Actual source code: sfbasic.c

petsc-main 2021-04-20
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  1: #include <../src/vec/is/sf/impls/basic/sfbasic.h>
  2: #include <../src/vec/is/sf/impls/basic/sfpack.h>

  4: /*===================================================================================*/
  5: /*              SF public interface implementations                                  */
  6: /*===================================================================================*/
  7: PETSC_INTERN PetscErrorCode PetscSFSetUp_Basic(PetscSF sf)
  8: {
 10:   PetscSF_Basic  *bas = (PetscSF_Basic*)sf->data;
 11:   PetscInt       *rlengths,*ilengths,i,nRemoteRootRanks,nRemoteLeafRanks;
 12:   PetscMPIInt    rank,niranks,*iranks,tag;
 13:   MPI_Comm       comm;
 14:   MPI_Group      group;
 15:   MPI_Request    *rootreqs,*leafreqs;

 18:   MPI_Comm_group(PETSC_COMM_SELF,&group);
 19:   PetscSFSetUpRanks(sf,group);
 20:   MPI_Group_free(&group);
 21:   PetscObjectGetComm((PetscObject)sf,&comm);
 22:   PetscObjectGetNewTag((PetscObject)sf,&tag);
 23:   MPI_Comm_rank(comm,&rank);
 24:   /*
 25:    * Inform roots about how many leaves and from which ranks
 26:    */
 27:   PetscMalloc1(sf->nranks,&rlengths);
 28:   /* Determine number, sending ranks and length of incoming */
 29:   for (i=0; i<sf->nranks; i++) {
 30:     rlengths[i] = sf->roffset[i+1] - sf->roffset[i]; /* Number of roots referenced by my leaves; for rank sf->ranks[i] */
 31:   }
 32:   nRemoteRootRanks = sf->nranks-sf->ndranks;
 33:   PetscCommBuildTwoSided(comm,1,MPIU_INT,nRemoteRootRanks,sf->ranks+sf->ndranks,rlengths+sf->ndranks,&niranks,&iranks,(void**)&ilengths);

 35:   /* Sort iranks. See use of VecScatterGetRemoteOrdered_Private() in MatGetBrowsOfAoCols_MPIAIJ() on why.
 36:      We could sort ranks there at the price of allocating extra working arrays. Presumably, niranks is
 37:      small and the sorting is cheap.
 38:    */
 39:   PetscSortMPIIntWithIntArray(niranks,iranks,ilengths);

 41:   /* Partition into distinguished and non-distinguished incoming ranks */
 42:   bas->ndiranks = sf->ndranks;
 43:   bas->niranks = bas->ndiranks + niranks;
 44:   PetscMalloc2(bas->niranks,&bas->iranks,bas->niranks+1,&bas->ioffset);
 45:   bas->ioffset[0] = 0;
 46:   for (i=0; i<bas->ndiranks; i++) {
 47:     bas->iranks[i] = sf->ranks[i];
 48:     bas->ioffset[i+1] = bas->ioffset[i] + rlengths[i];
 49:   }
 50:   if (bas->ndiranks > 1 || (bas->ndiranks == 1 && bas->iranks[0] != rank)) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Broken setup for shared ranks");
 51:   for (; i<bas->niranks; i++) {
 52:     bas->iranks[i] = iranks[i-bas->ndiranks];
 53:     bas->ioffset[i+1] = bas->ioffset[i] + ilengths[i-bas->ndiranks];
 54:   }
 55:   bas->itotal = bas->ioffset[i];
 56:   PetscFree(rlengths);
 57:   PetscFree(iranks);
 58:   PetscFree(ilengths);

