1: #include <petsc/private/dmimpl.h>
  2: #include <petsc/private/snesimpl.h>   /*I "petscsnes.h" I*/

  4: typedef struct {
  5:   PetscErrorCode (*residuallocal)(DM,Vec,Vec,void*);
  6:   PetscErrorCode (*jacobianlocal)(DM,Vec,Mat,Mat,void*);
  7:   void *residuallocalctx;
  8:   void *jacobianlocalctx;
  9: } DMSNES_Local;

 13: static PetscErrorCode DMSNESDestroy_DMLocal(DMSNES sdm)
 14: {

 18:   PetscFree(sdm->data);
 19:   return(0);
 20: }

 24: static PetscErrorCode DMSNESDuplicate_DMLocal(DMSNES oldsdm,DMSNES sdm)
 25: {

 29:   PetscNewLog(sdm,(DMSNES_Local**)&sdm->data);
 30:   if (oldsdm->data) {
 31:     PetscMemcpy(sdm->data,oldsdm->data,sizeof(DMSNES_Local));
 32:   }
 33:   return(0);
 34: }

 38: static PetscErrorCode DMLocalSNESGetContext(DM dm,DMSNES sdm,DMSNES_Local **dmlocalsnes)
 39: {

 43:   *dmlocalsnes = NULL;
 44:   if (!sdm->data) {
 45:     PetscNewLog(dm,(DMSNES_Local**)&sdm->data);

 47:     sdm->ops->destroy   = DMSNESDestroy_DMLocal;
 48:     sdm->ops->duplicate = DMSNESDuplicate_DMLocal;
 49:   }
 50:   *dmlocalsnes = (DMSNES_Local*)sdm->data;
 51:   return(0);
 52: }

 56: static PetscErrorCode SNESComputeFunction_DMLocal(SNES snes,Vec X,Vec F,void *ctx)
 57: {
 59:   DM             dm;
 60:   DMSNES_Local   *dmlocalsnes = (DMSNES_Local*)ctx;
 61:   Vec            Xloc,Floc;

 67:   SNESGetDM(snes,&dm);
 68:   DMGetLocalVector(dm,&Xloc);
 69:   DMGetLocalVector(dm,&Floc);
 70:   VecZeroEntries(Xloc);
 71:   VecZeroEntries(Floc);
 72:   DMGlobalToLocalBegin(dm,X,INSERT_VALUES,Xloc);
 73:   DMGlobalToLocalEnd(dm,X,INSERT_VALUES,Xloc);
 74:   CHKMEMQ;
 75:   (*dmlocalsnes->residuallocal)(dm,Xloc,Floc,dmlocalsnes->residuallocalctx);
 76:   CHKMEMQ;
 77:   VecZeroEntries(F);
 78:   DMLocalToGlobalBegin(dm,Floc,ADD_VALUES,F);
 79:   DMLocalToGlobalEnd(dm,Floc,ADD_VALUES,F);
 80:   DMRestoreLocalVector(dm,&Floc);
 81:   DMRestoreLocalVector(dm,&Xloc);
 82:   return(0);
 83: }

 87: static PetscErrorCode SNESComputeJacobian_DMLocal(SNES snes,Vec X,Mat A,Mat B,void *ctx)
 88: {
 90:   DM             dm;
 91:   DMSNES_Local   *dmlocalsnes = (DMSNES_Local*)ctx;
 92:   Vec            Xloc;

 95:   SNESGetDM(snes,&dm);
 96:   if (dmlocalsnes->jacobianlocal) {
 97:     DMGetLocalVector(dm,&Xloc);
 98:     VecZeroEntries(Xloc);
 99:     DMGlobalToLocalBegin(dm,X,INSERT_VALUES,Xloc);
100:     DMGlobalToLocalEnd(dm,X,INSERT_VALUES,Xloc);
101:     CHKMEMQ;
102:     (*dmlocalsnes->jacobianlocal)(dm,Xloc,A,B,dmlocalsnes->jacobianlocalctx);
103:     CHKMEMQ;
104:     DMRestoreLocalVector(dm,&Xloc);
105:   } else {
106:     MatFDColoring fdcoloring;
107:     PetscObjectQuery((PetscObject)dm,"DMDASNES_FDCOLORING",(PetscObject*)&fdcoloring);
108:     if (!fdcoloring) {
109:       ISColoring coloring;

