Actual source code: matstash.c

petsc-3.9.0 2018-04-07
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  2:  #include <petsc/private/matimpl.h>

  4: #define DEFAULT_STASH_SIZE   10000

  6: static PetscErrorCode MatStashScatterBegin_Ref(Mat,MatStash*,PetscInt*);
  7: static PetscErrorCode MatStashScatterGetMesg_Ref(MatStash*,PetscMPIInt*,PetscInt**,PetscInt**,PetscScalar**,PetscInt*);
  8: static PetscErrorCode MatStashScatterEnd_Ref(MatStash*);
  9: #if !defined(PETSC_HAVE_MPIUNI)
 10: static PetscErrorCode MatStashScatterBegin_BTS(Mat,MatStash*,PetscInt*);
 11: static PetscErrorCode MatStashScatterGetMesg_BTS(MatStash*,PetscMPIInt*,PetscInt**,PetscInt**,PetscScalar**,PetscInt*);
 12: static PetscErrorCode MatStashScatterEnd_BTS(MatStash*);
 13: static PetscErrorCode MatStashScatterDestroy_BTS(MatStash*);
 14: #endif

 16: /*
 17:   MatStashCreate_Private - Creates a stash,currently used for all the parallel
 18:   matrix implementations. The stash is where elements of a matrix destined
 19:   to be stored on other processors are kept until matrix assembly is done.

 21:   This is a simple minded stash. Simply adds entries to end of stash.

 23:   Input Parameters:
 24:   comm - communicator, required for scatters.
 25:   bs   - stash block size. used when stashing blocks of values

 27:   Output Parameters:
 28:   stash    - the newly created stash
 29: */
 30: PetscErrorCode MatStashCreate_Private(MPI_Comm comm,PetscInt bs,MatStash *stash)
 31: {
 33:   PetscInt       max,*opt,nopt,i;
 34:   PetscBool      flg;

 37:   /* Require 2 tags,get the second using PetscCommGetNewTag() */
 38:   stash->comm = comm;

 40:   PetscCommGetNewTag(stash->comm,&stash->tag1);
 41:   PetscCommGetNewTag(stash->comm,&stash->tag2);
 42:   MPI_Comm_size(stash->comm,&stash->size);
 43:   MPI_Comm_rank(stash->comm,&stash->rank);
 44:   PetscMalloc1(2*stash->size,&stash->flg_v);
 45:   for (i=0; i<2*stash->size; i++) stash->flg_v[i] = -1;


 48:   nopt = stash->size;
 49:   PetscMalloc1(nopt,&opt);
 50:   PetscOptionsGetIntArray(NULL,NULL,"-matstash_initial_size",opt,&nopt,&flg);
 51:   if (flg) {
 52:     if (nopt == 1)                max = opt[0];
 53:     else if (nopt == stash->size) max = opt[stash->rank];
 54:     else if (stash->rank < nopt)  max = opt[stash->rank];
 55:     else                          max = 0; /* Use default */
 56:     stash->umax = max;
 57:   } else {
 58:     stash->umax = 0;
 59:   }
 60:   PetscFree(opt);
 61:   if (bs <= 0) bs = 1;

 63:   stash->bs         = bs;
 64:   stash->nmax       = 0;
 65:   stash->oldnmax    = 0;
 66:   stash->n          = 0;
 67:   stash->reallocs   = -1;
 68:   stash->space_head = 0;
 69:   stash->space      = 0;

 71:   stash->send_waits  = 0;
 72:   stash->recv_waits  = 0;
 73:   stash->send_status = 0;
 74:   stash->nsends      = 0;
 75:   stash->nrecvs      = 0;
 76:   stash->svalues     = 0;
 77:   stash->rvalues     = 0;
 78:   stash->rindices    = 0;
 79:   stash->nprocessed  = 0;
 80:   stash->reproduce   = PETSC_FALSE;
 81:   stash->blocktype   = MPI_DATATYPE_NULL;

