Actual source code: nasm.c

  1: #include <petsc/private/snesimpl.h>
  2: #include <petscdm.h>

  4: typedef struct {
  5:   PetscInt    n;             /* local subdomains */
  6:   SNES       *subsnes;       /* nonlinear solvers for each subdomain */
  7:   Vec        *x;             /* solution vectors */
  8:   Vec        *xl;            /* solution local vectors */
  9:   Vec        *y;             /* step vectors */
 10:   Vec        *b;             /* rhs vectors */
 11:   Vec         weight;        /* weighting for adding updates on overlaps, in global space */
 12:   VecScatter *oscatter;      /* scatter from global space to the subdomain global space */
 13:   VecScatter *oscatter_copy; /* copy of the above */
 14:   VecScatter *iscatter;      /* scatter from global space to the nonoverlapping subdomain space */
 15:   VecScatter *gscatter;      /* scatter from global space to the subdomain local space */
 16:   PCASMType   type;          /* ASM type */
 17:   PetscBool   usesdm;        /* use the DM for setting up the subproblems */
 18:   PetscBool   finaljacobian; /* compute the jacobian of the converged solution */
 19:   PetscReal   damping;       /* damping parameter for updates from the blocks */
 20:   PetscBool   weight_set;    /* use a weight in the overlap updates */

 22:   /* logging events */
 23:   PetscLogEvent eventrestrictinterp;
 24:   PetscLogEvent eventsubsolve;

 26:   PetscInt fjtype; /* type of computed jacobian */
 27:   Vec      xinit;  /* initial solution in case the final jacobian type is computed as first */
 28: } SNES_NASM;

 30: const char *const SNESNASMTypes[]   = {"NONE", "RESTRICT", "INTERPOLATE", "BASIC", "PCASMType", "PC_ASM_", NULL};
 31: const char *const SNESNASMFJTypes[] = {"FINALOUTER", "FINALINNER", "INITIAL"};

 33: static PetscErrorCode SNESReset_NASM(SNES snes)
 34: {
 35:   SNES_NASM *nasm = (SNES_NASM *)snes->data;
 36:   PetscInt   i;

 38:   PetscFunctionBegin;
 39:   for (i = 0; i < nasm->n; i++) {
 40:     if (nasm->xl) PetscCall(VecDestroy(&nasm->xl[i]));
 41:     if (nasm->x) PetscCall(VecDestroy(&nasm->x[i]));
 42:     if (nasm->y) PetscCall(VecDestroy(&nasm->y[i]));
 43:     if (nasm->b) PetscCall(VecDestroy(&nasm->b[i]));

 45:     if (nasm->subsnes) PetscCall(SNESDestroy(&nasm->subsnes[i]));
 46:     if (nasm->oscatter) PetscCall(VecScatterDestroy(&nasm->oscatter[i]));
 47:     if (nasm->oscatter_copy) PetscCall(VecScatterDestroy(&nasm->oscatter_copy[i]));
 48:     if (nasm->iscatter) PetscCall(VecScatterDestroy(&nasm->iscatter[i]));
 49:     if (nasm->gscatter) PetscCall(VecScatterDestroy(&nasm->gscatter[i]));
 50:   }

 52:   PetscCall(PetscFree(nasm->x));
 53:   PetscCall(PetscFree(nasm->xl));
 54:   PetscCall(PetscFree(nasm->y));
 55:   PetscCall(PetscFree(nasm->b));

 57:   if (nasm->xinit) PetscCall(VecDestroy(&nasm->xinit));

 59:   PetscCall(PetscFree(nasm->subsnes));
 60:   PetscCall(PetscFree(nasm->oscatter));
 61:   PetscCall(PetscFree(nasm->oscatter_copy));
 62:   PetscCall(PetscFree(nasm->iscatter));
 63:   PetscCall(PetscFree(nasm->gscatter));

 65:   if (nasm->weight_set) PetscCall(VecDestroy(&nasm->weight));

 67:   nasm->eventrestrictinterp = 0;
 68:   nasm->eventsubsolve       = 0;
 69:   PetscFunctionReturn(PETSC_SUCCESS);
 70: }

 72: static PetscErrorCode SNESDestroy_NASM(SNES snes)
 73: {
 74:   PetscFunctionBegin;
 75:   PetscCall(SNESReset_NASM(snes));
 76:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetType_C", NULL));
 77:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetType_C", NULL));
 78:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetSubdomains_C", NULL));
 79:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetSubdomains_C", NULL));
 80:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetDamping_C", NULL));
 81:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetDamping_C", NULL));
 82:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetSubdomainVecs_C", NULL));
 83:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetComputeFinalJacobian_C", NULL));
 84:   PetscCall(PetscFree(snes->data));
 85:   PetscFunctionReturn(PETSC_SUCCESS);
 86: }

 88: static PetscErrorCode DMGlobalToLocalSubDomainDirichletHook_Private(DM dm, Vec g, InsertMode mode, Vec l, void *ctx)
 89: {
 90:   Vec bcs = (Vec)ctx;

 92:   PetscFunctionBegin;
 93:   PetscCall(VecCopy(bcs, l));
 94:   PetscFunctionReturn(PETSC_SUCCESS);
 95: }

 97: static PetscErrorCode SNESSetUp_NASM(SNES snes)
 98: {
 99:   SNES_NASM  *nasm = (SNES_NASM *)snes->data;
100:   DM          dm, subdm;
101:   DM         *subdms;
102:   PetscInt    i;
103:   const char *optionsprefix;
104:   Vec         F;

106:   PetscFunctionBegin;
107:   if (!nasm->subsnes) {
108:     PetscCall(SNESGetDM(snes, &dm));
109:     if (dm) {
110:       nasm->usesdm = PETSC_TRUE;
111:       PetscCall(DMCreateDomainDecomposition(dm, &nasm->n, NULL, NULL, NULL, &subdms));
112:       PetscCheck(subdms, PetscObjectComm((PetscObject)dm), PETSC_ERR_ARG_WRONGSTATE, "DM has no default decomposition defined.  Set subsolves manually with SNESNASMSetSubdomains().");
113:       PetscCall(DMCreateDomainDecompositionScatters(dm, nasm->n, subdms, &nasm->iscatter, &nasm->oscatter, &nasm->gscatter));
114:       PetscCall(PetscMalloc1(nasm->n, &nasm->oscatter_copy));
115:       for (i = 0; i < nasm->n; i++) PetscCall(VecScatterCopy(nasm->oscatter[i], &nasm->oscatter_copy[i]));

