xref: /petsc/src/dm/impls/da/dadd.c (revision 40234c9204d1c3b217f10af5160c724bbf37e02c)
1 #include <petsc-private/dmdaimpl.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   ierr = PetscObjectGetComm((PetscObject)da,&comm);CHKERRQ(ierr);
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,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,NULL,NULL,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,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,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   PetscErrorCode ierr;
120   DMDALocalInfo  info;
121   PetscReal      lmin[3],lmax[3];
122   PetscInt       xsize,ysize,zsize;
123   PetscInt       xo,yo,zo;
124   PetscInt       xol,yol,zol;
125 
126   PetscFunctionBegin;
127   ierr = DMDAGetLocalInfo(dm,&info);CHKERRQ(ierr);
128   ierr = DMDAGetOverlap(dm,&xol,&yol,&zol);CHKERRQ(ierr);
129 
130   ierr = DMDACreate(PETSC_COMM_SELF,&da);CHKERRQ(ierr);
131   ierr = DMSetOptionsPrefix(da,"sub_");CHKERRQ(ierr);
132   ierr = DMDASetDim(da, info.dim);CHKERRQ(ierr);
133   ierr = DMDASetDof(da, info.dof);CHKERRQ(ierr);
134 
135   ierr = DMDASetStencilType(da,info.st);CHKERRQ(ierr);
136   ierr = DMDASetStencilWidth(da,info.sw);CHKERRQ(ierr);
137 
138   /* local with overlap */
139   xsize = info.xm;
140   ysize = info.ym;
141   zsize = info.zm;
142   xo    = info.xs;
143   yo    = info.ys;
144   zo    = info.zs;
145   if (info.bx == DMDA_BOUNDARY_PERIODIC || (info.xs != 0)) {
146     xsize += xol;
147     xo    -= xol;
148   }
149   if (info.by == DMDA_BOUNDARY_PERIODIC || (info.ys != 0)) {
150     ysize += yol;
151     yo    -= yol;
152   }
153   if (info.bz == DMDA_BOUNDARY_PERIODIC || (info.zs != 0)) {
154     zsize += zol;
155     zo    -= zol;
156   }
157 
158   if (info.bx == DMDA_BOUNDARY_PERIODIC || (info.xs+info.xm != info.mx)) xsize += xol;
159   if (info.by == DMDA_BOUNDARY_PERIODIC || (info.ys+info.ym != info.my)) ysize += yol;
160   if (info.bz == DMDA_BOUNDARY_PERIODIC || (info.zs+info.zm != info.mz)) zsize += zol;
161 
162   ierr = DMDASetSizes(da, xsize, ysize, zsize);CHKERRQ(ierr);
163   ierr = DMDASetNumProcs(da, 1, 1, 1);CHKERRQ(ierr);
164   ierr = DMDASetBoundaryType(da, DMDA_BOUNDARY_GHOSTED, DMDA_BOUNDARY_GHOSTED, DMDA_BOUNDARY_GHOSTED);CHKERRQ(ierr);
165 
166   /* set up as a block instead */
167   ierr = DMSetUp(da);CHKERRQ(ierr);
168 
169   /* todo - nonuniform coordinates */
170   ierr = DMDAGetLocalBoundingBox(dm,lmin,lmax);CHKERRQ(ierr);
171   ierr = DMDASetUniformCoordinates(da,lmin[0],lmax[0],lmin[1],lmax[1],lmin[2],lmax[2]);CHKERRQ(ierr);
172 
173   /* nonoverlapping region */
174   ierr = DMDASetNonOverlappingRegion(da,info.xs,info.ys,info.zs,info.xm,info.ym,info.zm);CHKERRQ(ierr);
175 
176   /* this alters the behavior of DMDAGetInfo, DMDAGetLocalInfo, DMDAGetCorners, and DMDAGetGhostedCorners and should be used with care */
177   ierr = DMDASetOffset(da,xo,yo,zo,info.mx,info.my,info.mz);CHKERRQ(ierr);
178   *dddm = da;
179   PetscFunctionReturn(0);
180 }
181 
182 #undef __FUNCT__
183 #define __FUNCT__ "DMCreateDomainDecompositionScatters_DA"
