xref: /petsc/src/snes/impls/nasm/nasm.c (revision a4f1787623b00ac75b859ba8d8c035f42daafb83)
1 #include <petsc-private/snesimpl.h>             /*I   "petscsnes.h"   I*/
2 #include <petscdm.h>
3 
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   VecScatter *oscatter;           /* scatter from global space to the subdomain global space */
12   VecScatter *iscatter;           /* scatter from global space to the nonoverlapping subdomain space */
13   VecScatter *gscatter;           /* scatter from global space to the subdomain local space */
14   PCASMType  type;                /* ASM type */
15   PetscBool  usesdm;              /* use the DM for setting up the subproblems */
16   PetscBool  finaljacobian;       /* compute the jacobian of the converged solution */
17   PetscBool  same_local_solves;   /* flag to determine if the solvers have been individually modified */
18 
19   /* logging events */
20   PetscLogEvent eventrestrictinterp;
21   PetscLogEvent eventsubsolve;
22 } SNES_NASM;
23 
24 const char *const SNESNASMTypes[] = {"NONE","RESTRICT","INTERPOLATE","BASIC","PCASMType","PC_ASM_",0};
25 
26 #undef __FUNCT__
27 #define __FUNCT__ "SNESReset_NASM"
28 PetscErrorCode SNESReset_NASM(SNES snes)
29 {
30   SNES_NASM      *nasm = (SNES_NASM*)snes->data;
31   PetscErrorCode ierr;
32   PetscInt       i;
33 
34   PetscFunctionBegin;
35   for (i=0; i<nasm->n; i++) {
36     if (nasm->xl) { ierr = VecDestroy(&nasm->xl[i]);CHKERRQ(ierr); }
37     if (nasm->x) { ierr = VecDestroy(&nasm->x[i]);CHKERRQ(ierr); }
38     if (nasm->y) { ierr = VecDestroy(&nasm->y[i]);CHKERRQ(ierr); }
39     if (nasm->b) { ierr = VecDestroy(&nasm->b[i]);CHKERRQ(ierr); }
40 
41     if (nasm->subsnes) { ierr = SNESDestroy(&nasm->subsnes[i]);CHKERRQ(ierr); }
42     if (nasm->oscatter) { ierr = VecScatterDestroy(&nasm->oscatter[i]);CHKERRQ(ierr); }
43     if (nasm->iscatter) { ierr = VecScatterDestroy(&nasm->iscatter[i]);CHKERRQ(ierr); }
44     if (nasm->gscatter) { ierr = VecScatterDestroy(&nasm->gscatter[i]);CHKERRQ(ierr); }
45   }
46 
47   if (nasm->x) {ierr = PetscFree(nasm->x);CHKERRQ(ierr);}
48   if (nasm->xl) {ierr = PetscFree(nasm->xl);CHKERRQ(ierr);}
49   if (nasm->y) {ierr = PetscFree(nasm->y);CHKERRQ(ierr);}
50   if (nasm->b) {ierr = PetscFree(nasm->b);CHKERRQ(ierr);}
51 
52   if (nasm->subsnes) {ierr = PetscFree(nasm->subsnes);CHKERRQ(ierr);}
53   if (nasm->oscatter) {ierr = PetscFree(nasm->oscatter);CHKERRQ(ierr);}
54   if (nasm->iscatter) {ierr = PetscFree(nasm->iscatter);CHKERRQ(ierr);}
55   if (nasm->gscatter) {ierr = PetscFree(nasm->gscatter);CHKERRQ(ierr);}
56 
57   nasm->eventrestrictinterp = 0;
58   nasm->eventsubsolve = 0;
59   PetscFunctionReturn(0);
60 }
61 
62 #undef __FUNCT__
63 #define __FUNCT__ "SNESDestroy_NASM"
64 PetscErrorCode SNESDestroy_NASM(SNES snes)
65 {
66   PetscErrorCode ierr;
67 
68   PetscFunctionBegin;
69   ierr = SNESReset_NASM(snes);CHKERRQ(ierr);
70   ierr = PetscFree(snes->data);CHKERRQ(ierr);
71   PetscFunctionReturn(0);
72 }
73 
74 #undef __FUNCT__
75 #define __FUNCT__ "DMGlobalToLocalSubDomainDirichletHook_Private"
76 PetscErrorCode DMGlobalToLocalSubDomainDirichletHook_Private(DM dm,Vec g,InsertMode mode,Vec l,void *ctx)
77 {
78   PetscErrorCode ierr;
79   Vec            bcs = (Vec)ctx;
80 
81   PetscFunctionBegin;
82   ierr = VecCopy(bcs,l);CHKERRQ(ierr);
83   PetscFunctionReturn(0);
84 }
85 
86 #undef __FUNCT__
87 #define __FUNCT__ "SNESSetUp_NASM"
88 PetscErrorCode SNESSetUp_NASM(SNES snes)
89 {
90   SNES_NASM      *nasm = (SNES_NASM*)snes->data;
91   PetscErrorCode ierr;
92   DM             dm,subdm;
93   DM             *subdms;
94   PetscInt       i;
95   const char     *optionsprefix;
96   Vec            F;
97   PetscMPIInt    size;
98   KSP            ksp;
99   PC             pc;
100 
101   PetscFunctionBegin;
102   if (!nasm->subsnes) {
103     ierr = SNESGetDM(snes,&dm);CHKERRQ(ierr);
104     if (dm) {
105       nasm->usesdm = PETSC_TRUE;
106       ierr         = DMCreateDomainDecomposition(dm,&nasm->n,NULL,NULL,NULL,&subdms);CHKERRQ(ierr);
107       if (!subdms) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_WRONGSTATE,"DM has no default decomposition defined.  Set subsolves manually with SNESNASMSetSubdomains().");
108       ierr = DMCreateDomainDecompositionScatters(dm,nasm->n,subdms,&nasm->iscatter,&nasm->oscatter,&nasm->gscatter);CHKERRQ(ierr);
