Actual source code: snespatch.c
1: /*
2: Defines a SNES that can consist of a collection of SNESes on patches of the domain
3: */
4: #include <petsc/private/vecimpl.h>
5: #include <petsc/private/snesimpl.h>
6: #include <petsc/private/pcpatchimpl.h>
7: #include <petscsf.h>
8: #include <petscsection.h>
10: typedef struct {
11: PC pc; /* The linear patch preconditioner */
12: } SNES_Patch;
14: static PetscErrorCode SNESPatchComputeResidual_Private(SNES snes, Vec x, Vec F, void *ctx)
15: {
16: PC pc = (PC)ctx;
17: PC_PATCH *pcpatch = (PC_PATCH *)pc->data;
18: PetscInt pt, size, i;
19: const PetscInt *indices;
20: const PetscScalar *X;
21: PetscScalar *XWithAll;
23: PetscFunctionBegin;
24: /* scatter from x to patch->patchStateWithAll[pt] */
25: pt = pcpatch->currentPatch;
26: PetscCall(ISGetSize(pcpatch->dofMappingWithoutToWithAll[pt], &size));
28: PetscCall(ISGetIndices(pcpatch->dofMappingWithoutToWithAll[pt], &indices));
29: PetscCall(VecGetArrayRead(x, &X));
30: PetscCall(VecGetArray(pcpatch->patchStateWithAll, &XWithAll));
32: for (i = 0; i < size; ++i) XWithAll[indices[i]] = X[i];
34: PetscCall(VecRestoreArray(pcpatch->patchStateWithAll, &XWithAll));
35: PetscCall(VecRestoreArrayRead(x, &X));
36: PetscCall(ISRestoreIndices(pcpatch->dofMappingWithoutToWithAll[pt], &indices));
38: PetscCall(PCPatchComputeFunction_Internal(pc, pcpatch->patchStateWithAll, F, pt));
39: PetscFunctionReturn(PETSC_SUCCESS);
40: }
42: static PetscErrorCode SNESPatchComputeJacobian_Private(SNES snes, Vec x, Mat J, Mat M, void *ctx)
43: {
44: PC pc = (PC)ctx;
45: PC_PATCH *pcpatch = (PC_PATCH *)pc->data;
46: PetscInt pt, size, i;
47: const PetscInt *indices;
48: const PetscScalar *X;
49: PetscScalar *XWithAll;
51: PetscFunctionBegin;
52: /* scatter from x to patch->patchStateWithAll[pt] */
53: pt = pcpatch->currentPatch;
54: PetscCall(ISGetSize(pcpatch->dofMappingWithoutToWithAll[pt], &size));
56: PetscCall(ISGetIndices(pcpatch->dofMappingWithoutToWithAll[pt], &indices));
57: PetscCall(VecGetArrayRead(x, &X));
58: PetscCall(VecGetArray(pcpatch->patchStateWithAll, &XWithAll));
60: for (i = 0; i < size; ++i) XWithAll[indices[i]] = X[i];
62: PetscCall(VecRestoreArray(pcpatch->patchStateWithAll, &XWithAll));
63: PetscCall(VecRestoreArrayRead(x, &X));
64: PetscCall(ISRestoreIndices(pcpatch->dofMappingWithoutToWithAll[pt], &indices));
66: PetscCall(PCPatchComputeOperator_Internal(pc, pcpatch->patchStateWithAll, M, pcpatch->currentPatch, PETSC_FALSE));
67: PetscFunctionReturn(PETSC_SUCCESS);
68: }
70: static PetscErrorCode PCSetUp_PATCH_Nonlinear(PC pc)
71: {
72: PC_PATCH *patch = (PC_PATCH *)pc->data;
73: const char *prefix;
74: PetscInt i, pStart, dof, maxDof = -1;
76: PetscFunctionBegin;
77: if (!pc->setupcalled) {
78: PetscCall(PetscMalloc1(patch->npatch, &patch->solver));
79: PetscCall(PCGetOptionsPrefix(pc, &prefix));
80: PetscCall(PetscSectionGetChart(patch->gtolCounts, &pStart, NULL));
81: for (i = 0; i < patch->npatch; ++i) {
82: SNES snes;
84: PetscCall(SNESCreate(PETSC_COMM_SELF, &snes));
85: PetscCall(SNESSetOptionsPrefix(snes, prefix));
86: PetscCall(SNESAppendOptionsPrefix(snes, "sub_"));
87: PetscCall(PetscObjectIncrementTabLevel((PetscObject)snes, (PetscObject)pc, 2));
