Actual source code: isltog.c

  1: #define PETSCVEC_DLL

 3:  #include petscvec.h
 4:  #include include/private/isimpl.h

  6: PetscCookie  IS_LTOGM_COOKIE = 0;

 10: /*@C
 11:     ISLocalToGlobalMappingGetSize - Gets the local size of a local to global mapping.

 13:     Not Collective

 15:     Input Parameter:
 16: .   ltog - local to global mapping

 18:     Output Parameter:
 19: .   n - the number of entries in the local mapping

 21:     Level: advanced

 23:     Concepts: mapping^local to global

 25: .seealso: ISLocalToGlobalMappingDestroy(), ISLocalToGlobalMappingCreate()
 26: @*/
 27: PetscErrorCode  ISLocalToGlobalMappingGetSize(ISLocalToGlobalMapping mapping,PetscInt *n)
 28: {
 32:   *n = mapping->n;
 33:   return(0);
 34: }

 38: /*@C
 39:     ISLocalToGlobalMappingView - View a local to global mapping

 41:     Not Collective

 43:     Input Parameters:
 44: +   ltog - local to global mapping
 45: -   viewer - viewer

 47:     Level: advanced

 49:     Concepts: mapping^local to global

 51: .seealso: ISLocalToGlobalMappingDestroy(), ISLocalToGlobalMappingCreate()
 52: @*/
 53: PetscErrorCode  ISLocalToGlobalMappingView(ISLocalToGlobalMapping mapping,PetscViewer viewer)
 54: {
 55:   PetscInt        i;
 56:   PetscMPIInt     rank;
 57:   PetscTruth      iascii;
 58:   PetscErrorCode  ierr;

 62:   if (!viewer) {
 63:     PetscViewerASCIIGetStdout(((PetscObject)mapping)->comm,&viewer);
 64:   }

 67:   MPI_Comm_rank(((PetscObject)mapping)->comm,&rank);
 68:   PetscTypeCompare((PetscObject)viewer,PETSC_VIEWER_ASCII,&iascii);
 69:   if (iascii) {
 70:     for (i=0; i<mapping->n; i++) {
 71:       PetscViewerASCIISynchronizedPrintf(viewer,"[%d] %d %d\n",rank,i,mapping->indices[i]);
 72:     }
 73:     PetscViewerFlush(viewer);
 74:   } else {
 75:     SETERRQ1(PETSC_ERR_SUP,"Viewer type %s not supported for ISLocalToGlobalMapping",((PetscObject)viewer)->type_name);
 76:   }

 78:   return(0);
 79: }

 83: /*@
 84:     ISLocalToGlobalMappingCreateIS - Creates a mapping between a local (0 to n)
 85:     ordering and a global parallel ordering.

 87:     Not collective

 89:     Input Parameter:
 90: .   is - index set containing the global numbers for each local

 92:     Output Parameter:
 93: .   mapping - new mapping data structure

 95:     Level: advanced

 97:     Concepts: mapping^local to global

 99: .seealso: ISLocalToGlobalMappingDestroy(), ISLocalToGlobalMappingCreate()
100: @*/
101: PetscErrorCode  ISLocalToGlobalMappingCreateIS(IS is,ISLocalToGlobalMapping *mapping)
102: {
104:   PetscInt       n,*indices;
105:   MPI_Comm       comm;


111:   PetscObjectGetComm((PetscObject)is,&comm);
112:   ISGetLocalSize(is,&n);
113:   ISGetIndices(is,&indices);
114:   ISLocalToGlobalMappingCreate(comm,n,indices,mapping);
115:   ISRestoreIndices(is,&indices);

117:   return(0);
118: }


123: /*@
124:     ISLocalToGlobalMappingCreate - Creates a mapping between a local (0 to n)
125:     ordering and a global parallel ordering.

127:     Not Collective, but communicator may have more than one process

129:     Input Parameters:
130: +   comm - MPI communicator
131: .   n - the number of local elements
132: -   indices - the global index for each local element

134:     Output Parameter:
135: .   mapping - new mapping data structure

137:     Level: advanced

139:     Concepts: mapping^local to global

141: .seealso: ISLocalToGlobalMappingDestroy(), ISLocalToGlobalMappingCreateIS(), ISLocalToGlobalMappingCreateNC()
142: @*/
143: PetscErrorCode  ISLocalToGlobalMappingCreate(MPI_Comm cm,PetscInt n,const PetscInt indices[],ISLocalToGlobalMapping *mapping)
144: {
146:   PetscInt       *in;

151:   PetscMalloc(n*sizeof(PetscInt),&in);
152:   PetscMemcpy(in,indices,n*sizeof(PetscInt));
153:   ISLocalToGlobalMappingCreateNC(cm,n,in,mapping);
154:   return(0);
155: }

159: /*@C
160:     ISLocalToGlobalMappingCreateNC - Creates a mapping between a local (0 to n)
161:     ordering and a global parallel ordering.