117:       PetscCall(SNESGetOptionsPrefix(snes, &optionsprefix));
118:       PetscCall(PetscMalloc1(nasm->n, &nasm->subsnes));
119:       for (i = 0; i < nasm->n; i++) {
120:         PetscCall(SNESCreate(PetscObjectComm((PetscObject)subdms[i]), &nasm->subsnes[i]));
121:         PetscCall(PetscObjectIncrementTabLevel((PetscObject)nasm->subsnes[i], (PetscObject)snes, 1));
122:         PetscCall(SNESAppendOptionsPrefix(nasm->subsnes[i], optionsprefix));
123:         PetscCall(SNESAppendOptionsPrefix(nasm->subsnes[i], "sub_"));
124:         PetscCall(SNESSetDM(nasm->subsnes[i], subdms[i]));
125:         if (snes->ops->usercompute) {
126:           PetscCall(SNESSetComputeApplicationContext(nasm->subsnes[i], snes->ops->usercompute, snes->ops->userdestroy));
127:         } else {
128:           void *ctx;

130:           PetscCall(SNESGetApplicationContext(snes, &ctx));
131:           PetscCall(SNESSetApplicationContext(nasm->subsnes[i], ctx));
132:         }
133:         PetscCall(SNESSetFromOptions(nasm->subsnes[i]));
134:         PetscCall(DMDestroy(&subdms[i]));
135:       }
136:       PetscCall(PetscFree(subdms));
137:     } else SETERRQ(PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "Cannot construct local problems automatically without a DM!");
138:   } else SETERRQ(PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "Must set subproblems manually if there is no DM!");
139:   /* allocate the global vectors */
140:   if (!nasm->x) PetscCall(PetscCalloc1(nasm->n, &nasm->x));
141:   if (!nasm->xl) PetscCall(PetscCalloc1(nasm->n, &nasm->xl));
142:   if (!nasm->y) PetscCall(PetscCalloc1(nasm->n, &nasm->y));
143:   if (!nasm->b) PetscCall(PetscCalloc1(nasm->n, &nasm->b));

145:   for (i = 0; i < nasm->n; i++) {
146:     PetscCall(SNESGetFunction(nasm->subsnes[i], &F, NULL, NULL));
147:     if (!nasm->x[i]) PetscCall(VecDuplicate(F, &nasm->x[i]));
148:     if (!nasm->y[i]) PetscCall(VecDuplicate(F, &nasm->y[i]));
149:     if (!nasm->b[i]) PetscCall(VecDuplicate(F, &nasm->b[i]));
150:     if (!nasm->xl[i]) {
151:       PetscCall(SNESGetDM(nasm->subsnes[i], &subdm));
152:       PetscCall(DMCreateLocalVector(subdm, &nasm->xl[i]));
153:       PetscCall(DMGlobalToLocalHookAdd(subdm, DMGlobalToLocalSubDomainDirichletHook_Private, NULL, nasm->xl[i]));
154:     }
155:   }
156:   if (nasm->finaljacobian) {
157:     PetscCall(SNESSetUpMatrices(snes));
158:     if (nasm->fjtype == 2) PetscCall(VecDuplicate(snes->vec_sol, &nasm->xinit));
159:     for (i = 0; i < nasm->n; i++) PetscCall(SNESSetUpMatrices(nasm->subsnes[i]));
160:   }
161:   PetscFunctionReturn(PETSC_SUCCESS);
162: }

164: static PetscErrorCode SNESSetFromOptions_NASM(SNES snes, PetscOptionItems *PetscOptionsObject)
165: {
166:   PCASMType  asmtype;
167:   PetscBool  flg, monflg;
168:   SNES_NASM *nasm = (SNES_NASM *)snes->data;

170:   PetscFunctionBegin;
171:   PetscOptionsHeadBegin(PetscOptionsObject, "Nonlinear Additive Schwarz options");
172:   PetscCall(PetscOptionsEnum("-snes_nasm_type", "Type of restriction/extension", "", SNESNASMTypes, (PetscEnum)nasm->type, (PetscEnum *)&asmtype, &flg));
173:   if (flg) PetscCall(SNESNASMSetType(snes, asmtype));
174:   flg    = PETSC_FALSE;
175:   monflg = PETSC_TRUE;
176:   PetscCall(PetscOptionsReal("-snes_nasm_damping", "The new solution is obtained as old solution plus dmp times (sum of the solutions on the subdomains)", "SNESNASMSetDamping", nasm->damping, &nasm->damping, &flg));
177:   if (flg) PetscCall(SNESNASMSetDamping(snes, nasm->damping));
178:   PetscCall(PetscOptionsDeprecated("-snes_nasm_sub_view", NULL, "3.15", "Use -snes_view ::ascii_info_detail"));
179:   PetscCall(PetscOptionsBool("-snes_nasm_finaljacobian", "Compute the global jacobian of the final iterate (for ASPIN)", "", nasm->finaljacobian, &nasm->finaljacobian, NULL));
180:   PetscCall(PetscOptionsEList("-snes_nasm_finaljacobian_type", "The type of the final jacobian computed.", "", SNESNASMFJTypes, 3, SNESNASMFJTypes[0], &nasm->fjtype, NULL));
181:   PetscCall(PetscOptionsBool("-snes_nasm_log", "Log times for subSNES solves and restriction", "", monflg, &monflg, &flg));
182:   if (flg) {
183:     PetscCall(PetscLogEventRegister("SNESNASMSubSolve", ((PetscObject)snes)->classid, &nasm->eventsubsolve));
184:     PetscCall(PetscLogEventRegister("SNESNASMRestrict", ((PetscObject)snes)->classid, &nasm->eventrestrictinterp));
185:   }
186:   PetscOptionsHeadEnd();
187:   PetscFunctionReturn(PETSC_SUCCESS);
188: }

190: static PetscErrorCode SNESView_NASM(SNES snes, PetscViewer viewer)
191: {
192:   SNES_NASM        *nasm = (SNES_NASM *)snes->data;
193:   PetscMPIInt       rank, size;
194:   PetscInt          i, N, bsz;
195:   PetscBool         iascii, isstring;
196:   PetscViewer       sviewer;
197:   MPI_Comm          comm;
198:   PetscViewerFormat format;
199:   const char       *prefix;

