xref: /petsc/src/dm/impls/da/dadd.c (revision 047240e14af00aad1ef65e96f6fface8924f7f7e)
1 #include <petsc-private/daimpl.h>
2 
3 #undef __FUNCT__
4 #define __FUNCT__ "DMDACreatePatchIS"
5 
6 PetscErrorCode DMDACreatePatchIS(DM da,MatStencil *lower,MatStencil *upper,IS *is)
7 {
8   PetscErrorCode ierr;
9   PetscInt       i,j,k,idx;
10   PetscInt       ii,jj,kk;
11   Vec            v;
12   PetscInt       n,pn,bs;
13   PetscMPIInt    rank;
14   PetscSF        sf,psf;
15   PetscLayout    map;
16   MPI_Comm       comm;
17   PetscInt       *natidx,*globidx,*leafidx;
18   PetscInt       *pnatidx,*pleafidx;
19   PetscInt       base;
20   PetscInt       ox,oy,oz;
21   DM_DA          *dd;
22 
23   PetscFunctionBegin;
24   comm = ((PetscObject)da)->comm;
25   ierr = MPI_Comm_rank(comm,&rank);CHKERRQ(ierr);
26   dd   = (DM_DA*)da->data;
27 
28   /* construct the natural mapping */
29   ierr = DMGetGlobalVector(da,&v);CHKERRQ(ierr);
30   ierr = VecGetLocalSize(v,&n);CHKERRQ(ierr);
31   ierr = VecGetOwnershipRange(v,&base,PETSC_NULL);CHKERRQ(ierr);
32   ierr = VecGetBlockSize(v,&bs);CHKERRQ(ierr);
33   ierr = DMRestoreGlobalVector(da,&v);CHKERRQ(ierr);
34 
35   /* construct the layout */
36   ierr = PetscLayoutCreate(comm,&map);CHKERRQ(ierr);
37   ierr = PetscLayoutSetBlockSize(map,1);CHKERRQ(ierr);
38   ierr = PetscLayoutSetLocalSize(map,n);CHKERRQ(ierr);
39   ierr = PetscLayoutSetUp(map);CHKERRQ(ierr);
40 
41   /* construct the list of natural indices on this process when PETSc ordering is considered */
42   ierr = DMDAGetOffset(da,&ox,&oy,&oz,PETSC_NULL,PETSC_NULL,PETSC_NULL);CHKERRQ(ierr);
43   ierr = PetscMalloc(sizeof(PetscInt)*n,&natidx);CHKERRQ(ierr);
44   ierr = PetscMalloc(sizeof(PetscInt)*n,&globidx);CHKERRQ(ierr);
45   ierr = PetscMalloc(sizeof(PetscInt)*n,&leafidx);CHKERRQ(ierr);
46   idx  = 0;
47   for (k=dd->zs; k<dd->ze; k++) {
48     for (j=dd->ys; j<dd->ye; j++) {
49       for (i=dd->xs; i<dd->xe; i++) {
50         natidx[idx]  = i + dd->w*(j*dd->M + k*dd->M*dd->N);
51         globidx[idx] = base + idx;
52         leafidx[idx] = 0;
53         idx++;
54       }
55     }
56   }
57 
58   if (idx != n) SETERRQ(comm,PETSC_ERR_ARG_WRONGSTATE, "for some reason the count is wrong.");
59 
60   /* construct the SF going from the natural indices to the local set of PETSc indices */
61   ierr = PetscSFCreate(comm,&sf);CHKERRQ(ierr);
62   ierr = PetscSFSetFromOptions(sf);CHKERRQ(ierr);
63   ierr = PetscSFSetGraphLayout(sf,map,n,PETSC_NULL,PETSC_OWN_POINTER,natidx);CHKERRQ(ierr);
64 
65   /* broadcast the global indices over to the corresponding natural indices */
66   ierr = PetscSFGatherBegin(sf,MPIU_INT,globidx,leafidx);CHKERRQ(ierr);
67   ierr = PetscSFGatherEnd(sf,MPIU_INT,globidx,leafidx);CHKERRQ(ierr);
68   ierr = PetscSFDestroy(&sf);CHKERRQ(ierr);
69 
70 
