xref: /petsc/src/dm/impls/da/dadd.c (revision bf388a1f1fb7cbb324cb4eba80ecc0a331d4a847)
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   PetscFunctionBegin;
23 
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);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 
112   PetscFunctionReturn(0);
113 }
114 
115 #undef __FUNCT__
116 #define __FUNCT__ "DMDASubDomainDA_Private"
117 PetscErrorCode DMDASubDomainDA_Private(DM dm, DM *dddm) {
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)) {
160     xsize += dd->overlap;
161   }
162   if (info.by == DMDA_BOUNDARY_PERIODIC || (info.ys+info.ym != info.my)) {
163     ysize += dd->overlap;
164   }
165   if (info.bz == DMDA_BOUNDARY_PERIODIC || (info.zs+info.zm != info.mz)) {
166     zsize += dd->overlap;
167   }
168 
169   ierr = DMDASetSizes(da, xsize, ysize, zsize);CHKERRQ(ierr);
170   ierr = DMDASetNumProcs(da, 1, 1, 1);CHKERRQ(ierr);
171   ierr = DMDASetBoundaryType(da, DMDA_BOUNDARY_GHOSTED, DMDA_BOUNDARY_GHOSTED, DMDA_BOUNDARY_GHOSTED);CHKERRQ(ierr);
172 
173   /* set up as a block instead */
174   ierr = DMSetUp(da);CHKERRQ(ierr);
175   ierr = DMDASetOffset(da,xo,yo,zo);CHKERRQ(ierr);
176 
177 
178   /* todo - nonuniform coordinates */
179   ierr = DMDAGetLocalBoundingBox(dm,lmin,lmax);CHKERRQ(ierr);
180   ierr = DMDASetUniformCoordinates(da,lmin[0],lmax[0],lmin[1],lmax[1],lmin[2],lmax[2]);CHKERRQ(ierr);
181 
182   dd = (DM_DA *)da->data;
183   dd->Mo = info.mx;
184   dd->No = info.my;
185   dd->Po = info.mz;
186 
187   *dddm = da;
188 
189   PetscFunctionReturn(0);
190 }
191 
192 #undef __FUNCT__
193 #define __FUNCT__ "DMCreateDomainDecompositionScatters_DA"
194 /*
195  Fills the local vector problem on the subdomain from the global problem.
196 
197  Right now this assumes one subdomain per processor.
198 
199  */
200 PetscErrorCode DMCreateDomainDecompositionScatters_DA(DM dm,PetscInt nsubdms,DM *subdms,VecScatter **iscat,VecScatter **oscat, VecScatter **lscat) {
201   PetscErrorCode   ierr;
202   DMDALocalInfo    info,subinfo;
203   DM               subdm;
204   MatStencil       upper,lower;
205   IS               idis,isis,odis,osis,gdis;
206   Vec              svec,dvec,slvec;
207 
208   PetscFunctionBegin;
209 
210   if (nsubdms != 1) SETERRQ(((PetscObject)dm)->comm,PETSC_ERR_ARG_OUTOFRANGE,"Cannot have more than one subdomain per processor (yet)");
211 
212   /* allocate the arrays of scatters */
213   if (iscat) {ierr = PetscMalloc(sizeof(VecScatter *),iscat);CHKERRQ(ierr);}
214   if (oscat) {ierr = PetscMalloc(sizeof(VecScatter *),oscat);CHKERRQ(ierr);}
215   if (lscat) {ierr = PetscMalloc(sizeof(VecScatter *),lscat);CHKERRQ(ierr);}
216 
217   ierr = DMDAGetLocalInfo(dm,&info);CHKERRQ(ierr);
218   subdm = subdms[0];
219   ierr = DMDAGetLocalInfo(subdm,&subinfo);CHKERRQ(ierr);
220 
221   /* create the global and subdomain index sets for the inner domain */
222   /* TODO - make this actually support multiple subdomains -- subdomain needs to provide where it's nonoverlapping portion belongs */
223   lower.i = info.xs;
224   lower.j = info.ys;
225   lower.k = info.zs;
226   upper.i = info.xs+info.xm;
227   upper.j = info.ys+info.ym;
228   upper.k = info.zs+info.zm;
229   ierr = DMDACreatePatchIS(dm,&lower,&upper,&idis);CHKERRQ(ierr);
230   ierr = DMDACreatePatchIS(subdm,&lower,&upper,&isis);CHKERRQ(ierr);
231 
232   /* create the global and subdomain index sets for the outer subdomain */
233   lower.i = subinfo.xs;
234   lower.j = subinfo.ys;
235   lower.k = subinfo.zs;
236   upper.i = subinfo.xs+subinfo.xm;
237   upper.j = subinfo.ys+subinfo.ym;
238   upper.k = subinfo.zs+subinfo.zm;
239   ierr = DMDACreatePatchIS(dm,&lower,&upper,&odis);CHKERRQ(ierr);
240   ierr = DMDACreatePatchIS(subdm,&lower,&upper,&osis);CHKERRQ(ierr);
241 
242   /* global and subdomain ISes for the local indices of the subdomain */
243   /* todo - make this not loop over at nonperiodic boundaries, which will be more involved */