201:   PetscFunctionBegin;
202:   PetscCall(PetscObjectGetComm((PetscObject)snes, &comm));
203:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
204:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERSTRING, &isstring));
205:   PetscCallMPI(MPI_Comm_rank(comm, &rank));
206:   PetscCallMPI(MPI_Comm_size(comm, &size));
207:   PetscCall(MPIU_Allreduce(&nasm->n, &N, 1, MPIU_INT, MPI_SUM, comm));
208:   if (iascii) {
209:     PetscCall(PetscViewerASCIIPrintf(viewer, "  total subdomain blocks = %" PetscInt_FMT "\n", N));
210:     PetscCall(PetscViewerGetFormat(viewer, &format));
211:     if (format != PETSC_VIEWER_ASCII_INFO_DETAIL) {
212:       if (nasm->subsnes) {
213:         PetscCall(PetscViewerASCIIPrintf(viewer, "  Local solver information for first block on rank 0:\n"));
214:         PetscCall(SNESGetOptionsPrefix(snes, &prefix));
215:         PetscCall(PetscViewerASCIIPrintf(viewer, "  Use -%ssnes_view ::ascii_info_detail to display information for all blocks\n", prefix ? prefix : ""));
216:         PetscCall(PetscViewerASCIIPushTab(viewer));
217:         PetscCall(PetscViewerGetSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
218:         if (rank == 0) {
219:           PetscCall(PetscViewerASCIIPushTab(sviewer));
220:           PetscCall(SNESView(nasm->subsnes[0], sviewer));
221:           PetscCall(PetscViewerASCIIPopTab(sviewer));
222:         }
223:         PetscCall(PetscViewerRestoreSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
224:         PetscCall(PetscViewerASCIIPopTab(viewer));
225:       }
226:     } else {
227:       /* print the solver on each block */
228:       PetscCall(PetscViewerASCIIPushSynchronized(viewer));
229:       PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "  [%d] number of local blocks = %" PetscInt_FMT "\n", (int)rank, nasm->n));
230:       PetscCall(PetscViewerFlush(viewer));
231:       PetscCall(PetscViewerASCIIPopSynchronized(viewer));
232:       PetscCall(PetscViewerASCIIPrintf(viewer, "  Local solver information for each block is in the following SNES objects:\n"));
233:       PetscCall(PetscViewerASCIIPushTab(viewer));
234:       PetscCall(PetscViewerASCIIPrintf(viewer, "- - - - - - - - - - - - - - - - - -\n"));
235:       PetscCall(PetscViewerGetSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
236:       for (i = 0; i < nasm->n; i++) {
237:         PetscCall(VecGetLocalSize(nasm->x[i], &bsz));
238:         PetscCall(PetscViewerASCIIPrintf(sviewer, "[%d] local block number %" PetscInt_FMT ", size = %" PetscInt_FMT "\n", (int)rank, i, bsz));
239:         PetscCall(SNESView(nasm->subsnes[i], sviewer));
240:         PetscCall(PetscViewerASCIIPrintf(sviewer, "- - - - - - - - - - - - - - - - - -\n"));
241:       }
242:       PetscCall(PetscViewerRestoreSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
243:       PetscCall(PetscViewerASCIIPopTab(viewer));
244:     }
245:   } else if (isstring) {
246:     PetscCall(PetscViewerStringSPrintf(viewer, " blocks=%" PetscInt_FMT ",type=%s", N, SNESNASMTypes[nasm->type]));
247:     PetscCall(PetscViewerGetSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
248:     if (nasm->subsnes && rank == 0) PetscCall(SNESView(nasm->subsnes[0], sviewer));
249:     PetscCall(PetscViewerRestoreSubViewer(viewer, PETSC_COMM_SELF, &sviewer));
250:   }
251:   PetscFunctionReturn(PETSC_SUCCESS);
252: }

254: /*@
255:   SNESNASMSetType - Set the type of subdomain update used for the nonlinear additive Schwarz solver `SNESNASM`

257:   Logically Collective

259:   Input Parameters:
260: + snes - the `SNES` context
261: - type - the type of update, `PC_ASM_BASIC` or `PC_ASM_RESTRICT`

263:   Options Database Key:
264: . -snes_nasm_type <basic,restrict> - type of subdomain update used

266:   Level: intermediate

268: .seealso: [](ch_snes), `SNES`, `SNESNASM`, `SNESNASMGetType()`, `PCASMSetType()`, `PC_ASM_BASIC`, `PC_ASM_RESTRICT`, `PCASMType`
269: @*/
270: PetscErrorCode SNESNASMSetType(SNES snes, PCASMType type)
271: {
272:   PetscErrorCode (*f)(SNES, PCASMType);

274:   PetscFunctionBegin;
275:   PetscCall(PetscObjectQueryFunction((PetscObject)snes, "SNESNASMSetType_C", &f));
276:   if (f) PetscCall((f)(snes, type));
277:   PetscFunctionReturn(PETSC_SUCCESS);
278: }

280: static PetscErrorCode SNESNASMSetType_NASM(SNES snes, PCASMType type)
281: {
282:   SNES_NASM *nasm = (SNES_NASM *)snes->data;

284:   PetscFunctionBegin;
285:   PetscCheck(type == PC_ASM_BASIC || type == PC_ASM_RESTRICT, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "SNESNASM only supports basic and restrict types");
286:   nasm->type = type;
287:   PetscFunctionReturn(PETSC_SUCCESS);
288: }

290: /*@
291:   SNESNASMGetType - Get the type of subdomain update used for the nonlinear additive Schwarz solver `SNESNASM`

293:   Logically Collective

295:   Input Parameter:
296: . snes - the `SNES` context

298:   Output Parameter:
299: . type - the type of update

301:   Level: intermediate

303: .seealso: [](ch_snes), `SNES`, `SNESNASM`, `SNESNASMSetType()`, `PCASMGetType()`, `PC_ASM_BASIC`, `PC_ASM_RESTRICT`, `PCASMType`
304: @*/
305: PetscErrorCode SNESNASMGetType(SNES snes, PCASMType *type)
306: {
307:   PetscFunctionBegin;
308:   PetscUseMethod(snes, "SNESNASMGetType_C", (SNES, PCASMType *), (snes, type));
309:   PetscFunctionReturn(PETSC_SUCCESS);
310: }

312: static PetscErrorCode SNESNASMGetType_NASM(SNES snes, PCASMType *type)
313: {
314:   SNES_NASM *nasm = (SNES_NASM *)snes->data;

316:   PetscFunctionBegin;
317:   *type = nasm->type;
318:   PetscFunctionReturn(PETSC_SUCCESS);
319: }