71   pn   = dd->w*(upper->k - lower->k)*(upper->j - lower->j)*(upper->i - lower->i);
72   ierr = PetscMalloc(sizeof(PetscInt)*pn,&pnatidx);CHKERRQ(ierr);
73   ierr = PetscMalloc(sizeof(PetscInt)*pn,&pleafidx);CHKERRQ(ierr);
74   idx  = 0;
75   for (k=lower->k-oz; k<upper->k-oz; k++) {
76     for (j=lower->j-oy; j<upper->j-oy; j++) {
77       for (i=dd->w*(lower->i-ox); i<dd->w*(upper->i-ox); i++) {
78         ii = i % (dd->w*dd->M);
79         jj = j % dd->N;
80         kk = k % dd->P;
81         if (ii < 0) ii = dd->w*dd->M + ii;
82         if (jj < 0) jj = dd->N + jj;
83         if (kk < 0) kk = dd->P + kk;
84         pnatidx[idx] = ii + dd->w*(jj*dd->M + kk*dd->M*dd->N);
85         idx++;
86       }
87     }
88   }
89 
90   if (idx != pn) SETERRQ(comm,PETSC_ERR_ARG_WRONGSTATE, "for some reason the count is wrong");
91 
92   ierr = PetscSFCreate(comm,&psf);CHKERRQ(ierr);
93   ierr = PetscSFSetFromOptions(psf);CHKERRQ(ierr);
94   ierr = PetscSFSetGraphLayout(psf,map,pn,PETSC_NULL,PETSC_OWN_POINTER,pnatidx);CHKERRQ(ierr);
95 
96   /* broadcast the global indices through to the patch */
97   ierr = PetscSFBcastBegin(psf,MPIU_INT,leafidx,pleafidx);CHKERRQ(ierr);
98   ierr = PetscSFBcastEnd(psf,MPIU_INT,leafidx,pleafidx);CHKERRQ(ierr);
99 
100   /* create the IS */
101   ierr = ISCreateGeneral(comm,pn,pleafidx,PETSC_OWN_POINTER,is);CHKERRQ(ierr);
102 
103   ierr = PetscSFDestroy(&psf);CHKERRQ(ierr);
104 
105   ierr = PetscLayoutDestroy(&map);CHKERRQ(ierr);
106 
107   ierr = PetscFree(globidx);CHKERRQ(ierr);
108   ierr = PetscFree(leafidx);CHKERRQ(ierr);
109   ierr = PetscFree(natidx);CHKERRQ(ierr);
110   ierr = PetscFree(pnatidx);CHKERRQ(ierr);
111   PetscFunctionReturn(0);
112 }
113 
114 #undef __FUNCT__
115 #define __FUNCT__ "DMDASubDomainDA_Private"
116 PetscErrorCode DMDASubDomainDA_Private(DM dm, DM *dddm)
117 {
118   DM             da;
119   DM_DA          *dd;
120   PetscErrorCode ierr;
121   DMDALocalInfo  info;
122   PetscReal      lmin[3],lmax[3];
123   PetscInt       xsize,ysize,zsize;
124   PetscInt       xo,yo,zo;
125 
126   PetscFunctionBegin;
127   ierr = DMDAGetLocalInfo(dm,&info);CHKERRQ(ierr);
128   ierr = DMDACreate(PETSC_COMM_SELF,&da);CHKERRQ(ierr);
129   ierr = DMSetOptionsPrefix(da,"sub_");CHKERRQ(ierr);
130 
131   ierr = DMDASetDim(da, info.dim);CHKERRQ(ierr);
132   ierr = DMDASetDof(da, info.dof);CHKERRQ(ierr);
133 
134   ierr = DMDASetStencilType(da,info.st);CHKERRQ(ierr);
135   ierr = DMDASetStencilWidth(da,info.sw);CHKERRQ(ierr);
136 
137   dd = (DM_DA*)dm->data;
138 
139   /* local with overlap */
140   xsize = info.xm;
141   ysize = info.ym;
142   zsize = info.zm;
143   xo    = info.xs;
144   yo    = info.ys;
145   zo    = info.zs;
146   if (info.bx == DMDA_BOUNDARY_PERIODIC || (info.xs != 0)) {
147     xsize += dd->overlap;
148     xo    -= dd->overlap;
149   }
150   if (info.by == DMDA_BOUNDARY_PERIODIC || (info.ys != 0)) {