 83:   PetscOptionsGetBool(NULL,NULL,"-matstash_reproduce",&stash->reproduce,NULL);
 84: #if !defined(PETSC_HAVE_MPIUNI)
 85:   PetscOptionsGetBool(NULL,NULL,"-matstash_legacy",&flg,NULL);
 86:   if (!flg) {
 87:     stash->ScatterBegin   = MatStashScatterBegin_BTS;
 88:     stash->ScatterGetMesg = MatStashScatterGetMesg_BTS;
 89:     stash->ScatterEnd     = MatStashScatterEnd_BTS;
 90:     stash->ScatterDestroy = MatStashScatterDestroy_BTS;
 91:   } else {
 92: #endif
 93:     stash->ScatterBegin   = MatStashScatterBegin_Ref;
 94:     stash->ScatterGetMesg = MatStashScatterGetMesg_Ref;
 95:     stash->ScatterEnd     = MatStashScatterEnd_Ref;
 96:     stash->ScatterDestroy = NULL;
 97: #if !defined(PETSC_HAVE_MPIUNI)
 98:   }
 99: #endif
100:   return(0);
101: }

103: /*
104:    MatStashDestroy_Private - Destroy the stash
105: */
106: PetscErrorCode MatStashDestroy_Private(MatStash *stash)
107: {

111:   PetscMatStashSpaceDestroy(&stash->space_head);
112:   if (stash->ScatterDestroy) {(*stash->ScatterDestroy)(stash);}

114:   stash->space = 0;

116:   PetscFree(stash->flg_v);
117:   return(0);
118: }

120: /*
121:    MatStashScatterEnd_Private - This is called as the final stage of
122:    scatter. The final stages of message passing is done here, and
123:    all the memory used for message passing is cleaned up. This
124:    routine also resets the stash, and deallocates the memory used
125:    for the stash. It also keeps track of the current memory usage
126:    so that the same value can be used the next time through.
127: */
128: PetscErrorCode MatStashScatterEnd_Private(MatStash *stash)
129: {

133:   (*stash->ScatterEnd)(stash);
134:   return(0);
135: }

137: static PetscErrorCode MatStashScatterEnd_Ref(MatStash *stash)
138: {
140:   PetscInt       nsends=stash->nsends,bs2,oldnmax,i;
141:   MPI_Status     *send_status;

144:   for (i=0; i<2*stash->size; i++) stash->flg_v[i] = -1;
145:   /* wait on sends */
146:   if (nsends) {
147:     PetscMalloc1(2*nsends,&send_status);
148:     MPI_Waitall(2*nsends,stash->send_waits,send_status);
149:     PetscFree(send_status);
150:   }

152:   /* Now update nmaxold to be app 10% more than max n used, this way the
153:      wastage of space is reduced the next time this stash is used.
154:      Also update the oldmax, only if it increases */
155:   if (stash->n) {
156:     bs2     = stash->bs*stash->bs;
157:     oldnmax = ((int)(stash->n * 1.1) + 5)*bs2;
158:     if (oldnmax > stash->oldnmax) stash->oldnmax = oldnmax;
159:   }

161:   stash->nmax       = 0;
162:   stash->n          = 0;
163:   stash->reallocs   = -1;
164:   stash->nprocessed = 0;

166:   PetscMatStashSpaceDestroy(&stash->space_head);

168:   stash->space = 0;

170:   PetscFree(stash->send_waits);
171:   PetscFree(stash->recv_waits);
172:   PetscFree2(stash->svalues,stash->sindices);
173:   PetscFree(stash->rvalues[0]);
174:   PetscFree(stash->rvalues);
175:   PetscFree(stash->rindices[0]);
176:   PetscFree(stash->rindices);
177:   return(0);
178: }

180: /*
181:    MatStashGetInfo_Private - Gets the relavant statistics of the stash

183:    Input Parameters:
184:    stash    - the stash
185:    nstash   - the size of the stash. Indicates the number of values stored.
186:    reallocs - the number of additional mallocs incurred.

188: */
189: PetscErrorCode MatStashGetInfo_Private(MatStash *stash,PetscInt *nstash,PetscInt *reallocs)
190: {
191:   PetscInt bs2 = stash->bs*stash->bs;

194:   if (nstash) *nstash = stash->n*bs2;
195:   if (reallocs) {
196:     if (stash->reallocs < 0) *reallocs = 0;
197:     else                     *reallocs = stash->reallocs;
198:   }
199:   return(0);
200: }

202: /*
203:    MatStashSetInitialSize_Private - Sets the initial size of the stash

205:    Input Parameters:
206:    stash  - the stash
207:    max    - the value that is used as the max size of the stash.
208:             this value is used while allocating memory.
209: */
210: PetscErrorCode MatStashSetInitialSize_Private(MatStash *stash,PetscInt max)
211: {
213:   stash->umax = max;
214:   return(0);
215: }

217: /* MatStashExpand_Private - Expand the stash. This function is called
218:    when the space in the stash is not sufficient to add the new values
219:    being inserted into the stash.