109 
110       ierr = SNESGetOptionsPrefix(snes, &optionsprefix);CHKERRQ(ierr);
111       ierr = PetscMalloc(nasm->n*sizeof(SNES),&nasm->subsnes);CHKERRQ(ierr);
112       for (i=0; i<nasm->n; i++) {
113         ierr = SNESCreate(PETSC_COMM_SELF,&nasm->subsnes[i]);CHKERRQ(ierr);
114         ierr = SNESAppendOptionsPrefix(nasm->subsnes[i],optionsprefix);CHKERRQ(ierr);
115         ierr = SNESAppendOptionsPrefix(nasm->subsnes[i],"sub_");CHKERRQ(ierr);
116         ierr = SNESSetDM(nasm->subsnes[i],subdms[i]);CHKERRQ(ierr);
117         ierr = MPI_Comm_size(PetscObjectComm((PetscObject)nasm->subsnes[i]),&size);CHKERRQ(ierr);
118         if (size == 1) {
119           ierr = SNESGetKSP(nasm->subsnes[i],&ksp);CHKERRQ(ierr);
120           ierr = KSPGetPC(ksp,&pc);CHKERRQ(ierr);
121           ierr = KSPSetType(ksp,KSPPREONLY);CHKERRQ(ierr);
122           ierr = PCSetType(pc,PCLU);CHKERRQ(ierr);
123         }
124         ierr = SNESSetFromOptions(nasm->subsnes[i]);CHKERRQ(ierr);
125         ierr = DMDestroy(&subdms[i]);CHKERRQ(ierr);
126       }
127       ierr = PetscFree(subdms);CHKERRQ(ierr);
128     } else SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONGSTATE,"Cannot construct local problems automatically without a DM!");
129   } else SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONGSTATE,"Must set subproblems manually if there is no DM!");
130   /* allocate the global vectors */
131   if (!nasm->x) {
132     ierr = PetscMalloc(nasm->n*sizeof(Vec),&nasm->x);CHKERRQ(ierr);
133     ierr = PetscMemzero(nasm->x,nasm->n*sizeof(Vec));CHKERRQ(ierr);
134   }
135   if (!nasm->xl) {
136     ierr = PetscMalloc(nasm->n*sizeof(Vec),&nasm->xl);CHKERRQ(ierr);
137     ierr = PetscMemzero(nasm->xl,nasm->n*sizeof(Vec));CHKERRQ(ierr);
138   }
139   if (!nasm->y) {
140     ierr = PetscMalloc(nasm->n*sizeof(Vec),&nasm->y);CHKERRQ(ierr);
141     ierr = PetscMemzero(nasm->y,nasm->n*sizeof(Vec));CHKERRQ(ierr);
142   }
143   if (!nasm->b) {
144     ierr = PetscMalloc(nasm->n*sizeof(Vec),&nasm->b);CHKERRQ(ierr);
145     ierr = PetscMemzero(nasm->b,nasm->n*sizeof(Vec));CHKERRQ(ierr);
146   }
147 
148   for (i=0; i<nasm->n; i++) {
149     ierr = SNESGetFunction(nasm->subsnes[i],&F,NULL,NULL);CHKERRQ(ierr);
150     if (!nasm->x[i]) {ierr = VecDuplicate(F,&nasm->x[i]);CHKERRQ(ierr);}
151     if (!nasm->y[i]) {ierr = VecDuplicate(F,&nasm->y[i]);CHKERRQ(ierr);}
152     if (!nasm->b[i]) {ierr = VecDuplicate(F,&nasm->b[i]);CHKERRQ(ierr);}
153     if (!nasm->xl[i]) {
154       ierr = SNESGetDM(nasm->subsnes[i],&subdm);CHKERRQ(ierr);
155       ierr = DMCreateLocalVector(subdm,&nasm->xl[i]);CHKERRQ(ierr);
156     }
157     ierr = DMGlobalToLocalHookAdd(subdm,DMGlobalToLocalSubDomainDirichletHook_Private,NULL,nasm->xl[i]);CHKERRQ(ierr);
158   }
159   if (nasm->finaljacobian) {ierr = SNESSetUpMatrices(snes);CHKERRQ(ierr);}
160   PetscFunctionReturn(0);
161 }
162 
163 #undef __FUNCT__
164 #define __FUNCT__ "SNESSetFromOptions_NASM"
165 PetscErrorCode SNESSetFromOptions_NASM(SNES snes)
166 {
167   PetscErrorCode    ierr;
168   PCASMType         asmtype;
169   PetscBool         flg,monflg,subviewflg;
170   SNES_NASM         *nasm = (SNES_NASM*)snes->data;
171 
172   PetscFunctionBegin;
173   ierr = PetscOptionsHead("Nonlinear Additive Schwartz options");CHKERRQ(ierr);
174   ierr = PetscOptionsEnum("-snes_nasm_type","Type of restriction/extension","",SNESNASMTypes,(PetscEnum)nasm->type,(PetscEnum*)&asmtype,&flg);CHKERRQ(ierr);
175   if (flg) nasm->type = asmtype;
176   flg    = PETSC_FALSE;
177   monflg = PETSC_TRUE;
178   subviewflg = PETSC_FALSE;
179   ierr   = PetscOptionsBool("-snes_nasm_sub_view","Print detailed information for every processor when using -snes_view","",subviewflg,&subviewflg,&flg);CHKERRQ(ierr);
180   if (flg) {
181     nasm->same_local_solves = PETSC_FALSE;
182     if (!subviewflg) {
183       nasm->same_local_solves = PETSC_TRUE;
184     }
185   }
186   ierr   = PetscOptionsBool("-snes_nasm_finaljacobian","Compute the global jacobian of the final iterate (for ASPIN)","",nasm->finaljacobian,&nasm->finaljacobian,NULL);CHKERRQ(ierr);
187   ierr   = PetscOptionsBool("-snes_nasm_log","Log times for subSNES solves and restriction","",monflg,&monflg,&flg);CHKERRQ(ierr);
