Actual source code: dadd.c
petsc-3.15.0 2021-03-30
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      1: #include <petsc/private/dmdaimpl.h>

      3: /*@
      4:   DMDACreatePatchIS - Creates an index set corresponding to a patch of the DA.

      6:   Collective

      8:   Input Parameters:
      9: +  da - the DMDA
     10: .  lower - a matstencil with i, j and k corresponding to the lower corner of the patch
     11: .  upper - a matstencil with i, j and k corresponding to the upper corner of the patch
     12: -  offproc - indicate whether the returned IS will contain off process indices

     14:   Output Parameters:
     15: .  is - the IS corresponding to the patch

     17:   Level: developer

     19: Notes:
     20: This routine always returns an IS on the DMDA's comm, if offproc is set to PETSC_TRUE,
     21: the routine returns an IS with all the indices requested regardless of whether these indices
     22: are present on the requesting rank or not. Thus, it is upon the caller to ensure that
     23: the indices returned in this mode are appropriate. If offproc is set to PETSC_FALSE,
     24: the IS only returns the subset of indices that are present on the requesting rank and there
     25: is no duplication of indices.

     27: .seealso: DMDACreateDomainDecomposition(), DMDACreateDomainDecompositionScatters()
     28: @*/
     29: PetscErrorCode DMDACreatePatchIS(DM da,MatStencil *lower,MatStencil *upper,IS *is, PetscBool offproc)
     30: {
     31:   PetscInt       ms=0,ns=0,ps=0;
     32:   PetscInt       mw=0,nw=0,pw=0;
     33:   PetscInt       me=1,ne=1,pe=1;
     34:   PetscInt       mr=0,nr=0,pr=0;
     35:   PetscInt       ii,jj,kk;
     36:   PetscInt       si,sj,sk;
     37:   PetscInt       i,j,k,l,idx=0;
     38:   PetscInt       base;
     39:   PetscInt       xm=1,ym=1,zm=1;
     40:   PetscInt       ox,oy,oz;
     41:   PetscInt       m,n,p,M,N,P,dof;
     42:   const PetscInt *lx,*ly,*lz;
     43:   PetscInt       nindices;
     44:   PetscInt       *indices;
     45:   DM_DA          *dd = (DM_DA*)da->data;
     46:   PetscBool      skip_i=PETSC_TRUE, skip_j=PETSC_TRUE, skip_k=PETSC_TRUE;
     47:   PetscBool      valid_j=PETSC_FALSE, valid_k=PETSC_FALSE; /* DMDA has at least 1 dimension */

     51:   M = dd->M; N = dd->N; P = dd->P;
     52:   m = dd->m; n = dd->n; p = dd->p;
     53:   dof = dd->w;

     55:   nindices = -1;
     56:   if (PetscLikely(upper->i - lower->i)) {
     57:     nindices = nindices*(upper->i - lower->i);
     58:     skip_i=PETSC_FALSE;
     59:   }
     60:   if (N>1) {
     61:     valid_j = PETSC_TRUE;
     62:     if (PetscLikely(upper->j - lower->j)) {
     63:       nindices = nindices*(upper->j - lower->j);
     64:       skip_j=PETSC_FALSE;
     65:     }
     66:   }
     67:   if (P>1) {
     68:     valid_k = PETSC_TRUE;
     69:     if (PetscLikely(upper->k - lower->k)) {
     70:       nindices = nindices*(upper->k - lower->k);
     71:       skip_k=PETSC_FALSE;
     72:     }
     73:   }
     74:   if (PetscLikely(nindices<0)) {
     75:     if (PetscUnlikely(skip_i && skip_j && skip_k)) {
     76:       nindices = 0;
     77:     } else nindices = nindices*(-1);
     78:   } else SETERRQ(PetscObjectComm((PetscObject)da),PETSC_ERR_ARG_WRONG,"Lower and Upper stencils are identical! Please check inputs.");