221:    Input Parameters:
222:    stash - the stash
223:    incr  - the minimum increase requested

225:    Notes:
226:    This routine doubles the currently used memory.
227:  */
228: static PetscErrorCode MatStashExpand_Private(MatStash *stash,PetscInt incr)
229: {
231:   PetscInt       newnmax,bs2= stash->bs*stash->bs;

234:   /* allocate a larger stash */
235:   if (!stash->oldnmax && !stash->nmax) { /* new stash */
236:     if (stash->umax)                  newnmax = stash->umax/bs2;
237:     else                              newnmax = DEFAULT_STASH_SIZE/bs2;
238:   } else if (!stash->nmax) { /* resuing stash */
239:     if (stash->umax > stash->oldnmax) newnmax = stash->umax/bs2;
240:     else                              newnmax = stash->oldnmax/bs2;
241:   } else                              newnmax = stash->nmax*2;
242:   if (newnmax  < (stash->nmax + incr)) newnmax += 2*incr;

244:   /* Get a MatStashSpace and attach it to stash */
245:   PetscMatStashSpaceGet(bs2,newnmax,&stash->space);
246:   if (!stash->space_head) { /* new stash or resuing stash->oldnmax */
247:     stash->space_head = stash->space;
248:   }

250:   stash->reallocs++;
251:   stash->nmax = newnmax;
252:   return(0);
253: }
254: /*
255:   MatStashValuesRow_Private - inserts values into the stash. This function
256:   expects the values to be roworiented. Multiple columns belong to the same row
257:   can be inserted with a single call to this function.

259:   Input Parameters:
260:   stash  - the stash
261:   row    - the global row correspoiding to the values
262:   n      - the number of elements inserted. All elements belong to the above row.
263:   idxn   - the global column indices corresponding to each of the values.
264:   values - the values inserted
265: */
266: PetscErrorCode MatStashValuesRow_Private(MatStash *stash,PetscInt row,PetscInt n,const PetscInt idxn[],const PetscScalar values[],PetscBool ignorezeroentries)
267: {
268:   PetscErrorCode     ierr;
269:   PetscInt           i,k,cnt = 0;
270:   PetscMatStashSpace space=stash->space;

273:   /* Check and see if we have sufficient memory */
274:   if (!space || space->local_remaining < n) {
275:     MatStashExpand_Private(stash,n);
276:   }
277:   space = stash->space;
278:   k     = space->local_used;
279:   for (i=0; i<n; i++) {
280:     if (ignorezeroentries && (values[i] == 0.0)) continue;
281:     space->idx[k] = row;
282:     space->idy[k] = idxn[i];
283:     space->val[k] = values[i];
284:     k++;
285:     cnt++;
286:   }
287:   stash->n               += cnt;
288:   space->local_used      += cnt;
289:   space->local_remaining -= cnt;
290:   return(0);
291: }

293: /*
294:   MatStashValuesCol_Private - inserts values into the stash. This function
295:   expects the values to be columnoriented. Multiple columns belong to the same row
296:   can be inserted with a single call to this function.

298:   Input Parameters:
299:   stash   - the stash
300:   row     - the global row correspoiding to the values
301:   n       - the number of elements inserted. All elements belong to the above row.
302:   idxn    - the global column indices corresponding to each of the values.
303:   values  - the values inserted
304:   stepval - the consecutive values are sepated by a distance of stepval.
305:             this happens because the input is columnoriented.
306: */
307: PetscErrorCode MatStashValuesCol_Private(MatStash *stash,PetscInt row,PetscInt n,const PetscInt idxn[],const PetscScalar values[],PetscInt stepval,PetscBool ignorezeroentries)
308: {
309:   PetscErrorCode     ierr;
310:   PetscInt           i,k,cnt = 0;
311:   PetscMatStashSpace space=stash->space;