88: patch->solver[i] = (PetscObject)snes;
90: PetscCall(PetscSectionGetDof(patch->gtolCountsWithAll, i + pStart, &dof));
91: maxDof = PetscMax(maxDof, dof);
92: }
93: PetscCall(VecDuplicate(patch->localUpdate, &patch->localState));
94: PetscCall(VecDuplicate(patch->patchRHS, &patch->patchResidual));
95: PetscCall(VecDuplicate(patch->patchUpdate, &patch->patchState));
97: PetscCall(VecCreateSeq(PETSC_COMM_SELF, maxDof, &patch->patchStateWithAll));
98: PetscCall(VecSetUp(patch->patchStateWithAll));
99: }
100: for (i = 0; i < patch->npatch; ++i) {
101: SNES snes = (SNES)patch->solver[i];
103: PetscCall(SNESSetFunction(snes, patch->patchResidual, SNESPatchComputeResidual_Private, pc));
104: PetscCall(SNESSetJacobian(snes, patch->mat[i], patch->mat[i], SNESPatchComputeJacobian_Private, pc));
105: }
106: if (!pc->setupcalled && patch->optionsSet)
107: for (i = 0; i < patch->npatch; ++i) PetscCall(SNESSetFromOptions((SNES)patch->solver[i]));
108: PetscFunctionReturn(PETSC_SUCCESS);
109: }
111: static PetscErrorCode PCApply_PATCH_Nonlinear(PC pc, PetscInt i, Vec patchRHS, Vec patchUpdate)
112: {
113: PC_PATCH *patch = (PC_PATCH *)pc->data;
114: PetscInt pStart, n;
116: PetscFunctionBegin;
117: patch->currentPatch = i;
118: PetscCall(PetscLogEventBegin(PC_Patch_Solve, pc, 0, 0, 0));
120: /* Scatter the overlapped global state to our patch state vector */
121: PetscCall(PetscSectionGetChart(patch->gtolCounts, &pStart, NULL));
122: PetscCall(PCPatch_ScatterLocal_Private(pc, i + pStart, patch->localState, patch->patchState, INSERT_VALUES, SCATTER_FORWARD, SCATTER_INTERIOR));
123: PetscCall(PCPatch_ScatterLocal_Private(pc, i + pStart, patch->localState, patch->patchStateWithAll, INSERT_VALUES, SCATTER_FORWARD, SCATTER_WITHALL));
125: PetscCall(MatGetLocalSize(patch->mat[i], NULL, &n));
126: patch->patchState->map->n = n;
127: patch->patchState->map->N = n;
128: patchUpdate->map->n = n;
129: patchUpdate->map->N = n;
130: patchRHS->map->n = n;
131: patchRHS->map->N = n;
132: /* Set initial guess to be current state*/
133: PetscCall(VecCopy(patch->patchState, patchUpdate));
134: /* Solve for new state */
135: PetscCall(SNESSolve((SNES)patch->solver[i], patchRHS, patchUpdate));
136: /* To compute update, subtract off previous state */
137: PetscCall(VecAXPY(patchUpdate, -1.0, patch->patchState));
139: PetscCall(PetscLogEventEnd(PC_Patch_Solve, pc, 0, 0, 0));
140: PetscFunctionReturn(PETSC_SUCCESS);
141: }
143: static PetscErrorCode PCReset_PATCH_Nonlinear(PC pc)
144: {
145: PC_PATCH *patch = (PC_PATCH *)pc->data;
146: PetscInt i;
148: PetscFunctionBegin;
149: if (patch->solver) {
150: for (i = 0; i < patch->npatch; ++i) PetscCall(SNESReset((SNES)patch->solver[i]));
151: }
153: PetscCall(VecDestroy(&patch->patchResidual));
154: PetscCall(VecDestroy(&patch->patchState));
155: PetscCall(VecDestroy(&patch->patchStateWithAll));
157: PetscCall(VecDestroy(&patch->localState));
158: PetscFunctionReturn(PETSC_SUCCESS);
159: }
161: static PetscErrorCode PCDestroy_PATCH_Nonlinear(PC pc)
162: {
163: PC_PATCH *patch = (PC_PATCH *)pc->data;
164: PetscInt i;
166: PetscFunctionBegin;
167: if (patch->solver) {
168: for (i = 0; i < patch->npatch; ++i) PetscCall(SNESDestroy((SNES *)&patch->solver[i]));
