETSC_TRUE, &cl_size, &closure));

738:         { // Determine periodic orientation w/rt donor vertices and reorient
739:           PetscInt      depth, *p2d_cone, face_is_array[1] = {periodic_face};
740:           IS           *is_arrays, face_is;
741:           PetscSection *section_arrays;
742:           PetscInt     *donor_cone_array = &leaf_donor_cones[cones_offset + num_verts];

744:           PetscCall(ISCreateGeneral(PETSC_COMM_SELF, 1, face_is_array, PETSC_USE_POINTER, &face_is));
745:           PetscCall(DMPlexGetConeRecursive(dm, face_is, &depth, &is_arrays, &section_arrays));
746:           PetscCall(ISDestroy(&face_is));
747:           PetscCall(DMGetWorkArray(dm, maxConeSize, MPIU_INT, &p2d_cone));
748:           for (PetscInt d = 0; d < depth - 1; d++) {
749:             PetscInt        pStart, pEnd;
750:             PetscSection    section = section_arrays[d];
751:             const PetscInt *periodic_cone_arrays, *periodic_point_arrays;

753:             PetscCall(ISGetIndices(is_arrays[d], &periodic_cone_arrays));
754:             PetscCall(ISGetIndices(is_arrays[d + 1], &periodic_point_arrays)); // Points at d+1 correspond to the cones at d
755:             PetscCall(PetscSectionGetChart(section_arrays[d], &pStart, &pEnd));
756:             for (PetscInt p = pStart; p < pEnd; p++) {
757:               PetscInt periodic_cone_size, periodic_cone_offset, periodic_point = periodic_point_arrays[p];

759:               PetscCall(PetscSectionGetDof(section, p, &periodic_cone_size));
760:               PetscCall(PetscSectionGetOffset(section, p, &periodic_cone_offset));
761:               const PetscInt *periodic_cone = &periodic_cone_arrays[periodic_cone_offset];
762:               PetscCall(TranslateConeP2D(periodic_cone, periodic_cone_size, periodic2donor, p2d_count, p2d_cone));

764:               // Find the donor cone that matches the periodic point's cone
765:               PetscInt  donor_cone_offset = 0, donor_point = -1, *donor_cone = NULL;
766:               PetscBool cone_matches = PETSC_FALSE;
767:               while (donor_cone_offset < cones_size - num_verts) {
768:                 PetscInt donor_cone_size = donor_cone_array[donor_cone_offset];
769:                 donor_point              = donor_cone_array[donor_cone_offset + 1];
770:                 donor_cone               = &donor_cone_array[donor_cone_offset + 2];

772:                 if (donor_cone_size != periodic_cone_size) goto next_cone;
773:                 for (PetscInt c = 0; c < periodic_cone_size; c++) {
774:                   cone_matches = SearchIntArray(donor_cone[c], periodic_cone_size, p2d_cone);
775:                   if (!cone_matches) goto next_cone;
776:                 }
777:                 // Save the found donor cone's point to the translation array. These will be used for higher depth points.
778:                 // i.e. we save the edge translations for when we look for face cones
779:                 periodic2donor[2 * p2d_count + 0] = periodic_point;
780:                 periodic2donor[2 * p2d_count + 1] = donor_point;
781:                 p2d_count++;
782:                 break;

784:               next_cone:
785:                 donor_cone_offset += donor_cone_size + 2;
786:               }
787:               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);

789:               { // Compare the donor cone with the translated periodic cone and reorient
790:                 PetscInt       ornt;
791:                 DMPolytopeType cell_type;
792:                 PetscBool      found;
793:                 PetscCall(DMPlexGetCellType(dm, periodic_point, &cell_type));
794:                 PetscCall(DMPolytopeMatchOrientation(cell_type, donor_cone, p2d_cone, &ornt, &found));
795:                 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);
796:                 if (debug_printing) PetscCall(PetscPrintf(PETSC_COMM_SELF, "Reorienting point %" PetscInt_FMT " by %" PetscInt_FMT "\n", periodic_point, ornt));
797:                 PetscCall(DMPlexOrientPointWithCorrections(dm, periodic_point, ornt, localSection, local_vec_length, local_vec_perm));
798:               }
799:             }
800:             PetscCall(ISRestoreIndices(is_arrays[d], &periodic_cone_arrays));
801:             PetscCall(ISRestoreIndices(is_arrays[d + 1], &periodic_point_arrays));
802:           }
803:           PetscCall(DMRestoreWorkArray(dm, maxConeSize, MPIU_INT, &p2d_cone));
804:           PetscCall(DMPlexRestoreConeRecursive(dm, face_is, &depth, &is_arrays, &section_arrays));
805:         }

807:         PetscCall(DMPlexRestoreTransitiveClosure(dm, periodic_face, PETSC_TRUE, &cl_size, &closure));
808:         cones_offset += cones_size;
809:       }
810:       PetscCall(DMRestoreWorkArray(dm, 2 * PetscPowInt(maxConeSize, dm_depth - 1), MPIU_INT, &periodic2donor));
811:     }
812:     // Re-set local coordinates (i.e. destroy global coordinates if they were modified)
813:     PetscCall(DMSetCoordinatesLocal(dm, coordinates));

815:     PetscCall(PetscFree2(leaf_donor_coords, leaf_donor_cones));
816:     PetscCall(PetscFree2(face_vertices_size, face_cones_size));
817:   }

819:   if (sfNatural_old) { // Correct SFNatural based on the permutation of the local vector
820:     PetscSF      newglob_to_oldglob_sf, sfNatural_old, sfNatural_new;
821:     PetscSFNode *remote;

823:     { // Translate permutation of local Vec into permutation of global Vec
824:       PetscInt g = 0;
825:       PetscBT  global_vec_check; // Verify that global indices aren't doubled
826:       PetscCall(PetscBTCreate(global_vec_length, &global_vec_check));
827:       for (PetscInt l = 0; l < local_vec_length; l++) {
828:         PetscInt global_index = local_vec_perm[l];
829:         if (global_index < 0) continue;
830:         PetscCheck(!PetscBTLookupSet(global_vec_check, global_index), PETSC_COMM_SELF, PETSC_ERR_PLIB, "Found duplicate global index %" PetscInt_FMT " in local_vec_perm", global_index);
831:         global_vec_perm[g++] = global_index;
832:       }
833:       PetscCheck(g == global_vec_length, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Wrong number of non-negative local indices");
834:       PetscCall(PetscBTDestroy(&global_vec_check));
835:     }