151     ysize += dd->overlap;
152     yo    -= dd->overlap;
153   }
154   if (info.bz == DMDA_BOUNDARY_PERIODIC || (info.zs != 0)) {
155     zsize += dd->overlap;
156     zo    -= dd->overlap;
157   }
158 
159   if (info.bx == DMDA_BOUNDARY_PERIODIC || (info.xs+info.xm != info.mx)) xsize += dd->overlap;
160   if (info.by == DMDA_BOUNDARY_PERIODIC || (info.ys+info.ym != info.my)) ysize += dd->overlap;
161   if (info.bz == DMDA_BOUNDARY_PERIODIC || (info.zs+info.zm != info.mz)) zsize += dd->overlap;
162 
163   ierr = DMDASetSizes(da, xsize, ysize, zsize);CHKERRQ(ierr);
164   ierr = DMDASetNumProcs(da, 1, 1, 1);CHKERRQ(ierr);
165   ierr = DMDASetBoundaryType(da, DMDA_BOUNDARY_GHOSTED, DMDA_BOUNDARY_GHOSTED, DMDA_BOUNDARY_GHOSTED);CHKERRQ(ierr);
166 
167   /* set up as a block instead */
168   ierr = DMSetUp(da);CHKERRQ(ierr);
169 
170   /* todo - nonuniform coordinates */
171   ierr = DMDAGetLocalBoundingBox(dm,lmin,lmax);CHKERRQ(ierr);
172   ierr = DMDASetUniformCoordinates(da,lmin[0],lmax[0],lmin[1],lmax[1],lmin[2],lmax[2]);CHKERRQ(ierr);
173 
174   /* this alters the behavior of DMDAGetInfo, DMDAGetLocalInfo, DMDAGetCorners, and DMDAGetGhostedCorners and should be used with care */
175   ierr = DMDASetOffset(da,xo,yo,zo,info.mx,info.my,info.mz);CHKERRQ(ierr);
176 
177   *dddm = da;
178   PetscFunctionReturn(0);
179 }
180 
181 #undef __FUNCT__
182 #define __FUNCT__ "DMCreateDomainDecompositionScatters_DA"
183 /*
184  Fills the local vector problem on the subdomain from the global problem.
185 
186  Right now this assumes one subdomain per processor.
187 
188  */
189 PetscErrorCode DMCreateDomainDecompositionScatters_DA(DM dm,PetscInt nsubdms,DM *subdms,VecScatter **iscat,VecScatter **oscat, VecScatter **lscat)
190 {
191   PetscErrorCode ierr;
192   DMDALocalInfo  info,subinfo;
193   DM             subdm;
194   MatStencil     upper,lower;
195   IS             idis,isis,odis,osis,gdis;
196   Vec            svec,dvec,slvec;
197 
198   PetscFunctionBegin;
199   if (nsubdms != 1) SETERRQ(((PetscObject)dm)->comm,PETSC_ERR_ARG_OUTOFRANGE,"Cannot have more than one subdomain per processor (yet)");
200 
201   /* allocate the arrays of scatters */
202   if (iscat) {ierr = PetscMalloc(sizeof(VecScatter*),iscat);CHKERRQ(ierr);}
203   if (oscat) {ierr = PetscMalloc(sizeof(VecScatter*),oscat);CHKERRQ(ierr);}
204   if (lscat) {ierr = PetscMalloc(sizeof(VecScatter*),lscat);CHKERRQ(ierr);}
205 
206   ierr  = DMDAGetLocalInfo(dm,&info);CHKERRQ(ierr);
207   subdm = subdms[0];
208   ierr  = DMDAGetLocalInfo(subdm,&subinfo);CHKERRQ(ierr);
209 
210   /* create the global and subdomain index sets for the inner domain */
211   /* TODO - make this actually support multiple subdomains -- subdomain needs to provide where it's nonoverlapping portion belongs */
212   lower.i = info.xs;
213   lower.j = info.ys;
