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 SNES patchsolver = (SNES) ctx; 15 SNES_Patch *patch = (SNES_Patch *) patchsolver->data; 16 PC_PATCH *pcpatch = (PC_PATCH *) patch->pc->data; 17 PetscErrorCode ierr; 18 19 PetscFunctionBegin; 20 ierr = PCPatchComputeFunction_Internal(patch->pc, x, F, pcpatch->currentPatch);CHKERRQ(ierr); 21 PetscFunctionReturn(0); 22 } 23 24 static PetscErrorCode SNESPatchComputeJacobian_Private(SNES snes, Vec x, Mat J, Mat M, void *ctx) 25 { 26 SNES patchsolver = (SNES) ctx; 27 SNES_Patch *patch = (SNES_Patch *) patchsolver->data; 28 PC_PATCH *pcpatch = (PC_PATCH *) patch->pc->data; 29 PetscErrorCode ierr; 30 31 PetscFunctionBegin; 32 ierr = PCPatchComputeOperator_Internal(patch->pc, x, M, pcpatch->currentPatch, PETSC_FALSE);CHKERRQ(ierr); 33 PetscFunctionReturn(0); 34 } 35 36 static PetscErrorCode PCSetUp_PATCH_Nonlinear(PC pc) 37 { 38 PC_PATCH *patch = (PC_PATCH *) pc->data; 39 const char *prefix; 40 PetscInt i; 41 PetscErrorCode ierr; 42 43 PetscFunctionBegin; 44 if (!pc->setupcalled) { 45 ierr = PetscMalloc1(patch->npatch, &patch->solver);CHKERRQ(ierr); 46 ierr = PCGetOptionsPrefix(pc, &prefix);CHKERRQ(ierr); 47 for (i = 0; i < patch->npatch; ++i) { 48 SNES snes; 49 KSP subksp; 50 51 ierr = SNESCreate(PETSC_COMM_SELF, &snes);CHKERRQ(ierr); 52 ierr = SNESSetOptionsPrefix(snes, prefix);CHKERRQ(ierr); 53 ierr = SNESAppendOptionsPrefix(snes, "sub_");CHKERRQ(ierr); 54 ierr = PetscObjectIncrementTabLevel((PetscObject) snes, (PetscObject) pc, 1);CHKERRQ(ierr); 55 ierr = SNESGetKSP(snes, &subksp);CHKERRQ(ierr); 56 ierr = PetscObjectIncrementTabLevel((PetscObject) subksp, (PetscObject) pc, 1);CHKERRQ(ierr); 57 ierr = PetscLogObjectParent((PetscObject) pc, (PetscObject) snes);CHKERRQ(ierr); 58 patch->solver[i] = (PetscObject) snes; 59 } 60 } 61 for (i = 0; i < patch->npatch; ++i) { 62 SNES snes = (SNES) patch->solver[i]; 63 64 ierr = SNESSetFunction(snes, patch->patchX[i], SNESPatchComputeResidual_Private, snes);CHKERRQ(ierr); 65 ierr = SNESSetJacobian(snes, patch->mat[i], patch->mat[i], SNESPatchComputeJacobian_Private, snes);CHKERRQ(ierr); 66 } 67 if (!pc->setupcalled && patch->optionsSet) for (i = 0; i < patch->npatch; ++i) {ierr = SNESSetFromOptions((SNES) patch->solver[i]);CHKERRQ(ierr);} 68 PetscFunctionReturn(0); 69 } 70 71 static PetscErrorCode PCApply_PATCH_Nonlinear(PC pc, PetscInt i, Vec x, Vec y) 72 { 73 PC_PATCH *patch = (PC_PATCH *) pc->data; 74 PetscErrorCode ierr; 75 76 PetscFunctionBegin; 77 patch->currentPatch = i; 78 ierr = PetscLogEventBegin(PC_Patch_Solve, pc, 0, 0, 0);CHKERRQ(ierr); 79 ierr = SNESSolve((SNES) patch->solver[i], x, y);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 PetscErrorCode ierr; 161 162 PetscFunctionBegin; 163 ierr = PetscOptionsHead(PetscOptionsObject, "Patch nonlinear preconditioner options");CHKERRQ(ierr); 164 ierr = PetscOptionsEnum("-snes_patch_type", "Type of composition", "SNESPatchSetType", SNESCompositeTypes, (PetscEnum) patch->type, (PetscEnum *) &patch->type, &flg);CHKERRQ(ierr); 165 if (flg) {ierr = SNESPatchSetType(snes, patch->type);CHKERRQ(ierr);} 166 ierr = PetscOptionsTail();CHKERRQ(ierr); 167 168 ierr = PCSetFromOptions(patch->pc);CHKERRQ(ierr); 169 PetscFunctionReturn(0); 170 } 171 172 static PetscErrorCode SNESView_Patch(SNES snes,PetscViewer viewer) 173 { 174 SNES_Patch *patch = (SNES_Patch *) snes->data; 175 PetscBool iascii; 176 PetscErrorCode ierr; 177 178 PetscFunctionBegin; 179 ierr = PetscObjectTypeCompare((PetscObject) viewer, PETSCVIEWERASCII, &iascii);CHKERRQ(ierr); 180 if (iascii) { 181 ierr = PetscViewerASCIIPrintf(viewer," type - %s\n",SNESCompositeTypes[patch->type]);CHKERRQ(ierr); 182 } 183 ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr); 184 ierr = PCView(patch->pc, viewer);CHKERRQ(ierr); 185 ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr); 186 PetscFunctionReturn(0); 187 } 188 189 static PetscErrorCode SNESSolve_Patch(SNES snes) 190 { 191 PetscFunctionBegin; 192 PetscFunctionReturn(0); 193 } 194 195 static PetscErrorCode SNESPatchSetType_Patch(SNES snes, SNESCompositeType type) 196 { 197 SNES_Patch *patch = (SNES_Patch *) snes->data; 198 199 PetscFunctionBegin; 200 patch->type = type; 201 PetscFunctionReturn(0); 202 } 203 204 /*MC 205 SNESPATCH - Build a preconditioner by composing together many nonlinear solvers on patches 206 207 Options Database Keys: 208 . -snes_patch_type <type: one of additive, multiplicative, symmetric_multiplicative> - Sets composition type 209 210 Level: intermediate 211 212 Concepts: composing solvers 213 214 .seealso: SNESCreate(), SNESSetType(), SNESType (for list of available types), SNES, 215 PCPATCH 216 217 References: 218 . 1. - Peter R. Brune, Matthew G. Knepley, Barry F. Smith, and Xuemin Tu, "Composing Scalable Nonlinear Algebraic Solvers", SIAM Review, 57(4), 2015 219 220 M*/ 221 PETSC_EXTERN PetscErrorCode SNESCreate_Patch(SNES snes) 222 { 223 PetscErrorCode ierr; 224 SNES_Patch *patch; 225 226 PetscFunctionBegin; 227 ierr = PetscNewLog(snes, &patch);CHKERRQ(ierr); 228 229 snes->ops->solve = SNESSolve_Patch; 230 snes->ops->setup = SNESSetUp_Patch; 231 snes->ops->reset = SNESReset_Patch; 232 snes->ops->destroy = SNESDestroy_Patch; 233 snes->ops->setfromoptions = SNESSetFromOptions_Patch; 234 snes->ops->view = SNESView_Patch; 235 236 snes->alwayscomputesfinalresidual = PETSC_FALSE; 237 238 snes->data = (void *) patch; 239 patch->type = SNES_COMPOSITE_ADDITIVE; 240 ierr = PCCreate(PetscObjectComm((PetscObject) snes), &patch->pc);CHKERRQ(ierr); 241 ierr = PCSetType(patch->pc, PCPATCH);CHKERRQ(ierr); 242 243 ((PC_PATCH *) patch->pc->data)->setupsolver = PCSetUp_PATCH_Nonlinear; 244 ((PC_PATCH *) patch->pc->data)->applysolver = PCApply_PATCH_Nonlinear; 245 ((PC_PATCH *) patch->pc->data)->resetsolver = PCReset_PATCH_Nonlinear; 246 ((PC_PATCH *) patch->pc->data)->destroysolver = PCDestroy_PATCH_Nonlinear; 247 248 ierr = PetscObjectComposeFunction((PetscObject) snes, "SNESPatchSetType_C", SNESPatchSetType_Patch);CHKERRQ(ierr); 249 PetscFunctionReturn(0); 250 } 251 252 /*@ 253 SNESPatchSetType - Sets the type of composition. 254 255 Logically Collective on SNES 256 257 Input Parameter: 258 + snes - the preconditioner context 259 - type - SNES_COMPOSITE_ADDITIVE (default), SNES_COMPOSITE_MULTIPLICATIVE, etc. 260 261 Options Database Key: 262 . -snes_composite_type <type: one of additive, multiplicative, etc> - Sets composite preconditioner type 263 264 Level: Developer 265 266 .keywords: SNES, set, type, composite preconditioner, additive, multiplicative 267 @*/ 268 PetscErrorCode SNESPatchSetType(SNES snes, SNESCompositeType type) 269 { 270 PetscErrorCode ierr; 271 272 PetscFunctionBegin; 273 PetscValidHeaderSpecific(snes, SNES_CLASSID, 1); 274 PetscValidLogicalCollectiveEnum(snes,type, 2); 275 ierr = PetscTryMethod(snes, "SNESPatchSetType_C", (SNES,SNESCompositeType), (snes,type));CHKERRQ(ierr); 276 PetscFunctionReturn(0); 277 } 278