     80:   PetscMalloc1(nindices*dof,&indices);
     81:   DMDAGetOffset(da,&ox,&oy,&oz,NULL,NULL,NULL);

     83:   if (!valid_k) {
     84:     k = 0;
     85:     upper->k=0;
     86:     lower->k=0;
     87:   }
     88:   if (!valid_j) {
     89:     j = 0;
     90:     upper->j=0;
     91:     lower->j=0;
     92:   }

     94:   if (offproc) {
     95:     DMDAGetOwnershipRanges(da,&lx,&ly,&lz);
     96:     /* start at index 0 on processor 0 */
     97:     mr = 0;
     98:     nr = 0;
     99:     pr = 0;
    100:     ms = 0;
    101:     ns = 0;
    102:     ps = 0;
    103:     if (lx) me = lx[0];
    104:     if (ly) ne = ly[0];
    105:     if (lz) pe = lz[0];
    106:     /*
    107:        If no indices are to be returned, create an empty is,
    108:        this prevents hanging in while loops
    109:     */
    110:     if (skip_i && skip_j && skip_k) goto createis;
    111:     /*
    112:        do..while loops to ensure the block gets entered once,
    113:        regardless of control condition being met, necessary for
    114:        cases when a subset of skip_i/j/k is true
    115:     */
    116:     if (skip_k) k = upper->k-oz; else k = lower->k-oz;
    117:     do {
    118:       if (skip_j) j = upper->j-oy; else j = lower->j-oy;
    119:       do {
    120:         if (skip_i) i = upper->i-ox; else i = lower->i-ox;
    121:         do {
    122:           /* "actual" indices rather than ones outside of the domain */
    123:           ii = i;
    124:           jj = j;
    125:           kk = k;
    126:           if (ii < 0) ii = M + ii;
    127:           if (jj < 0) jj = N + jj;
    128:           if (kk < 0) kk = P + kk;
    129:           if (ii > M-1) ii = ii - M;
    130:           if (jj > N-1) jj = jj - N;
    131:           if (kk > P-1) kk = kk - P;
    132:           /* gone out of processor range on x axis */
    133:           while (ii > me-1 || ii < ms) {
    134:             if (mr == m-1) {
    135:               ms = 0;
    136:               me = lx[0];
    137:               mr = 0;
    138:             } else {
    139:               mr++;
    140:               ms = me;
    141:               me += lx[mr];
    142:             }
    143:           }
    144:           /* gone out of processor range on y axis */
    145:           while (jj > ne-1 || jj < ns) {
    146:             if (nr == n-1) {
    147:               ns = 0;
    148:               ne = ly[0];
    149:               nr = 0;
    150:             } else {
    151:               nr++;
    152:               ns = ne;
    153:               ne += ly[nr];
    154:             }
    155:           }
    156:           /* gone out of processor range on z axis */
    157:           while (kk > pe-1 || kk < ps) {
    158:             if (pr == p-1) {
    159:               ps = 0;
    160:               pe = lz[0];
    161:               pr = 0;
    162:             } else {
    163:               pr++;
    164:               ps = pe;
    165:               pe += lz[pr];
    166:             }
    167:           }
    168:           /* compute the vector base on owning processor */
    169:           xm = me - ms;
    170:           ym = ne - ns;
    171:           zm = pe - ps;
    172:           base = ms*ym*zm + ns*M*zm + ps*M*N;
    173:           /* compute the local coordinates on owning processor */
    174:           si = ii - ms;
    175:           sj = jj - ns;
    176:           sk = kk - ps;
    177:           for (l=0;l<dof;l++) {
    178:             indices[idx] = l + dof*(base + si + xm*sj + xm*ym*sk);
    179:             idx++;
    180:           }
    181:           i++;
    182:         } while (i<upper->i-ox);
    183:         j++;
    184:       } while (j<upper->j-oy);
    185:       k++;
    186:     } while (k<upper->k-oz);
    187:   }