188   if (flg) {
189     ierr = PetscLogEventRegister("SNESNASMSubSolve",((PetscObject)snes)->classid,&nasm->eventsubsolve);CHKERRQ(ierr);
190     ierr = PetscLogEventRegister("SNESNASMRestrict",((PetscObject)snes)->classid,&nasm->eventrestrictinterp);CHKERRQ(ierr);
191   }
192   ierr = PetscOptionsTail();CHKERRQ(ierr);
193   PetscFunctionReturn(0);
194 }
195 
196 #undef __FUNCT__
197 #define __FUNCT__ "SNESView_NASM"
198 PetscErrorCode SNESView_NASM(SNES snes, PetscViewer viewer)
199 {
200   SNES_NASM      *nasm = (SNES_NASM*)snes->data;
201   PetscErrorCode ierr;
202   PetscMPIInt    rank,size;
203   PetscInt       i,j,N,bsz,nmax,nmin;
204   PetscBool      iascii,isstring;
205   PetscViewer    sviewer;
206   MPI_Comm       comm;
207 
208   PetscFunctionBegin;
209   ierr = PetscObjectGetComm((PetscObject)snes,&comm);CHKERRQ(ierr);
210   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);CHKERRQ(ierr);
211   ierr = PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERSTRING,&isstring);CHKERRQ(ierr);
212   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
213   ierr = MPI_Comm_size(comm,&size);CHKERRQ(ierr);
214   ierr = MPI_Reduce(&nasm->n,&N,1,MPIU_INT,MPIU_SUM,0,comm);CHKERRQ(ierr);
215   if (iascii) {
216     ierr = PetscViewerASCIIPrintf(viewer, "  Nonlinear Additive Schwarz: total subdomain blocks = %D\n",N);CHKERRQ(ierr);
217     ierr = MPI_Reduce(&nasm->n,&nmax,1,MPIU_INT,MPIU_MAX,0,comm);CHKERRQ(ierr);
218     ierr = MPI_Reduce(&nasm->n,&nmin,1,MPIU_INT,MPIU_MIN,0,comm);CHKERRQ(ierr);
219     if (nasm->same_local_solves) {
220       if (nasm->subsnes) {
221         ierr = PetscViewerASCIIPrintf(viewer,"  Local solve is the same for all blocks:\n");CHKERRQ(ierr);
222         ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
223         ierr = PetscViewerGetSingleton(viewer,&sviewer);CHKERRQ(ierr);
224         if (!rank) {
225           ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
226           ierr = SNESView(nasm->subsnes[0],sviewer);CHKERRQ(ierr);
227           ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
228         }
229         ierr = PetscViewerRestoreSingleton(viewer,&sviewer);CHKERRQ(ierr);
230         ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
231       }
232     } else {
233       /* print the solver on each block */
234       ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_TRUE);CHKERRQ(ierr);
235       ierr = PetscViewerASCIISynchronizedPrintf(viewer,"  [%d] number of local blocks = %D\n",(int)rank,nasm->n);CHKERRQ(ierr);
236       ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
237       ierr = PetscViewerASCIISynchronizedAllow(viewer,PETSC_FALSE);CHKERRQ(ierr);
238       ierr = PetscViewerASCIIPrintf(viewer,"  Local solve info for each block is in the following SNES objects:\n");CHKERRQ(ierr);
239       ierr = PetscViewerASCIIPushTab(viewer);CHKERRQ(ierr);
240       ierr = PetscViewerASCIIPrintf(viewer,"- - - - - - - - - - - - - - - - - -\n");CHKERRQ(ierr);
241       for (j=0; j<size; j++) {
242         ierr = PetscViewerGetSingleton(viewer,&sviewer);CHKERRQ(ierr);
243         if (rank == j) {
244           for (i=0; i<nasm->n; i++) {
245             ierr = VecGetLocalSize(nasm->x[i],&bsz);CHKERRQ(ierr);
246             ierr = PetscViewerASCIIPrintf(sviewer,"[%d] local block number %D, size = %D\n",(int)rank,i,bsz);CHKERRQ(ierr);
247             ierr = SNESView(nasm->subsnes[i],sviewer);CHKERRQ(ierr);
248             ierr = PetscViewerASCIIPrintf(sviewer,"- - - - - - - - - - - - - - - - - -\n");CHKERRQ(ierr);
249           }
250         }
251         ierr = PetscViewerRestoreSingleton(viewer,&sviewer);CHKERRQ(ierr);
252         ierr = PetscViewerFlush(viewer);CHKERRQ(ierr);
253       }
254       ierr = PetscViewerASCIIPopTab(viewer);CHKERRQ(ierr);
255     }
256   } else if (isstring) {
257     ierr = PetscViewerStringSPrintf(viewer," blocks=%D,type=%s",N,SNESNASMTypes[nasm->type]);CHKERRQ(ierr);
258     ierr = PetscViewerGetSingleton(viewer,&sviewer);CHKERRQ(ierr);
259     if (nasm->subsnes && !rank) {ierr = SNESView(nasm->subsnes[0],sviewer);CHKERRQ(ierr);}
260     ierr = PetscViewerRestoreSingleton(viewer,&sviewer);CHKERRQ(ierr);
261   }
262   PetscFunctionReturn(0);
263 }
264 
265 #undef __FUNCT__
266 #define __FUNCT__ "SNESNASMSetSubdomains"