321: /*@
322:   SNESNASMSetSubdomains - Manually Set the context required to restrict and solve subdomain problems in the nonlinear additive Schwarz solver

324:   Logically Collective

326:   Input Parameters:
327: + snes     - the `SNES` context
328: . n        - the number of local subdomains
329: . subsnes  - solvers defined on the local subdomains
330: . iscatter - scatters into the nonoverlapping portions of the local subdomains
331: . oscatter - scatters into the overlapping portions of the local subdomains
332: - gscatter - scatters into the (ghosted) local vector of the local subdomain

334:   Level: intermediate

336: .seealso: [](ch_snes), `SNES`, `SNESNASM`, `SNESNASMGetSubdomains()`
337: @*/
338: PetscErrorCode SNESNASMSetSubdomains(SNES snes, PetscInt n, SNES subsnes[], VecScatter iscatter[], VecScatter oscatter[], VecScatter gscatter[])
339: {
340:   PetscErrorCode (*f)(SNES, PetscInt, SNES *, VecScatter *, VecScatter *, VecScatter *);

342:   PetscFunctionBegin;
343:   PetscCall(PetscObjectQueryFunction((PetscObject)snes, "SNESNASMSetSubdomains_C", &f));
344:   if (f) PetscCall((f)(snes, n, subsnes, iscatter, oscatter, gscatter));
345:   PetscFunctionReturn(PETSC_SUCCESS);
346: }

348: static PetscErrorCode SNESNASMSetSubdomains_NASM(SNES snes, PetscInt n, SNES subsnes[], VecScatter iscatter[], VecScatter oscatter[], VecScatter gscatter[])
349: {
350:   PetscInt   i;
351:   SNES_NASM *nasm = (SNES_NASM *)snes->data;

353:   PetscFunctionBegin;
354:   PetscCheck(!snes->setupcalled, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "SNESNASMSetSubdomains() should be called before calling SNESSetUp().");

356:   /* tear down the previously set things */
357:   PetscCall(SNESReset(snes));

359:   nasm->n = n;
360:   if (oscatter) {
361:     for (i = 0; i < n; i++) PetscCall(PetscObjectReference((PetscObject)oscatter[i]));
362:   }
363:   if (iscatter) {
364:     for (i = 0; i < n; i++) PetscCall(PetscObjectReference((PetscObject)iscatter[i]));
365:   }
366:   if (gscatter) {
367:     for (i = 0; i < n; i++) PetscCall(PetscObjectReference((PetscObject)gscatter[i]));
368:   }
369:   if (oscatter) {
370:     PetscCall(PetscMalloc1(n, &nasm->oscatter));
371:     PetscCall(PetscMalloc1(n, &nasm->oscatter_copy));
372:     for (i = 0; i < n; i++) {
373:       nasm->oscatter[i] = oscatter[i];
374:       PetscCall(VecScatterCopy(oscatter[i], &nasm->oscatter_copy[i]));
375:     }
376:   }
377:   if (iscatter) {
378:     PetscCall(PetscMalloc1(n, &nasm->iscatter));
379:     for (i = 0; i < n; i++) nasm->iscatter[i] = iscatter[i];
380:   }
381:   if (gscatter) {
382:     PetscCall(PetscMalloc1(n, &nasm->gscatter));
383:     for (i = 0; i < n; i++) nasm->gscatter[i] = gscatter[i];
384:   }

386:   if (subsnes) {
387:     PetscCall(PetscMalloc1(n, &nasm->subsnes));
388:     for (i = 0; i < n; i++) nasm->subsnes[i] = subsnes[i];
389:   }
390:   PetscFunctionReturn(PETSC_SUCCESS);
391: }

393: /*@
394:   SNESNASMGetSubdomains - Get the local subdomain contexts for the nonlinear additive Schwarz solver

396:   Not Collective but some of the objects returned will be parallel

398:   Input Parameter:
399: . snes - the `SNES` context

401:   Output Parameters:
402: + n        - the number of local subdomains
403: . subsnes  - solvers defined on the local subdomains
404: . iscatter - scatters into the nonoverlapping portions of the local subdomains
405: . oscatter - scatters into the overlapping portions of the local subdomains
406: - gscatter - scatters into the (ghosted) local vector of the local subdomain

408:   Level: intermediate

410: .seealso: [](ch_snes), `SNES`, `SNESNASM`, `SNESNASMSetSubdomains()`
411: @*/
412: PetscErrorCode SNESNASMGetSubdomains(SNES snes, PetscInt *n, SNES *subsnes[], VecScatter *iscatter[], VecScatter *oscatter[], VecScatter *gscatter[])
413: {
414:   PetscErrorCode (*f)(SNES, PetscInt *, SNES **, VecScatter **, VecScatter **, VecScatter **);

416:   PetscFunctionBegin;
417:   PetscCall(PetscObjectQueryFunction((PetscObject)snes, "SNESNASMGetSubdomains_C", &f));
418:   if (f) PetscCall((f)(snes, n, subsnes, iscatter, oscatter, gscatter));
419:   PetscFunctionReturn(PETSC_SUCCESS);
420: }

422: static PetscErrorCode SNESNASMGetSubdomains_NASM(SNES snes, PetscInt *n, SNES *subsnes[], VecScatter *iscatter[], VecScatter *oscatter[], VecScatter *gscatter[])
423: {
424:   SNES_NASM *nasm = (SNES_NASM *)snes->data;

426:   PetscFunctionBegin;
427:   if (n) *n = nasm->n;
428:   if (oscatter) *oscatter = nasm->oscatter;
429:   if (iscatter) *iscatter = nasm->iscatter;
430:   if (gscatter) *gscatter = nasm->gscatter;
431:   if (subsnes) *subsnes = nasm->subsnes;
432:   PetscFunctionReturn(PETSC_SUCCESS);
433: }

435: /*@
436:   SNESNASMGetSubdomainVecs - Get the processor-local subdomain vectors for the nonlinear additive Schwarz solver

438:   Not Collective

440:   Input Parameter:
441: . snes - the `SNES` context

443:   Output Parameters:
444: + n  - the number of local subdomains
445: . x  - The subdomain solution vector
446: . y  - The subdomain step vector
447: . b  - The subdomain RHS vector
448: - xl - The subdomain local vectors (ghosted)

450:   Level: developer

452: .seealso: [](ch_snes), `SNES`, `SNESNASM`, `SNESNASMGetSubdomains()`
453: @*/
454: PetscErrorCode SNESNASMGetSubdomainVecs(SNES snes, PetscInt *n, Vec **x, Vec **y, Vec **b, Vec **xl)
455: {
456:   PetscErrorCode (*f)(SNES, PetscInt *, Vec **, Vec **, Vec **, Vec **);