837:     PetscCall(PetscMalloc1(global_vec_length, &remote));
838:     for (PetscInt i = 0; i < global_vec_length; i++) {
839:       remote[i].rank  = myrank;
840:       remote[i].index = global_vec_perm[i];
841:     }
842:     PetscCall(PetscFree2(global_vec_perm, local_vec_perm));
843:     PetscCall(PetscSFCreate(comm, &newglob_to_oldglob_sf));
844:     PetscCall(PetscSFSetGraph(newglob_to_oldglob_sf, global_vec_length, global_vec_length, NULL, PETSC_USE_POINTER, remote, PETSC_OWN_POINTER));
845:     PetscCall(DMGetNaturalSF(dm, &sfNatural_old));
846:     PetscCall(PetscSFCompose(newglob_to_oldglob_sf, sfNatural_old, &sfNatural_new));
847:     PetscCall(DMSetNaturalSF(dm, sfNatural_new));
848:     PetscCall(PetscSFDestroy(&sfNatural_new));
849:     PetscCall(PetscSFDestroy(&newglob_to_oldglob_sf));
850:   }
851:   PetscFunctionReturn(PETSC_SUCCESS);
852: }

854: // Start with an SF for a positive depth (e.g., faces) and create a new SF for matched closure.
855: //
856: // Output Arguments:
857: //
858: // + closure_sf - augmented point SF (see `DMGetPointSF()`) that includes the faces and all points in its closure. This
859: //   can be used to create a global section and section SF.
860: // - is_points - array of index sets for just the points in the closure of `face_sf`. These may be used to apply an affine
861: //   transformation to periodic dofs; see DMPeriodicCoordinateSetUp_Internal().
862: //
863: static PetscErrorCode DMPlexCreateIsoperiodicPointSF_Private(DM dm, PetscInt num_face_sfs, PetscSF *face_sfs, PetscSF *closure_sf, IS **is_points)
864: {
865:   MPI_Comm           comm;
866:   PetscMPIInt        rank;
867:   PetscSF            point_sf;
868:   PetscInt           nroots, nleaves;
869:   const PetscInt    *filocal;
870:   const PetscSFNode *firemote;

872:   PetscFunctionBegin;
873:   PetscCall(PetscObjectGetComm((PetscObject)dm, &comm));
874:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
875:   PetscCall(DMGetPointSF(dm, &point_sf)); // Point SF has remote points
876:   PetscCall(PetscMalloc1(num_face_sfs, is_points));

878:   PetscCall(DMPlexCorrectOrientationForIsoperiodic(dm));

880:   for (PetscInt f = 0; f < num_face_sfs; f++) {
881:     PetscSF   face_sf = face_sfs[f];
882:     PetscInt *cl_sizes;
883:     PetscInt  fStart, fEnd, rootbuffersize, leafbuffersize;
884:     PetscSF   sf_closure;
885:     PetscBT   rootbt;

887:     PetscCall(DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd));
888:     PetscCall(PetscMalloc1(fEnd - fStart, &cl_sizes));
889:     for (PetscInt f = fStart, index = 0; f < fEnd; f++, index++) {
890:       PetscInt cl_size, *closure = NULL;
891:       PetscCall(DMPlexGetTransitiveClosure(dm, f, PETSC_TRUE, &cl_size, &closure));
892:       cl_sizes[index] = cl_size - 1;
893:       PetscCall(DMPlexRestoreTransitiveClosure(dm, f, PETSC_TRUE, &cl_size, &closure));
894:     }

896:     PetscCall(CreateDonorToPeriodicSF(dm, face_sf, fStart, fEnd, cl_sizes, &rootbuffersize, &leafbuffersize, &rootbt, &sf_closure));
897:     PetscCall(PetscFree(cl_sizes));
898:     PetscCall(PetscSFGetGraph(face_sf, &nroots, &nleaves, &filocal, &firemote));

900:     PetscSFNode *leaf_donor_closure;
901:     { // Pack root buffer with owner for every point in the root cones
902:       PetscSFNode       *donor_closure;
903:       const PetscInt    *pilocal;
904:       const PetscSFNode *piremote;
905:       PetscInt           npoints;

907:       PetscCall(PetscSFGetGraph(point_sf, NULL, &npoints, &pilocal, &piremote));
908:       PetscCall(PetscCalloc1(rootbuffersize, &donor_closure));
909:       for (PetscInt p = 0, root_offset = 0; p < nroots; p++) {
910:         if (!PetscBTLookup(rootbt, p)) continue;
911:         PetscInt cl_size, *closure = NULL;
912:         PetscCall(DMPlexGetTransitiveClosure(dm, p, PETSC_TRUE, &cl_size, &closure));
913:         for (PetscInt j = 1; j < cl_size; j++) {
914:           PetscInt c = closure[2 * j];
915:           if (pilocal) {
916:             PetscInt found = -1;
917:             if (npoints > 0) PetscCall(PetscFindInt(c, npoints, pilocal, &found));
918:             if (found >= 0) {
919:               donor_closure[root_offset++] = piremote[found];
920:               continue;
921:             }
922:           }
923:           // we own c
924:           donor_closure[root_offset].rank  = rank;
925:           donor_closure[root_offset].index = c;
926:           root_offset++;
927:         }
928:         PetscCall(DMPlexRestoreTransitiveClosure(dm, p, PETSC_TRUE, &cl_size, &closure));
929:       }

931:       PetscCall(PetscMalloc1(leafbuffersize, &leaf_donor_closure));
932:       PetscCall(PetscSFBcastBegin(sf_closure, MPIU_SF_NODE, donor_closure, leaf_donor_closure, MPI_REPLACE));
933:       PetscCall(PetscSFBcastEnd(sf_closure, MPIU_SF_NODE, donor_closure, leaf_donor_closure, MPI_REPLACE));
934:       PetscCall(PetscSFDestroy(&sf_closure));
935:       PetscCall(PetscFree(donor_closure));
936:     }