314:   /* Check and see if we have sufficient memory */
315:   if (!space || space->local_remaining < n) {
316:     MatStashExpand_Private(stash,n);
317:   }
318:   space = stash->space;
319:   k     = space->local_used;
320:   for (i=0; i<n; i++) {
321:     if (ignorezeroentries && (values[i*stepval] == 0.0)) continue;
322:     space->idx[k] = row;
323:     space->idy[k] = idxn[i];
324:     space->val[k] = values[i*stepval];
325:     k++;
326:     cnt++;
327:   }
328:   stash->n               += cnt;
329:   space->local_used      += cnt;
330:   space->local_remaining -= cnt;
331:   return(0);
332: }

334: /*
335:   MatStashValuesRowBlocked_Private - inserts blocks of values into the stash.
336:   This function expects the values to be roworiented. Multiple columns belong
337:   to the same block-row can be inserted with a single call to this function.
338:   This function extracts the sub-block of values based on the dimensions of
339:   the original input block, and the row,col values corresponding to the blocks.

341:   Input Parameters:
342:   stash  - the stash
343:   row    - the global block-row correspoiding to the values
344:   n      - the number of elements inserted. All elements belong to the above row.
345:   idxn   - the global block-column indices corresponding to each of the blocks of
346:            values. Each block is of size bs*bs.
347:   values - the values inserted
348:   rmax   - the number of block-rows in the original block.
349:   cmax   - the number of block-columsn on the original block.
350:   idx    - the index of the current block-row in the original block.
351: */
352: PetscErrorCode MatStashValuesRowBlocked_Private(MatStash *stash,PetscInt row,PetscInt n,const PetscInt idxn[],const PetscScalar values[],PetscInt rmax,PetscInt cmax,PetscInt idx)
353: {
354:   PetscErrorCode     ierr;
355:   PetscInt           i,j,k,bs2,bs=stash->bs,l;
356:   const PetscScalar  *vals;
357:   PetscScalar        *array;
358:   PetscMatStashSpace space=stash->space;

361:   if (!space || space->local_remaining < n) {
362:     MatStashExpand_Private(stash,n);
363:   }
364:   space = stash->space;
365:   l     = space->local_used;
366:   bs2   = bs*bs;
367:   for (i=0; i<n; i++) {
368:     space->idx[l] = row;
369:     space->idy[l] = idxn[i];
370:     /* Now copy over the block of values. Store the values column oriented.
371:        This enables inserting multiple blocks belonging to a row with a single
372:        funtion call */
373:     array = space->val + bs2*l;
374:     vals  = values + idx*bs2*n + bs*i;
375:     for (j=0; j<bs; j++) {
376:       for (k=0; k<bs; k++) array[k*bs] = vals[k];
377:       array++;
378:       vals += cmax*bs;
379:     }
380:     l++;
381:   }
382:   stash->n               += n;
383:   space->local_used      += n;
384:   space->local_remaining -= n;
385:   return(0);
386: }

388: /*
389:   MatStashValuesColBlocked_Private - inserts blocks of values into the stash.
390:   This function expects the values to be roworiented. Multiple columns belong
391:   to the same block-row can be inserted with a single call to this function.
392:   This function extracts the sub-block of values based on the dimensions of
393:   the original input block, and the row,col values corresponding to the blocks.

395:   Input Parameters:
396:   stash  - the stash
397:   row    - the global block-row correspoiding to the values
398:   n      - the number of elements inserted. All elements belong to the above row.
399:   idxn   - the global block-column indices corresponding to each of the blocks of
400:            values. Each block is of size bs*bs.
401:   values - the values inserted
402:   rmax   - the number of block-rows in the original block.
403:   cmax   - the number of block-columsn on the original block.
404:   idx    - the index of the current block-row in the original block.
405: */
406: PetscErrorCode MatStashValuesColBlocked_Private(MatStash *stash,PetscInt row,PetscInt n,const PetscInt idxn[],const PetscScalar values[],PetscInt rmax,PetscInt cmax,PetscInt idx)
407: {
408:   PetscErrorCode     ierr;
409:   PetscInt           i,j,k,bs2,bs=stash->bs,l;
410:   const PetscScalar  *vals;
411:   PetscScalar        *array;
412:   PetscMatStashSpace space=stash->space;