184 /*
185  Fills the local vector problem on the subdomain from the global problem.
186 
187  Right now this assumes one subdomain per processor.
188 
189  */
190 PetscErrorCode DMCreateDomainDecompositionScatters_DA(DM dm,PetscInt nsubdms,DM *subdms,VecScatter **iscat,VecScatter **oscat, VecScatter **lscat)
191 {
192   PetscErrorCode ierr;
193   DMDALocalInfo  info,subinfo;
194   DM             subdm;
195   MatStencil     upper,lower;
196   IS             idis,isis,odis,osis,gdis;
197   Vec            svec,dvec,slvec;
198   PetscInt       xm,ym,zm,xs,ys,zs;
199 
200   PetscFunctionBegin;
201   if (nsubdms != 1) SETERRQ(PetscObjectComm((PetscObject)dm),PETSC_ERR_ARG_OUTOFRANGE,"Cannot have more than one subdomain per processor (yet)");
202 
203   /* allocate the arrays of scatters */
204   if (iscat) {ierr = PetscMalloc(sizeof(VecScatter*),iscat);CHKERRQ(ierr);}
205   if (oscat) {ierr = PetscMalloc(sizeof(VecScatter*),oscat);CHKERRQ(ierr);}
206   if (lscat) {ierr = PetscMalloc(sizeof(VecScatter*),lscat);CHKERRQ(ierr);}
207 
208   ierr  = DMDAGetLocalInfo(dm,&info);CHKERRQ(ierr);
209   subdm = subdms[0];
210   ierr  = DMDAGetLocalInfo(subdm,&subinfo);CHKERRQ(ierr);
211 
212   /* create the global and subdomain index sets for the inner domain */
213   /* TODO - make this actually support multiple subdomains -- subdomain needs to provide where it's nonoverlapping portion belongs */
214   ierr = DMDAGetNonOverlappingRegion(subdm,&xs,&ys,&zs,&xm,&ym,&zm);CHKERRQ(ierr);
215   lower.i = xs;
216   lower.j = ys;
217   lower.k = zs;
218   upper.i = xs+xm;
219   upper.j = ys+ym;
220   upper.k = zs+zm;
221   ierr    = DMDACreatePatchIS(dm,&lower,&upper,&idis);CHKERRQ(ierr);
222   ierr    = DMDACreatePatchIS(subdm,&lower,&upper,&isis);CHKERRQ(ierr);
223 
224   /* create the global and subdomain index sets for the outer subdomain */
225   lower.i = subinfo.xs;
226   lower.j = subinfo.ys;
227   lower.k = subinfo.zs;
228   upper.i = subinfo.xs+subinfo.xm;
229   upper.j = subinfo.ys+subinfo.ym;
230   upper.k = subinfo.zs+subinfo.zm;
231   ierr    = DMDACreatePatchIS(dm,&lower,&upper,&odis);CHKERRQ(ierr);
232   ierr    = DMDACreatePatchIS(subdm,&lower,&upper,&osis);CHKERRQ(ierr);
233 
234   /* global and subdomain ISes for the local indices of the subdomain */
235   /* todo - make this not loop over at nonperiodic boundaries, which will be more involved */
236   lower.i = subinfo.gxs;
237   lower.j = subinfo.gys;
238   lower.k = subinfo.gzs;
239   upper.i = subinfo.gxs+subinfo.gxm;
240   upper.j = subinfo.gys+subinfo.gym;
241   upper.k = subinfo.gzs+subinfo.gzm;
242 
243   ierr = DMDACreatePatchIS(dm,&lower,&upper,&gdis);CHKERRQ(ierr);
244 
245   /* form the scatter */
246   ierr = DMGetGlobalVector(dm,&dvec);CHKERRQ(ierr);
247   ierr = DMGetGlobalVector(subdm,&svec);CHKERRQ(ierr);
248   ierr = DMGetLocalVector(subdm,&slvec);CHKERRQ(ierr);
249 
250   if (iscat) {ierr = VecScatterCreate(dvec,idis,svec,isis,&(*iscat)[0]);CHKERRQ(ierr);}
251   if (oscat) {ierr = VecScatterCreate(dvec,odis,svec,osis,&(*oscat)[0]);CHKERRQ(ierr);}
252   if (lscat) {ierr = VecScatterCreate(dvec,gdis,slvec,NULL,&(*lscat)[0]);CHKERRQ(ierr);}
