1 /* 2 Defines a SNES that can consist of a collection of SNESes on patches of the domain 3 */ 4 #include <petsc/private/snesimpl.h> /*I "petscsnes.h" I*/ 5 #include <petsc/private/pcpatchimpl.h> /* We need internal access to PCPatch right now, until that part is moved to Plex */ 6 7 typedef struct { 8 PC pc; /* The linear patch preconditioner */ 9 SNESCompositeType type; 10 } SNES_Patch; 11 12 static PetscErrorCode SNESPatchComputeResidual_Private(SNES snes, Vec x, Vec F, void *ctx) 13 { 14 PC pc = (PC) ctx; 15 PC_PATCH *pcpatch = (PC_PATCH *) pc->data; 16 PetscErrorCode ierr; 17 18 PetscFunctionBegin; 19 ierr = PCPatchComputeFunction_Internal(pc, x, F, pcpatch->currentPatch);CHKERRQ(ierr); 20 PetscFunctionReturn(0); 21 } 22 23 static PetscErrorCode SNESPatchComputeJacobian_Private(SNES snes, Vec x, Mat J, Mat M, void *ctx) 24 { 25 PC pc = (PC) ctx; 26 PC_PATCH *pcpatch = (PC_PATCH *) pc->data; 27 PetscErrorCode ierr; 28 29 PetscFunctionBegin; 30 ierr = PCPatchComputeOperator_Internal(pc, x, M, pcpatch->currentPatch, PETSC_FALSE);CHKERRQ(ierr); 31 PetscFunctionReturn(0); 32 } 33 34 static PetscErrorCode PCSetUp_PATCH_Nonlinear(PC pc) 35 { 36 PC_PATCH *patch = (PC_PATCH *) pc->data; 37 const char *prefix; 38 PetscInt i; 39 PetscErrorCode ierr; 40 41 PetscFunctionBegin; 42 if (!pc->setupcalled) { 43 ierr = PetscMalloc1(patch->npatch, &patch->solver);CHKERRQ(ierr); 44 ierr = PCGetOptionsPrefix(pc, &prefix);CHKERRQ(ierr); 45 for (i = 0; i < patch->npatch; ++i) { 46 SNES snes; 47 KSP subksp; 48 49 ierr = SNESCreate(PETSC_COMM_SELF, &snes);CHKERRQ(ierr); 50 ierr = SNESSetOptionsPrefix(snes, prefix);CHKERRQ(ierr); 51 ierr = SNESAppendOptionsPrefix(snes, "sub_");CHKERRQ(ierr); 52 ierr = PetscObjectIncrementTabLevel((PetscObject) snes, (PetscObject) pc, 1);CHKERRQ(ierr); 53 ierr = SNESGetKSP(snes, &subksp);CHKERRQ(ierr); 54 ierr = PetscObjectIncrementTabLevel((PetscObject) subksp, (PetscObject) pc, 1);CHKERRQ(ierr); 55 ierr = PetscLogObjectParent((PetscObject) pc, (PetscObject) snes);CHKERRQ(ierr); 56 patch->solver[i] = (PetscObject) snes; 57 } 58 } 59 for (i = 0; i < patch->npatch; ++i) { 60 SNES snes = (SNES) patch->solver[i]; 61 62 ierr = SNESSetFunction(snes, patch->patchX[i], SNESPatchComputeResidual_Private, pc);CHKERRQ(ierr); 63 ierr = SNESSetJacobian(snes, patch->mat[i], patch->mat[i], SNESPatchComputeJacobian_Private, pc);CHKERRQ(ierr); 64 } 65 if (!pc->setupcalled && patch->optionsSet) for (i = 0; i < patch->npatch; ++i) {ierr = SNESSetFromOptions((SNES) patch->solver[i]);CHKERRQ(ierr);} 66 PetscFunctionReturn(0); 67 } 68 69 static PetscErrorCode PCApply_PATCH_Nonlinear(PC pc, PetscInt i, Vec x, Vec y) 70 { 71 PC_PATCH *patch = (PC_PATCH *) pc->data; 72 PetscErrorCode ierr; 73 74 PetscFunctionBegin; 75 patch->currentPatch = i; 76 ierr = PetscLogEventBegin(PC_Patch_Solve, pc, 0, 0, 0);CHKERRQ(ierr); 77 ierr = VecCopy(x, y);CHKERRQ(ierr); 78 ierr = SNESSolve((SNES) patch->solver[i], NULL, y);CHKERRQ(ierr); /* FIXME: RHS for FAS */ 79 ierr = VecAXPY(y, -1.0, x);CHKERRQ(ierr); 80 ierr = PetscLogEventEnd(PC_Patch_Solve, pc, 0, 0, 0);CHKERRQ(ierr); 81 PetscFunctionReturn(0); 82 } 83 84 static