169: PetscCall(PetscFree(patch->solver));
170: }
171: PetscFunctionReturn(PETSC_SUCCESS);
172: }
174: static PetscErrorCode PCUpdateMultiplicative_PATCH_Nonlinear(PC pc, PetscInt i, PetscInt pStart)
175: {
176: PC_PATCH *patch = (PC_PATCH *)pc->data;
178: PetscFunctionBegin;
179: PetscCall(PCPatch_ScatterLocal_Private(pc, i + pStart, patch->patchUpdate, patch->localState, ADD_VALUES, SCATTER_REVERSE, SCATTER_INTERIOR));
180: PetscFunctionReturn(PETSC_SUCCESS);
181: }
183: static PetscErrorCode SNESSetUp_Patch(SNES snes)
184: {
185: SNES_Patch *patch = (SNES_Patch *)snes->data;
186: DM dm;
187: Mat dummy;
188: Vec F;
189: PetscInt n, N;
191: PetscFunctionBegin;
192: PetscCall(SNESGetDM(snes, &dm));
193: PetscCall(PCSetDM(patch->pc, dm));
194: PetscCall(SNESGetFunction(snes, &F, NULL, NULL));
195: PetscCall(VecGetLocalSize(F, &n));
196: PetscCall(VecGetSize(F, &N));
197: PetscCall(MatCreateShell(PetscObjectComm((PetscObject)snes), n, n, N, N, (void *)snes, &dummy));
198: PetscCall(PCSetOperators(patch->pc, dummy, dummy));
199: PetscCall(MatDestroy(&dummy));
200: PetscCall(PCSetUp(patch->pc));
201: /* allocate workspace */
202: PetscFunctionReturn(PETSC_SUCCESS);
203: }
205: static PetscErrorCode SNESReset_Patch(SNES snes)
206: {
207: SNES_Patch *patch = (SNES_Patch *)snes->data;
209: PetscFunctionBegin;
210: PetscCall(PCReset(patch->pc));
211: PetscFunctionReturn(PETSC_SUCCESS);
212: }
214: static PetscErrorCode SNESDestroy_Patch(SNES snes)
215: {
216: SNES_Patch *patch = (SNES_Patch *)snes->data;
218: PetscFunctionBegin;
219: PetscCall(SNESReset_Patch(snes));
220: PetscCall(PCDestroy(&patch->pc));
221: PetscCall(PetscFree(snes->data));
222: PetscFunctionReturn(PETSC_SUCCESS);
223: }
225: static PetscErrorCode SNESSetFromOptions_Patch(SNES snes, PetscOptionItems *PetscOptionsObject)
226: {
227: SNES_Patch *patch = (SNES_Patch *)snes->data;
228: const char *prefix;
230: PetscFunctionBegin;
231: PetscCall(PetscObjectGetOptionsPrefix((PetscObject)snes, &prefix));
232: PetscCall(PetscObjectSetOptionsPrefix((PetscObject)patch->pc, prefix));
233: PetscCall(PCSetFromOptions(patch->pc));
234: PetscFunctionReturn(PETSC_SUCCESS);
235: }
237: static PetscErrorCode SNESView_Patch(SNES snes, PetscViewer viewer)
238: {
239: SNES_Patch *patch = (SNES_Patch *)snes->data;
240: PetscBool iascii;
242: PetscFunctionBegin;
243: PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &iascii));
244: if (iascii) PetscCall(PetscViewerASCIIPrintf(viewer, "SNESPATCH\n"));
245: PetscCall(PetscViewerASCIIPushTab(viewer));
246: PetscCall(PCView(patch->pc, viewer));
247: PetscCall(PetscViewerASCIIPopTab(viewer));
248: PetscFunctionReturn(PETSC_SUCCESS);
249: }
251: static PetscErrorCode SNESSolve_Patch(SNES snes)
252: {
253: SNES_Patch *patch = (SNES_Patch *)snes->data;
254: PC_PATCH *pcpatch = (PC_PATCH *)patch->pc->data;
255: SNESLineSearch ls;
256: Vec rhs, update, state, residual;
257: const PetscScalar *globalState = NULL;
258: PetscScalar *localState = NULL;
259: PetscInt its = 0;
260: PetscReal xnorm = 0.0, ynorm = 0.0, fnorm = 0.0;
262: PetscFunctionBegin;
263: PetscCall(SNESGetSolution(snes, &state));
264: PetscCall(SNESGetSolutionUpdate(snes, &update));