938:     PetscSFNode *new_iremote;
939:     PetscCall(PetscCalloc1(nroots, &new_iremote));
940:     for (PetscInt i = 0; i < nroots; i++) new_iremote[i].rank = -1;
941:     // Walk leaves and match vertices
942:     for (PetscInt i = 0, leaf_offset = 0; i < nleaves; i++) {
943:       PetscInt  point   = filocal[i], cl_size;
944:       PetscInt *closure = NULL;
945:       PetscCall(DMPlexGetTransitiveClosure(dm, point, PETSC_TRUE, &cl_size, &closure));
946:       for (PetscInt j = 1; j < cl_size; j++) {
947:         PetscInt    c  = closure[2 * j];
948:         PetscSFNode lc = leaf_donor_closure[leaf_offset];
949:         // printf("[%d] face %d.%d: %d ?-- (%d,%d)\n", rank, point, j, c, lc.rank, lc.index);
950:         if (new_iremote[c].rank == -1) {
951:           new_iremote[c] = lc;
952:         } 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");
953:         leaf_offset++;
954:       }
955:       PetscCall(DMPlexRestoreTransitiveClosure(dm, point, PETSC_TRUE, &cl_size, &closure));
956:     }
957:     PetscCall(PetscFree(leaf_donor_closure));

959:     // Include face points in closure SF
960:     for (PetscInt i = 0; i < nleaves; i++) new_iremote[filocal[i]] = firemote[i];
961:     // consolidate leaves
962:     PetscInt *leafdata;
963:     PetscCall(PetscMalloc1(nroots, &leafdata));
964:     PetscInt num_new_leaves = 0;
965:     for (PetscInt i = 0; i < nroots; i++) {
966:       if (new_iremote[i].rank == -1) continue;
967:       new_iremote[num_new_leaves] = new_iremote[i];
968:       leafdata[num_new_leaves]    = i;
969:       num_new_leaves++;
970:     }
971:     PetscCall(ISCreateGeneral(PETSC_COMM_SELF, num_new_leaves, leafdata, PETSC_COPY_VALUES, &(*is_points)[f]));

973:     PetscSF csf;
974:     PetscCall(PetscSFCreate(comm, &csf));
975:     PetscCall(PetscSFSetGraph(csf, nroots, num_new_leaves, leafdata, PETSC_COPY_VALUES, new_iremote, PETSC_COPY_VALUES));
976:     PetscCall(PetscFree(new_iremote)); // copy and delete because new_iremote is longer than it needs to be
977:     PetscCall(PetscFree(leafdata));
978:     PetscCall(PetscBTDestroy(&rootbt));

980:     PetscInt npoints;
981:     PetscCall(PetscSFGetGraph(point_sf, NULL, &npoints, NULL, NULL));
982:     if (npoints < 0) { // empty point_sf
983:       *closure_sf = csf;
984:     } else {
985:       PetscCall(PetscSFMerge(point_sf, csf, closure_sf));
986:       PetscCall(PetscSFDestroy(&csf));
987:     }
988:     if (f > 0) PetscCall(PetscSFDestroy(&point_sf)); // Only destroy if point_sf is from previous calls to PetscSFMerge
989:     point_sf = *closure_sf;                          // Use combined point + isoperiodic SF to define point ownership for further face_sf
990:   }
991:   PetscCall(PetscObjectSetName((PetscObject)*closure_sf, "Composed Periodic Points"));
992:   PetscFunctionReturn(PETSC_SUCCESS);
993: }

995: static PetscErrorCode DMGetIsoperiodicPointSF_Plex(DM dm, PetscSF *sf)
996: {
997:   DM_Plex *plex = (DM_Plex *)dm->data;

999:   PetscFunctionBegin;
1000:   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));
1001:   if (sf) *sf = plex->periodic.composed_sf;
1002:   PetscFunctionReturn(PETSC_SUCCESS);
1003: }

1005: PetscErrorCode DMPlexMigrateIsoperiodicFaceSF_Internal(DM old_dm, DM dm, PetscSF sf_migration)
1006: {
1007:   DM_Plex    *plex = (DM_Plex *)old_dm->data;
1008:   PetscSF     sf_point, *new_face_sfs;
1009:   PetscMPIInt rank;

1011:   PetscFunctionBegin;
1012:   if (!plex->periodic.face_sfs) PetscFunctionReturn(PETSC_SUCCESS);
1013:   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank));
1014:   PetscCall(DMGetPointSF(dm, &sf_point));
1015:   PetscCall(PetscMalloc1(plex->periodic.num_face_sfs, &new_face_sfs));

1017:   for (PetscInt f = 0; f < plex->periodic.num_face_sfs; f++) {
1018:     PetscInt           old_npoints, new_npoints, old_nleaf, new_nleaf, point_nleaf;
1019:     PetscSFNode       *new_leafdata, *rootdata, *leafdata;
1020:     const PetscInt    *old_local, *point_local;
1021:     const PetscSFNode *old_remote, *point_remote;

1023:     PetscCall(PetscSFGetGraph(plex->periodic.face_sfs[f], &old_npoints, &old_nleaf, &old_local, &old_remote));
1024:     PetscCall(PetscSFGetGraph(sf_migration, NULL, &new_nleaf, NULL, NULL));
1025:     PetscCall(PetscSFGetGraph(sf_point, &new_npoints, &point_nleaf, &point_local, &point_remote));
1026:     PetscAssert(new_nleaf == new_npoints, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Expected migration leaf space to match new point root space");
1027:     PetscCall(PetscMalloc3(old_npoints, &rootdata, old_npoints, &leafdata, new_npoints, &new_leafdata));

1029:     // Fill new_leafdata with new owners of all points
1030:     for (PetscInt i = 0; i < new_npoints; i++) {
1031:       new_leafdata[i].rank  = rank;
1032:       new_leafdata[i].index = i;
1033:     }
1034:     for (PetscInt i = 0; i < point_nleaf; i++) {
1035:       PetscInt j      = point_local[i];
1036:       new_leafdata[j] = point_remote[i];
1037:     }
1038:     // REPLACE is okay because every leaf agrees about the new owners
1039:     PetscCall(PetscSFReduceBegin(sf_migration, MPIU_SF_NODE, new_leafdata, rootdata, MPI_REPLACE));
1040:     PetscCall(PetscSFReduceEnd(sf_migration, MPIU_SF_NODE, new_leafdata, rootdata, MPI_REPLACE));
1041:     // rootdata now contains the new owners