PetscErrorCode PCReset_PATCH_Nonlinear(PC pc) 85 { 86 PC_PATCH *patch = (PC_PATCH *) pc->data; 87 PetscInt i; 88 PetscErrorCode ierr; 89 90 PetscFunctionBegin; 91 if (patch->solver) { 92 for (i = 0; i < patch->npatch; ++i) {ierr = SNESReset((SNES) patch->solver[i]);CHKERRQ(ierr);} 93 } 94 PetscFunctionReturn(0); 95 } 96 97 static PetscErrorCode PCDestroy_PATCH_Nonlinear(PC pc) 98 { 99 PC_PATCH *patch = (PC_PATCH *) pc->data; 100 PetscInt i; 101 PetscErrorCode ierr; 102 103 PetscFunctionBegin; 104 if (patch->solver) { 105 for (i = 0; i < patch->npatch; ++i) {ierr = SNESDestroy((SNES *) &patch->solver[i]);CHKERRQ(ierr);} 106 ierr = PetscFree(patch->solver);CHKERRQ(ierr); 107 } 108 PetscFunctionReturn(0); 109 } 110 111 static PetscErrorCode SNESSetUp_Patch(SNES snes) 112 { 113 SNES_Patch *patch = (SNES_Patch *) snes->data; 114 DM dm; 115 Mat dummy; 116 Vec F; 117 PetscInt n, N; 118 PetscErrorCode ierr; 119 120 PetscFunctionBegin; 121 ierr = SNESGetDM(snes, &dm);CHKERRQ(ierr); 122 ierr = PCSetDM(patch->pc, dm);CHKERRQ(ierr); 123 ierr = SNESGetFunction(snes, &F, NULL, NULL);CHKERRQ(ierr); 124 ierr = VecGetLocalSize(F, &n);CHKERRQ(ierr); 125 ierr = VecGetSize(F, &N);CHKERRQ(ierr); 126 ierr = MatCreateShell(PetscObjectComm((PetscObject) snes), n, n, N, N, (void *) snes, &dummy);CHKERRQ(ierr); 127 ierr = PCSetOperators(patch->pc, dummy, dummy);CHKERRQ(ierr); 128 ierr = MatDestroy(&dummy);CHKERRQ(ierr); 129 ierr = PCSetUp(patch->pc);CHKERRQ(ierr); 130 /* allocate workspace */ 131 PetscFunctionReturn(0); 132 } 133 134 static PetscErrorCode SNESReset_Patch(SNES snes) 135 { 136 SNES_Patch *patch = (SNES_Patch *) snes->data; 137 PetscErrorCode ierr; 138 139 PetscFunctionBegin; 140 ierr = PCReset(patch->pc);CHKERRQ(ierr); 141 PetscFunctionReturn(0); 142 } 143 144 static PetscErrorCode SNESDestroy_Patch(SNES snes) 145 { 146 SNES_Patch *patch = (SNES_Patch *) snes->data; 147 PetscErrorCode ierr; 148 149 PetscFunctionBegin; 150 ierr = SNESReset_Patch(snes);CHKERRQ(ierr); 151 ierr = PCDestroy(&patch->pc);CHKERRQ(ierr); 152 ierr = PetscFree(snes->data);CHKERRQ(ierr); 153 PetscFunctionReturn(0); 154 } 155 156 static PetscErrorCode SNESSetFromOptions_Patch(PetscOptionItems *PetscOptionsObject, SNES snes) 157 { 158 SNES_Patch *patch = (SNES_Patch *) snes->data; 159 PetscBool flg; 160 const char *prefix; 161 PetscErrorCode ierr; 162 163 PetscFunctionBegin; 164 ierr = PetscOptionsHead(PetscOptionsObject, "Patch nonlinear preconditioner options");CHKERRQ(ierr); 165 ierr = PetscOptionsEnum("-snes_patch_type", "Type of composition", "SNESPatchSetType", SNESCompositeTypes, (PetscEnum) patch->type, (PetscEnum *) &patch->type, &flg);CHKERRQ(ierr); 166 if (flg) {ierr = SNESPatchSetType(snes, patch->type);CHKERRQ(ierr);} 167 ierr = PetscOptionsTail();CHKERRQ(ierr); 168 169 ierr = PetscObjectGetOptionsPrefix((PetscObject)snes, &prefix);CHKERRQ(ierr); 170 ierr = PetscObjectSetOptionsPrefix((PetscObject)patch->pc, prefix);CHKERRQ(ierr); 171 ierr = PCSetFromOptions(patch->pc);CHKERRQ(ierr); 172 PetscFunctionReturn(0); 173 } 174 175 static PetscErrorCode SNESView_Patch(SNES snes,PetscViewer viewer) 176 { 177 SNES_Patch *patch = (SNES_Patch *) snes->data; 178 PetscBool iascii; 179 PetscErrorCode ierr; 180 181 PetscFunctionBegin; 182 ierr = PetscObjectTypeCompare((PetscObject) viewer, PETSCVIEWERASCII, &iascii);CHKERRQ(ierr); 183 if (iascii) { 184 ierr = PetscViewerASCIIPrintf(viewer," type - %s\n",SNESCompositeTypes[patch->type]);CHKERRQ(ierr); 185 } 186 ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr); 187 ierr = PCView(patch->pc, viewer);CHKERRQ(ierr); 188 ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr); 189 PetscFunctionReturn(0); 190 } 191 192 static PetscErrorCode SNESSolve_Patch(SNES snes) 193 { 194 SNES_Patch *patch = (SNES_Patch *) snes->data; 195 Vec x, y; 196 PetscErrorCode ierr; 197 198 PetscFunctionBegin; 199 ierr = SNESGetSolution(snes, &x);CHKERRQ(ierr); 200 ierr = SNESGetSolutionUpdate(snes, &y);CHKERRQ(ierr); 201 ierr = PCApply(patch->pc, x, y); 202 ierr = VecAXPY(x, 1.0, y);CHKERRQ(ierr); /* FIXME: line search */ 203 ierr = SNESSetConvergedReason(snes, SNES_CONVERGED_ITS);CHKERRQ(ierr); 204 PetscFunctionReturn(0); 205 } 206 207 static PetscErrorCode SNESPatchSetType_Patch(SNES snes, SNESCompositeType type) 208 { 209 SNES_Patch *patch = (SNES_Patch *) snes->data; 210 211 PetscFunctionBegin; 212 patch->type = type; 213 PetscFunctionReturn(0); 214 } 215 216 /*MC 217 SNESPATCH - Solve a nonlinear problem by composing together many nonlinear solvers on patches 218 219 Options Database Keys: 220 . -snes_patch_type <type: one of additive, multiplicative, symmetric_multiplicative> - Sets composition type 221 222 Level: intermediate 223 224 Concepts: composing solvers 225 226 .seealso: SNESCreate(), SNESSetType(), SNESType (for list of available types), SNES, 227 PCPATCH 228 229 References: 230 . 1. - Peter R. Brune, Matthew G. Knepley, Barry F. Smith, and Xuemin Tu, "Composing Scalable Nonlinear Algebraic Solvers", SIAM Review, 57(4), 2015 231 232 M*/ 233 PETSC_EXTERN PetscErrorCode SNESCreate_Patch(SNES snes) 234 { 235 PetscErrorCode ierr; 236 SNES_Patch *patch; 237 238 PetscFunctionBegin; 239 ierr = PetscNewLog(snes, &patch);CHKERRQ(ierr); 240 241 snes->ops->solve = SNESSolve_Patch; 242 snes->ops->setup = SNESSetUp_Patch; 243 snes->ops->reset = SNESReset_Patch; 244 snes->ops->destroy = SNESDestroy_Patch; 245 snes->ops->setfromoptions = SNESSetFromOptions_Patch; 246 snes->ops->view = SNESView_Patch; 247 248 snes->alwayscomputesfinalresidual = PETSC_FALSE; 249 250 snes->data = (void *) patch; 251 patch->type = SNES_COMPOSITE_ADDITIVE; 252 ierr = PCCreate(PetscObjectComm((PetscObject) snes), &patch->pc);CHKERRQ(ierr); 253 ierr = PCSetType(patch->pc, PCPATCH);CHKERRQ(ierr); 254 255 ((PC_PATCH *) patch->pc->data)->setupsolver = PCSetUp_PATCH_Nonlinear; 256 ((PC_PATCH *) patch->pc->data)->applysolver = PCApply_PATCH_Nonlinear; 257 ((PC_PATCH *) patch->pc->data)->resetsolver = PCReset_PATCH_Nonlinear; 258 ((PC_PATCH *) patch->pc->data)->destroysolver = PCDestroy_PATCH_Nonlinear; 259 260 ierr = PetscObjectComposeFunction((PetscObject) snes, "SNESPatchSetType_C", SNESPatchSetType_Patch);CHKERRQ(ierr); 261 PetscFunctionReturn(0); 262 } 263 264 /*@ 265 SNESPatchSetType - Sets the type of composition. 