415:   if (!space || space->local_remaining < n) {
416:     MatStashExpand_Private(stash,n);
417:   }
418:   space = stash->space;
419:   l     = space->local_used;
420:   bs2   = bs*bs;
421:   for (i=0; i<n; i++) {
422:     space->idx[l] = row;
423:     space->idy[l] = idxn[i];
424:     /* Now copy over the block of values. Store the values column oriented.
425:      This enables inserting multiple blocks belonging to a row with a single
426:      funtion call */
427:     array = space->val + bs2*l;
428:     vals  = values + idx*bs2*n + bs*i;
429:     for (j=0; j<bs; j++) {
430:       for (k=0; k<bs; k++) array[k] = vals[k];
431:       array += bs;
432:       vals  += rmax*bs;
433:     }
434:     l++;
435:   }
436:   stash->n               += n;
437:   space->local_used      += n;
438:   space->local_remaining -= n;
439:   return(0);
440: }
441: /*
442:   MatStashScatterBegin_Private - Initiates the transfer of values to the
443:   correct owners. This function goes through the stash, and check the
444:   owners of each stashed value, and sends the values off to the owner
445:   processors.

447:   Input Parameters:
448:   stash  - the stash
449:   owners - an array of size 'no-of-procs' which gives the ownership range
450:            for each node.

452:   Notes: The 'owners' array in the cased of the blocked-stash has the
453:   ranges specified blocked global indices, and for the regular stash in
454:   the proper global indices.
455: */
456: PetscErrorCode MatStashScatterBegin_Private(Mat mat,MatStash *stash,PetscInt *owners)
457: {

461:   (*stash->ScatterBegin)(mat,stash,owners);
462:   return(0);
463: }

465: static PetscErrorCode MatStashScatterBegin_Ref(Mat mat,MatStash *stash,PetscInt *owners)
466: {
467:   PetscInt           *owner,*startv,*starti,tag1=stash->tag1,tag2=stash->tag2,bs2;
468:   PetscInt           size=stash->size,nsends;
469:   PetscErrorCode     ierr;
470:   PetscInt           count,*sindices,**rindices,i,j,idx,lastidx,l;
471:   PetscScalar        **rvalues,*svalues;
472:   MPI_Comm           comm = stash->comm;
473:   MPI_Request        *send_waits,*recv_waits,*recv_waits1,*recv_waits2;
474:   PetscMPIInt        *sizes,*nlengths,nreceives;
475:   PetscInt           *sp_idx,*sp_idy;
476:   PetscScalar        *sp_val;
477:   PetscMatStashSpace space,space_next;

480:   {                             /* make sure all processors are either in INSERTMODE or ADDMODE */
481:     InsertMode addv;
482:     MPIU_Allreduce((PetscEnum*)&mat->insertmode,(PetscEnum*)&addv,1,MPIU_ENUM,MPI_BOR,PetscObjectComm((PetscObject)mat));
483:     if (addv == (ADD_VALUES|INSERT_VALUES)) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_ARG_WRONGSTATE,"Some processors inserted others added");
484:     mat->insertmode = addv; /* in case this processor had no cache */
485:   }

487:   bs2 = stash->bs*stash->bs;

489:   /*  first count number of contributors to each processor */
490:   PetscCalloc1(size,&sizes);
491:   PetscCalloc1(size,&nlengths);
492:   PetscMalloc1(stash->n+1,&owner);

494:   i       = j    = 0;
495:   lastidx = -1;
496:   space   = stash->space_head;
497:   while (space) {
498:     space_next = space->next;
499:     sp_idx     = space->idx;
500:     for (l=0; l<space->local_used; l++) {
501:       /* if indices are NOT locally sorted, need to start search at the beginning */
502:       if (lastidx > (idx = sp_idx[l])) j = 0;
503:       lastidx = idx;
504:       for (; j<size; j++) {
505:         if (idx >= owners[j] && idx < owners[j+1]) {
506:           nlengths[j]++; owner[i] = j; break;
507:         }
508:       }
509:       i++;
510:     }
511:     space = space_next;
512:   }
513:   /* Now check what procs get messages - and compute nsends. */
514:   for (i=0, nsends=0; i<size; i++) {
515:     if (nlengths[i]) {
516:       sizes[i] = 1; nsends++;
517:     }
518:   }