267 /*@
268    SNESNASMSetSubdomains - Manually Set the context required to restrict and solve subdomain problems.
269 
270    Not Collective
271 
272    Input Parameters:
273 +  SNES - the SNES context
274 .  n - the number of local subdomains
275 .  subsnes - solvers defined on the local subdomains
276 .  iscatter - scatters into the nonoverlapping portions of the local subdomains
277 .  oscatter - scatters into the overlapping portions of the local subdomains
278 -  gscatter - scatters into the (ghosted) local vector of the local subdomain
279 
280    Level: intermediate
281 
282 .keywords: SNES, NASM
283 
284 .seealso: SNESNASM, SNESNASMGetSubdomains()
285 @*/
286 PetscErrorCode SNESNASMSetSubdomains(SNES snes,PetscInt n,SNES subsnes[],VecScatter iscatter[],VecScatter oscatter[],VecScatter gscatter[])
287 {
288   PetscErrorCode ierr;
289   PetscErrorCode (*f)(SNES,PetscInt,SNES*,VecScatter*,VecScatter*,VecScatter*);
290 
291   PetscFunctionBegin;
292   ierr = PetscObjectQueryFunction((PetscObject)snes,"SNESNASMSetSubdomains_C",&f);CHKERRQ(ierr);
293   ierr = (f)(snes,n,subsnes,iscatter,oscatter,gscatter);CHKERRQ(ierr);
294   PetscFunctionReturn(0);
295 }
296 
297 #undef __FUNCT__
298 #define __FUNCT__ "SNESNASMSetSubdomains_NASM"
299 PetscErrorCode SNESNASMSetSubdomains_NASM(SNES snes,PetscInt n,SNES subsnes[],VecScatter iscatter[],VecScatter oscatter[],VecScatter gscatter[])
300 {
301   PetscInt       i;
302   PetscErrorCode ierr;
303   SNES_NASM      *nasm = (SNES_NASM*)snes->data;
304 
305   PetscFunctionBegin;
306   if (snes->setupcalled) SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONGSTATE,"SNESNASMSetSubdomains() should be called before calling SNESSetUp().");
307 
308   /* tear down the previously set things */
309   ierr = SNESReset(snes);CHKERRQ(ierr);
310 
311   nasm->n = n;
312   if (oscatter) {
313     for (i=0; i<n; i++) {ierr = PetscObjectReference((PetscObject)oscatter[i]);CHKERRQ(ierr);}
314   }
315   if (iscatter) {
316     for (i=0; i<n; i++) {ierr = PetscObjectReference((PetscObject)iscatter[i]);CHKERRQ(ierr);}
317   }
318   if (gscatter) {
319     for (i=0; i<n; i++) {ierr = PetscObjectReference((PetscObject)gscatter[i]);CHKERRQ(ierr);}
320   }
321   if (oscatter) {
322     ierr = PetscMalloc(n*sizeof(IS),&nasm->oscatter);CHKERRQ(ierr);
323     for (i=0; i<n; i++) {
324       nasm->oscatter[i] = oscatter[i];
325     }
326   }
327   if (iscatter) {
328     ierr = PetscMalloc(n*sizeof(IS),&nasm->iscatter);CHKERRQ(ierr);
329     for (i=0; i<n; i++) {
330       nasm->iscatter[i] = iscatter[i];
331     }
332   }
333   if (gscatter) {
334     ierr = PetscMalloc(n*sizeof(IS),&nasm->gscatter);CHKERRQ(ierr);
335     for (i=0; i<n; i++) {
336       nasm->gscatter[i] = gscatter[i];
337     }
338   }
339 
340   if (subsnes) {
341     ierr = PetscMalloc(n*sizeof(SNES),&nasm->subsnes);CHKERRQ(ierr);
342     for (i=0; i<n; i++) {
343       nasm->subsnes[i] = subsnes[i];
344     }
345     nasm->same_local_solves = PETSC_FALSE;
346   }
347   PetscFunctionReturn(0);
348 }
349 
350 #undef __FUNCT__
351 #define __FUNCT__ "SNESNASMGetSubdomains"