1043:     // Send to leaves of old space
1044:     for (PetscInt i = 0; i < old_npoints; i++) {
1045:       leafdata[i].rank  = -1;
1046:       leafdata[i].index = -1;
1047:     }
1048:     PetscCall(PetscSFBcastBegin(plex->periodic.face_sfs[f], MPIU_SF_NODE, rootdata, leafdata, MPI_REPLACE));
1049:     PetscCall(PetscSFBcastEnd(plex->periodic.face_sfs[f], MPIU_SF_NODE, rootdata, leafdata, MPI_REPLACE));

1051:     // Send to new leaf space
1052:     PetscCall(PetscSFBcastBegin(sf_migration, MPIU_SF_NODE, leafdata, new_leafdata, MPI_REPLACE));
1053:     PetscCall(PetscSFBcastEnd(sf_migration, MPIU_SF_NODE, leafdata, new_leafdata, MPI_REPLACE));

1055:     PetscInt     nface = 0, *new_local;
1056:     PetscSFNode *new_remote;
1057:     for (PetscInt i = 0; i < new_npoints; i++) nface += (new_leafdata[i].rank >= 0);
1058:     PetscCall(PetscMalloc1(nface, &new_local));
1059:     PetscCall(PetscMalloc1(nface, &new_remote));
1060:     nface = 0;
1061:     for (PetscInt i = 0; i < new_npoints; i++) {
1062:       if (new_leafdata[i].rank == -1) continue;
1063:       new_local[nface]  = i;
1064:       new_remote[nface] = new_leafdata[i];
1065:       nface++;
1066:     }
1067:     PetscCall(PetscFree3(rootdata, leafdata, new_leafdata));
1068:     PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), &new_face_sfs[f]));
1069:     PetscCall(PetscSFSetGraph(new_face_sfs[f], new_npoints, nface, new_local, PETSC_OWN_POINTER, new_remote, PETSC_OWN_POINTER));
1070:     {
1071:       char new_face_sf_name[PETSC_MAX_PATH_LEN];
1072:       PetscCall(PetscSNPrintf(new_face_sf_name, sizeof new_face_sf_name, "Migrated Isoperiodic Faces #%" PetscInt_FMT, f));
1073:       PetscCall(PetscObjectSetName((PetscObject)new_face_sfs[f], new_face_sf_name));
1074:     }
1075:   }

1077:   PetscCall(DMPlexSetIsoperiodicFaceSF(dm, plex->periodic.num_face_sfs, new_face_sfs));
1078:   PetscCall(DMPlexSetIsoperiodicFaceTransform(dm, plex->periodic.num_face_sfs, (PetscScalar *)plex->periodic.transform));
1079:   for (PetscInt f = 0; f < plex->periodic.num_face_sfs; f++) PetscCall(PetscSFDestroy(&new_face_sfs[f]));
1080:   PetscCall(PetscFree(new_face_sfs));
1081:   PetscFunctionReturn(PETSC_SUCCESS);
1082: }

1084: PetscErrorCode DMPeriodicCoordinateSetUp_Internal(DM dm)
1085: {
1086:   DM_Plex   *plex = (DM_Plex *)dm->data;
1087:   PetscCount count;
1088:   IS         isdof;
1089:   PetscInt   dim;

1091:   PetscFunctionBegin;
1092:   if (!plex->periodic.face_sfs) PetscFunctionReturn(PETSC_SUCCESS);
1093:   PetscCheck(plex->periodic.periodic_points, PETSC_COMM_SELF, PETSC_ERR_ARG_WRONGSTATE, "Isoperiodic PointSF must be created before this function is called");

1095:   PetscCall(DMGetCoordinateDim(dm, &dim));
1096:   dm->periodic.num_affines = plex->periodic.num_face_sfs;
1097:   PetscCall(PetscFree2(dm->periodic.affine_to_local, dm->periodic.affine));
1098:   PetscCall(PetscMalloc2(dm->periodic.num_affines, &dm->periodic.affine_to_local, dm->periodic.num_affines, &dm->periodic.affine));

1100:   for (PetscInt f = 0; f < plex->periodic.num_face_sfs; f++) {
1101:     PetscInt        npoints, vsize, isize;
1102:     const PetscInt *points;
1103:     IS              is = plex->periodic.periodic_points[f];
1104:     PetscSegBuffer  seg;
1105:     PetscSection    section;
1106:     PetscInt       *ind;
1107:     Vec             L, P;
1108:     VecType         vec_type;
1109:     VecScatter      scatter;
1110:     PetscScalar    *x;

1112:     PetscCall(DMGetLocalSection(dm, &section));
1113:     PetscCall(PetscSegBufferCreate(sizeof(PetscInt), 32, &seg));
1114:     PetscCall(ISGetSize(is, &npoints));
1115:     PetscCall(ISGetIndices(is, &points));
1116:     for (PetscInt i = 0; i < npoints; i++) {
1117:       PetscInt point = points[i], off, dof;

1119:       PetscCall(PetscSectionGetOffset(section, point, &off));
1120:       PetscCall(PetscSectionGetDof(section, point, &dof));
1121:       PetscAssert(dof % dim == 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Unexpected dof %" PetscInt_FMT " not divisible by dimension %" PetscInt_FMT, dof, dim);
1122:       for (PetscInt j = 0; j < dof / dim; j++) {
1123:         PetscInt *slot;

1125:         PetscCall(PetscSegBufferGetInts(seg, 1, &slot));
1126:         *slot = off / dim + j;
1127:       }
1128:     }
1129:     PetscCall(PetscSegBufferGetSize(seg, &count));
1130:     PetscCall(PetscSegBufferExtractAlloc(seg, &ind));
1131:     PetscCall(PetscSegBufferDestroy(&seg));
1132:     PetscCall(PetscIntCast(count, &isize));
1133:     PetscCall(ISCreateBlock(PETSC_COMM_SELF, dim, isize, ind, PETSC_OWN_POINTER, &isdof));