    189:   if (!offproc){
    190:     DMDAGetCorners(da, &ms, &ns, &ps, &mw, &nw, &pw);
    191:     me = ms + mw;
    192:     if (N>1) ne = ns + nw;
    193:     if (P>1) pe = ps + pw;
    194:     /* Account for DM offsets */
    195:     ms = ms - ox; me = me - ox;
    196:     ns = ns - oy; ne = ne - oy;
    197:     ps = ps - oz; pe = pe - oz;

    199:     /* compute the vector base on owning processor */
    200:     xm = me - ms;
    201:     ym = ne - ns;
    202:     zm = pe - ps;
    203:     base = ms*ym*zm + ns*M*zm + ps*M*N;
    204:     /*
    205:        if no indices are to be returned, create an empty is,
    206:        this prevents hanging in while loops
    207:     */
    208:     if (skip_i && skip_j && skip_k) goto createis;
    209:     /*
    210:        do..while loops to ensure the block gets entered once,
    211:        regardless of control condition being met, necessary for
    212:        cases when a subset of skip_i/j/k is true
    213:     */
    214:     if (skip_k) k = upper->k-oz; else k = lower->k-oz;
    215:     do {
    216:       if (skip_j) j = upper->j-oy; else j = lower->j-oy;
    217:       do {
    218:         if (skip_i) i = upper->i-ox; else i = lower->i-ox;
    219:         do {
    220:           if (k>=ps && k<=pe-1) {
    221:             if (j>=ns && j<=ne-1) {
    222:               if (i>=ms && i<=me-1) {
    223:                 /* compute the local coordinates on owning processor */
    224:                 si = i - ms;
    225:                 sj = j - ns;
    226:                 sk = k - ps;
    227:                 for (l=0; l<dof; l++) {
    228:                   indices[idx] = l + dof*(base + si + xm*sj + xm*ym*sk);
    229:                   idx++;
    230:                 }
    231:               }
    232:             }
    233:           }
    234:           i++;
    235:         } while (i<upper->i-ox);
    236:         j++;
    237:       } while (j<upper->j-oy);
    238:       k++;
    239:     } while (k<upper->k-oz);

    241:     PetscRealloc((size_t)(idx*sizeof(PetscInt)), (void*)&indices);
    242:   }

    244:   createis:
    245:   ISCreateGeneral(PetscObjectComm((PetscObject)da),idx,indices,PETSC_OWN_POINTER,is);
    246:   return(0);
    247: }

    249: PetscErrorCode DMDASubDomainDA_Private(DM dm, PetscInt *nlocal, DM **sdm)
    250: {
    251:   DM             *da;
    252:   PetscInt       dim,size,i,j,k,idx;
    254:   DMDALocalInfo  info;
    255:   PetscInt       xsize,ysize,zsize;
    256:   PetscInt       xo,yo,zo;
    257:   PetscInt       xs,ys,zs;
    258:   PetscInt       xm=1,ym=1,zm=1;
    259:   PetscInt       xol,yol,zol;
    260:   PetscInt       m=1,n=1,p=1;
    261:   PetscInt       M,N,P;
    262:   PetscInt       pm,mtmp;

    265:   DMDAGetLocalInfo(dm,&info);
    266:   DMDAGetOverlap(dm,&xol,&yol,&zol);
    267:   DMDAGetNumLocalSubDomains(dm,&size);
    268:   PetscMalloc1(size,&da);

    270:   if (nlocal) *nlocal = size;

    272:   dim = info.dim;

    274:   M = info.xm;
    275:   N = info.ym;
    276:   P = info.zm;