458:   PetscFunctionBegin;
459:   PetscCall(PetscObjectQueryFunction((PetscObject)snes, "SNESNASMGetSubdomainVecs_C", &f));
460:   if (f) PetscCall((f)(snes, n, x, y, b, xl));
461:   PetscFunctionReturn(PETSC_SUCCESS);
462: }

464: static PetscErrorCode SNESNASMGetSubdomainVecs_NASM(SNES snes, PetscInt *n, Vec **x, Vec **y, Vec **b, Vec **xl)
465: {
466:   SNES_NASM *nasm = (SNES_NASM *)snes->data;

468:   PetscFunctionBegin;
469:   if (n) *n = nasm->n;
470:   if (x) *x = nasm->x;
471:   if (y) *y = nasm->y;
472:   if (b) *b = nasm->b;
473:   if (xl) *xl = nasm->xl;
474:   PetscFunctionReturn(PETSC_SUCCESS);
475: }

477: /*@
478:   SNESNASMSetComputeFinalJacobian - Schedules the computation of the global and subdomain Jacobians upon convergence for the
479:   nonlinear additive Schwarz solver

481:   Collective

483:   Input Parameters:
484: + snes - the SNES context
485: - flg  - `PETSC_TRUE` to compute the Jacobians

487:   Level: developer

489:   Notes:
490:   This is used almost exclusively in the implementation of `SNESASPIN`, where the converged subdomain and global Jacobian
491:   is needed at each linear iteration.

493: .seealso: [](ch_snes), `SNES`, `SNESNASM`, `SNESNASMGetSubdomains()`
494: @*/
495: PetscErrorCode SNESNASMSetComputeFinalJacobian(SNES snes, PetscBool flg)
496: {
497:   PetscErrorCode (*f)(SNES, PetscBool);

499:   PetscFunctionBegin;
500:   PetscCall(PetscObjectQueryFunction((PetscObject)snes, "SNESNASMSetComputeFinalJacobian_C", &f));
501:   if (f) PetscCall((f)(snes, flg));
502:   PetscFunctionReturn(PETSC_SUCCESS);
503: }

505: static PetscErrorCode SNESNASMSetComputeFinalJacobian_NASM(SNES snes, PetscBool flg)
506: {
507:   SNES_NASM *nasm = (SNES_NASM *)snes->data;

509:   PetscFunctionBegin;
510:   nasm->finaljacobian = flg;
511:   PetscFunctionReturn(PETSC_SUCCESS);
512: }

514: /*@
515:   SNESNASMSetDamping - Sets the update damping for `SNESNASM` the nonlinear additive Schwarz solver

517:   Logically Collective

519:   Input Parameters:
520: + snes - the `SNES` context
521: - dmp  - damping

523:   Options Database Key:
524: . -snes_nasm_damping <dmp> - the new solution is obtained as old solution plus `dmp` times (sum of the solutions on the subdomains)

526:   Level: intermediate

528:   Note:
529:   The new solution is obtained as old solution plus dmp times (sum of the solutions on the subdomains)

531: .seealso: [](ch_snes), `SNES`, `SNESNASM`, `SNESNASMGetDamping()`
532: @*/
533: PetscErrorCode SNESNASMSetDamping(SNES snes, PetscReal dmp)
534: {
535:   PetscErrorCode (*f)(SNES, PetscReal);

537:   PetscFunctionBegin;
538:   PetscCall(PetscObjectQueryFunction((PetscObject)snes, "SNESNASMSetDamping_C", (void (**)(void)) & f));
539:   if (f) PetscCall((f)(snes, dmp));
540:   PetscFunctionReturn(PETSC_SUCCESS);
541: }

543: static PetscErrorCode SNESNASMSetDamping_NASM(SNES snes, PetscReal dmp)
544: {
545:   SNES_NASM *nasm = (SNES_NASM *)snes->data;

547:   PetscFunctionBegin;
548:   nasm->damping = dmp;
549:   PetscFunctionReturn(PETSC_SUCCESS);
550: }

552: /*@
553:   SNESNASMGetDamping - Gets the update damping for `SNESNASM` the nonlinear additive Schwarz solver

555:   Not Collective

557:   Input Parameter:
558: . snes - the `SNES` context

560:   Output Parameter:
561: . dmp - damping

563:   Level: intermediate

565: .seealso: [](ch_snes), `SNES`, `SNESNASM`, `SNESNASMSetDamping()`
566: @*/
567: PetscErrorCode SNESNASMGetDamping(SNES snes, PetscReal *dmp)
568: {
569:   PetscFunctionBegin;
570:   PetscUseMethod(snes, "SNESNASMGetDamping_C", (SNES, PetscReal *), (snes, dmp));
571:   PetscFunctionReturn(PETSC_SUCCESS);
572: }

574: static PetscErrorCode SNESNASMGetDamping_NASM(SNES snes, PetscReal *dmp)
575: {
576:   SNES_NASM *nasm = (SNES_NASM *)snes->data;

578:   PetscFunctionBegin;
579:   *dmp = nasm->damping;
580:   PetscFunctionReturn(PETSC_SUCCESS);
581: }

583: /*
584:   Input Parameters:
585: + snes - The solver
586: . B - The RHS vector
587: - X - The initial guess

589:   Output Parameter:
590: . Y - The solution update

592:   TODO: All scatters should be packed into one
593: */
594: static PetscErrorCode SNESNASMSolveLocal_Private(SNES snes, Vec B, Vec Y, Vec X)
595: {
596:   SNES_NASM *nasm = (SNES_NASM *)snes->data;
597:   SNES       subsnes;
598:   PetscInt   i;
599:   PetscReal  dmp;
600:   Vec        Xl, Bl, Yl, Xlloc;
601:   VecScatter iscat, oscat, gscat, oscat_copy;
602:   DM         dm, subdm;
603:   PCASMType  type;