253 
254   ierr = DMRestoreGlobalVector(dm,&dvec);CHKERRQ(ierr);
255   ierr = DMRestoreGlobalVector(subdm,&svec);CHKERRQ(ierr);
256   ierr = DMRestoreLocalVector(subdm,&slvec);CHKERRQ(ierr);
257 
258   ierr = ISDestroy(&idis);CHKERRQ(ierr);
259   ierr = ISDestroy(&isis);CHKERRQ(ierr);
260 
261   ierr = ISDestroy(&odis);CHKERRQ(ierr);
262   ierr = ISDestroy(&osis);CHKERRQ(ierr);
263 
264   ierr = ISDestroy(&gdis);CHKERRQ(ierr);
265   PetscFunctionReturn(0);
266 }
267 
268 #undef __FUNCT__
269 #define __FUNCT__ "DMDASubDomainIS_Private"
270 /* We have that the interior regions are going to be the same, but the ghost regions might not match up
271 
272 ----------
273 ----------
274 --++++++o=
275 --++++++o=
276 --++++++o=
277 --++++++o=
278 --ooooooo=
279 --========
280 
281 Therefore, for each point in the overall, we must check if it's:
282 
283 1. +: In the interior of the global dm; it lines up
284 2. o: In the overlap region -- for now the same as 1; no overlap
285 3. =: In the shared ghost region -- handled by DMCreateDomainDecompositionLocalScatter()
286 4. -: In the nonshared ghost region
287  */
288 
289 PetscErrorCode DMDASubDomainIS_Private(DM dm,DM subdm,IS *iis,IS *ois)
290 {
291   PetscErrorCode ierr;
292   DMDALocalInfo  info,subinfo;
293   MatStencil     lower,upper;
294 
295   PetscFunctionBegin;
296   ierr = DMDAGetLocalInfo(dm,&info);CHKERRQ(ierr);
297   ierr = DMDAGetLocalInfo(subdm,&subinfo);CHKERRQ(ierr);
298 
299   /* create the inner IS */
300   lower.i = info.xs;
301   lower.j = info.ys;
302   lower.k = info.zs;
303   upper.i = info.xs+info.xm;
304   upper.j = info.ys+info.ym;
305   upper.k = info.zs+info.zm;
306 
307   ierr = DMDACreatePatchIS(dm,&lower,&upper,iis);CHKERRQ(ierr);
308 
309   /* create the outer IS */
310   lower.i = subinfo.xs;
311   lower.j = subinfo.ys;
312   lower.k = subinfo.zs;
313   upper.i = subinfo.xs+subinfo.xm;
314   upper.j = subinfo.ys+subinfo.ym;
315   upper.k = subinfo.zs+subinfo.zm;
316   ierr    = DMDACreatePatchIS(dm,&lower,&upper,ois);CHKERRQ(ierr);
317   PetscFunctionReturn(0);
318 }
319 
320 #undef __FUNCT__
321 #define __FUNCT__ "DMCreateDomainDecomposition_DA"
322 PetscErrorCode DMCreateDomainDecomposition_DA(DM dm,PetscInt *len,char ***names,IS **iis,IS **ois,DM **subdm)
323 {
324   PetscErrorCode ierr;
325   IS             iis0,ois0;
326   DM             subdm0;
327 
328   PetscFunctionBegin;
329   if (len) *len = 1;
330 
331   if (iis) {ierr = PetscMalloc(sizeof(IS*),iis);CHKERRQ(ierr);}
332   if (ois) {ierr = PetscMalloc(sizeof(IS*),ois);CHKERRQ(ierr);}
333   if (subdm) {ierr = PetscMalloc(sizeof(DM*),subdm);CHKERRQ(ierr);}
334   if (names) {ierr = PetscMalloc(sizeof(char*),names);CHKERRQ(ierr);}
335   ierr = DMDASubDomainDA_Private(dm,&subdm0);CHKERRQ(ierr);
336   ierr = DMDASubDomainIS_Private(dm,subdm0,&iis0,&ois0);CHKERRQ(ierr);
337   if (iis) (*iis)[0] = iis0;
338   else {
339     ierr = ISDestroy(&iis0);CHKERRQ(ierr);
340   }
341   if (ois) (*ois)[0] = ois0;
342   else {
343     ierr = ISDestroy(&ois0);CHKERRQ(ierr);
344   }
345   if (subdm) (*subdm)[0] = subdm0;
346   if (names) (*names)[0] = 0;
347   PetscFunctionReturn(0);
348 }
349