352 /*@
353    SNESNASMGetSubdomains - Get the local subdomain context.
354 
355    Not Collective
356 
357    Input Parameters:
358 .  SNES - the SNES context
359 
360    Output Parameters:
361 +  n - the number of local subdomains
362 .  subsnes - solvers defined on the local subdomains
363 .  iscatter - scatters into the nonoverlapping portions of the local subdomains
364 .  oscatter - scatters into the overlapping portions of the local subdomains
365 -  gscatter - scatters into the (ghosted) local vector of the local subdomain
366 
367    Level: intermediate
368 
369 .keywords: SNES, NASM
370 
371 .seealso: SNESNASM, SNESNASMSetSubdomains()
372 @*/
373 PetscErrorCode SNESNASMGetSubdomains(SNES snes,PetscInt *n,SNES *subsnes[],VecScatter *iscatter[],VecScatter *oscatter[],VecScatter *gscatter[])
374 {
375   PetscErrorCode ierr;
376   PetscErrorCode (*f)(SNES,PetscInt*,SNES**,VecScatter**,VecScatter**,VecScatter**);
377 
378   PetscFunctionBegin;
379   ierr = PetscObjectQueryFunction((PetscObject)snes,"SNESNASMGetSubdomains_C",&f);CHKERRQ(ierr);
380   ierr = (f)(snes,n,subsnes,iscatter,oscatter,gscatter);CHKERRQ(ierr);
381   PetscFunctionReturn(0);
382 }
383 
384 #undef __FUNCT__
385 #define __FUNCT__ "SNESNASMGetSubdomains_NASM"
386 PetscErrorCode SNESNASMGetSubdomains_NASM(SNES snes,PetscInt *n,SNES *subsnes[],VecScatter *iscatter[],VecScatter *oscatter[],VecScatter *gscatter[])
387 {
388   SNES_NASM      *nasm = (SNES_NASM*)snes->data;
389 
390   PetscFunctionBegin;
391   if (n) *n = nasm->n;
392   if (oscatter) *oscatter = nasm->oscatter;
393   if (iscatter) *iscatter = nasm->iscatter;
394   if (gscatter) *gscatter = nasm->gscatter;
395   if (subsnes)  {
396     *subsnes  = nasm->subsnes;
397     nasm->same_local_solves = PETSC_FALSE;
398   }
399   PetscFunctionReturn(0);
400 }
401 
402 #undef __FUNCT__
403 #define __FUNCT__ "SNESNASMGetSubdomainVecs"
404 /*@
405    SNESNASMGetSubdomainVecs - Get the processor-local subdomain vectors
406 
407    Not Collective
408 
409    Input Parameters:
410 .  SNES - the SNES context
411 
412    Output Parameters:
413 +  n - the number of local subdomains
414 .  x - The subdomain solution vector
415 .  y - The subdomain step vector
416 .  b - The subdomain RHS vector
417 -  xl - The subdomain local vectors (ghosted)
418 
419    Level: developer
420 
421 .keywords: SNES, NASM
422 
423 .seealso: SNESNASM, SNESNASMGetSubdomains()
424 @*/
425 PetscErrorCode SNESNASMGetSubdomainVecs(SNES snes,PetscInt *n,Vec **x,Vec **y,Vec **b, Vec **xl)
426 {
427   PetscErrorCode ierr;
428   PetscErrorCode (*f)(SNES,PetscInt*,Vec**,Vec**,Vec**,Vec**);
429 
430   PetscFunctionBegin;
431   ierr = PetscObjectQueryFunction((PetscObject)snes,"SNESNASMGetSubdomainVecs_C",&f);CHKERRQ(ierr);
432   ierr = (f)(snes,n,x,y,b,xl);CHKERRQ(ierr);
433   PetscFunctionReturn(0);
434 }
435 
436 #undef __FUNCT__
437 #define __FUNCT__ "SNESNASMGetSubdomainVecs_NASM"
438 PetscErrorCode SNESNASMGetSubdomainVecs_NASM(SNES snes,PetscInt *n,Vec **x,Vec **y,Vec **b,Vec **xl)
439 {
440   SNES_NASM      *nasm = (SNES_NASM*)snes->data;
441 
442   PetscFunctionBegin;
443   if (n)  *n  = nasm->n;
444   if (x)  *x  = nasm->x;
445   if (y)  *y  = nasm->y;
446   if (b)  *b  = nasm->b;
447   if (xl) *xl = nasm->xl;
448   PetscFunctionReturn(0);
449 }
450 
451 #undef __FUNCT__
452 #define __FUNCT__ "SNESNASMSetComputeFinalJacobian"
453 /*@
454    SNESNASMSetComputeFinalJacobian - Schedules the computation of the global and subdomain jacobians upon convergence
455 
456    Collective on SNES
457 
458    Input Parameters:
459 +  SNES - the SNES context
460 -  flg - indication of whether to compute the jacobians or not
461 
462    Level: developer
463 
464    Notes: This is used almost exclusively in the implementation of ASPIN, where the converged subdomain and global jacobian
465    is needed at each linear iteration.
466 
467 .keywords: SNES, NASM, ASPIN
468 
469 .seealso: SNESNASM, SNESNASMGetSubdomains()
470 @*/
471 PetscErrorCode SNESNASMSetComputeFinalJacobian(SNES snes,PetscBool flg)
472 {
473   PetscErrorCode (*f)(SNES,PetscBool);
474   PetscErrorCode ierr;
475 
476   PetscFunctionBegin;
477   ierr = PetscObjectQueryFunction((PetscObject)snes,"SNESNASMSetComputeFinalJacobian_C",&f);CHKERRQ(ierr);
478   ierr = (f)(snes,flg);CHKERRQ(ierr);
479   PetscFunctionReturn(0);
480 }
481 
482 #undef __FUNCT__
483 #define __FUNCT__ "SNESNASMSetComputeFinalJacobian_NASM"
484 PetscErrorCode SNESNASMSetComputeFinalJacobian_NASM(SNES snes,PetscBool flg)
485 {
486   SNES_NASM      *nasm = (SNES_NASM*)snes->data;
487 