    278:   if (dim == 1) {
    279:     m = size;
    280:   } else if (dim == 2) {
    281:     m = (PetscInt)(0.5 + PetscSqrtReal(((PetscReal)M)*((PetscReal)size)/((PetscReal)N)));
    282:     while (m > 0) {
    283:       n = size/m;
    284:       if (m*n*p == size) break;
    285:       m--;
    286:     }
    287:   } else if (dim == 3) {
    288:     n = (PetscInt)(0.5 + PetscPowReal(((PetscReal)N*N)*((PetscReal)size)/((PetscReal)P*M),(PetscReal)(1./3.))); if (!n) n = 1;
    289:     while (n > 0) {
    290:       pm = size/n;
    291:       if (n*pm == size) break;
    292:       n--;
    293:     }
    294:     if (!n) n = 1;
    295:     m = (PetscInt)(0.5 + PetscSqrtReal(((PetscReal)M)*((PetscReal)size)/((PetscReal)P*n)));
    296:     if (!m) m = 1;
    297:     while (m > 0) {
    298:       p = size/(m*n);
    299:       if (m*n*p == size) break;
    300:       m--;
    301:     }
    302:     if (M > P && m < p) {mtmp = m; m = p; p = mtmp;}
    303:   }

    305:   zs = info.zs;
    306:   idx = 0;
    307:   for (k = 0; k < p; k++) {
    308:     ys = info.ys;
    309:     for (j = 0; j < n; j++) {
    310:       xs = info.xs;
    311:       for (i = 0; i < m; i++) {
    312:         if (dim == 1) {
    313:           xm = M/m + ((M % m) > i);
    314:         } else if (dim == 2) {
    315:           xm = M/m + ((M % m) > i);
    316:           ym = N/n + ((N % n) > j);
    317:         } else if (dim == 3) {
    318:           xm = M/m + ((M % m) > i);
    319:           ym = N/n + ((N % n) > j);
    320:           zm = P/p + ((P % p) > k);
    321:         }

    323:         xsize = xm;
    324:         ysize = ym;
    325:         zsize = zm;
    326:         xo = xs;
    327:         yo = ys;
    328:         zo = zs;

    330:         DMDACreate(PETSC_COMM_SELF,&(da[idx]));
    331:         DMSetOptionsPrefix(da[idx],"sub_");
    332:         DMSetDimension(da[idx], info.dim);
    333:         DMDASetDof(da[idx], info.dof);

    335:         DMDASetStencilType(da[idx],info.st);
    336:         DMDASetStencilWidth(da[idx],info.sw);

    338:         if (info.bx == DM_BOUNDARY_PERIODIC || (xs != 0)) {
    339:           xsize += xol;
    340:           xo    -= xol;
    341:         }
    342:         if (info.by == DM_BOUNDARY_PERIODIC || (ys != 0)) {
    343:           ysize += yol;
    344:           yo    -= yol;
    345:         }
    346:         if (info.bz == DM_BOUNDARY_PERIODIC || (zs != 0)) {
    347:           zsize += zol;
    348:           zo    -= zol;
    349:         }

    351:         if (info.bx == DM_BOUNDARY_PERIODIC || (xs+xm != info.mx)) xsize += xol;
    352:         if (info.by == DM_BOUNDARY_PERIODIC || (ys+ym != info.my)) ysize += yol;
    353:         if (info.bz == DM_BOUNDARY_PERIODIC || (zs+zm != info.mz)) zsize += zol;

    355:         if (info.bx != DM_BOUNDARY_PERIODIC) {
    356:           if (xo < 0) {
    357:             xsize += xo;
    358:             xo = 0;
    359:           }
    360:           if (xo+xsize > info.mx-1) {
    361:             xsize -= xo+xsize - info.mx;
    362:           }
    363:         }
    364:         if (info.by != DM_BOUNDARY_PERIODIC) {
    365:           if (yo < 0) {
    366:             ysize += yo;
    367:             yo = 0;
    368:           }
    369:           if (yo+ysize > info.my-1) {
    370:             ysize -= yo+ysize - info.my;
    371:           }
    372:         }
    373:         if (info.bz != DM_BOUNDARY_PERIODIC) {
    374:           if (zo < 0) {
    375:             zsize += zo;
    376:             zo = 0;
    377:           }
    378:           if (zo+zsize > info.mz-1) {
    379:             zsize -= zo+zsize - info.mz;
    380:           }
    381:         }