214   lower.k = info.zs;
215   upper.i = info.xs+info.xm;
216   upper.j = info.ys+info.ym;
217   upper.k = info.zs+info.zm;
218   ierr    = DMDACreatePatchIS(dm,&lower,&upper,&idis);CHKERRQ(ierr);
219   ierr    = DMDACreatePatchIS(subdm,&lower,&upper,&isis);CHKERRQ(ierr);
220 
221   /* create the global and subdomain index sets for the outer subdomain */
222   lower.i = subinfo.xs;
223   lower.j = subinfo.ys;
224   lower.k = subinfo.zs;
225   upper.i = subinfo.xs+subinfo.xm;
226   upper.j = subinfo.ys+subinfo.ym;
227   upper.k = subinfo.zs+subinfo.zm;
228   ierr    = DMDACreatePatchIS(dm,&lower,&upper,&odis);CHKERRQ(ierr);
229   ierr    = DMDACreatePatchIS(subdm,&lower,&upper,&osis);CHKERRQ(ierr);
230 
231   /* global and subdomain ISes for the local indices of the subdomain */
232   /* todo - make this not loop over at nonperiodic boundaries, which will be more involved */
233   lower.i = subinfo.gxs;
234   lower.j = subinfo.gys;
235   lower.k = subinfo.gzs;
236   upper.i = subinfo.gxs+subinfo.gxm;
237   upper.j = subinfo.gys+subinfo.gym;
238   upper.k = subinfo.gzs+subinfo.gzm;
239 
240   ierr = DMDACreatePatchIS(dm,&lower,&upper,&gdis);CHKERRQ(ierr);
241 
242   /* form the scatter */
243   ierr = DMGetGlobalVector(dm,&dvec);CHKERRQ(ierr);
244   ierr = DMGetGlobalVector(subdm,&svec);CHKERRQ(ierr);
245   ierr = DMGetLocalVector(subdm,&slvec);CHKERRQ(ierr);
246 
247   if (iscat) {ierr = VecScatterCreate(dvec,idis,svec,isis,&(*iscat)[0]);CHKERRQ(ierr);}
248   if (oscat) {ierr = VecScatterCreate(dvec,odis,svec,osis,&(*oscat)[0]);CHKERRQ(ierr);}
249   if (lscat) {ierr = VecScatterCreate(dvec,gdis,slvec,PETSC_NULL,&(*lscat)[0]);CHKERRQ(ierr);}
250 
251   ierr = DMRestoreGlobalVector(dm,&dvec);CHKERRQ(ierr);
252   ierr = DMRestoreGlobalVector(subdm,&svec);CHKERRQ(ierr);
253   ierr = DMRestoreLocalVector(subdm,&slvec);CHKERRQ(ierr);
254 
255   ierr = ISDestroy(&idis);CHKERRQ(ierr);
256   ierr = ISDestroy(&isis);CHKERRQ(ierr);
257 
258   ierr = ISDestroy(&odis);CHKERRQ(ierr);
259   ierr = ISDestroy(&osis);CHKERRQ(ierr);
260 
261   ierr = ISDestroy(&gdis);CHKERRQ(ierr);
262   PetscFunctionReturn(0);
263 }
264 
265 #undef __FUNCT__
266 #define __FUNCT__ "DMDASubDomainIS_Private"
267 /* We have that the interior regions are going to be the same, but the ghost regions might not match up
268 
269 ----------
270 ----------
271 --++++++o=
272 --++++++o=
273 --++++++o=
274 --++++++o=
275 --ooooooo=
276 --========
277 
278 Therefore, for each point in the overall, we must check if it's:
279 
280 1. +: In the interior of the global dm; it lines up
281 2. o: In the overlap region -- for now the same as 1; no overlap
282 3. =: In the shared ghost region -- handled by DMCreateDomainDecompositionLocalScatter()
283 4. -: In the nonshared ghost region
284  */
285 
286 PetscErrorCode DMDASubDomainIS_Private(DM dm,DM subdm,IS *iis,IS *ois)