163:     Not Collective, but communicator may have more than one process

165:     Input Parameters:
166: +   comm - MPI communicator
167: .   n - the number of local elements
168: -   indices - the global index for each local element

170:     Output Parameter:
171: .   mapping - new mapping data structure

173:     Level: developer

175:     Notes: Does not copy the indices, just keeps the pointer to the indices. The ISLocalToGlobalMappingDestroy()
176:     will free the space so it must be obtained with PetscMalloc() and it must not be freed elsewhere.

178:     Concepts: mapping^local to global

180: .seealso: ISLocalToGlobalMappingDestroy(), ISLocalToGlobalMappingCreateIS(), ISLocalToGlobalMappingCreate()
181: @*/
182: PetscErrorCode  ISLocalToGlobalMappingCreateNC(MPI_Comm cm,PetscInt n,const PetscInt indices[],ISLocalToGlobalMapping *mapping)
183: {

189:   *mapping = PETSC_NULL;
190: #ifndef PETSC_USE_DYNAMIC_LIBRARIES
191:   ISInitializePackage(PETSC_NULL);
192: #endif

194:   PetscHeaderCreate(*mapping,_p_ISLocalToGlobalMapping,int,IS_LTOGM_COOKIE,0,"ISLocalToGlobalMapping",
195:                            cm,ISLocalToGlobalMappingDestroy,ISLocalToGlobalMappingView);

197:   (*mapping)->n       = n;
198:   (*mapping)->indices = (PetscInt*)indices;
199:   PetscLogObjectMemory(*mapping,n*sizeof(PetscInt));

201:   /*
202:     Do not create the global to local mapping. This is only created if 
203:     ISGlobalToLocalMapping() is called 
204:   */
205:   (*mapping)->globals = 0;
206:   return(0);
207: }

211: /*@
212:     ISLocalToGlobalMappingBlock - Creates a blocked index version of an 
213:        ISLocalToGlobalMapping that is appropriate for MatSetLocalToGlobalMappingBlock()
214:        and VecSetLocalToGlobalMappingBlock().

216:     Not Collective, but communicator may have more than one process

218:     Input Parameters:
219: +    inmap - original point-wise mapping
220: -    bs - block size

222:     Output Parameter:
223: .   outmap - block based mapping; the indices are relative to BLOCKS, not individual vector or matrix entries.

225:     Level: advanced

227:     Concepts: mapping^local to global

229: .seealso: ISLocalToGlobalMappingDestroy(), ISLocalToGlobalMappingCreate(), ISLocalToGlobalMappingCreateIS()
230: @*/
231: PetscErrorCode  ISLocalToGlobalMappingBlock(ISLocalToGlobalMapping inmap,PetscInt bs,ISLocalToGlobalMapping *outmap)
232: {
234:   PetscInt       *ii,i,n;

239:   if (bs > 1) {
240:     n    = inmap->n/bs;
241:     if (n*bs != inmap->n) SETERRQ(PETSC_ERR_ARG_INCOMP,"Pointwise mapping length is not divisible by block size");
242:     PetscMalloc(n*sizeof(PetscInt),&ii);
243:     for (i=0; i<n; i++) {
244:       ii[i] = inmap->indices[bs*i]/bs;
245:     }
246:     ISLocalToGlobalMappingCreate(((PetscObject)inmap)->comm,n,ii,outmap);
247:     PetscFree(ii);
248:   } else {
249:     PetscObjectReference((PetscObject)inmap);
250:     *outmap = inmap;
251:   }
252:   return(0);
253: }
254: 
257: /*@
258:    ISLocalToGlobalMappingDestroy - Destroys a mapping between a local (0 to n)
259:    ordering and a global parallel ordering.

261:    Note Collective

263:    Input Parameters:
264: .  mapping - mapping data structure

266:    Level: advanced

268: .seealso: ISLocalToGlobalMappingCreate()
269: @*/
270: PetscErrorCode  ISLocalToGlobalMappingDestroy(ISLocalToGlobalMapping mapping)
271: {
275:   if (--((PetscObject)mapping)->refct > 0) return(0);
276:   PetscFree(mapping->indices);
277:   PetscFree(mapping->globals);
278:   PetscHeaderDestroy(mapping);
279:   return(0);
280: }
281: 
284: /*@
285:     ISLocalToGlobalMappingApplyIS - Creates from an IS in the local numbering
286:     a new index set using the global numbering defined in an ISLocalToGlobalMapping
287:     context.