1135:     PetscCall(PetscIntCast(count * dim, &vsize));
1136:     PetscCall(DMGetLocalVector(dm, &L));
1137:     PetscCall(VecCreate(PETSC_COMM_SELF, &P));
1138:     PetscCall(VecSetSizes(P, vsize, vsize));
1139:     PetscCall(VecGetType(L, &vec_type));
1140:     PetscCall(VecSetType(P, vec_type));
1141:     PetscCall(VecScatterCreate(P, NULL, L, isdof, &scatter));
1142:     PetscCall(DMRestoreLocalVector(dm, &L));
1143:     PetscCall(ISDestroy(&isdof));

1145:     PetscCall(VecGetArrayWrite(P, &x));
1146:     for (PetscCount i = 0; i < count; i++) {
1147:       for (PetscInt j = 0; j < dim; j++) x[i * dim + j] = plex->periodic.transform[f][j][3];
1148:     }
1149:     PetscCall(VecRestoreArrayWrite(P, &x));

1151:     dm->periodic.affine_to_local[f] = scatter;
1152:     dm->periodic.affine[f]          = P;
1153:   }
1154:   PetscCall(DMGlobalToLocalHookAdd(dm, NULL, DMCoordAddPeriodicOffsets_Private, NULL));
1155:   PetscFunctionReturn(PETSC_SUCCESS);
1156: }

1158: PetscErrorCode DMPlexCreateBoxMesh_Tensor_SFC_Internal(DM dm, PetscInt dim, const PetscInt faces[], const PetscReal lower[], const PetscReal upper[], const DMBoundaryType periodicity[], PetscBool interpolate)
1159: {
1160:   PetscInt  eextent[3] = {1, 1, 1}, vextent[3] = {1, 1, 1};
1161:   const Ijk closure_1[] = {
1162:     {0, 0, 0},
1163:     {1, 0, 0},
1164:   };
1165:   const Ijk closure_2[] = {
1166:     {0, 0, 0},
1167:     {1, 0, 0},
1168:     {1, 1, 0},
1169:     {0, 1, 0},
1170:   };
1171:   const Ijk closure_3[] = {
1172:     {0, 0, 0},
1173:     {0, 1, 0},
1174:     {1, 1, 0},
1175:     {1, 0, 0},
1176:     {0, 0, 1},
1177:     {1, 0, 1},
1178:     {1, 1, 1},
1179:     {0, 1, 1},
1180:   };
1181:   const Ijk *const closure_dim[] = {NULL, closure_1, closure_2, closure_3};
1182:   // This must be kept consistent with DMPlexCreateCubeMesh_Internal
1183:   const PetscInt        face_marker_1[]   = {1, 2};
1184:   const PetscInt        face_marker_2[]   = {4, 2, 1, 3};
1185:   const PetscInt        face_marker_3[]   = {6, 5, 3, 4, 1, 2};
1186:   const PetscInt *const face_marker_dim[] = {NULL, face_marker_1, face_marker_2, face_marker_3};
1187:   // Orient faces so the normal is in the positive axis and the first vertex is the one closest to zero.
1188:   // These orientations can be determined by examining cones of a reference quad and hex element.
1189:   const PetscInt        face_orient_1[]   = {0, 0};
1190:   const PetscInt        face_orient_2[]   = {-1, 0, 0, -1};
1191:   const PetscInt        face_orient_3[]   = {-2, 0, -2, 1, -2, 0};
1192:   const PetscInt *const face_orient_dim[] = {NULL, face_orient_1, face_orient_2, face_orient_3};

1194:   PetscFunctionBegin;
1195:   PetscCall(PetscLogEventBegin(DMPLEX_CreateBoxSFC, dm, 0, 0, 0));
1196:   PetscAssertPointer(dm, 1);
1198:   PetscCall(DMSetDimension(dm, dim));
1199:   PetscMPIInt rank, size;
1200:   PetscCallMPI(MPI_Comm_size(PetscObjectComm((PetscObject)dm), &size));
1201:   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)dm), &rank));
1202:   for (PetscInt i = 0; i < dim; i++) {
1203:     eextent[i] = faces[i];
1204:     vextent[i] = faces[i] + 1;
1205:   }
1206:   ZLayout layout;
1207:   PetscCall(ZLayoutCreate(size, eextent, vextent, &layout));
1208:   PetscZSet vset; // set of all vertices in the closure of the owned elements
1209:   PetscCall(PetscZSetCreate(&vset));
1210:   PetscInt local_elems = 0;
1211:   for (ZCode z = layout.zstarts[rank]; z < layout.zstarts[rank + 1]; z++) {
1212:     Ijk loc = ZCodeSplit(z);
1213:     if (IjkActive(layout.vextent, loc)) PetscCall(PetscZSetAdd(vset, z));
1214:     else {
1215:       z += ZStepOct(z);
1216:       continue;
1217:     }
1218:     if (IjkActive(layout.eextent, loc)) {
1219:       local_elems++;
1220:       // Add all neighboring vertices to set
1221:       for (PetscInt n = 0; n < PetscPowInt(2, dim); n++) {
1222:         Ijk   inc  = closure_dim[dim][n];
1223:         Ijk   nloc = {loc.i + inc.i, loc.j + inc.j, loc.k + inc.k};
1224:         ZCode v    = ZEncode(nloc);
1225:         PetscCall(PetscZSetAdd(vset, v));
1226:       }
1227:     }
1228:   }
1229:   PetscInt local_verts, off = 0;
1230:   ZCode   *vert_z;
1231:   PetscCall(PetscZSetGetSize(vset, &local_verts));
1232:   PetscCall(PetscMalloc1(local_verts, &vert_z));
1233:   PetscCall(PetscZSetGetElems(vset, &off, vert_z));
1234:   PetscCall(PetscZSetDestroy(&vset));
1235:   // ZCode is unsigned for bitwise convenience, but highest bit should never be set, so can interpret as signed
1236:   PetscCall(PetscSortInt64(local_verts, (PetscInt64 *)vert_z));