287 {
288   PetscErrorCode ierr;
289   DMDALocalInfo  info,subinfo;
290   MatStencil     lower,upper;
291 
292   PetscFunctionBegin;
293   ierr = DMDAGetLocalInfo(dm,&info);CHKERRQ(ierr);
294   ierr = DMDAGetLocalInfo(subdm,&subinfo);CHKERRQ(ierr);
295 
296   /* create the inner IS */
297   lower.i = info.xs;
298   lower.j = info.ys;
299   lower.k = info.zs;
300   upper.i = info.xs+info.xm;
301   upper.j = info.ys+info.ym;
302   upper.k = info.zs+info.zm;
303 
304   ierr = DMDACreatePatchIS(dm,&lower,&upper,iis);CHKERRQ(ierr);
305 
306   /* create the outer IS */
307   lower.i = subinfo.xs;
308   lower.j = subinfo.ys;
309   lower.k = subinfo.zs;
310   upper.i = subinfo.xs+subinfo.xm;
311   upper.j = subinfo.ys+subinfo.ym;
312   upper.k = subinfo.zs+subinfo.zm;
313   ierr    = DMDACreatePatchIS(dm,&lower,&upper,ois);CHKERRQ(ierr);
314   PetscFunctionReturn(0);
315 }
316 
317 #undef __FUNCT__
318 #define __FUNCT__ "DMCreateDomainDecomposition_DA"
319 PetscErrorCode DMCreateDomainDecomposition_DA(DM dm,PetscInt *len,char ***names,IS **iis,IS **ois,DM **subdm)
320 {
321   PetscErrorCode ierr;
322   IS             iis0,ois0;
323   DM             subdm0;
324   DM_DA          *dd = (DM_DA*)dm;
325 
326   PetscFunctionBegin;
327   /* fix to enable PCASM default behavior as taking overlap from the matrix */
328   if (!dd->decompositiondm) {
329     if (len) *len=0;
330     if (names) *names=0;
331     if (iis) *iis=0;
332     if (ois) *ois=0;
333     if (subdm) *subdm=0;
334     PetscFunctionReturn(0);
335   }
336 
337   if (len) *len = 1;
338 
339   if (iis) {ierr = PetscMalloc(sizeof(IS*),iis);CHKERRQ(ierr);}
340   if (ois) {ierr = PetscMalloc(sizeof(IS*),ois);CHKERRQ(ierr);}
341   if (subdm) {ierr = PetscMalloc(sizeof(DM*),subdm);CHKERRQ(ierr);}
342   if (names) {ierr = PetscMalloc(sizeof(char*),names);CHKERRQ(ierr);}
343   ierr = DMDASubDomainDA_Private(dm,&subdm0);CHKERRQ(ierr);
344   ierr = DMDASubDomainIS_Private(dm,subdm0,&iis0,&ois0);CHKERRQ(ierr);
345   if (iis) (*iis)[0] = iis0;
346   else {
347     ierr = ISDestroy(&iis0);CHKERRQ(ierr);
348   }
349   if (ois) (*ois)[0] = ois0;
350   else {
351     ierr = ISDestroy(&ois0);CHKERRQ(ierr);
352   }
353   if (subdm) (*subdm)[0] = subdm0;
354   if (names) (*names)[0] = 0;
355   PetscFunctionReturn(0);
356 }
357 
358 #undef __FUNCT__
359 #define __FUNCT__ "DMCreateDomainDecompositionDM_DA"
360 PetscErrorCode DMCreateDomainDecompositionDM_DA(DM dm,const char *name,DM *ddm)
361 {
362   DM_DA          *dd = (DM_DA*)dm;
363   PetscBool      flg;
364   PetscErrorCode ierr;
365 
366   PetscFunctionBegin;
367   ierr = PetscStrcmp(name,"default",&flg);CHKERRQ(ierr);
368   if (flg) {
369     dd->decompositiondm = PETSC_TRUE;
370     *ddm = dm;
371   } else dd->decompositiondm = PETSC_FALSE;
372   PetscFunctionReturn(0);
373 }
374