488   PetscFunctionBegin;
489   nasm->finaljacobian = flg;
490   PetscFunctionReturn(0);
491 }
492 
493 #undef __FUNCT__
494 #define __FUNCT__ "SNESNASMSolveLocal_Private"
495 PetscErrorCode SNESNASMSolveLocal_Private(SNES snes,Vec B,Vec Y,Vec X)
496 {
497   SNES_NASM      *nasm = (SNES_NASM*)snes->data;
498   SNES           subsnes;
499   PetscInt       i;
500   PetscErrorCode ierr;
501   Vec            Xlloc,Xl,Bl,Yl;
502   VecScatter     iscat,oscat,gscat;
503   DM             dm,subdm;
504 
505   PetscFunctionBegin;
506   ierr = SNESGetDM(snes,&dm);CHKERRQ(ierr);
507   ierr = VecSet(Y,0);CHKERRQ(ierr);
508   if (nasm->eventrestrictinterp) {ierr = PetscLogEventBegin(nasm->eventrestrictinterp,snes,0,0,0);CHKERRQ(ierr);}
509   for (i=0; i<nasm->n; i++) {
510     /* scatter the solution to the local solution */
511     Xlloc = nasm->xl[i];
512     gscat   = nasm->gscatter[i];
513     oscat   = nasm->oscatter[i];
514     ierr = VecScatterBegin(gscat,X,Xlloc,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
515     if (B) {
516       /* scatter the RHS to the local RHS */
517       Bl   = nasm->b[i];
518       ierr = VecScatterBegin(oscat,B,Bl,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
519     }
520   }
521   if (nasm->eventrestrictinterp) {ierr = PetscLogEventEnd(nasm->eventrestrictinterp,snes,0,0,0);CHKERRQ(ierr);}
522 
523 
524   if (nasm->eventsubsolve) {ierr = PetscLogEventBegin(nasm->eventsubsolve,snes,0,0,0);CHKERRQ(ierr);}
525   for (i=0; i<nasm->n; i++) {
526     Xl    = nasm->x[i];
527     Xlloc = nasm->xl[i];
528     Yl    = nasm->y[i];
529     subsnes = nasm->subsnes[i];
530     ierr    = SNESGetDM(subsnes,&subdm);CHKERRQ(ierr);
531     iscat   = nasm->iscatter[i];
532     oscat   = nasm->oscatter[i];
533     gscat   = nasm->gscatter[i];
534     ierr = VecScatterEnd(gscat,X,Xlloc,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
535     if (B) {
536       Bl   = nasm->b[i];
537       ierr = VecScatterEnd(oscat,B,Bl,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
538     } else Bl = NULL;
539     ierr = DMSubDomainRestrict(dm,oscat,gscat,subdm);CHKERRQ(ierr);
540     ierr = DMLocalToGlobalBegin(subdm,Xlloc,INSERT_VALUES,Xl);CHKERRQ(ierr);
541     ierr = DMLocalToGlobalEnd(subdm,Xlloc,INSERT_VALUES,Xl);CHKERRQ(ierr);
542     ierr = VecCopy(Xl,Yl);CHKERRQ(ierr);
543     ierr = SNESSolve(subsnes,Bl,Xl);CHKERRQ(ierr);
544     ierr = VecAYPX(Yl,-1.0,Xl);CHKERRQ(ierr);
545     if (nasm->type == PC_ASM_BASIC) {
546       ierr = VecScatterBegin(oscat,Yl,Y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
547     } else if (nasm->type == PC_ASM_RESTRICT) {
548       ierr = VecScatterBegin(iscat,Yl,Y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
549     } else SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONGSTATE,"Only basic and restrict types are supported for SNESNASM");
550   }
551   if (nasm->eventsubsolve) {ierr = PetscLogEventEnd(nasm->eventsubsolve,snes,0,0,0);CHKERRQ(ierr);}
552   if (nasm->eventrestrictinterp) {ierr = PetscLogEventBegin(nasm->eventrestrictinterp,snes,0,0,0);CHKERRQ(ierr);}
553   for (i=0; i<nasm->n; i++) {
554     Yl    = nasm->y[i];
555     iscat   = nasm->iscatter[i];
556     oscat   = nasm->oscatter[i];
557     if (nasm->type == PC_ASM_BASIC) {
558       ierr = VecScatterEnd(oscat,Yl,Y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
559     } else if (nasm->type == PC_ASM_RESTRICT) {
560       ierr = VecScatterEnd(iscat,Yl,Y,ADD_VALUES,SCATTER_REVERSE);CHKERRQ(ierr);
561     } else SETERRQ(PetscObjectComm((PetscObject)snes),PETSC_ERR_ARG_WRONGSTATE,"Only basic and restrict types are supported for SNESNASM");
562   }
563   if (nasm->eventrestrictinterp) {ierr = PetscLogEventEnd(nasm->eventrestrictinterp,snes,0,0,0);CHKERRQ(ierr);}
564   ierr = VecAXPY(X,1.0,Y);CHKERRQ(ierr);
565   PetscFunctionReturn(0);
566 }
567 
568 #undef __FUNCT__
569 #define __FUNCT__ "SNESNASMComputeFinalJacobian_Private"
570 PetscErrorCode SNESNASMComputeFinalJacobian_Private(SNES snes, Vec X)
571 {
572   SNES_NASM      *nasm = (SNES_NASM*)snes->data;
573   SNES           subsnes;
574   PetscInt       i,lag = 1;
575   PetscErrorCode ierr;
576   Vec            Xlloc,Xl,Fl,F;
577   VecScatter     oscat,gscat;
578   DM             dm,subdm;
579   MatStructure   flg = DIFFERENT_NONZERO_PATTERN;
580   PetscFunctionBegin;
581   F = snes->vec_func;
582   if (snes->normtype == SNES_NORM_NONE) {ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr);}
583   ierr = SNESComputeJacobian(snes,X,&snes->jacobian,&snes->jacobian_pre,&flg);CHKERRQ(ierr);