289:     Not collective

291:     Input Parameters:
292: +   mapping - mapping between local and global numbering
293: -   is - index set in local numbering

295:     Output Parameters:
296: .   newis - index set in global numbering

298:     Level: advanced

300:     Concepts: mapping^local to global

302: .seealso: ISLocalToGlobalMappingApply(), ISLocalToGlobalMappingCreate(),
303:           ISLocalToGlobalMappingDestroy(), ISGlobalToLocalMappingApply()
304: @*/
305: PetscErrorCode  ISLocalToGlobalMappingApplyIS(ISLocalToGlobalMapping mapping,IS is,IS *newis)
306: {
308:   PetscInt       n,i,*idxin,*idxmap,*idxout,Nmax = mapping->n;


315:   ISGetLocalSize(is,&n);
316:   ISGetIndices(is,&idxin);
317:   idxmap = mapping->indices;
318: 
319:   PetscMalloc(n*sizeof(PetscInt),&idxout);
320:   for (i=0; i<n; i++) {
321:     if (idxin[i] >= Nmax) SETERRQ3(PETSC_ERR_ARG_OUTOFRANGE,"Local index %d too large %d (max) at %d",idxin[i],Nmax-1,i);
322:     idxout[i] = idxmap[idxin[i]];
323:   }
324:   ISRestoreIndices(is,&idxin);
325:   ISCreateGeneralNC(PETSC_COMM_SELF,n,idxout,newis);
326:   return(0);
327: }

329: /*MC
330:    ISLocalToGlobalMappingApply - Takes a list of integers in a local numbering
331:    and converts them to the global numbering.

333:    Not collective

335:    Input Parameters:
336: +  mapping - the local to global mapping context
337: .  N - number of integers
338: -  in - input indices in local numbering

340:    Output Parameter:
341: .  out - indices in global numbering

343:    Synopsis:
344:    PetscErrorCode ISLocalToGlobalMappingApply(ISLocalToGlobalMapping mapping,int N,int in[],int out[])

346:    Notes: 
347:    The in and out array parameters may be identical.

349:    Level: advanced

351: .seealso: ISLocalToGlobalMappingCreate(),ISLocalToGlobalMappingDestroy(), 
352:           ISLocalToGlobalMappingApplyIS(),AOCreateBasic(),AOApplicationToPetsc(),
353:           AOPetscToApplication(), ISGlobalToLocalMappingApply()

355:     Concepts: mapping^local to global

357: M*/

359: /* -----------------------------------------------------------------------------------------*/

363: /*
364:     Creates the global fields in the ISLocalToGlobalMapping structure
365: */
366: static PetscErrorCode ISGlobalToLocalMappingSetUp_Private(ISLocalToGlobalMapping mapping)
367: {
369:   PetscInt       i,*idx = mapping->indices,n = mapping->n,end,start,*globals;

372:   end   = 0;
373:   start = 100000000;

375:   for (i=0; i<n; i++) {
376:     if (idx[i] < 0) continue;
377:     if (idx[i] < start) start = idx[i];
378:     if (idx[i] > end)   end   = idx[i];
379:   }
380:   if (start > end) {start = 0; end = -1;}
381:   mapping->globalstart = start;
382:   mapping->globalend   = end;

384:   PetscMalloc((end-start+2)*sizeof(PetscInt),&globals);
385:   mapping->globals = globals;
386:   for (i=0; i<end-start+1; i++) {
387:     globals[i] = -1;
388:   }
389:   for (i=0; i<n; i++) {
390:     if (idx[i] < 0) continue;
391:     globals[idx[i] - start] = i;
392:   }

394:   PetscLogObjectMemory(mapping,(end-start+1)*sizeof(PetscInt));
395:   return(0);
396: }

400: /*@
401:     ISGlobalToLocalMappingApply - Provides the local numbering for a list of integers
402:     specified with a global numbering.

404:     Not collective

406:     Input Parameters:
407: +   mapping - mapping between local and global numbering
408: .   type - IS_GTOLM_MASK - replaces global indices with no local value with -1
409:            IS_GTOLM_DROP - drops the indices with no local value from the output list
410: .   n - number of global indices to map
411: -   idx - global indices to map

413:     Output Parameters:
414: +   nout - number of indices in output array (if type == IS_GTOLM_MASK then nout = n)
415: -   idxout - local index of each global index, one must pass in an array long enough 
416:              to hold all the indices. You can call ISGlobalToLocalMappingApply() with 
417:              idxout == PETSC_NULL to determine the required length (returned in nout)
418:              and then allocate the required space and call ISGlobalToLocalMappingApply()
419:              a second time to set the values.

421:     Notes:
422:     Either nout or idxout may be PETSC_NULL. idx and idxout may be identical.

424:     This is not scalable in memory usage. Each processor requires O(Nglobal) size 
425:     array to compute these.