111:       DMCreateColoring(dm,dm->coloringtype,&coloring);
112:       MatFDColoringCreate(B,coloring,&fdcoloring);
113:       ISColoringDestroy(&coloring);
114:       switch (dm->coloringtype) {
115:       case IS_COLORING_GLOBAL:
116:         MatFDColoringSetFunction(fdcoloring,(PetscErrorCode (*)(void))SNESComputeFunction_DMLocal,dmlocalsnes);
117:         break;
118:       default: SETERRQ1(PetscObjectComm((PetscObject)snes),PETSC_ERR_SUP,"No support for coloring type '%s'",ISColoringTypes[dm->coloringtype]);
119:       }
120:       PetscObjectSetOptionsPrefix((PetscObject)fdcoloring,((PetscObject)dm)->prefix);
121:       MatFDColoringSetFromOptions(fdcoloring);
122:       MatFDColoringSetUp(B,coloring,fdcoloring);
123:       PetscObjectCompose((PetscObject)dm,"DMDASNES_FDCOLORING",(PetscObject)fdcoloring);
124:       PetscObjectDereference((PetscObject)fdcoloring);

126:       /* The following breaks an ugly reference counting loop that deserves a paragraph. MatFDColoringApply() will call
127:        * VecDuplicate() with the state Vec and store inside the MatFDColoring. This Vec will duplicate the Vec, but the
128:        * MatFDColoring is composed with the DM. We dereference the DM here so that the reference count will eventually
129:        * drop to 0. Note the code in DMDestroy() that exits early for a negative reference count. That code path will be
130:        * taken when the PetscObjectList for the Vec inside MatFDColoring is destroyed.
131:        */
132:       PetscObjectDereference((PetscObject)dm);
133:     }
134:     MatFDColoringApply(B,fdcoloring,X,snes);
135:   }
136:   /* This will be redundant if the user called both, but it's too common to forget. */
137:   if (A != B) {
138:     MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
139:     MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
140:   }
141:   return(0);
142: }

146: /*@C
147:    DMSNESSetFunctionLocal - set a local residual evaluation function. This function is called with local vector
148:       containing the local vector information PLUS ghost point information. It should compute a result for all local
149:       elements and DMSNES will automatically accumulate the overlapping values.

151:    Logically Collective

153:    Input Arguments:
154: +  dm - DM to associate callback with
155: .  func - local residual evaluation
156: -  ctx - optional context for local residual evaluation

158:    Level: beginner

160: .seealso: DMSNESSetFunction(), DMDASNESSetJacobianLocal(), DMDACreate1d(), DMDACreate2d(), DMDACreate3d()
161: @*/
162: PetscErrorCode DMSNESSetFunctionLocal(DM dm,PetscErrorCode (*func)(DM,Vec,Vec,void*),void *ctx)
163: {
165:   DMSNES         sdm;
166:   DMSNES_Local   *dmlocalsnes;

170:   DMGetDMSNESWrite(dm,&sdm);
171:   DMLocalSNESGetContext(dm,sdm,&dmlocalsnes);

173:   dmlocalsnes->residuallocal    = func;
174:   dmlocalsnes->residuallocalctx = ctx;

176:   DMSNESSetFunction(dm,SNESComputeFunction_DMLocal,dmlocalsnes);
177:   if (!sdm->ops->computejacobian) {  /* Call us for the Jacobian too, can be overridden by the user. */
178:     DMSNESSetJacobian(dm,SNESComputeJacobian_DMLocal,dmlocalsnes);
179:   }
180:   return(0);
181: }

185: /*@C
186:    DMSNESSetJacobianLocal - set a local Jacobian evaluation function

188:    Logically Collective

190:    Input Arguments:
191: +  dm - DM to associate callback with
192: .  func - local Jacobian evaluation
193: -  ctx - optional context for local Jacobian evaluation

195:    Level: beginner

197: .seealso: DMSNESSetJacobian(), DMDASNESSetJacobian(), DMDACreate1d(), DMDACreate2d(), DMDACreate3d()
198: @*/
199: PetscErrorCode DMSNESSetJacobianLocal(DM dm,PetscErrorCode (*func)(DM,Vec,Mat,Mat,void*),void *ctx)
200: {
202:   DMSNES         sdm;
203:   DMSNES_Local   *dmlocalsnes;

207:   DMGetDMSNESWrite(dm,&sdm);
208:   DMLocalSNESGetContext(dm,sdm,&dmlocalsnes);

210:   dmlocalsnes->jacobianlocal    = func;
211:   dmlocalsnes->jacobianlocalctx = ctx;

213:   DMSNESSetJacobian(dm,SNESComputeJacobian_DMLocal,dmlocalsnes);
214:   return(0);
215: }