265: PetscCall(SNESGetRhs(snes, &rhs));
267: PetscCall(SNESGetFunction(snes, &residual, NULL, NULL));
268: PetscCall(SNESGetLineSearch(snes, &ls));
270: PetscCall(SNESSetConvergedReason(snes, SNES_CONVERGED_ITERATING));
271: PetscCall(VecSet(update, 0.0));
272: PetscCall(SNESComputeFunction(snes, state, residual));
274: PetscCall(VecNorm(state, NORM_2, &xnorm));
275: PetscCall(VecNorm(residual, NORM_2, &fnorm));
276: snes->ttol = fnorm * snes->rtol;
278: if (snes->ops->converged) {
279: PetscUseTypeMethod(snes, converged, its, xnorm, ynorm, fnorm, &snes->reason, snes->cnvP);
280: } else {
281: PetscCall(SNESConvergedSkip(snes, its, xnorm, ynorm, fnorm, &snes->reason, NULL));
282: }
283: PetscCall(SNESLogConvergenceHistory(snes, fnorm, 0)); /* should we count lits from the patches? */
284: PetscCall(SNESMonitor(snes, its, fnorm));
286: /* The main solver loop */
287: for (its = 0; its < snes->max_its; its++) {
288: PetscCall(SNESSetIterationNumber(snes, its));
290: /* Scatter state vector to overlapped vector on all patches.
291: The vector pcpatch->localState is scattered to each patch
292: in PCApply_PATCH_Nonlinear. */
293: PetscCall(VecGetArrayRead(state, &globalState));
294: PetscCall(VecGetArray(pcpatch->localState, &localState));
295: PetscCall(PetscSFBcastBegin(pcpatch->sectionSF, MPIU_SCALAR, globalState, localState, MPI_REPLACE));
296: PetscCall(PetscSFBcastEnd(pcpatch->sectionSF, MPIU_SCALAR, globalState, localState, MPI_REPLACE));
297: PetscCall(VecRestoreArray(pcpatch->localState, &localState));
298: PetscCall(VecRestoreArrayRead(state, &globalState));
300: /* The looping over patches happens here */
301: PetscCall(PCApply(patch->pc, rhs, update));
303: /* Apply a line search. This will often be basic with
304: damping = 1/(max number of patches a dof can be in),
305: but not always */
306: PetscCall(VecScale(update, -1.0));
307: PetscCall(SNESLineSearchApply(ls, state, residual, &fnorm, update));
309: PetscCall(VecNorm(state, NORM_2, &xnorm));
310: PetscCall(VecNorm(update, NORM_2, &ynorm));
312: if (snes->ops->converged) {
313: PetscUseTypeMethod(snes, converged, its, xnorm, ynorm, fnorm, &snes->reason, snes->cnvP);
314: } else {
315: PetscCall(SNESConvergedSkip(snes, its, xnorm, ynorm, fnorm, &snes->reason, NULL));
316: }
317: PetscCall(SNESLogConvergenceHistory(snes, fnorm, 0)); /* FIXME: should we count lits? */
318: PetscCall(SNESMonitor(snes, its, fnorm));
319: }
321: if (its == snes->max_its) PetscCall(SNESSetConvergedReason(snes, SNES_DIVERGED_MAX_IT));
322: PetscFunctionReturn(PETSC_SUCCESS);
323: }
325: /*MC
326: SNESPATCH - Solve a nonlinear problem or apply a nonlinear smoother by composing together many nonlinear solvers on (often overlapping) patches {cite}`bruneknepleysmithtu15`
328: Level: intermediate
330: .seealso: [](ch_snes), `SNESFAS`, `SNESCreate()`, `SNESSetType()`, `SNESType`, `SNES`, `PCPATCH`
331: M*/
332: PETSC_EXTERN PetscErrorCode SNESCreate_Patch(SNES snes)
333: {
334: SNES_Patch *patch;
335: PC_PATCH *patchpc;
336: SNESLineSearch linesearch;
338: PetscFunctionBegin;
339: PetscCall(PetscNew(&patch));
341: snes->ops->solve = SNESSolve_Patch;
342: snes->ops->setup = SNESSetUp_Patch;
343: snes->ops->reset = SNESReset_Patch;