427:     Level: advanced

429:     Concepts: mapping^global to local

431: .seealso: ISLocalToGlobalMappingApply(), ISLocalToGlobalMappingCreate(),
432:           ISLocalToGlobalMappingDestroy()
433: @*/
434: PetscErrorCode  ISGlobalToLocalMappingApply(ISLocalToGlobalMapping mapping,ISGlobalToLocalMappingType type,
435:                                   PetscInt n,const PetscInt idx[],PetscInt *nout,PetscInt idxout[])
436: {
437:   PetscInt       i,*globals,nf = 0,tmp,start,end;

442:   if (!mapping->globals) {
443:     ISGlobalToLocalMappingSetUp_Private(mapping);
444:   }
445:   globals = mapping->globals;
446:   start   = mapping->globalstart;
447:   end     = mapping->globalend;

449:   if (type == IS_GTOLM_MASK) {
450:     if (idxout) {
451:       for (i=0; i<n; i++) {
452:         if (idx[i] < 0) idxout[i] = idx[i];
453:         else if (idx[i] < start) idxout[i] = -1;
454:         else if (idx[i] > end)   idxout[i] = -1;
455:         else                     idxout[i] = globals[idx[i] - start];
456:       }
457:     }
458:     if (nout) *nout = n;
459:   } else {
460:     if (idxout) {
461:       for (i=0; i<n; i++) {
462:         if (idx[i] < 0) continue;
463:         if (idx[i] < start) continue;
464:         if (idx[i] > end) continue;
465:         tmp = globals[idx[i] - start];
466:         if (tmp < 0) continue;
467:         idxout[nf++] = tmp;
468:       }
469:     } else {
470:       for (i=0; i<n; i++) {
471:         if (idx[i] < 0) continue;
472:         if (idx[i] < start) continue;
473:         if (idx[i] > end) continue;
474:         tmp = globals[idx[i] - start];
475:         if (tmp < 0) continue;
476:         nf++;
477:       }
478:     }
479:     if (nout) *nout = nf;
480:   }

482:   return(0);
483: }

487: /*@C
488:     ISLocalToGlobalMappingGetInfo - Gets the neighbor information for each processor and 
489:      each index shared by more than one processor 

491:     Collective on ISLocalToGlobalMapping

493:     Input Parameters:
494: .   mapping - the mapping from local to global indexing

496:     Output Parameter:
497: +   nproc - number of processors that are connected to this one
498: .   proc - neighboring processors
499: .   numproc - number of indices for each subdomain (processor)
500: -   indices - indices of local nodes shared with neighbor (sorted by global numbering)

502:     Level: advanced

504:     Concepts: mapping^local to global

506:     Fortran Usage: 
507: $        ISLocalToGlobalMpngGetInfoSize(ISLocalToGlobalMapping,PetscInt nproc,PetscInt numprocmax,ierr) followed by 
508: $        ISLocalToGlobalMappingGetInfo(ISLocalToGlobalMapping,PetscInt nproc, PetscInt procs[nproc],PetscInt numprocs[nproc],
509:           PetscInt indices[nproc][numprocmax],ierr)
510:         There is no ISLocalToGlobalMappingRestoreInfo() in Fortran. You must make sure that procs[], numprocs[] and 
511:         indices[][] are large enough arrays, either by allocating them dynamically or defining static ones large enough.


514: .seealso: ISLocalToGlobalMappingDestroy(), ISLocalToGlobalMappingCreateIS(), ISLocalToGlobalMappingCreate(),
515:           ISLocalToGlobalMappingRestoreInfo()
516: @*/
517: PetscErrorCode  ISLocalToGlobalMappingGetInfo(ISLocalToGlobalMapping mapping,PetscInt *nproc,PetscInt *procs[],PetscInt *numprocs[],PetscInt **indices[])
518: {
520:   PetscMPIInt    size,rank,tag1,tag2,tag3,*len,*source,imdex;
521:   PetscInt       i,n = mapping->n,Ng,ng,max = 0,*lindices = mapping->indices;
522:   PetscInt       *nprocs,*owner,nsends,*sends,j,*starts,nmax,nrecvs,*recvs,proc;
523:   PetscInt       cnt,scale,*ownedsenders,*nownedsenders,rstart,nowned;
524:   PetscInt       node,nownedm,nt,*sends2,nsends2,*starts2,*lens2,*dest,nrecvs2,*starts3,*recvs2,k,*bprocs,*tmp;
525:   PetscInt       first_procs,first_numprocs,*first_indices;
526:   MPI_Request    *recv_waits,*send_waits;
527:   MPI_Status     recv_status,*send_status,*recv_statuses;
528:   MPI_Comm       comm = ((PetscObject)mapping)->comm;
529:   PetscTruth     debug = PETSC_FALSE;

533:   MPI_Comm_size(comm,&size);
534:   MPI_Comm_rank(comm,&rank);
535:   if (size == 1) {
536:     *nproc         = 0;
537:     *procs         = PETSC_NULL;
538:     PetscMalloc(sizeof(PetscInt),numprocs);
539:     (*numprocs)[0] = 0;
540:     PetscMalloc(sizeof(PetscInt*),indices);
541:     (*indices)[0]  = PETSC_NULL;
542:     return(0);
543:   }

545:   PetscOptionsHasName(PETSC_NULL,"-islocaltoglobalmappinggetinfo_debug",&debug);

547:   /*
548:     Notes on ISLocalToGlobalMappingGetInfo

550:     globally owned node - the nodes that have been assigned to this processor in global
551:            numbering, just for this routine.