244   lower.i = subinfo.gxs;
245   lower.j = subinfo.gys;
246   lower.k = subinfo.gzs;
247   upper.i = subinfo.gxs+subinfo.gxm;
248   upper.j = subinfo.gys+subinfo.gym;
249   upper.k = subinfo.gzs+subinfo.gzm;
250 
251   ierr = DMDACreatePatchIS(dm,&lower,&upper,&gdis);CHKERRQ(ierr);
252 
253     /* form the scatter */
254     ierr = DMGetGlobalVector(dm,&dvec);CHKERRQ(ierr);
255     ierr = DMGetGlobalVector(subdm,&svec);CHKERRQ(ierr);
256     ierr = DMGetLocalVector(subdm,&slvec);CHKERRQ(ierr);
257 
258     if (iscat) {ierr = VecScatterCreate(dvec,idis,svec,isis,&(*iscat)[0]);CHKERRQ(ierr);}
259     if (oscat) {ierr = VecScatterCreate(dvec,odis,svec,osis,&(*oscat)[0]);CHKERRQ(ierr);}
260     if (lscat) {ierr = VecScatterCreate(dvec,gdis,slvec,PETSC_NULL,&(*lscat)[0]);CHKERRQ(ierr);}
261 
262     ierr = DMRestoreGlobalVector(dm,&dvec);CHKERRQ(ierr);
263     ierr = DMRestoreGlobalVector(subdm,&svec);CHKERRQ(ierr);
264     ierr = DMRestoreLocalVector(subdm,&slvec);CHKERRQ(ierr);
265 
266     ierr = ISDestroy(&idis);CHKERRQ(ierr);
267     ierr = ISDestroy(&isis);CHKERRQ(ierr);
268 
269     ierr = ISDestroy(&odis);CHKERRQ(ierr);
270     ierr = ISDestroy(&osis);CHKERRQ(ierr);
271 
272     ierr = ISDestroy(&gdis);CHKERRQ(ierr);
273     PetscFunctionReturn(0);
274 }
275 
276 #undef __FUNCT__
277 #define __FUNCT__ "DMDASubDomainIS_Private"
278 /* We have that the interior regions are going to be the same, but the ghost regions might not match up
279 
280 ----------
281 ----------
282 --++++++o=
283 --++++++o=
284 --++++++o=
285 --++++++o=
286 --ooooooo=
287 --========
288 
289 Therefore, for each point in the overall, we must check if it's:
290 
291 1. +: In the interior of the global dm; it lines up
292 2. o: In the overlap region -- for now the same as 1; no overlap
293 3. =: In the shared ghost region -- handled by DMCreateDomainDecompositionLocalScatter()
294 4. -: In the nonshared ghost region
295  */
296 
297 PetscErrorCode DMDASubDomainIS_Private(DM dm,DM subdm,IS *iis,IS *ois) {
298   PetscErrorCode   ierr;
299   DMDALocalInfo    info,subinfo;
300   MatStencil       lower,upper;
301 
302   PetscFunctionBegin;
303   ierr = DMDAGetLocalInfo(dm,&info);CHKERRQ(ierr);
304   ierr = DMDAGetLocalInfo(subdm,&subinfo);CHKERRQ(ierr);
305 
306   /* create the inner IS */
307   lower.i = info.xs;
308   lower.j = info.ys;
309   lower.k = info.zs;
310   upper.i = info.xs+info.xm;
311   upper.j = info.ys+info.ym;
312   upper.k = info.zs+info.zm;
313 
314   ierr = DMDACreatePatchIS(dm,&lower,&upper,iis);CHKERRQ(ierr);
315 
316   /* create the outer IS */
317   lower.i = subinfo.xs;
318   lower.j = subinfo.ys;
319   lower.k = subinfo.zs;
320   upper.i = subinfo.xs+subinfo.xm;
321   upper.j = subinfo.ys+subinfo.ym;
322   upper.k = subinfo.zs+subinfo.zm;
323   ierr = DMDACreatePatchIS(dm,&lower,&upper,ois);CHKERRQ(ierr);
324 
325   PetscFunctionReturn(0);
326 }
327 
328 #undef __FUNCT__
329 #define __FUNCT__ "DMCreateDomainDecomposition_DA"
330 PetscErrorCode DMCreateDomainDecomposition_DA(DM dm,PetscInt *len,char ***names,IS **iis,IS **ois,DM **subdm) {
331   PetscErrorCode ierr;
332   IS             iis0,ois0;
333   DM             subdm0;
334   PetscFunctionBegin;
335   if (len)*len = 1;
336 
337   if (iis) {ierr = PetscMalloc(sizeof(IS *),iis);CHKERRQ(ierr);}
338   if (ois) {ierr = PetscMalloc(sizeof(IS *),ois);CHKERRQ(ierr);}
339   if (subdm) {ierr = PetscMalloc(sizeof(DM *),subdm);CHKERRQ(ierr);}
340   if (names) {ierr = PetscMalloc(sizeof(char *),names);CHKERRQ(ierr);}
341   ierr = DMDASubDomainDA_Private(dm,&subdm0);CHKERRQ(ierr);
342   ierr = DMDASubDomainIS_Private(dm,subdm0,&iis0,&ois0);CHKERRQ(ierr);
343   if (iis) {
344     (*iis)[0] = iis0;
345   } else {
346     ierr = ISDestroy(&iis0);CHKERRQ(ierr);
347   }
348   if (ois) {
349     (*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