1238:   PetscCall(DMPlexSetChart(dm, 0, local_elems + local_verts));
1239:   for (PetscInt e = 0; e < local_elems; e++) PetscCall(DMPlexSetConeSize(dm, e, PetscPowInt(2, dim)));
1240:   PetscCall(DMSetUp(dm));
1241:   {
1242:     PetscInt e = 0;
1243:     for (ZCode z = layout.zstarts[rank]; z < layout.zstarts[rank + 1]; z++) {
1244:       Ijk loc = ZCodeSplit(z);
1245:       if (!IjkActive(layout.eextent, loc)) {
1246:         z += ZStepOct(z);
1247:         continue;
1248:       }
1249:       PetscInt cone[8], orient[8] = {0};
1250:       for (PetscInt n = 0; n < PetscPowInt(2, dim); n++) {
1251:         Ijk      inc  = closure_dim[dim][n];
1252:         Ijk      nloc = {loc.i + inc.i, loc.j + inc.j, loc.k + inc.k};
1253:         ZCode    v    = ZEncode(nloc);
1254:         PetscInt ci   = ZCodeFind(v, local_verts, vert_z);
1255:         PetscAssert(ci >= 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Did not find neighbor vertex in set");
1256:         cone[n] = local_elems + ci;
1257:       }
1258:       PetscCall(DMPlexSetCone(dm, e, cone));
1259:       PetscCall(DMPlexSetConeOrientation(dm, e, orient));
1260:       e++;
1261:     }
1262:   }

1264:   PetscCall(DMPlexSymmetrize(dm));
1265:   PetscCall(DMPlexStratify(dm));

1267:   { // Create point SF
1268:     PetscSF sf;
1269:     PetscCall(PetscSFCreate(PetscObjectComm((PetscObject)dm), &sf));
1270:     PetscInt owned_verts = ZCodeFind(layout.zstarts[rank + 1], local_verts, vert_z);
1271:     if (owned_verts < 0) owned_verts = -(owned_verts + 1); // We don't care whether the key was found
1272:     PetscInt     num_ghosts = local_verts - owned_verts;   // Due to sorting, owned vertices always come first
1273:     PetscInt    *local_ghosts;
1274:     PetscSFNode *ghosts;
1275:     PetscCall(PetscMalloc1(num_ghosts, &local_ghosts));
1276:     PetscCall(PetscMalloc1(num_ghosts, &ghosts));
1277:     for (PetscInt i = 0; i < num_ghosts;) {
1278:       ZCode       z = vert_z[owned_verts + i];
1279:       PetscMPIInt remote_rank, remote_count = 0;

1281:       PetscCall(PetscMPIIntCast(ZCodeFind(z, size + 1, layout.zstarts), &remote_rank));
1282:       if (remote_rank < 0) remote_rank = -(remote_rank + 1) - 1;
1283:       // We have a new remote rank; find all the ghost indices (which are contiguous in vert_z)

1285:       // Count the elements on remote_rank
1286:       PetscInt remote_elem = ZLayoutElementsOnRank(&layout, remote_rank);

1288:       // Traverse vertices and make ghost links
1289:       for (ZCode rz = layout.zstarts[remote_rank]; rz < layout.zstarts[remote_rank + 1]; rz++) {
1290:         Ijk loc = ZCodeSplit(rz);
1291:         if (rz == z) {
1292:           local_ghosts[i] = local_elems + owned_verts + i;
1293:           ghosts[i].rank  = remote_rank;
1294:           ghosts[i].index = remote_elem + remote_count;
1295:           i++;
1296:           if (i == num_ghosts) break;
1297:           z = vert_z[owned_verts + i];
1298:         }
1299:         if (IjkActive(layout.vextent, loc)) remote_count++;
1300:         else rz += ZStepOct(rz);
1301:       }
1302:     }
1303:     PetscCall(PetscSFSetGraph(sf, local_elems + local_verts, num_ghosts, local_ghosts, PETSC_OWN_POINTER, ghosts, PETSC_OWN_POINTER));
1304:     PetscCall(PetscObjectSetName((PetscObject)sf, "SFC Point SF"));
1305:     PetscCall(DMSetPointSF(dm, sf));
1306:     PetscCall(PetscSFDestroy(&sf));
1307:   }
1308:   {
1309:     Vec          coordinates;
1310:     PetscScalar *coords;
1311:     PetscSection coord_section;
1312:     PetscInt     coord_size;
1313:     PetscCall(DMGetCoordinateSection(dm, &coord_section));
1314:     PetscCall(PetscSectionSetNumFields(coord_section, 1));
1315:     PetscCall(PetscSectionSetFieldComponents(coord_section, 0, dim));
1316:     PetscCall(PetscSectionSetChart(coord_section, local_elems, local_elems + local_verts));
1317:     for (PetscInt v = 0; v < local_verts; v++) {
1318:       PetscInt point = local_elems + v;
1319:       PetscCall(PetscSectionSetDof(coord_section, point, dim));
1320:       PetscCall(PetscSectionSetFieldDof(coord_section, point, 0, dim));
1321:     }
1322:     PetscCall(PetscSectionSetUp(coord_section));
1323:     PetscCall(PetscSectionGetStorageSize(coord_section, &coord_size));
1324:     PetscCall(VecCreate(PETSC_COMM_SELF, &coordinates));
1325:     PetscCall(PetscObjectSetName((PetscObject)coordinates, "coordinates"));
1326:     PetscCall(VecSetSizes(coordinates, coord_size, PETSC_DETERMINE));
1327:     PetscCall(VecSetBlockSize(coordinates, dim));
1328:     PetscCall(VecSetType(coordinates, VECSTANDARD));
1329:     PetscCall(VecGetArray(coordinates, &coords));
1330:     for (PetscInt v = 0; v < local_verts; v++) {
1331:       Ijk loc             = ZCodeSplit(vert_z[v]);
1332:       coords[v * dim + 0] = lower[0] + loc.i * (upper[0] - lower[0]) / layout.eextent.i;
1333:       if (dim > 1) coords[v * dim + 1] = lower[1] + loc.j * (upper[1] - lower[1]) / layout.eextent.j;
1334:       if (dim > 2) coords[v * dim + 2] = lower[2] + loc.k * (upper[2] - lower[2]) / layout.eextent.k;
1335:     }
1336:     PetscCall(VecRestoreArray(coordinates, &coords));
1337:     PetscCall(DMSetCoordinatesLocal(dm, coordinates));
1338:     PetscCall(VecDestroy(&coordinates));
1339:   }
1340:   if (interpolate) {
1341:     PetscCall(DMPlexInterpolateInPlace_Internal(dm));