553:     nontrivial globally owned node - node assigned to this processor that is on a subdomain
554:            boundary (i.e. is has more than one local owner)

556:     locally owned node - node that exists on this processors subdomain

558:     nontrivial locally owned node - node that is not in the interior (i.e. has more than one
559:            local subdomain
560:   */
561:   PetscObjectGetNewTag((PetscObject)mapping,&tag1);
562:   PetscObjectGetNewTag((PetscObject)mapping,&tag2);
563:   PetscObjectGetNewTag((PetscObject)mapping,&tag3);

565:   for (i=0; i<n; i++) {
566:     if (lindices[i] > max) max = lindices[i];
567:   }
568:   MPI_Allreduce(&max,&Ng,1,MPIU_INT,MPI_MAX,comm);
569:   Ng++;
570:   MPI_Comm_size(comm,&size);
571:   MPI_Comm_rank(comm,&rank);
572:   scale  = Ng/size + 1;
573:   ng     = scale; if (rank == size-1) ng = Ng - scale*(size-1); ng = PetscMax(1,ng);
574:   rstart = scale*rank;

576:   /* determine ownership ranges of global indices */
577:   PetscMalloc(2*size*sizeof(PetscInt),&nprocs);
578:   PetscMemzero(nprocs,2*size*sizeof(PetscInt));

580:   /* determine owners of each local node  */
581:   PetscMalloc(n*sizeof(PetscInt),&owner);
582:   for (i=0; i<n; i++) {
583:     proc             = lindices[i]/scale; /* processor that globally owns this index */
584:     nprocs[2*proc+1] = 1;                 /* processor globally owns at least one of ours */
585:     owner[i]         = proc;
586:     nprocs[2*proc]++;                     /* count of how many that processor globally owns of ours */
587:   }
588:   nsends = 0; for (i=0; i<size; i++) nsends += nprocs[2*i+1];
589:   PetscInfo1(mapping,"Number of global owners for my local data %d\n",nsends);

591:   /* inform other processors of number of messages and max length*/
592:   PetscMaxSum(comm,nprocs,&nmax,&nrecvs);
593:   PetscInfo1(mapping,"Number of local owners for my global data %d\n",nrecvs);

595:   /* post receives for owned rows */
596:   PetscMalloc((2*nrecvs+1)*(nmax+1)*sizeof(PetscInt),&recvs);
597:   PetscMalloc((nrecvs+1)*sizeof(MPI_Request),&recv_waits);
598:   for (i=0; i<nrecvs; i++) {
599:     MPI_Irecv(recvs+2*nmax*i,2*nmax,MPIU_INT,MPI_ANY_SOURCE,tag1,comm,recv_waits+i);
600:   }

602:   /* pack messages containing lists of local nodes to owners */
603:   PetscMalloc((2*n+1)*sizeof(PetscInt),&sends);
604:   PetscMalloc((size+1)*sizeof(PetscInt),&starts);
605:   starts[0]  = 0;
606:   for (i=1; i<size; i++) { starts[i] = starts[i-1] + 2*nprocs[2*i-2];}
607:   for (i=0; i<n; i++) {
608:     sends[starts[owner[i]]++] = lindices[i];
609:     sends[starts[owner[i]]++] = i;
610:   }
611:   PetscFree(owner);
612:   starts[0]  = 0;
613:   for (i=1; i<size; i++) { starts[i] = starts[i-1] + 2*nprocs[2*i-2];}

615:   /* send the messages */
616:   PetscMalloc((nsends+1)*sizeof(MPI_Request),&send_waits);
617:   PetscMalloc((nsends+1)*sizeof(PetscInt),&dest);
618:   cnt = 0;
619:   for (i=0; i<size; i++) {
620:     if (nprocs[2*i]) {
621:       MPI_Isend(sends+starts[i],2*nprocs[2*i],MPIU_INT,i,tag1,comm,send_waits+cnt);
622:       dest[cnt] = i;
623:       cnt++;
624:     }
625:   }
626:   PetscFree(starts);

628:   /* wait on receives */
629:   PetscMalloc((nrecvs+1)*sizeof(PetscMPIInt),&source);
630:   PetscMalloc((nrecvs+1)*sizeof(PetscMPIInt),&len);
631:   cnt  = nrecvs;
632:   PetscMalloc((ng+1)*sizeof(PetscInt),&nownedsenders);
633:   PetscMemzero(nownedsenders,ng*sizeof(PetscInt));
634:   while (cnt) {
635:     MPI_Waitany(nrecvs,recv_waits,&imdex,&recv_status);
636:     /* unpack receives into our local space */
637:     MPI_Get_count(&recv_status,MPIU_INT,&len[imdex]);
638:     source[imdex]  = recv_status.MPI_SOURCE;
639:     len[imdex]     = len[imdex]/2;
640:     /* count how many local owners for each of my global owned indices */
641:     for (i=0; i<len[imdex]; i++) nownedsenders[recvs[2*imdex*nmax+2*i]-rstart]++;
642:     cnt--;
643:   }
644:   PetscFree(recv_waits);