584   ierr = SNESGetDM(snes,&dm);CHKERRQ(ierr);
585   if (nasm->eventrestrictinterp) {ierr = PetscLogEventBegin(nasm->eventrestrictinterp,snes,0,0,0);CHKERRQ(ierr);}
586   for (i=0; i<nasm->n; i++) {
587     Xlloc = nasm->xl[i];
588     Fl    = nasm->subsnes[i]->vec_func;
589     gscat = nasm->gscatter[i];
590     oscat = nasm->oscatter[i];
591     ierr = VecScatterBegin(gscat,X,Xlloc,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
592     ierr = VecScatterBegin(oscat,F,Fl,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
593   }
594   if (nasm->eventrestrictinterp) {ierr = PetscLogEventEnd(nasm->eventrestrictinterp,snes,0,0,0);CHKERRQ(ierr);}
595   for (i=0; i<nasm->n; i++) {
596     Fl      = nasm->subsnes[i]->vec_func;
597     Xl      = nasm->x[i];
598     Xlloc   = nasm->xl[i];
599     subsnes = nasm->subsnes[i];
600     oscat   = nasm->oscatter[i];
601     gscat   = nasm->gscatter[i];
602     ierr = VecScatterEnd(gscat,X,Xlloc,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
603     ierr = VecScatterEnd(oscat,F,Fl,INSERT_VALUES,SCATTER_FORWARD);CHKERRQ(ierr);
604     ierr = SNESGetDM(subsnes,&subdm);CHKERRQ(ierr);
605     ierr = DMSubDomainRestrict(dm,oscat,gscat,subdm);CHKERRQ(ierr);
606     ierr = DMLocalToGlobalBegin(subdm,Xlloc,INSERT_VALUES,Xl);CHKERRQ(ierr);
607     ierr = DMLocalToGlobalEnd(subdm,Xlloc,INSERT_VALUES,Xl);CHKERRQ(ierr);
608 
609     if (subsnes->lagjacobian == -1)    subsnes->lagjacobian = -2;
610     else if (subsnes->lagjacobian > 1) lag = subsnes->lagjacobian;
611     ierr = SNESComputeJacobian(subsnes,Xl,&subsnes->jacobian,&subsnes->jacobian_pre,&flg);CHKERRQ(ierr);
612     if (lag > 1) subsnes->lagjacobian = lag;
613     ierr = KSPSetOperators(subsnes->ksp,subsnes->jacobian,subsnes->jacobian_pre,flg);CHKERRQ(ierr);
614   }
615   PetscFunctionReturn(0);
616 }
617 
618 #undef __FUNCT__
619 #define __FUNCT__ "SNESSolve_NASM"
620 PetscErrorCode SNESSolve_NASM(SNES snes)
621 {
622   Vec            F;
623   Vec            X;
624   Vec            B;
625   Vec            Y;
626   PetscInt       i;
627   PetscReal      fnorm = 0.0;
628   PetscErrorCode ierr;
629   SNESNormType   normtype;
630   SNES_NASM      *nasm = (SNES_NASM*)snes->data;
631 
632   PetscFunctionBegin;
633   X = snes->vec_sol;
634   Y = snes->vec_sol_update;
635   F = snes->vec_func;
636   B = snes->vec_rhs;
637 
638   ierr         = PetscObjectAMSTakeAccess((PetscObject)snes);CHKERRQ(ierr);
639   snes->iter   = 0;
640   snes->norm   = 0.;
641   ierr         = PetscObjectAMSGrantAccess((PetscObject)snes);CHKERRQ(ierr);
642   snes->reason = SNES_CONVERGED_ITERATING;
643   ierr         = SNESGetNormType(snes, &normtype);CHKERRQ(ierr);
644   if (normtype == SNES_NORM_FUNCTION || normtype == SNES_NORM_INITIAL_ONLY || normtype == SNES_NORM_INITIAL_FINAL_ONLY) {
645     /* compute the initial function and preconditioned update delX */
646     if (!snes->vec_func_init_set) {
647       ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr);
648       if (snes->domainerror) {
649         snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
650         PetscFunctionReturn(0);
651       }
652     } else snes->vec_func_init_set = PETSC_FALSE;
653 
654     /* convergence test */
655     if (!snes->norm_init_set) {
656       ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); /* fnorm <- ||F||  */
657       if (PetscIsInfOrNanReal(fnorm)) {
658         snes->reason = SNES_DIVERGED_FNORM_NAN;
659         PetscFunctionReturn(0);
660       }
661     } else {
662       fnorm               = snes->norm_init;
663       snes->norm_init_set = PETSC_FALSE;
664     }
665     ierr       = PetscObjectAMSTakeAccess((PetscObject)snes);CHKERRQ(ierr);
666     snes->iter = 0;
667     snes->norm = fnorm;
668     ierr       = PetscObjectAMSGrantAccess((PetscObject)snes);CHKERRQ(ierr);
669     ierr       = SNESLogConvergenceHistory(snes,snes->norm,0);CHKERRQ(ierr);
670     ierr       = SNESMonitor(snes,0,snes->norm);CHKERRQ(ierr);
671 
672     /* set parameter for default relative tolerance convergence test */
673     snes->ttol = fnorm*snes->rtol;
674 
675     /* test convergence */
676     ierr = (*snes->ops->converged)(snes,0,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);
677     if (snes->reason) PetscFunctionReturn(0);
678   } else {
679     ierr = PetscObjectAMSGrantAccess((PetscObject)snes);CHKERRQ(ierr);
680     ierr = SNESLogConvergenceHistory(snes,snes->norm,0);CHKERRQ(ierr);
681     ierr = SNESMonitor(snes,0,snes->norm);CHKERRQ(ierr);
682   }
683 
684   /* Call general purpose update function */
685   if (snes->ops->update) {