344: snes->ops->destroy = SNESDestroy_Patch;
345: snes->ops->setfromoptions = SNESSetFromOptions_Patch;
346: snes->ops->view = SNESView_Patch;
348: PetscCall(SNESGetLineSearch(snes, &linesearch));
349: if (!((PetscObject)linesearch)->type_name) PetscCall(SNESLineSearchSetType(linesearch, SNESLINESEARCHBASIC));
350: snes->usesksp = PETSC_FALSE;
352: snes->alwayscomputesfinalresidual = PETSC_FALSE;
354: snes->data = (void *)patch;
355: PetscCall(PCCreate(PetscObjectComm((PetscObject)snes), &patch->pc));
356: PetscCall(PCSetType(patch->pc, PCPATCH));
358: patchpc = (PC_PATCH *)patch->pc->data;
359: patchpc->classname = "snes";
360: patchpc->isNonlinear = PETSC_TRUE;
362: patchpc->setupsolver = PCSetUp_PATCH_Nonlinear;
363: patchpc->applysolver = PCApply_PATCH_Nonlinear;
364: patchpc->resetsolver = PCReset_PATCH_Nonlinear;
365: patchpc->destroysolver = PCDestroy_PATCH_Nonlinear;
366: patchpc->updatemultiplicative = PCUpdateMultiplicative_PATCH_Nonlinear;
367: PetscFunctionReturn(PETSC_SUCCESS);
368: }
370: PetscErrorCode SNESPatchSetDiscretisationInfo(SNES snes, PetscInt nsubspaces, DM *dms, PetscInt *bs, PetscInt *nodesPerCell, const PetscInt **cellNodeMap, const PetscInt *subspaceOffsets, PetscInt numGhostBcs, const PetscInt *ghostBcNodes, PetscInt numGlobalBcs, const PetscInt *globalBcNodes)
371: {
372: SNES_Patch *patch = (SNES_Patch *)snes->data;
373: DM dm;
375: PetscFunctionBegin;
376: PetscCall(SNESGetDM(snes, &dm));
377: PetscCheck(dm, PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "DM not yet set on patch SNES");
378: PetscCall(PCSetDM(patch->pc, dm));
379: PetscCall(PCPatchSetDiscretisationInfo(patch->pc, nsubspaces, dms, bs, nodesPerCell, cellNodeMap, subspaceOffsets, numGhostBcs, ghostBcNodes, numGlobalBcs, globalBcNodes));
380: PetscFunctionReturn(PETSC_SUCCESS);
381: }
383: PetscErrorCode SNESPatchSetComputeOperator(SNES snes, PetscErrorCode (*func)(PC, PetscInt, Vec, Mat, IS, PetscInt, const PetscInt *, const PetscInt *, void *), void *ctx)
384: {
385: SNES_Patch *patch = (SNES_Patch *)snes->data;
387: PetscFunctionBegin;
388: PetscCall(PCPatchSetComputeOperator(patch->pc, func, ctx));
389: PetscFunctionReturn(PETSC_SUCCESS);
390: }
392: PetscErrorCode SNESPatchSetComputeFunction(SNES snes, PetscErrorCode (*func)(PC, PetscInt, Vec, Vec, IS, PetscInt, const PetscInt *, const PetscInt *, void *), void *ctx)
393: {
394: SNES_Patch *patch = (SNES_Patch *)snes->data;
396: PetscFunctionBegin;
397: PetscCall(PCPatchSetComputeFunction(patch->pc, func, ctx));
398: PetscFunctionReturn(PETSC_SUCCESS);
399: }
401: PetscErrorCode SNESPatchSetConstructType(SNES snes, PCPatchConstructType ctype, PetscErrorCode (*func)(PC, PetscInt *, IS **, IS *, void *), void *ctx)
402: {
403: SNES_Patch *patch = (SNES_Patch *)snes->data;
405: PetscFunctionBegin;
406: PetscCall(PCPatchSetConstructType(patch->pc, ctype, func, ctx));
407: PetscFunctionReturn(PETSC_SUCCESS);
408: }
410: PetscErrorCode SNESPatchSetCellNumbering(SNES snes, PetscSection cellNumbering)
411: {
412: SNES_Patch *patch = (SNES_Patch *)snes->data;
414: PetscFunctionBegin;
415: PetscCall(PCPatchSetCellNumbering(patch->pc, cellNumbering));
416: PetscFunctionReturn(PETSC_SUCCESS);
417: }