1343:     DMLabel label;
1344:     PetscCall(DMCreateLabel(dm, "Face Sets"));
1345:     PetscCall(DMGetLabel(dm, "Face Sets", &label));
1346:     PetscSegBuffer per_faces[3], donor_face_closure[3], my_donor_faces[3];
1347:     for (PetscInt i = 0; i < 3; i++) {
1348:       PetscCall(PetscSegBufferCreate(sizeof(PetscInt), 64, &per_faces[i]));
1349:       PetscCall(PetscSegBufferCreate(sizeof(PetscInt), 64, &my_donor_faces[i]));
1350:       PetscCall(PetscSegBufferCreate(sizeof(ZCode), 64 * PetscPowInt(2, dim), &donor_face_closure[i]));
1351:     }
1352:     PetscInt fStart, fEnd, vStart, vEnd;
1353:     PetscCall(DMPlexGetHeightStratum(dm, 1, &fStart, &fEnd));
1354:     PetscCall(DMPlexGetDepthStratum(dm, 0, &vStart, &vEnd));
1355:     for (PetscInt f = fStart; f < fEnd; f++) {
1356:       PetscInt npoints, *points = NULL, num_fverts = 0, fverts[8];
1357:       PetscCall(DMPlexGetTransitiveClosure(dm, f, PETSC_TRUE, &npoints, &points));
1358:       PetscInt bc_count[6] = {0};
1359:       for (PetscInt i = 0; i < npoints; i++) {
1360:         PetscInt p = points[2 * i];
1361:         if (!IsPointInsideStratum(p, vStart, vEnd)) continue;
1362:         fverts[num_fverts++] = p;
1363:         Ijk loc              = ZCodeSplit(vert_z[p - vStart]);
1364:         // Convention here matches DMPlexCreateCubeMesh_Internal
1365:         bc_count[0] += loc.i == 0;
1366:         bc_count[1] += loc.i == layout.vextent.i - 1;
1367:         bc_count[2] += loc.j == 0;
1368:         bc_count[3] += loc.j == layout.vextent.j - 1;
1369:         bc_count[4] += loc.k == 0;
1370:         bc_count[5] += loc.k == layout.vextent.k - 1;
1371:       }
1372:       PetscCall(DMPlexRestoreTransitiveClosure(dm, f, PETSC_TRUE, &npoints, &points));
1373:       for (PetscInt bc = 0, bc_match = 0; bc < 2 * dim; bc++) {
1374:         if (bc_count[bc] == PetscPowInt(2, dim - 1)) {
1375:           PetscCall(DMPlexOrientPoint(dm, f, face_orient_dim[dim][bc]));
1376:           if (periodicity[bc / 2] == DM_BOUNDARY_PERIODIC) {
1377:             PetscInt *put;
1378:             if (bc % 2 == 0) { // donor face; no label
1379:               PetscCall(PetscSegBufferGet(my_donor_faces[bc / 2], 1, &put));
1380:               *put = f;
1381:             } else { // periodic face
1382:               PetscCall(PetscSegBufferGet(per_faces[bc / 2], 1, &put));
1383:               *put = f;
1384:               ZCode *zput;
1385:               PetscCall(PetscSegBufferGet(donor_face_closure[bc / 2], num_fverts, &zput));
1386:               for (PetscInt i = 0; i < num_fverts; i++) {
1387:                 Ijk loc = ZCodeSplit(vert_z[fverts[i] - vStart]);
1388:                 switch (bc / 2) {
1389:                 case 0:
1390:                   loc.i = 0;
1391:                   break;
1392:                 case 1:
1393:                   loc.j = 0;
1394:                   break;
1395:                 case 2:
1396:                   loc.k = 0;
1397:                   break;
1398:                 }
1399:                 *zput++ = ZEncode(loc);
1400:               }
1401:             }
1402:             continue;
1403:           }
1404:           PetscAssert(bc_match == 0, PETSC_COMM_SELF, PETSC_ERR_PLIB, "Face matches multiple face sets");
1405:           PetscCall(DMLabelSetValue(label, f, face_marker_dim[dim][bc]));
1406:           bc_match++;
1407:         }
1408:       }
1409:     }
1410:     // Ensure that the Coordinate DM has our new boundary labels
1411:     DM cdm;
1412:     PetscCall(DMGetCoordinateDM(dm, &cdm));
1413:     PetscCall(DMCopyLabels(dm, cdm, PETSC_COPY_VALUES, PETSC_FALSE, DM_COPY_LABELS_FAIL));
1414:     if (periodicity[0] == DM_BOUNDARY_PERIODIC || (dim > 1 && periodicity[1] == DM_BOUNDARY_PERIODIC) || (dim > 2 && periodicity[2] == DM_BOUNDARY_PERIODIC)) {
1415:       PetscCall(DMPlexCreateBoxMesh_Tensor_SFC_Periodicity_Private(dm, &layout, vert_z, per_faces, lower, upper, periodicity, donor_face_closure, my_donor_faces));
1416:     }
1417:     for (PetscInt i = 0; i < 3; i++) {
1418:       PetscCall(PetscSegBufferDestroy(&per_faces[i]));
1419:       PetscCall(PetscSegBufferDestroy(&donor_face_closure[i]));
1420:       PetscCall(PetscSegBufferDestroy(&my_donor_faces[i]));
1421:     }
1422:   }
1423:   PetscCall(PetscFree(layout.zstarts));
1424:   PetscCall(PetscFree(vert_z));
1425:   PetscCall(PetscLogEventEnd(DMPLEX_CreateBoxSFC, dm, 0, 0, 0));
1426:   PetscFunctionReturn(PETSC_SUCCESS);
1427: }

1429: /*@
1430:   DMPlexSetIsoperiodicFaceSF - Express periodicity from an existing mesh

1432:   Logically Collective

1434:   Input Parameters:
1435: + dm           - The `DMPLEX` on which to set periodicity
1436: . num_face_sfs - Number of `PetscSF`s in `face_sfs`
1437: - 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.