520:   {PetscMPIInt *onodes,*olengths;
521:    /* Determine the number of messages to expect, their lengths, from from-ids */
522:    PetscGatherNumberOfMessages(comm,sizes,nlengths,&nreceives);
523:    PetscGatherMessageLengths(comm,nsends,nreceives,nlengths,&onodes,&olengths);
524:    /* since clubbing row,col - lengths are multiplied by 2 */
525:    for (i=0; i<nreceives; i++) olengths[i] *=2;
526:    PetscPostIrecvInt(comm,tag1,nreceives,onodes,olengths,&rindices,&recv_waits1);
527:    /* values are size 'bs2' lengths (and remove earlier factor 2 */
528:    for (i=0; i<nreceives; i++) olengths[i] = olengths[i]*bs2/2;
529:    PetscPostIrecvScalar(comm,tag2,nreceives,onodes,olengths,&rvalues,&recv_waits2);
530:    PetscFree(onodes);
531:    PetscFree(olengths);}

533:   /* do sends:
534:       1) starts[i] gives the starting index in svalues for stuff going to
535:          the ith processor
536:   */
537:   PetscMalloc2(bs2*stash->n,&svalues,2*(stash->n+1),&sindices);
538:   PetscMalloc1(2*nsends,&send_waits);
539:   PetscMalloc2(size,&startv,size,&starti);
540:   /* use 2 sends the first with all_a, the next with all_i and all_j */
541:   startv[0] = 0; starti[0] = 0;
542:   for (i=1; i<size; i++) {
543:     startv[i] = startv[i-1] + nlengths[i-1];
544:     starti[i] = starti[i-1] + 2*nlengths[i-1];
545:   }

547:   i     = 0;
548:   space = stash->space_head;
549:   while (space) {
550:     space_next = space->next;
551:     sp_idx     = space->idx;
552:     sp_idy     = space->idy;
553:     sp_val     = space->val;
554:     for (l=0; l<space->local_used; l++) {
555:       j = owner[i];
556:       if (bs2 == 1) {
557:         svalues[startv[j]] = sp_val[l];
558:       } else {
559:         PetscInt    k;
560:         PetscScalar *buf1,*buf2;
561:         buf1 = svalues+bs2*startv[j];
562:         buf2 = space->val + bs2*l;
563:         for (k=0; k<bs2; k++) buf1[k] = buf2[k];
564:       }
565:       sindices[starti[j]]             = sp_idx[l];
566:       sindices[starti[j]+nlengths[j]] = sp_idy[l];
567:       startv[j]++;
568:       starti[j]++;
569:       i++;
570:     }
571:     space = space_next;
572:   }
573:   startv[0] = 0;
574:   for (i=1; i<size; i++) startv[i] = startv[i-1] + nlengths[i-1];

576:   for (i=0,count=0; i<size; i++) {
577:     if (sizes[i]) {
578:       MPI_Isend(sindices+2*startv[i],2*nlengths[i],MPIU_INT,i,tag1,comm,send_waits+count++);
579:       MPI_Isend(svalues+bs2*startv[i],bs2*nlengths[i],MPIU_SCALAR,i,tag2,comm,send_waits+count++);
580:     }
581:   }
582: #if defined(PETSC_USE_INFO)
583:   PetscInfo1(NULL,"No of messages: %d \n",nsends);
584:   for (i=0; i<size; i++) {
585:     if (sizes[i]) {
586:       PetscInfo2(NULL,"Mesg_to: %d: size: %d bytes\n",i,nlengths[i]*(bs2*sizeof(PetscScalar)+2*sizeof(PetscInt)));
587:     }
588:   }
589: #endif
590:   PetscFree(nlengths);
591:   PetscFree(owner);
592:   PetscFree2(startv,starti);
593:   PetscFree(sizes);

595:   /* recv_waits need to be contiguous for MatStashScatterGetMesg_Private() */
596:   PetscMalloc1(2*nreceives,&recv_waits);

598:   for (i=0; i<nreceives; i++) {
599:     recv_waits[2*i]   = recv_waits1[i];
600:     recv_waits[2*i+1] = recv_waits2[i];
601:   }
602:   stash->recv_waits = recv_waits;

604:   PetscFree(recv_waits1);
605:   PetscFree(recv_waits2);

607:   stash->svalues         = svalues;
608:   stash->sindices        = sindices;
609:   stash->rvalues         = rvalues;
610:   stash->rindices        = rindices;
611:   stash->send_waits      = send_waits;
612:   stash->nsends          = nsends;
613:   stash->nrecvs          = nreceives;
614:   stash->reproduce_count = 0;
615:   return(0);
616: }

618: /*
619:    MatStashScatterGetMesg_Private - This function waits on the receives posted
620:    in the function MatStashScatterBegin_Private() and returns one message at
621:    a time to the calling function. If no messages are left, it indicates this
622:    by setting flg = 0, else it sets flg = 1.