 60:   /* Send leaf identities to roots */
 61:   nRemoteLeafRanks = bas->niranks-bas->ndiranks;
 62:   PetscMalloc1(bas->itotal,&bas->irootloc);
 63:   PetscMalloc2(nRemoteLeafRanks,&rootreqs,nRemoteRootRanks,&leafreqs);
 64:   for (i=bas->ndiranks; i<bas->niranks; i++) {
 65:     MPI_Irecv(bas->irootloc+bas->ioffset[i],bas->ioffset[i+1]-bas->ioffset[i],MPIU_INT,bas->iranks[i],tag,comm,&rootreqs[i-bas->ndiranks]);
 66:   }
 67:   for (i=0; i<sf->nranks; i++) {
 68:     PetscMPIInt npoints;
 69:     PetscMPIIntCast(sf->roffset[i+1] - sf->roffset[i],&npoints);
 70:     if (i < sf->ndranks) {
 71:       if (sf->ranks[i] != rank) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Cannot interpret distinguished leaf rank");
 72:       if (bas->iranks[0] != rank) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Cannot interpret distinguished root rank");
 73:       if (npoints != bas->ioffset[1]-bas->ioffset[0]) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Distinguished rank exchange has mismatched lengths");
 74:       PetscArraycpy(bas->irootloc+bas->ioffset[0],sf->rremote+sf->roffset[i],npoints);
 75:       continue;
 76:     }
 77:     MPI_Isend(sf->rremote+sf->roffset[i],npoints,MPIU_INT,sf->ranks[i],tag,comm,&leafreqs[i-sf->ndranks]);
 78:   }
 79:   MPI_Waitall(nRemoteLeafRanks,rootreqs,MPI_STATUSES_IGNORE);
 80:   MPI_Waitall(nRemoteRootRanks,leafreqs,MPI_STATUSES_IGNORE);

 82:   sf->nleafreqs  = nRemoteRootRanks;
 83:   bas->nrootreqs = nRemoteLeafRanks;
 84:   sf->persistent = PETSC_TRUE;

 86:   /* Setup fields related to packing, such as rootbuflen[] */
 87:   PetscSFSetUpPackFields(sf);
 88:   PetscFree2(rootreqs,leafreqs);
 89:   return(0);
 90: }

 92: PETSC_INTERN PetscErrorCode PetscSFReset_Basic(PetscSF sf)
 93: {
 94:   PetscErrorCode    ierr;
 95:   PetscSF_Basic     *bas = (PetscSF_Basic*)sf->data;
 96:   PetscSFLink       link = bas->avail,next;

 99:   if (bas->inuse) SETERRQ(PetscObjectComm((PetscObject)sf),PETSC_ERR_ARG_WRONGSTATE,"Outstanding operation has not been completed");
100:   PetscFree2(bas->iranks,bas->ioffset);
101:   PetscFree(bas->irootloc);

103:  #if defined(PETSC_HAVE_DEVICE)
104:   for (PetscInt i=0; i<2; i++) {PetscSFFree(sf,PETSC_MEMTYPE_DEVICE,bas->irootloc_d[i]);}
105:  #endif

107:  #if defined(PETSC_HAVE_NVSHMEM)
108:   PetscSFReset_Basic_NVSHMEM(sf);
109:  #endif

111:   for (; link; link=next) {next = link->next; PetscSFLinkDestroy(sf,link);}
112:   bas->avail = NULL;
113:   PetscSFResetPackFields(sf);
114:   return(0);
115: }

117: PETSC_INTERN PetscErrorCode PetscSFDestroy_Basic(PetscSF sf)
118: {

122:   PetscSFReset_Basic(sf);
123:   PetscFree(sf->data);
124:   return(0);
125: }

127: #if defined(PETSC_USE_SINGLE_LIBRARY)
128: #include <petscmat.h>

130: PETSC_INTERN PetscErrorCode PetscSFView_Basic_PatternAndSizes(PetscSF sf,PetscViewer viewer)
131: {
132:   PetscErrorCode       ierr;
133:   PetscSF_Basic        *bas = (PetscSF_Basic*)sf->data;
134:   PetscSFLink          link = bas->avail;
135:   PetscInt             i,nrootranks,ndrootranks,myrank;
136:   const PetscInt       *rootoffset;
137:   PetscMPIInt          rank,size;
138:   MPI_Comm             comm = PetscObjectComm((PetscObject)sf);
139:   Mat                  A;

142:   MPI_Comm_size(comm,&size);
143:   MPI_Comm_rank(comm,&rank);
144:   myrank = rank;
145:   if (sf->persistent) {
146:     /* amount of data I send to other ranks - global to local */
147:     MatCreateAIJ(comm,1,1,size,size,20,NULL,20,NULL,&A);
148:     PetscSFGetRootInfo_Basic(sf,&nrootranks,&ndrootranks,NULL,&rootoffset,NULL);
149:     for (i=0; i<nrootranks; i++) {
150:       MatSetValue(A,myrank,bas->iranks[i],(rootoffset[i+1] - rootoffset[i])*link->unitbytes,INSERT_VALUES);
151:     }
152:     MatAssemblyBegin(A,MAT_FINAL_ASSEMBLY);
153:     MatAssemblyEnd(A,MAT_FINAL_ASSEMBLY);
154:     MatTranspose(A,MAT_INITIAL_MATRIX,&A);
155:     MatView(A,viewer);
156:     MatDestroy(&A);
157:   }
158:   return(0);
159: }
160: #endif