646:   /* count how many globally owned indices are on an edge multiplied by how many processors own them. */
647:   nowned  = 0;
648:   nownedm = 0;
649:   for (i=0; i<ng; i++) {
650:     if (nownedsenders[i] > 1) {nownedm += nownedsenders[i]; nowned++;}
651:   }

653:   /* create single array to contain rank of all local owners of each globally owned index */
654:   PetscMalloc((nownedm+1)*sizeof(PetscInt),&ownedsenders);
655:   PetscMalloc((ng+1)*sizeof(PetscInt),&starts);
656:   starts[0] = 0;
657:   for (i=1; i<ng; i++) {
658:     if (nownedsenders[i-1] > 1) starts[i] = starts[i-1] + nownedsenders[i-1];
659:     else starts[i] = starts[i-1];
660:   }

662:   /* for each nontrival globally owned node list all arriving processors */
663:   for (i=0; i<nrecvs; i++) {
664:     for (j=0; j<len[i]; j++) {
665:       node = recvs[2*i*nmax+2*j]-rstart;
666:       if (nownedsenders[node] > 1) {
667:         ownedsenders[starts[node]++] = source[i];
668:       }
669:     }
670:   }

672:   if (debug) { /* -----------------------------------  */
673:     starts[0]    = 0;
674:     for (i=1; i<ng; i++) {
675:       if (nownedsenders[i-1] > 1) starts[i] = starts[i-1] + nownedsenders[i-1];
676:       else starts[i] = starts[i-1];
677:     }
678:     for (i=0; i<ng; i++) {
679:       if (nownedsenders[i] > 1) {
680:         PetscSynchronizedPrintf(comm,"[%d] global node %d local owner processors: ",rank,i+rstart);
681:         for (j=0; j<nownedsenders[i]; j++) {
682:           PetscSynchronizedPrintf(comm,"%d ",ownedsenders[starts[i]+j]);
683:         }
684:         PetscSynchronizedPrintf(comm,"\n");
685:       }
686:     }
687:     PetscSynchronizedFlush(comm);
688:   }/* -----------------------------------  */

690:   /* wait on original sends */
691:   if (nsends) {
692:     PetscMalloc(nsends*sizeof(MPI_Status),&send_status);
693:     MPI_Waitall(nsends,send_waits,send_status);
694:     PetscFree(send_status);
695:   }
696:   PetscFree(send_waits);
697:   PetscFree(sends);
698:   PetscFree(nprocs);

700:   /* pack messages to send back to local owners */
701:   starts[0]    = 0;
702:   for (i=1; i<ng; i++) {
703:     if (nownedsenders[i-1] > 1) starts[i] = starts[i-1] + nownedsenders[i-1];
704:     else starts[i] = starts[i-1];
705:   }
706:   nsends2 = nrecvs;
707:   PetscMalloc((nsends2+1)*sizeof(PetscInt),&nprocs); /* length of each message */
708:   for (i=0; i<nrecvs; i++) {
709:     nprocs[i] = 1;
710:     for (j=0; j<len[i]; j++) {
711:       node = recvs[2*i*nmax+2*j]-rstart;
712:       if (nownedsenders[node] > 1) {
713:         nprocs[i] += 2 + nownedsenders[node];
714:       }
715:     }
716:   }
717:   nt = 0; for (i=0; i<nsends2; i++) nt += nprocs[i];
718:   PetscMalloc((nt+1)*sizeof(PetscInt),&sends2);
719:   PetscMalloc((nsends2+1)*sizeof(PetscInt),&starts2);
720:   starts2[0] = 0; for (i=1; i<nsends2; i++) starts2[i] = starts2[i-1] + nprocs[i-1];
721:   /*
722:      Each message is 1 + nprocs[i] long, and consists of 
723:        (0) the number of nodes being sent back 
724:        (1) the local node number,
725:        (2) the number of processors sharing it,
726:        (3) the processors sharing it
727:   */
728:   for (i=0; i<nsends2; i++) {
729:     cnt = 1;
730:     sends2[starts2[i]] = 0;
731:     for (j=0; j<len[i]; j++) {
732:       node = recvs[2*i*nmax+2*j]-rstart;
733:       if (nownedsenders[node] > 1) {
734:         sends2[starts2[i]]++;
735:         sends2[starts2[i]+cnt++] = recvs[2*i*nmax+2*j+1];
736:         sends2[starts2[i]+cnt++] = nownedsenders[node];
737:         PetscMemcpy(&sends2[starts2[i]+cnt],&ownedsenders[starts[node]],nownedsenders[node]*sizeof(PetscInt));
738:         cnt += nownedsenders[node];
739:       }
740:     }
741:   }