605:   PetscFunctionBegin;
606:   PetscCall(SNESNASMGetType(snes, &type));
607:   PetscCall(SNESGetDM(snes, &dm));
608:   PetscCall(VecSet(Y, 0));
609:   if (nasm->eventrestrictinterp) PetscCall(PetscLogEventBegin(nasm->eventrestrictinterp, snes, 0, 0, 0));
610:   for (i = 0; i < nasm->n; i++) { /* scatter the global solution to the overlap solution and the local solution */
611:     Xl         = nasm->x[i];
612:     Xlloc      = nasm->xl[i];
613:     oscat      = nasm->oscatter[i];
614:     oscat_copy = nasm->oscatter_copy[i];
615:     gscat      = nasm->gscatter[i];
616:     PetscCall(VecScatterBegin(oscat, X, Xl, INSERT_VALUES, SCATTER_FORWARD));
617:     PetscCall(VecScatterBegin(gscat, X, Xlloc, INSERT_VALUES, SCATTER_FORWARD));

619:     if (B) {
620:       /* scatter the RHS to the local RHS */
621:       Bl = nasm->b[i];
622:       PetscCall(VecScatterBegin(oscat_copy, B, Bl, INSERT_VALUES, SCATTER_FORWARD));
623:     }
624:   }
625:   if (nasm->eventrestrictinterp) PetscCall(PetscLogEventEnd(nasm->eventrestrictinterp, snes, 0, 0, 0));

627:   if (nasm->eventsubsolve) PetscCall(PetscLogEventBegin(nasm->eventsubsolve, snes, 0, 0, 0));
628:   for (i = 0; i < nasm->n; i++) {
629:     PetscErrorCode (*bl)(DM, Vec, void *);
630:     void *bctx;

632:     Xl      = nasm->x[i];
633:     Xlloc   = nasm->xl[i];
634:     Yl      = nasm->y[i];
635:     subsnes = nasm->subsnes[i];
636:     PetscCall(SNESGetDM(subsnes, &subdm));
637:     iscat      = nasm->iscatter[i];
638:     oscat      = nasm->oscatter[i];
639:     oscat_copy = nasm->oscatter_copy[i];
640:     gscat      = nasm->gscatter[i];
641:     PetscCall(VecScatterEnd(oscat, X, Xl, INSERT_VALUES, SCATTER_FORWARD));
642:     PetscCall(VecScatterEnd(gscat, X, Xlloc, INSERT_VALUES, SCATTER_FORWARD));
643:     if (B) {
644:       Bl = nasm->b[i];
645:       PetscCall(VecScatterEnd(oscat_copy, B, Bl, INSERT_VALUES, SCATTER_FORWARD));
646:     } else Bl = NULL;

648:     PetscCall(SNESGetDM(subsnes, &subdm));
649:     PetscCall(DMSNESGetBoundaryLocal(subdm, &bl, &bctx));
650:     if (bl) PetscCall((*bl)(subdm, Xlloc, bctx));

652:     PetscCall(DMSubDomainRestrict(dm, oscat, gscat, subdm));
653:     PetscCall(VecCopy(Xl, Yl));
654:     PetscCall(SNESSolve(subsnes, Bl, Xl));
655:     PetscCall(VecAYPX(Yl, -1.0, Xl));
656:     PetscCall(VecScale(Yl, nasm->damping));
657:     if (type == PC_ASM_BASIC) {
658:       PetscCall(VecScatterBegin(oscat, Yl, Y, ADD_VALUES, SCATTER_REVERSE));
659:       PetscCall(VecScatterEnd(oscat, Yl, Y, ADD_VALUES, SCATTER_REVERSE));
660:     } else if (type == PC_ASM_RESTRICT) {
661:       PetscCall(VecScatterBegin(iscat, Yl, Y, ADD_VALUES, SCATTER_REVERSE));
662:       PetscCall(VecScatterEnd(iscat, Yl, Y, ADD_VALUES, SCATTER_REVERSE));
663:     } else SETERRQ(PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "Only basic and restrict types are supported for SNESNASM");
664:   }
665:   if (nasm->eventsubsolve) PetscCall(PetscLogEventEnd(nasm->eventsubsolve, snes, 0, 0, 0));
666:   if (nasm->eventrestrictinterp) PetscCall(PetscLogEventBegin(nasm->eventrestrictinterp, snes, 0, 0, 0));
667:   if (nasm->weight_set) PetscCall(VecPointwiseMult(Y, Y, nasm->weight));
668:   if (nasm->eventrestrictinterp) PetscCall(PetscLogEventEnd(nasm->eventrestrictinterp, snes, 0, 0, 0));
669:   PetscCall(SNESNASMGetDamping(snes, &dmp));
670:   PetscCall(VecAXPY(X, dmp, Y));
671:   PetscFunctionReturn(PETSC_SUCCESS);
672: }

674: static PetscErrorCode SNESNASMComputeFinalJacobian_Private(SNES snes, Vec Xfinal)
675: {
676:   Vec        X    = Xfinal;
677:   SNES_NASM *nasm = (SNES_NASM *)snes->data;
678:   SNES       subsnes;
679:   PetscInt   i, lag = 1;
680:   Vec        Xlloc, Xl, Fl, F;
681:   VecScatter oscat, gscat;
682:   DM         dm, subdm;

684:   PetscFunctionBegin;
685:   if (nasm->fjtype == 2) X = nasm->xinit;
686:   F = snes->vec_func;
687:   if (snes->normschedule == SNES_NORM_NONE) PetscCall(SNESComputeFunction(snes, X, F));
688:   PetscCall(SNESComputeJacobian(snes, X, snes->jacobian, snes->jacobian_pre));
689:   PetscCall(SNESGetDM(snes, &dm));
690:   if (nasm->eventrestrictinterp) PetscCall(PetscLogEventBegin(nasm->eventrestrictinterp, snes, 0, 0, 0));
691:   if (nasm->fjtype != 1) {
692:     for (i = 0; i < nasm->n; i++) {
693:       Xlloc = nasm->xl[i];
694:       gscat = nasm->gscatter[i];
695:       PetscCall(VecScatterBegin(gscat, X, Xlloc, INSERT_VALUES, SCATTER_FORWARD));
696:     }
697:   }
698:   if (nasm->eventrestrictinterp) PetscCall(PetscLogEventEnd(nasm->eventrestrictinterp, snes, 0, 0, 0));
699:   for (i = 0; i < nasm->n; i++) {
700:     Fl      = nasm->subsnes[i]->vec_func;
701:     Xl      = nasm->x[i];
702:     Xlloc   = nasm->xl[i];
703:     subsnes = nasm->subsnes[i];
704:     oscat   = nasm->oscatter[i];
705:     gscat   = nasm->gscatter[i];
706:     if (nasm->fjtype != 1) PetscCall(VecScatterEnd(gscat, X, Xlloc, INSERT_VALUES, SCATTER_FORWARD));
707:     PetscCall(SNESGetDM(subsnes, &subdm));
708:     PetscCall(DMSubDomainRestrict(dm, oscat, gscat, subdm));
709:     if (nasm->fjtype != 1) {
710:       PetscCall(DMLocalToGlobalBegin(subdm, Xlloc, INSERT_VALUES, Xl));
711:       PetscCall(DMLocalToGlobalEnd(subdm, Xlloc, INSERT_VALUES, Xl));
712:     }
713:     if (subsnes->lagjacobian == -1) subsnes->lagjacobian = -2;
714:     else if (subsnes->lagjacobian > 1) lag = subsnes->lagjacobian;
715:     PetscCall(SNESComputeFunction(subsnes, Xl, Fl));
716:     PetscCall(SNESComputeJacobian(subsnes, Xl, subsnes->jacobian, subsnes->jacobian_pre));
717:     if (lag > 1) subsnes->lagjacobian = lag;
718:   }
719:   PetscFunctionReturn(PETSC_SUCCESS);
720: }