162: PETSC_INTERN PetscErrorCode PetscSFView_Basic(PetscSF sf,PetscViewer viewer)
163: {
165:   PetscBool      iascii;

168:   PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERASCII,&iascii);
169:   if (iascii) {PetscViewerASCIIPrintf(viewer,"  MultiSF sort=%s\n",sf->rankorder ? "rank-order" : "unordered");}
170:  #if defined(PETSC_USE_SINGLE_LIBRARY)
171:   {
172:     PetscBool ibinary;
173:     PetscObjectTypeCompare((PetscObject)viewer,PETSCVIEWERBINARY,&ibinary);
174:     if (ibinary) {PetscSFView_Basic_PatternAndSizes(sf,viewer);}
175:   }
176:  #endif
177:   return(0);
178: }

180: static PetscErrorCode PetscSFBcastBegin_Basic(PetscSF sf,MPI_Datatype unit,PetscMemType rootmtype,const void *rootdata,PetscMemType leafmtype,void *leafdata,MPI_Op op)
181: {
182:   PetscErrorCode    ierr;
183:   PetscSFLink       link = NULL;

186:   /* Create a communication link, which provides buffers, MPI requests etc (if MPI is used) */
187:   PetscSFLinkCreate(sf,unit,rootmtype,rootdata,leafmtype,leafdata,op,PETSCSF_BCAST,&link);
188:   /* Pack rootdata to rootbuf for remote communication */
189:   PetscSFLinkPackRootData(sf,link,PETSCSF_REMOTE,rootdata);
190:   /* Start communcation, e.g., post MPI_Isend */
191:   PetscSFLinkStartCommunication(sf,link,PETSCSF_../../../../../..2LEAF);
192:   /* Do local scatter (i.e., self to self communication), which overlaps with the remote communication above */
193:   PetscSFLinkScatterLocal(sf,link,PETSCSF_../../../../../..2LEAF,(void*)rootdata,leafdata,op);
194:   return(0);
195: }

197: PETSC_INTERN PetscErrorCode PetscSFBcastEnd_Basic(PetscSF sf,MPI_Datatype unit,const void *rootdata,void *leafdata,MPI_Op op)
198: {
199:   PetscErrorCode    ierr;
200:   PetscSFLink       link = NULL;

203:   /* Retrieve the link used in XxxBegin() with root/leafdata as key */
204:   PetscSFLinkGetInUse(sf,unit,rootdata,leafdata,PETSC_OWN_POINTER,&link);
205:   /* Finish remote communication, e.g., post MPI_Waitall */
206:   PetscSFLinkFinishCommunication(sf,link,PETSCSF_../../../../../..2LEAF);
207:   /* Unpack data in leafbuf to leafdata for remote communication */
208:   PetscSFLinkUnpackLeafData(sf,link,PETSCSF_REMOTE,leafdata,op);
209:   /* Recycle the link */
210:   PetscSFLinkReclaim(sf,&link);
211:   return(0);
212: }

214: /* Shared by ReduceBegin and FetchAndOpBegin */
215: PETSC_STATIC_INLINE PetscErrorCode PetscSFLeafToRootBegin_Basic(PetscSF sf,MPI_Datatype unit,PetscMemType leafmtype,const void *leafdata,PetscMemType rootmtype,void *rootdata,MPI_Op op,PetscSFOperation sfop,PetscSFLink *out)
216: {
217:   PetscErrorCode    ierr;
218:   PetscSFLink       link = NULL;

221:   PetscSFLinkCreate(sf,unit,rootmtype,rootdata,leafmtype,leafdata,op,sfop,&link);
222:   PetscSFLinkPackLeafData(sf,link,PETSCSF_REMOTE,leafdata);
223:   PetscSFLinkStartCommunication(sf,link,PETSCSF_LEAF2../../../../../..);
224:   *out = link;
225:   return(0);
226: }

228: /* leaf -> root with reduction */
229: static PetscErrorCode PetscSFReduceBegin_Basic(PetscSF sf,MPI_Datatype unit,PetscMemType leafmtype,const void *leafdata,PetscMemType rootmtype,void *rootdata,MPI_Op op)
230: {
231:   PetscErrorCode    ierr;
232:   PetscSFLink       link = NULL;