624:    Input Parameters:
625:    stash - the stash

627:    Output Parameters:
628:    nvals - the number of entries in the current message.
629:    rows  - an array of row indices (or blocked indices) corresponding to the values
630:    cols  - an array of columnindices (or blocked indices) corresponding to the values
631:    vals  - the values
632:    flg   - 0 indicates no more message left, and the current call has no values associated.
633:            1 indicates that the current call successfully received a message, and the
634:              other output parameters nvals,rows,cols,vals are set appropriately.
635: */
636: PetscErrorCode MatStashScatterGetMesg_Private(MatStash *stash,PetscMPIInt *nvals,PetscInt **rows,PetscInt **cols,PetscScalar **vals,PetscInt *flg)
637: {

641:   (*stash->ScatterGetMesg)(stash,nvals,rows,cols,vals,flg);
642:   return(0);
643: }

645: static PetscErrorCode MatStashScatterGetMesg_Ref(MatStash *stash,PetscMPIInt *nvals,PetscInt **rows,PetscInt **cols,PetscScalar **vals,PetscInt *flg)
646: {
648:   PetscMPIInt    i,*flg_v = stash->flg_v,i1,i2;
649:   PetscInt       bs2;
650:   MPI_Status     recv_status;
651:   PetscBool      match_found = PETSC_FALSE;

654:   *flg = 0; /* When a message is discovered this is reset to 1 */
655:   /* Return if no more messages to process */
656:   if (stash->nprocessed == stash->nrecvs) return(0);

658:   bs2 = stash->bs*stash->bs;
659:   /* If a matching pair of receives are found, process them, and return the data to
660:      the calling function. Until then keep receiving messages */
661:   while (!match_found) {
662:     if (stash->reproduce) {
663:       i    = stash->reproduce_count++;
664:       MPI_Wait(stash->recv_waits+i,&recv_status);
665:     } else {
666:       MPI_Waitany(2*stash->nrecvs,stash->recv_waits,&i,&recv_status);
667:     }
668:     if (recv_status.MPI_SOURCE < 0) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_PLIB,"Negative MPI source!");

670:     /* Now pack the received message into a structure which is usable by others */
671:     if (i % 2) {
672:       MPI_Get_count(&recv_status,MPIU_SCALAR,nvals);

674:       flg_v[2*recv_status.MPI_SOURCE] = i/2;

676:       *nvals = *nvals/bs2;
677:     } else {
678:       MPI_Get_count(&recv_status,MPIU_INT,nvals);

680:       flg_v[2*recv_status.MPI_SOURCE+1] = i/2;

682:       *nvals = *nvals/2; /* This message has both row indices and col indices */
683:     }

685:     /* Check if we have both messages from this proc */
686:     i1 = flg_v[2*recv_status.MPI_SOURCE];
687:     i2 = flg_v[2*recv_status.MPI_SOURCE+1];
688:     if (i1 != -1 && i2 != -1) {
689:       *rows = stash->rindices[i2];
690:       *cols = *rows + *nvals;
691:       *vals = stash->rvalues[i1];
692:       *flg  = 1;
693:       stash->nprocessed++;
694:       match_found = PETSC_TRUE;
695:     }
696:   }
697:   return(0);
698: }

700: #if !defined(PETSC_HAVE_MPIUNI)
701: typedef struct {
702:   PetscInt row;
703:   PetscInt col;
704:   PetscScalar vals[1];          /* Actually an array of length bs2 */
705: } MatStashBlock;

707: static PetscErrorCode MatStashSortCompress_Private(MatStash *stash,InsertMode insertmode)
708: {
710:   PetscMatStashSpace space;
711:   PetscInt n = stash->n,bs = stash->bs,bs2 = bs*bs,cnt,*row,*col,*perm,rowstart,i;
712:   PetscScalar **valptr;