1439:   Level: advanced

1441:   Note:
1442:   One can use `-dm_plex_shape zbox` to use this mode of periodicity, wherein the periodic points are distinct both globally
1443:   and locally, but are paired when creating a global dof space.

1445: .seealso: [](ch_unstructured), `DMPLEX`, `DMGetGlobalSection()`, `DMPlexGetIsoperiodicFaceSF()`
1446: @*/
1447: PetscErrorCode DMPlexSetIsoperiodicFaceSF(DM dm, PetscInt num_face_sfs, PetscSF *face_sfs)
1448: {
1449:   DM_Plex *plex = (DM_Plex *)dm->data;

1451:   PetscFunctionBegin;
1453:   if (num_face_sfs) {
1454:     PetscAssertPointer(face_sfs, 3);
1455:     PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMGetIsoperiodicPointSF_C", DMGetIsoperiodicPointSF_Plex));
1456:   } else PetscCall(PetscObjectComposeFunction((PetscObject)dm, "DMGetIsoperiodicPointSF_C", NULL));
1457:   if (num_face_sfs == plex->periodic.num_face_sfs && (num_face_sfs == 0 || face_sfs == plex->periodic.face_sfs)) PetscFunctionReturn(PETSC_SUCCESS);
1458:   PetscCall(DMSetGlobalSection(dm, NULL));

1460:   for (PetscInt i = 0; i < num_face_sfs; i++) PetscCall(PetscObjectReference((PetscObject)face_sfs[i]));
1461:   if (plex->periodic.num_face_sfs > 0) {
1462:     for (PetscInt i = 0; i < plex->periodic.num_face_sfs; i++) PetscCall(PetscSFDestroy(&plex->periodic.face_sfs[i]));
1463:     PetscCall(PetscFree(plex->periodic.face_sfs));
1464:   }

1466:   plex->periodic.num_face_sfs = num_face_sfs;
1467:   PetscCall(PetscCalloc1(num_face_sfs, &plex->periodic.face_sfs));
1468:   for (PetscInt i = 0; i < num_face_sfs; i++) plex->periodic.face_sfs[i] = face_sfs[i];

1470:   DM cdm = dm->coordinates[0].dm; // Can't DMGetCoordinateDM because it automatically creates one
1471:   if (cdm) {
1472:     PetscCall(DMPlexSetIsoperiodicFaceSF(cdm, num_face_sfs, face_sfs));
1473:     if (face_sfs) cdm->periodic.setup = DMPeriodicCoordinateSetUp_Internal;
1474:   }
1475:   PetscFunctionReturn(PETSC_SUCCESS);
1476: }

1478: /*@C
1479:   DMPlexGetIsoperiodicFaceSF - Obtain periodicity for a mesh

1481:   Logically Collective

1483:   Input Parameter:
1484: . dm - The `DMPLEX` for which to obtain periodic relation

1486:   Output Parameters:
1487: + num_face_sfs - Number of `PetscSF`s in the array
1488: - 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.

1490:   Level: advanced

1492: .seealso: [](ch_unstructured), `DMPLEX`, `DMGetGlobalSection()`, `DMPlexSetIsoperiodicFaceSF()`
1493: @*/
1494: PetscErrorCode DMPlexGetIsoperiodicFaceSF(DM dm, PetscInt *num_face_sfs, const PetscSF **face_sfs)
1495: {
1496:   PetscBool isPlex;

1498:   PetscFunctionBegin;
1500:   PetscCall(PetscObjectTypeCompare((PetscObject)dm, DMPLEX, &isPlex));
1501:   if (isPlex) {
1502:     DM_Plex *plex = (DM_Plex *)dm->data;
1503:     if (face_sfs) *face_sfs = plex->periodic.face_sfs;
1504:     if (num_face_sfs) *num_face_sfs = plex->periodic.num_face_sfs;
1505:   } else {
1506:     if (face_sfs) *face_sfs = NULL;
1507:     if (num_face_sfs) *num_face_sfs = 0;
1508:   }
1509:   PetscFunctionReturn(PETSC_SUCCESS);
1510: }

1512: /*@C
1513:   DMPlexSetIsoperiodicFaceTransform - set geometric transform from donor to periodic points

1515:   Logically Collective

1517:   Input Parameters:
1518: + dm - `DMPLEX` that has been configured with `DMPlexSetIsoperiodicFaceSF()`
1519: . n  - Number of transforms in array
1520: - t  - Array of 4x4 affine transformation basis.

1522:   Level: advanced

1524:   Notes:
1525:   Affine transforms are 4x4 matrices in which the leading 3x3 block expresses a rotation (or identity for no rotation),
1526:   the last column contains a translation vector, and the bottom row is all zero except the last entry, which must always
1527:   be 1. This representation is common in geometric modeling and allows affine transformations to be composed using
1528:   simple matrix multiplication.

1530:   Although the interface accepts a general affine transform, only affine translation is supported at present.

1532:   Developer Notes:
1533:   This interface should be replaced by making BasisTransform public, expanding it to support affine representations, and
1534:   adding GPU implementations to apply the G2L/L2G transforms.

1536: .seealso: [](ch_unstructured), `DMPLEX`, `DMGetGlobalSection()`, `DMPlexSetIsoperiodicFaceSF()`
1537: @*/
1538: PetscErrorCode DMPlexSetIsoperiodicFaceTransform(DM dm, PetscInt n, const PetscScalar t[])
1539: {
1540:   DM_Plex *plex = (DM_Plex *)dm->data;

1542:   PetscFunctionBegin;
1544:   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);

1546:   PetscCall(PetscFree(plex->periodic.transform));
1547:   PetscCall(PetscMalloc1(n, &plex->periodic.transform));
1548:   for (PetscInt i = 0; i < n; i++) {
1549:     for (PetscInt j = 0; j < 4; j++) {
1550:       for (PetscInt k = 0; k < 4; k++) {
1551:         PetscCheck(j != k || t[i * 16 + j * 4 + k] == 1., PetscObjectComm((PetscObject)dm), PETSC_ERR_SUP, "Rotated transforms not supported");
1552:         plex->periodic.transform[i][j][k] = t[i * 16 + j * 4 + k];
1553:       }
1554:     }
1555:   }
1556:   PetscFunctionReturn(PETSC_SUCCESS);
1557: }