235:   PetscSFLeafToRootBegin_Basic(sf,unit,leafmtype,leafdata,rootmtype,rootdata,op,PETSCSF_REDUCE,&link);
236:   PetscSFLinkScatterLocal(sf,link,PETSCSF_LEAF2../../../../../..,rootdata,(void*)leafdata,op);
237:   return(0);
238: }

240: PETSC_INTERN PetscErrorCode PetscSFReduceEnd_Basic(PetscSF sf,MPI_Datatype unit,const void *leafdata,void *rootdata,MPI_Op op)
241: {
242:   PetscErrorCode    ierr;
243:   PetscSFLink       link = NULL;

246:   PetscSFLinkGetInUse(sf,unit,rootdata,leafdata,PETSC_OWN_POINTER,&link);
247:   PetscSFLinkFinishCommunication(sf,link,PETSCSF_LEAF2../../../../../..);
248:   PetscSFLinkUnpackRootData(sf,link,PETSCSF_REMOTE,rootdata,op);
249:   PetscSFLinkReclaim(sf,&link);
250:   return(0);
251: }

253: PETSC_INTERN PetscErrorCode PetscSFFetchAndOpBegin_Basic(PetscSF sf,MPI_Datatype unit,PetscMemType rootmtype,void *rootdata,PetscMemType leafmtype,const void *leafdata,void *leafupdate,MPI_Op op)
254: {
255:   PetscErrorCode    ierr;
256:   PetscSFLink       link = NULL;

259:   PetscSFLeafToRootBegin_Basic(sf,unit,leafmtype,leafdata,rootmtype,rootdata,op,PETSCSF_FETCH,&link);
260:   PetscSFLinkFetchAndOpLocal(sf,link,rootdata,leafdata,leafupdate,op);
261:   return(0);
262: }

264: static PetscErrorCode PetscSFFetchAndOpEnd_Basic(PetscSF sf,MPI_Datatype unit,void *rootdata,const void *leafdata,void *leafupdate,MPI_Op op)
265: {
266:   PetscErrorCode    ierr;
267:   PetscSFLink       link = NULL;

270:   PetscSFLinkGetInUse(sf,unit,rootdata,leafdata,PETSC_OWN_POINTER,&link);
271:   /* This implementation could be changed to unpack as receives arrive, at the cost of non-determinism */
272:   PetscSFLinkFinishCommunication(sf,link,PETSCSF_LEAF2../../../../../..);
273:   /* Do fetch-and-op, the (remote) update results are in rootbuf */
274:   PetscSFLinkFetchAndOpRemote(sf,link,rootdata,op);
275:   /* Bcast rootbuf to leafupdate */
276:   PetscSFLinkStartCommunication(sf,link,PETSCSF_../../../../../..2LEAF);
277:   PetscSFLinkFinishCommunication(sf,link,PETSCSF_../../../../../..2LEAF);
278:   /* Unpack and insert fetched data into leaves */
279:   PetscSFLinkUnpackLeafData(sf,link,PETSCSF_REMOTE,leafupdate,MPI_REPLACE);
280:   PetscSFLinkReclaim(sf,&link);
281:   return(0);
282: }

284: PETSC_INTERN PetscErrorCode PetscSFGetLeafRanks_Basic(PetscSF sf,PetscInt *niranks,const PetscMPIInt **iranks,const PetscInt **ioffset,const PetscInt **irootloc)
285: {
286:   PetscSF_Basic *bas = (PetscSF_Basic*)sf->data;

289:   if (niranks)  *niranks  = bas->niranks;
290:   if (iranks)   *iranks   = bas->iranks;
291:   if (ioffset)  *ioffset  = bas->ioffset;
292:   if (irootloc) *irootloc = bas->irootloc;
293:   return(0);
294: }

296: /* An optimized PetscSFCreateEmbeddedRootSF. We aggresively make use of the established communication on sf.
297:    We need one bcast on sf, and no communication anymore to build the embedded sf. Note that selected[]
298:    was sorted before calling the routine.
299:  */
300: PETSC_INTERN PetscErrorCode PetscSFCreateEmbeddedRootSF_Basic(PetscSF sf,PetscInt nselected,const PetscInt *selected,PetscSF *newsf)
301: {
302:   PetscSF           esf;
303:   PetscInt          esf_nranks,esf_ndranks,*esf_roffset,*esf_rmine,*esf_rremote;
304:   PetscInt          i,j,p,q,nroots,esf_nleaves,*new_ilocal,nranks,ndranks,niranks,ndiranks,minleaf,maxleaf,maxlocal;
305:   char              *rootdata,*leafdata,*leafmem; /* Only stores 0 or 1, so we can save memory with char */
306:   PetscMPIInt       *esf_ranks;
307:   const PetscMPIInt *ranks,*iranks;
308:   const PetscInt    *roffset,*rmine,*rremote,*ioffset,*irootloc;
309:   PetscBool         connected;
310:   PetscSFNode       *new_iremote;
311:   PetscSF_Basic     *bas;
312:   PetscErrorCode    ierr;