722: static PetscErrorCode SNESSolve_NASM(SNES snes)
723: {
724:   Vec              F;
725:   Vec              X;
726:   Vec              B;
727:   Vec              Y;
728:   PetscInt         i;
729:   PetscReal        fnorm = 0.0;
730:   SNESNormSchedule normschedule;
731:   SNES_NASM       *nasm = (SNES_NASM *)snes->data;

733:   PetscFunctionBegin;
734:   PetscCheck(!snes->xl & !snes->xu && !snes->ops->computevariablebounds, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "SNES solver %s does not support bounds", ((PetscObject)snes)->type_name);

736:   PetscCall(PetscCitationsRegister(SNESCitation, &SNEScite));
737:   X = snes->vec_sol;
738:   Y = snes->vec_sol_update;
739:   F = snes->vec_func;
740:   B = snes->vec_rhs;

742:   PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
743:   snes->iter = 0;
744:   snes->norm = 0.;
745:   PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
746:   snes->reason = SNES_CONVERGED_ITERATING;
747:   PetscCall(SNESGetNormSchedule(snes, &normschedule));
748:   if (normschedule == SNES_NORM_ALWAYS || normschedule == SNES_NORM_INITIAL_ONLY || normschedule == SNES_NORM_INITIAL_FINAL_ONLY || !snes->max_its) {
749:     /* compute the initial function and preconditioned update delX */
750:     if (!snes->vec_func_init_set) {
751:       PetscCall(SNESComputeFunction(snes, X, F));
752:     } else snes->vec_func_init_set = PETSC_FALSE;

754:     PetscCall(VecNorm(F, NORM_2, &fnorm)); /* fnorm <- ||F||  */
755:     SNESCheckFunctionNorm(snes, fnorm);
756:     PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
757:     snes->iter = 0;
758:     snes->norm = fnorm;
759:     PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
760:     PetscCall(SNESLogConvergenceHistory(snes, snes->norm, 0));

762:     /* test convergence */
763:     PetscCall(SNESConverged(snes, 0, 0.0, 0.0, fnorm));
764:     PetscCall(SNESMonitor(snes, 0, snes->norm));
765:     if (snes->reason) PetscFunctionReturn(PETSC_SUCCESS);
766:   } else {
767:     PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
768:     PetscCall(SNESLogConvergenceHistory(snes, snes->norm, 0));
769:     PetscCall(SNESMonitor(snes, snes->iter, snes->norm));
770:   }

772:   /* Call general purpose update function */
773:   PetscTryTypeMethod(snes, update, snes->iter);
774:   /* copy the initial solution over for later */
775:   if (nasm->fjtype == 2) PetscCall(VecCopy(X, nasm->xinit));

777:   for (i = 0; i < snes->max_its; i++) {
778:     PetscCall(SNESNASMSolveLocal_Private(snes, B, Y, X));
779:     if (normschedule == SNES_NORM_ALWAYS || ((i == snes->max_its - 1) && (normschedule == SNES_NORM_INITIAL_FINAL_ONLY || normschedule == SNES_NORM_FINAL_ONLY))) {
780:       PetscCall(SNESComputeFunction(snes, X, F));
781:       PetscCall(VecNorm(F, NORM_2, &fnorm)); /* fnorm <- ||F||  */
782:       SNESCheckFunctionNorm(snes, fnorm);
783:     }
784:     /* Monitor convergence */
785:     PetscCall(PetscObjectSAWsTakeAccess((PetscObject)snes));
786:     snes->iter = i + 1;
787:     snes->norm = fnorm;
788:     PetscCall(PetscObjectSAWsGrantAccess((PetscObject)snes));
789:     PetscCall(SNESLogConvergenceHistory(snes, snes->norm, 0));
790:     /* Test for convergence */
791:     PetscCall(SNESConverged(snes, snes->iter, 0.0, 0.0, fnorm));
792:     PetscCall(SNESMonitor(snes, snes->iter, snes->norm));
793:     if (snes->reason) break;
794:     /* Call general purpose update function */
795:     PetscTryTypeMethod(snes, update, snes->iter);
796:   }
797:   if (nasm->finaljacobian) {
798:     PetscCall(SNESNASMComputeFinalJacobian_Private(snes, X));
799:     SNESCheckJacobianDomainerror(snes);
800:   }
801:   PetscFunctionReturn(PETSC_SUCCESS);
802: }

804: /*MC
805:   SNESNASM - Nonlinear Additive Schwarz solver {cite}`ck02`, {cite}`bruneknepleysmithtu15`

807:    Options Database Keys:
808: +  -snes_nasm_log                                                - enable logging events for the communication and solve stages
809: .  -snes_nasm_type <basic,restrict>                              - type of subdomain update used
810: .  -snes_nasm_damping <dmp>                                      - the new solution is obtained as old solution plus dmp times (sum of the solutions on the subdomains)
811: .  -snes_nasm_finaljacobian                                      - compute the local and global Jacobians of the final iterate
812: .  -snes_nasm_finaljacobian_type <finalinner,finalouter,initial> - pick state the Jacobian is calculated at
813: .  -sub_snes_                                                    - options prefix of the subdomain nonlinear solves
814: .  -sub_ksp_                                                     - options prefix of the subdomain Krylov solver
815: -  -sub_pc_                                                      - options prefix of the subdomain preconditioner

817:    Level: advanced

819:    Note:
820:    This is not often used directly as a solver, it converges too slowly. However it works well as a nonlinear preconditioner for
821:    the `SNESASPIN` solver

823:    Developer Note:
824:    This is a non-Newton based nonlinear solver that does not directly require a Jacobian; hence the flag snes->usesksp is set to
825:    false and `SNESView()` and -snes_view do not display a `KSP` object. However, if the flag nasm->finaljacobian is set (for example, if
826:    `SNESNASM` is used as a nonlinear preconditioner for  `SNESASPIN`) then `SNESSetUpMatrices()` is called to generate the
827:    Jacobian (needed by `SNESASPIN`)
828:    and this utilizes the inner `KSP` object for storing the matrices, but the `KSP` is never used for solving a linear system. When `SNESNASM` is
829:    used by `SNESASPIN` they share the same Jacobian matrices because `SNESSetUp()` (called on the outer `SNESASPIN`) causes the inner `SNES`
830:    object (in this case `SNESNASM`) to inherit the outer Jacobian matrices.