    383:         DMDASetSizes(da[idx], xsize, ysize, zsize);
    384:         DMDASetNumProcs(da[idx], 1, 1, 1);
    385:         DMDASetBoundaryType(da[idx], DM_BOUNDARY_GHOSTED, DM_BOUNDARY_GHOSTED, DM_BOUNDARY_GHOSTED);

    387:         /* set up as a block instead */
    388:         DMSetUp(da[idx]);

    390:         /* nonoverlapping region */
    391:         DMDASetNonOverlappingRegion(da[idx],xs,ys,zs,xm,ym,zm);

    393:         /* this alters the behavior of DMDAGetInfo, DMDAGetLocalInfo, DMDAGetCorners, and DMDAGetGhostedCorners and should be used with care */
    394:         DMDASetOffset(da[idx],xo,yo,zo,info.mx,info.my,info.mz);
    395:         xs += xm;
    396:         idx++;
    397:       }
    398:       ys += ym;
    399:     }
    400:     zs += zm;
    401:   }
    402:   *sdm = da;
    403:   return(0);
    404: }

    406: /*
    407:    Fills the local vector problem on the subdomain from the global problem.

    409:    Right now this assumes one subdomain per processor.

    411: */
    412: PetscErrorCode DMCreateDomainDecompositionScatters_DA(DM dm,PetscInt nsubdms,DM *subdms,VecScatter **iscat,VecScatter **oscat, VecScatter **lscat)
    413: {
    415:   DMDALocalInfo  info,subinfo;
    416:   DM             subdm;
    417:   MatStencil     upper,lower;
    418:   IS             idis,isis,odis,osis,gdis;
    419:   Vec            svec,dvec,slvec;
    420:   PetscInt       xm,ym,zm,xs,ys,zs;
    421:   PetscInt       i;
    422:   PetscBool      patchis_offproc = PETSC_TRUE;

    425:   /* allocate the arrays of scatters */
    426:   if (iscat) {PetscMalloc1(nsubdms,iscat);}
    427:   if (oscat) {PetscMalloc1(nsubdms,oscat);}
    428:   if (lscat) {PetscMalloc1(nsubdms,lscat);}

    430:   DMDAGetLocalInfo(dm,&info);
    431:   for (i = 0; i < nsubdms; i++) {
    432:     subdm = subdms[i];
    433:     DMDAGetLocalInfo(subdm,&subinfo);
    434:     DMDAGetNonOverlappingRegion(subdm,&xs,&ys,&zs,&xm,&ym,&zm);

    436:     /* create the global and subdomain index sets for the inner domain */
    437:     lower.i = xs;
    438:     lower.j = ys;
    439:     lower.k = zs;
    440:     upper.i = xs+xm;
    441:     upper.j = ys+ym;
    442:     upper.k = zs+zm;
    443:     DMDACreatePatchIS(dm,&lower,&upper,&idis,patchis_offproc);
    444:     DMDACreatePatchIS(subdm,&lower,&upper,&isis,patchis_offproc);

    446:     /* create the global and subdomain index sets for the outer subdomain */
    447:     lower.i = subinfo.xs;
    448:     lower.j = subinfo.ys;
    449:     lower.k = subinfo.zs;
    450:     upper.i = subinfo.xs+subinfo.xm;
    451:     upper.j = subinfo.ys+subinfo.ym;
    452:     upper.k = subinfo.zs+subinfo.zm;
    453:     DMDACreatePatchIS(dm,&lower,&upper,&odis,patchis_offproc);
    454:     DMDACreatePatchIS(subdm,&lower,&upper,&osis,patchis_offproc);