686     ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr);
687   }
688 
689   for (i = 0; i < snes->max_its; i++) {
690     ierr = SNESNASMSolveLocal_Private(snes,B,Y,X);CHKERRQ(ierr);
691     if (normtype == SNES_NORM_FUNCTION || ((i == snes->max_its - 1) && (normtype == SNES_NORM_INITIAL_FINAL_ONLY || normtype == SNES_NORM_FINAL_ONLY))) {
692       ierr = SNESComputeFunction(snes,X,F);CHKERRQ(ierr);
693       if (snes->domainerror) {
694         snes->reason = SNES_DIVERGED_FUNCTION_DOMAIN;
695         break;
696       }
697       ierr = VecNorm(F, NORM_2, &fnorm);CHKERRQ(ierr); /* fnorm <- ||F||  */
698       if (PetscIsInfOrNanReal(fnorm)) {
699         snes->reason = SNES_DIVERGED_FNORM_NAN;
700         break;
701       }
702     }
703     /* Monitor convergence */
704     ierr       = PetscObjectAMSTakeAccess((PetscObject)snes);CHKERRQ(ierr);
705     snes->iter = i+1;
706     snes->norm = fnorm;
707     ierr       = PetscObjectAMSGrantAccess((PetscObject)snes);CHKERRQ(ierr);
708     ierr       = SNESLogConvergenceHistory(snes,snes->norm,0);CHKERRQ(ierr);
709     ierr       = SNESMonitor(snes,snes->iter,snes->norm);CHKERRQ(ierr);
710     /* Test for convergence */
711     if (normtype == SNES_NORM_FUNCTION) {ierr = (*snes->ops->converged)(snes,snes->iter,0.0,0.0,fnorm,&snes->reason,snes->cnvP);CHKERRQ(ierr);}
712     if (snes->reason) break;
713     /* Call general purpose update function */
714     if (snes->ops->update) {ierr = (*snes->ops->update)(snes, snes->iter);CHKERRQ(ierr);}
715   }
716   if (nasm->finaljacobian) {ierr = SNESNASMComputeFinalJacobian_Private(snes,X);CHKERRQ(ierr);}
717   if (normtype == SNES_NORM_FUNCTION) {
718     if (i == snes->max_its) {
719       ierr = PetscInfo1(snes,"Maximum number of iterations has been reached: %D\n",snes->max_its);CHKERRQ(ierr);
720       if (!snes->reason) snes->reason = SNES_DIVERGED_MAX_IT;
721     }
722   } else if (!snes->reason) snes->reason = SNES_CONVERGED_ITS; /* NASM is meant to be used as a preconditioner */
723   PetscFunctionReturn(0);
724 }
725 
726 /*MC
727   SNESNASM - Nonlinear Additive Schwartz
728 
729    Options Database:
730 +  -snes_nasm_log - enable logging events for the communication and solve stages
731 .  -snes_nasm_type <basic,restrict> - type of subdomain update used
732 .  -snes_nasm_finaljacobian - compute the local and global jacobians of the final iterate
733 .  -sub_snes_ - options prefix of the subdomain nonlinear solves
734 .  -sub_ksp_ - options prefix of the subdomain Krylov solver
735 -  -sub_pc_ - options prefix of the subdomain preconditioner
736 
737    Level: advanced
738 
739 .seealso: SNESCreate(), SNES, SNESSetType(), SNESType (for list of available types)
740 M*/
741 
742 #undef __FUNCT__
743 #define __FUNCT__ "SNESCreate_NASM"
744 PETSC_EXTERN PetscErrorCode SNESCreate_NASM(SNES snes)
745 {
746   SNES_NASM      *nasm;
747   PetscErrorCode ierr;
748 
749   PetscFunctionBegin;
750   ierr       = PetscNewLog(snes, SNES_NASM, &nasm);CHKERRQ(ierr);
751   snes->data = (void*)nasm;
752 
753   nasm->n        = PETSC_DECIDE;
754   nasm->subsnes  = 0;
755   nasm->x        = 0;
756   nasm->xl       = 0;
757   nasm->y        = 0;
758   nasm->b        = 0;
759   nasm->oscatter = 0;
760   nasm->iscatter = 0;
761   nasm->gscatter = 0;
762 
763   nasm->type = PC_ASM_BASIC;
764   nasm->finaljacobian = PETSC_FALSE;
765   nasm->same_local_solves = PETSC_TRUE;
766 
767   snes->ops->destroy        = SNESDestroy_NASM;
768   snes->ops->setup          = SNESSetUp_NASM;
769   snes->ops->setfromoptions = SNESSetFromOptions_NASM;
770   snes->ops->view           = SNESView_NASM;
771   snes->ops->solve          = SNESSolve_NASM;
772   snes->ops->reset          = SNESReset_NASM;
773 
774   snes->usesksp = PETSC_FALSE;
775   snes->usespc  = PETSC_FALSE;
776 
777   nasm->eventrestrictinterp = 0;
778   nasm->eventsubsolve       = 0;
779 
780   if (!snes->tolerancesset) {
781     snes->max_its   = 10000;
782     snes->max_funcs = 10000;
783   }
784 
785   ierr = PetscObjectComposeFunction((PetscObject)snes,"SNESNASMSetSubdomains_C",SNESNASMSetSubdomains_NASM);CHKERRQ(ierr);
786   ierr = PetscObjectComposeFunction((PetscObject)snes,"SNESNASMGetSubdomains_C",SNESNASMGetSubdomains_NASM);CHKERRQ(ierr);
787   ierr = PetscObjectComposeFunction((PetscObject)snes,"SNESNASMGetSubdomainVecs_C",SNESNASMGetSubdomainVecs_NASM);CHKERRQ(ierr);
788   ierr = PetscObjectComposeFunction((PetscObject)snes,"SNESNASMSetComputeFinalJacobian_C",SNESNASMSetComputeFinalJacobian_NASM);CHKERRQ(ierr);
789   PetscFunctionReturn(0);
790 }
791 
792