743:   /* receive the message lengths */
744:   nrecvs2 = nsends;
745:   PetscMalloc((nrecvs2+1)*sizeof(PetscInt),&lens2);
746:   PetscMalloc((nrecvs2+1)*sizeof(PetscInt),&starts3);
747:   PetscMalloc((nrecvs2+1)*sizeof(MPI_Request),&recv_waits);
748:   for (i=0; i<nrecvs2; i++) {
749:     MPI_Irecv(&lens2[i],1,MPIU_INT,dest[i],tag2,comm,recv_waits+i);
750:   }

752:   /* send the message lengths */
753:   for (i=0; i<nsends2; i++) {
754:     MPI_Send(&nprocs[i],1,MPIU_INT,source[i],tag2,comm);
755:   }

757:   /* wait on receives of lens */
758:   if (nrecvs2) {
759:     PetscMalloc(nrecvs2*sizeof(MPI_Status),&recv_statuses);
760:     MPI_Waitall(nrecvs2,recv_waits,recv_statuses);
761:     PetscFree(recv_statuses);
762:   }
763:   PetscFree(recv_waits);

765:   starts3[0] = 0;
766:   nt         = 0;
767:   for (i=0; i<nrecvs2-1; i++) {
768:     starts3[i+1] = starts3[i] + lens2[i];
769:     nt          += lens2[i];
770:   }
771:   nt += lens2[nrecvs2-1];

773:   PetscMalloc((nt+1)*sizeof(PetscInt),&recvs2);
774:   PetscMalloc((nrecvs2+1)*sizeof(MPI_Request),&recv_waits);
775:   for (i=0; i<nrecvs2; i++) {
776:     MPI_Irecv(recvs2+starts3[i],lens2[i],MPIU_INT,dest[i],tag3,comm,recv_waits+i);
777:   }
778: 
779:   /* send the messages */
780:   PetscMalloc((nsends2+1)*sizeof(MPI_Request),&send_waits);
781:   for (i=0; i<nsends2; i++) {
782:     MPI_Isend(sends2+starts2[i],nprocs[i],MPIU_INT,source[i],tag3,comm,send_waits+i);
783:   }

785:   /* wait on receives */
786:   if (nrecvs2) {
787:     PetscMalloc(nrecvs2*sizeof(MPI_Status),&recv_statuses);
788:     MPI_Waitall(nrecvs2,recv_waits,recv_statuses);
789:     PetscFree(recv_statuses);
790:   }
791:   PetscFree(recv_waits);
792:   PetscFree(nprocs);

794:   if (debug) { /* -----------------------------------  */
795:     cnt = 0;
796:     for (i=0; i<nrecvs2; i++) {
797:       nt = recvs2[cnt++];
798:       for (j=0; j<nt; j++) {
799:         PetscSynchronizedPrintf(comm,"[%d] local node %d number of subdomains %d: ",rank,recvs2[cnt],recvs2[cnt+1]);
800:         for (k=0; k<recvs2[cnt+1]; k++) {
801:           PetscSynchronizedPrintf(comm,"%d ",recvs2[cnt+2+k]);
802:         }
803:         cnt += 2 + recvs2[cnt+1];
804:         PetscSynchronizedPrintf(comm,"\n");
805:       }
806:     }
807:     PetscSynchronizedFlush(comm);
808:   } /* -----------------------------------  */

810:   /* count number subdomains for each local node */
811:   PetscMalloc(size*sizeof(PetscInt),&nprocs);
812:   PetscMemzero(nprocs,size*sizeof(PetscInt));
813:   cnt  = 0;
814:   for (i=0; i<nrecvs2; i++) {
815:     nt = recvs2[cnt++];
816:     for (j=0; j<nt; j++) {
817:       for (k=0; k<recvs2[cnt+1]; k++) {
818:         nprocs[recvs2[cnt+2+k]]++;
819:       }
820:       cnt += 2 + recvs2[cnt+1];
821:     }
822:   }
823:   nt = 0; for (i=0; i<size; i++) nt += (nprocs[i] > 0);
824:   *nproc    = nt;
825:   PetscMalloc((nt+1)*sizeof(PetscInt),procs);
826:   PetscMalloc((nt+1)*sizeof(PetscInt),numprocs);
827:   PetscMalloc((nt+1)*sizeof(PetscInt*),indices);
828:   PetscMalloc(size*sizeof(PetscInt),&bprocs);
829:   cnt       = 0;
830:   for (i=0; i<size; i++) {
831:     if (nprocs[i] > 0) {
832:       bprocs[i]        = cnt;
833:       (*procs)[cnt]    = i;
834:       (*numprocs)[cnt] = nprocs[i];
835:       PetscMalloc(nprocs[i]*sizeof(PetscInt),&(*indices)[cnt]);
836:       cnt++;
837:     }
838:   }