    456:     /* global and subdomain ISes for the local indices of the subdomain */
    457:     /* todo - make this not loop over at nonperiodic boundaries, which will be more involved */
    458:     lower.i = subinfo.gxs;
    459:     lower.j = subinfo.gys;
    460:     lower.k = subinfo.gzs;
    461:     upper.i = subinfo.gxs+subinfo.gxm;
    462:     upper.j = subinfo.gys+subinfo.gym;
    463:     upper.k = subinfo.gzs+subinfo.gzm;
    464:     DMDACreatePatchIS(dm,&lower,&upper,&gdis,patchis_offproc);

    466:     /* form the scatter */
    467:     DMGetGlobalVector(dm,&dvec);
    468:     DMGetGlobalVector(subdm,&svec);
    469:     DMGetLocalVector(subdm,&slvec);

    471:     if (iscat) {VecScatterCreate(dvec,idis,svec,isis,&(*iscat)[i]);}
    472:     if (oscat) {VecScatterCreate(dvec,odis,svec,osis,&(*oscat)[i]);}
    473:     if (lscat) {VecScatterCreate(dvec,gdis,slvec,NULL,&(*lscat)[i]);}

    475:     DMRestoreGlobalVector(dm,&dvec);
    476:     DMRestoreGlobalVector(subdm,&svec);
    477:     DMRestoreLocalVector(subdm,&slvec);

    479:     ISDestroy(&idis);
    480:     ISDestroy(&isis);

    482:     ISDestroy(&odis);
    483:     ISDestroy(&osis);

    485:     ISDestroy(&gdis);
    486:   }
    487:   return(0);
    488: }

    490: PetscErrorCode DMDASubDomainIS_Private(DM dm,PetscInt n,DM *subdm,IS **iis,IS **ois)
    491: {
    493:   PetscInt       i;
    494:   DMDALocalInfo  info,subinfo;
    495:   MatStencil     lower,upper;
    496:   PetscBool      patchis_offproc = PETSC_TRUE;

    499:   DMDAGetLocalInfo(dm,&info);
    500:   if (iis) {PetscMalloc1(n,iis);}
    501:   if (ois) {PetscMalloc1(n,ois);}

    503:   for (i = 0;i < n; i++) {
    504:     DMDAGetLocalInfo(subdm[i],&subinfo);
    505:     if (iis) {
    506:       /* create the inner IS */
    507:       lower.i = info.xs;
    508:       lower.j = info.ys;
    509:       lower.k = info.zs;
    510:       upper.i = info.xs+info.xm;
    511:       upper.j = info.ys+info.ym;
    512:       upper.k = info.zs+info.zm;
    513:       DMDACreatePatchIS(dm,&lower,&upper,&(*iis)[i],patchis_offproc);
    514:     }

    516:     if (ois) {
    517:       /* create the outer IS */
    518:       lower.i = subinfo.xs;
    519:       lower.j = subinfo.ys;
    520:       lower.k = subinfo.zs;
    521:       upper.i = subinfo.xs+subinfo.xm;
    522:       upper.j = subinfo.ys+subinfo.ym;
    523:       upper.k = subinfo.zs+subinfo.zm;
    524:       DMDACreatePatchIS(dm,&lower,&upper,&(*ois)[i],patchis_offproc);
    525:     }
    526:   }
    527:   return(0);
    528: }

    530: PetscErrorCode DMCreateDomainDecomposition_DA(DM dm,PetscInt *len,char ***names,IS **iis,IS **ois,DM **subdm)
    531: {
    533:   DM             *sdm;
    534:   PetscInt       n,i;

    537:   DMDASubDomainDA_Private(dm,&n,&sdm);
    538:   if (names) {
    539:     PetscMalloc1(n,names);
    540:     for (i=0;i<n;i++) (*names)[i] = NULL;
    541:   }
    542:   DMDASubDomainIS_Private(dm,n,sdm,iis,ois);
    543:   if (subdm) *subdm = sdm;
    544:   else {
    545:     for (i=0;i<n;i++) {
    546:       DMDestroy(&sdm[i]);
    547:     }
    548:   }
    549:   if (len) *len = n;
    550:   return(0);
    551: }