832: .seealso: [](ch_snes), `SNESCreate()`, `SNES`, `SNESSetType()`, `SNESType`, `SNESNASMSetType()`, `SNESNASMGetType()`, `SNESNASMSetSubdomains()`, `SNESNASMGetSubdomains()`,
833:           `SNESNASMGetSubdomainVecs()`, `SNESNASMSetComputeFinalJacobian()`, `SNESNASMSetDamping()`, `SNESNASMGetDamping()`, `SNESNASMSetWeight()`,
834:           `SNESNASMGetSNES()`, `SNESNASMGetNumber()`
835: M*/

837: PETSC_EXTERN PetscErrorCode SNESCreate_NASM(SNES snes)
838: {
839:   SNES_NASM *nasm;

841:   PetscFunctionBegin;
842:   PetscCall(PetscNew(&nasm));
843:   snes->data = (void *)nasm;

845:   nasm->n             = PETSC_DECIDE;
846:   nasm->subsnes       = NULL;
847:   nasm->x             = NULL;
848:   nasm->xl            = NULL;
849:   nasm->y             = NULL;
850:   nasm->b             = NULL;
851:   nasm->oscatter      = NULL;
852:   nasm->oscatter_copy = NULL;
853:   nasm->iscatter      = NULL;
854:   nasm->gscatter      = NULL;
855:   nasm->damping       = 1.;

857:   nasm->type          = PC_ASM_BASIC;
858:   nasm->finaljacobian = PETSC_FALSE;
859:   nasm->weight_set    = PETSC_FALSE;

861:   snes->ops->destroy        = SNESDestroy_NASM;
862:   snes->ops->setup          = SNESSetUp_NASM;
863:   snes->ops->setfromoptions = SNESSetFromOptions_NASM;
864:   snes->ops->view           = SNESView_NASM;
865:   snes->ops->solve          = SNESSolve_NASM;
866:   snes->ops->reset          = SNESReset_NASM;

868:   snes->usesksp = PETSC_FALSE;
869:   snes->usesnpc = PETSC_FALSE;

871:   snes->alwayscomputesfinalresidual = PETSC_FALSE;

873:   nasm->fjtype              = 0;
874:   nasm->xinit               = NULL;
875:   nasm->eventrestrictinterp = 0;
876:   nasm->eventsubsolve       = 0;

878:   if (!snes->tolerancesset) {
879:     snes->max_its   = 10000;
880:     snes->max_funcs = 10000;
881:   }

883:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetType_C", SNESNASMSetType_NASM));
884:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetType_C", SNESNASMGetType_NASM));
885:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetSubdomains_C", SNESNASMSetSubdomains_NASM));
886:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetSubdomains_C", SNESNASMGetSubdomains_NASM));
887:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetDamping_C", SNESNASMSetDamping_NASM));
888:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetDamping_C", SNESNASMGetDamping_NASM));
889:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMGetSubdomainVecs_C", SNESNASMGetSubdomainVecs_NASM));
890:   PetscCall(PetscObjectComposeFunction((PetscObject)snes, "SNESNASMSetComputeFinalJacobian_C", SNESNASMSetComputeFinalJacobian_NASM));
891:   PetscFunctionReturn(PETSC_SUCCESS);
892: }

894: /*@
895:   SNESNASMGetSNES - Gets a subsolver

897:   Not Collective

899:   Input Parameters:
900: + snes - the `SNES` context
901: - i    - the number of the subsnes to get

903:   Output Parameter:
904: . subsnes - the subsolver context

906:   Level: intermediate

908: .seealso: [](ch_snes), `SNESNASM`, `SNESNASMGetNumber()`
909: @*/
910: PetscErrorCode SNESNASMGetSNES(SNES snes, PetscInt i, SNES *subsnes)
911: {
912:   SNES_NASM *nasm = (SNES_NASM *)snes->data;

914:   PetscFunctionBegin;
915:   PetscCheck(i >= 0 && i < nasm->n, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_OUTOFRANGE, "No such subsolver");
916:   *subsnes = nasm->subsnes[i];
917:   PetscFunctionReturn(PETSC_SUCCESS);
918: }

920: /*@
921:   SNESNASMGetNumber - Gets number of subsolvers

923:   Not Collective

925:   Input Parameter:
926: . snes - the `SNES` context

928:   Output Parameter:
929: . n - the number of subsolvers

931:   Level: intermediate

933: .seealso: [](ch_snes), `SNESNASM`, `SNESNASMGetSNES()`
934: @*/
935: PetscErrorCode SNESNASMGetNumber(SNES snes, PetscInt *n)
936: {
937:   SNES_NASM *nasm = (SNES_NASM *)snes->data;

939:   PetscFunctionBegin;
940:   *n = nasm->n;
941:   PetscFunctionReturn(PETSC_SUCCESS);
942: }

944: /*@
945:   SNESNASMSetWeight - Sets weight to use when adding overlapping updates

947:   Collective

949:   Input Parameters:
950: + snes   - the `SNES` context
951: - weight - the weights to use (typically 1/N for each dof, where N is the number of patches it appears in)

953:   Level: intermediate

955: .seealso: [](ch_snes), `SNESNASM`
956: @*/
957: PetscErrorCode SNESNASMSetWeight(SNES snes, Vec weight)
958: {
959:   SNES_NASM *nasm = (SNES_NASM *)snes->data;

961:   PetscFunctionBegin;
962:   PetscCall(VecDestroy(&nasm->weight));
963:   nasm->weight_set = PETSC_TRUE;
964:   nasm->weight     = weight;
965:   PetscCall(PetscObjectReference((PetscObject)nasm->weight));
966:   PetscFunctionReturn(PETSC_SUCCESS);
967: }