315:   PetscSFCreate(PetscObjectComm((PetscObject)sf),&esf);
316:   PetscSFSetFromOptions(esf);
317:   PetscSFSetType(esf,PETSCSFBASIC); /* This optimized routine can only create a basic sf */

319:   /* Find out which leaves are still connected to roots in the embedded sf by doing a Bcast */
320:   PetscSFGetGraph(sf,&nroots,NULL,NULL,NULL);
321:   PetscSFGetLeafRange(sf,&minleaf,&maxleaf);
322:   maxlocal = maxleaf - minleaf + 1;
323:   PetscCalloc2(nroots,&rootdata,maxlocal,&leafmem);
324:   leafdata = leafmem - minleaf;
325:   /* Tag selected roots */
326:   for (i=0; i<nselected; ++i) rootdata[selected[i]] = 1;

328:   PetscSFBcastBegin(sf,MPI_CHAR,rootdata,leafdata,MPI_REPLACE);
329:   PetscSFBcastEnd(sf,MPI_CHAR,rootdata,leafdata,MPI_REPLACE);
330:   PetscSFGetLeafInfo_Basic(sf,&nranks,&ndranks,&ranks,&roffset,&rmine,&rremote); /* Get send info */
331:   esf_nranks = esf_ndranks = esf_nleaves = 0;
332:   for (i=0; i<nranks; i++) {
333:     connected = PETSC_FALSE; /* Is this process still connected to this remote root rank? */
334:     for (j=roffset[i]; j<roffset[i+1]; j++) {if (leafdata[rmine[j]]) {esf_nleaves++; connected = PETSC_TRUE;}}
335:     if (connected) {esf_nranks++; if (i < ndranks) esf_ndranks++;}
336:   }

338:   /* Set graph of esf and also set up its outgoing communication (i.e., send info), which is usually done by PetscSFSetUpRanks */
339:   PetscMalloc1(esf_nleaves,&new_ilocal);
340:   PetscMalloc1(esf_nleaves,&new_iremote);
341:   PetscMalloc4(esf_nranks,&esf_ranks,esf_nranks+1,&esf_roffset,esf_nleaves,&esf_rmine,esf_nleaves,&esf_rremote);
342:   p    = 0; /* Counter for connected root ranks */
343:   q    = 0; /* Counter for connected leaves */
344:   esf_roffset[0] = 0;
345:   for (i=0; i<nranks; i++) { /* Scan leaf data again to fill esf arrays */
346:     connected = PETSC_FALSE;
347:     for (j=roffset[i]; j<roffset[i+1]; j++) {
348:       if (leafdata[rmine[j]]) {
349:         esf_rmine[q]         = new_ilocal[q] = rmine[j];
350:         esf_rremote[q]       = rremote[j];
351:         new_iremote[q].index = rremote[j];
352:         new_iremote[q].rank  = ranks[i];
353:         connected            = PETSC_TRUE;
354:         q++;
355:       }
356:     }
357:     if (connected) {
358:       esf_ranks[p]     = ranks[i];
359:       esf_roffset[p+1] = q;
360:       p++;
361:     }
362:   }

364:   /* SetGraph internally resets the SF, so we only set its fields after the call */
365:   PetscSFSetGraph(esf,nroots,esf_nleaves,new_ilocal,PETSC_OWN_POINTER,new_iremote,PETSC_OWN_POINTER);
366:   esf->nranks    = esf_nranks;
367:   esf->ndranks   = esf_ndranks;
368:   esf->ranks     = esf_ranks;
369:   esf->roffset   = esf_roffset;
370:   esf->rmine     = esf_rmine;
371:   esf->rremote   = esf_rremote;
372:   esf->nleafreqs = esf_nranks - esf_ndranks;