266 267 Logically Collective on SNES 268 269 Input Parameter: 270 + snes - the preconditioner context 271 - type - SNES_COMPOSITE_ADDITIVE (default), SNES_COMPOSITE_MULTIPLICATIVE, etc. 272 273 Options Database Key: 274 . -snes_composite_type <type: one of additive, multiplicative, etc> - Sets composite preconditioner type 275 276 Level: Developer 277 278 .keywords: SNES, set, type, composite preconditioner, additive, multiplicative 279 @*/ 280 PetscErrorCode SNESPatchSetType(SNES snes, SNESCompositeType type) 281 { 282 PetscErrorCode ierr; 283 284 PetscFunctionBegin; 285 PetscValidHeaderSpecific(snes, SNES_CLASSID, 1); 286 PetscValidLogicalCollectiveEnum(snes,type, 2); 287 ierr = PetscTryMethod(snes, "SNESPatchSetType_C", (SNES,SNESCompositeType), (snes,type));CHKERRQ(ierr); 288 PetscFunctionReturn(0); 289 } 290 291 PetscErrorCode SNESPatchSetDiscretisationInfo(SNES snes, PetscInt nsubspaces, DM *dms, PetscInt *bs, PetscInt *nodesPerCell, const PetscInt **cellNodeMap, 292 const PetscInt *subspaceOffsets, PetscInt numGhostBcs, const PetscInt *ghostBcNodes, PetscInt numGlobalBcs, const PetscInt *globalBcNodes) 293 { 294 SNES_Patch *patch = (SNES_Patch *) snes->data; 295 PetscErrorCode ierr; 296 DM dm; 297 298 PetscFunctionBegin; 299 ierr = SNESGetDM(snes, &dm);CHKERRQ(ierr); 300 if (!dm) SETERRQ(PetscObjectComm((PetscObject)snes), PETSC_ERR_ARG_WRONGSTATE, "DM not yet set on patch SNES\n"); 301 ierr = PCSetDM(patch->pc, dm);CHKERRQ(ierr); 302 ierr = PCPatchSetDiscretisationInfo(patch->pc, nsubspaces, dms, bs, nodesPerCell, cellNodeMap, subspaceOffsets, numGhostBcs, ghostBcNodes, numGlobalBcs, globalBcNodes);CHKERRQ(ierr); 303 PetscFunctionReturn(0); 304 } 305 306 PetscErrorCode SNESPatchSetComputeOperator(SNES snes, PetscErrorCode (*func)(PC, PetscInt, Vec, Mat, IS, PetscInt, const PetscInt *, void *), void *ctx) 307 { 308 SNES_Patch *patch = (SNES_Patch *) snes->data; 309 PetscErrorCode ierr; 310 311 PetscFunctionBegin; 312 ierr = PCPatchSetComputeOperator(patch->pc, func, ctx);CHKERRQ(ierr); 313 PetscFunctionReturn(0); 314 } 315 316 PetscErrorCode SNESPatchSetComputeFunction(SNES snes, PetscErrorCode (*func)(PC, PetscInt, Vec, Vec, IS, PetscInt, const PetscInt *, void *), void *ctx) 317 { 318 SNES_Patch *patch = (SNES_Patch *) snes->data; 319 PetscErrorCode ierr; 320 321 PetscFunctionBegin; 322 ierr = PCPatchSetComputeFunction(patch->pc, func, ctx);CHKERRQ(ierr); 323 PetscFunctionReturn(0); 324 } 325 326 PetscErrorCode SNESPatchSetConstructType(SNES snes, PCPatchConstructType ctype, PetscErrorCode (*func)(PC, PetscInt *, IS **, IS *, void *), void *ctx) 327 { 328 SNES_Patch *patch = (SNES_Patch *) snes->data; 329 PetscErrorCode ierr; 330 331 PetscFunctionBegin; 332 ierr = PCPatchSetConstructType(patch->pc, ctype, func, ctx);CHKERRQ(ierr); 333 PetscFunctionReturn(0); 334 } 335 336 PetscErrorCode SNESPatchSetCellNumbering(SNES snes, PetscSection cellNumbering) 337 { 338 SNES_Patch *patch = (SNES_Patch *) snes->data; 339 PetscErrorCode ierr; 340 341 PetscFunctionBegin; 342 ierr = PCPatchSetCellNumbering(patch->pc, cellNumbering);CHKERRQ(ierr); 343 PetscFunctionReturn(0); 344 } 345