840:   /* make the list of subdomains for each nontrivial local node */
841:   PetscMemzero(*numprocs,nt*sizeof(PetscInt));
842:   cnt  = 0;
843:   for (i=0; i<nrecvs2; i++) {
844:     nt = recvs2[cnt++];
845:     for (j=0; j<nt; j++) {
846:       for (k=0; k<recvs2[cnt+1]; k++) {
847:         (*indices)[bprocs[recvs2[cnt+2+k]]][(*numprocs)[bprocs[recvs2[cnt+2+k]]]++] = recvs2[cnt];
848:       }
849:       cnt += 2 + recvs2[cnt+1];
850:     }
851:   }
852:   PetscFree(bprocs);
853:   PetscFree(recvs2);

855:   /* sort the node indexing by their global numbers */
856:   nt = *nproc;
857:   for (i=0; i<nt; i++) {
858:     PetscMalloc(((*numprocs)[i])*sizeof(PetscInt),&tmp);
859:     for (j=0; j<(*numprocs)[i]; j++) {
860:       tmp[j] = lindices[(*indices)[i][j]];
861:     }
862:     PetscSortIntWithArray((*numprocs)[i],tmp,(*indices)[i]);
863:     PetscFree(tmp);
864:   }

866:   if (debug) { /* -----------------------------------  */
867:     nt = *nproc;
868:     for (i=0; i<nt; i++) {
869:       PetscSynchronizedPrintf(comm,"[%d] subdomain %d number of indices %d: ",rank,(*procs)[i],(*numprocs)[i]);
870:       for (j=0; j<(*numprocs)[i]; j++) {
871:         PetscSynchronizedPrintf(comm,"%d ",(*indices)[i][j]);
872:       }
873:       PetscSynchronizedPrintf(comm,"\n");
874:     }
875:     PetscSynchronizedFlush(comm);
876:   } /* -----------------------------------  */

878:   /* wait on sends */
879:   if (nsends2) {
880:     PetscMalloc(nsends2*sizeof(MPI_Status),&send_status);
881:     MPI_Waitall(nsends2,send_waits,send_status);
882:     PetscFree(send_status);
883:   }

885:   PetscFree(starts3);
886:   PetscFree(dest);
887:   PetscFree(send_waits);

889:   PetscFree(nownedsenders);
890:   PetscFree(ownedsenders);
891:   PetscFree(starts);
892:   PetscFree(starts2);
893:   PetscFree(lens2);

895:   PetscFree(source);
896:   PetscFree(len);
897:   PetscFree(recvs);
898:   PetscFree(nprocs);
899:   PetscFree(sends2);

901:   /* put the information about myself as the first entry in the list */
902:   first_procs    = (*procs)[0];
903:   first_numprocs = (*numprocs)[0];
904:   first_indices  = (*indices)[0];
905:   for (i=0; i<*nproc; i++) {
906:     if ((*procs)[i] == rank) {
907:       (*procs)[0]    = (*procs)[i];
908:       (*numprocs)[0] = (*numprocs)[i];
909:       (*indices)[0]  = (*indices)[i];
910:       (*procs)[i]    = first_procs;
911:       (*numprocs)[i] = first_numprocs;
912:       (*indices)[i]  = first_indices;
913:       break;
914:     }
915:   }
916:   return(0);
917: }

921: /*@C
922:     ISLocalToGlobalMappingRestoreInfo - Frees the memory allocated by ISLocalToGlobalMappingGetInfo()

924:     Collective on ISLocalToGlobalMapping

926:     Input Parameters:
927: .   mapping - the mapping from local to global indexing

929:     Output Parameter:
930: +   nproc - number of processors that are connected to this one
931: .   proc - neighboring processors
932: .   numproc - number of indices for each processor
933: -   indices - indices of local nodes shared with neighbor (sorted by global numbering)

935:     Level: advanced

937: .seealso: ISLocalToGlobalMappingDestroy(), ISLocalToGlobalMappingCreateIS(), ISLocalToGlobalMappingCreate(),
938:           ISLocalToGlobalMappingGetInfo()
939: @*/
940: PetscErrorCode  ISLocalToGlobalMappingRestoreInfo(ISLocalToGlobalMapping mapping,PetscInt *nproc,PetscInt *procs[],PetscInt *numprocs[],PetscInt **indices[])
941: {
943:   PetscInt       i;

946:   PetscFree(*procs);
947:   PetscFree(*numprocs);
948:   if (*indices) {
949:     PetscFree((*indices)[0]);
950:     for (i=1; i<*nproc; i++) {
951:       PetscFree((*indices)[i]);
952:     }
953:     PetscFree(*indices);
954:   }
955:   return(0);
956: }