374:   /* Set up the incoming communication (i.e., recv info) stored in esf->data, which is usually done by PetscSFSetUp_Basic */
375:   bas  = (PetscSF_Basic*)esf->data;
376:   PetscSFGetRootInfo_Basic(sf,&niranks,&ndiranks,&iranks,&ioffset,&irootloc); /* Get recv info */
377:   /* Embedded sf always has simpler communication than the original one. We might allocate longer arrays than needed here. But we
378:      we do not care since these arrays are usually short. The benefit is we can fill these arrays by just parsing irootloc once.
379:    */
380:   PetscMalloc2(niranks,&bas->iranks,niranks+1,&bas->ioffset);
381:   PetscMalloc1(ioffset[niranks],&bas->irootloc);
382:   bas->niranks = bas->ndiranks = bas->ioffset[0] = 0;
383:   p = 0; /* Counter for connected leaf ranks */
384:   q = 0; /* Counter for connected roots */
385:   for (i=0; i<niranks; i++) {
386:     connected = PETSC_FALSE; /* Is the current process still connected to this remote leaf rank? */
387:     for (j=ioffset[i]; j<ioffset[i+1]; j++) {
388:       if (rootdata[irootloc[j]]) {
389:         bas->irootloc[q++] = irootloc[j];
390:         connected = PETSC_TRUE;
391:       }
392:     }
393:     if (connected) {
394:       bas->niranks++;
395:       if (i<ndiranks) bas->ndiranks++; /* Note that order of ranks (including distinguished ranks) is kept */
396:       bas->iranks[p]    = iranks[i];
397:       bas->ioffset[p+1] = q;
398:       p++;
399:     }
400:   }
401:   bas->itotal     = q;
402:   bas->nrootreqs  = bas->niranks - bas->ndiranks;
403:   esf->persistent = PETSC_TRUE;
404:   /* Setup packing related fields */
405:   PetscSFSetUpPackFields(esf);

407:   /* Copy from PetscSFSetUp(), since this method wants to skip PetscSFSetUp(). */
408: #if defined(PETSC_HAVE_CUDA)
409:   if (esf->backend == PETSCSF_BACKEND_CUDA) {
410:     esf->ops->Malloc = PetscSFMalloc_CUDA;
411:     esf->ops->Free   = PetscSFFree_CUDA;
412:   }
413: #endif

415: #if defined(PETSC_HAVE_HIP)
416:   /* TODO: Needs debugging */
417:   if (esf->backend == PETSCSF_BACKEND_HIP) {
418:     esf->ops->Malloc = PetscSFMalloc_HIP;
419:     esf->ops->Free   = PetscSFFree_HIP;
420:   }
421: #endif

423: #if defined(PETSC_HAVE_KOKKOS)
424:   if (esf->backend == PETSCSF_BACKEND_KOKKOS) {
425:     esf->ops->Malloc = PetscSFMalloc_Kokkos;
426:     esf->ops->Free   = PetscSFFree_Kokkos;
427:   }
428: #endif
429:   esf->setupcalled = PETSC_TRUE; /* We have done setup ourselves! */
430:   PetscFree2(rootdata,leafmem);
431:   *newsf = esf;
432:   return(0);
433: }

435: PETSC_EXTERN PetscErrorCode PetscSFCreate_Basic(PetscSF sf)
436: {
437:   PetscSF_Basic  *dat;

441:   sf->ops->SetUp                = PetscSFSetUp_Basic;
442:   sf->ops->Reset                = PetscSFReset_Basic;
443:   sf->ops->Destroy              = PetscSFDestroy_Basic;
444:   sf->ops->View                 = PetscSFView_Basic;
445:   sf->ops->BcastBegin           = PetscSFBcastBegin_Basic;
446:   sf->ops->BcastEnd             = PetscSFBcastEnd_Basic;
447:   sf->ops->ReduceBegin          = PetscSFReduceBegin_Basic;
448:   sf->ops->ReduceEnd            = PetscSFReduceEnd_Basic;
449:   sf->ops->FetchAndOpBegin      = PetscSFFetchAndOpBegin_Basic;
450:   sf->ops->FetchAndOpEnd        = PetscSFFetchAndOpEnd_Basic;
451:   sf->ops->GetLeafRanks         = PetscSFGetLeafRanks_Basic;
452:   sf->ops->CreateEmbeddedRootSF = PetscSFCreateEmbeddedRootSF_Basic;

454:   PetscNewLog(sf,&dat);
455:   sf->data = (void*)dat;
456:   return(0);
457: }