715:   PetscMalloc4(n,&row,n,&col,n,&valptr,n,&perm);
716:   for (space=stash->space_head,cnt=0; space; space=space->next) {
717:     for (i=0; i<space->local_used; i++) {
718:       row[cnt] = space->idx[i];
719:       col[cnt] = space->idy[i];
720:       valptr[cnt] = &space->val[i*bs2];
721:       perm[cnt] = cnt;          /* Will tell us where to find valptr after sorting row[] and col[] */
722:       cnt++;
723:     }
724:   }
725:   if (cnt != n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"MatStash n %D, but counted %D entries",n,cnt);
726:   PetscSortIntWithArrayPair(n,row,col,perm);
727:   /* Scan through the rows, sorting each one, combining duplicates, and packing send buffers */
728:   for (rowstart=0,cnt=0,i=1; i<=n; i++) {
729:     if (i == n || row[i] != row[rowstart]) {         /* Sort the last row. */
730:       PetscInt colstart;
731:       PetscSortIntWithArray(i-rowstart,&col[rowstart],&perm[rowstart]);
732:       for (colstart=rowstart; colstart<i; ) { /* Compress multiple insertions to the same location */
733:         PetscInt j,l;
734:         MatStashBlock *block;
735:         PetscSegBufferGet(stash->segsendblocks,1,&block);
736:         block->row = row[rowstart];
737:         block->col = col[colstart];
738:         PetscMemcpy(block->vals,valptr[perm[colstart]],bs2*sizeof(block->vals[0]));
739:         for (j=colstart+1; j<i && col[j] == col[colstart]; j++) { /* Add any extra stashed blocks at the same (row,col) */
740:           if (insertmode == ADD_VALUES) {
741:             for (l=0; l<bs2; l++) block->vals[l] += valptr[perm[j]][l];
742:           } else {
743:             PetscMemcpy(block->vals,valptr[perm[j]],bs2*sizeof(block->vals[0]));
744:           }
745:         }
746:         colstart = j;
747:       }
748:       rowstart = i;
749:     }
750:   }
751:   PetscFree4(row,col,valptr,perm);
752:   return(0);
753: }

755: static PetscErrorCode MatStashBlockTypeSetUp(MatStash *stash)
756: {

760:   if (stash->blocktype == MPI_DATATYPE_NULL) {
761:     PetscInt     bs2 = PetscSqr(stash->bs);
762:     PetscMPIInt  blocklens[2];
763:     MPI_Aint     displs[2];
764:     MPI_Datatype types[2],stype;
765:     /* C++ std::complex is not my favorite datatype.  Since it is not POD, we cannot use offsetof to find the offset of
766:      * vals.  But the layout is actually guaranteed by the standard, so we do a little dance here with struct
767:      * DummyBlock, substituting PetscReal for PetscComplex so that we can determine the offset.
768:      */
769:     struct DummyBlock {PetscInt row,col; PetscReal vals;};

771:     stash->blocktype_size = offsetof(struct DummyBlock,vals) + bs2*sizeof(PetscScalar);
772:     if (stash->blocktype_size % sizeof(PetscInt)) { /* Implies that PetscInt is larger and does not satisfy alignment without padding */
773:       stash->blocktype_size += sizeof(PetscInt) - stash->blocktype_size % sizeof(PetscInt);
774:     }
775:     PetscSegBufferCreate(stash->blocktype_size,1,&stash->segsendblocks);
776:     PetscSegBufferCreate(stash->blocktype_size,1,&stash->segrecvblocks);
777:     PetscSegBufferCreate(sizeof(MatStashFrame),1,&stash->segrecvframe);
778:     blocklens[0] = 2;
779:     blocklens[1] = bs2;
780:     displs[0] = offsetof(struct DummyBlock,row);
781:     displs[1] = offsetof(struct DummyBlock,vals);
782:     types[0] = MPIU_INT;
783:     types[1] = MPIU_SCALAR;
784:     MPI_Type_create_struct(2,blocklens,displs,types,&stype);
785:     MPI_Type_commit(&stype);
786:     MPI_Type_create_resized(stype,0,stash->blocktype_size,&stash->blocktype); /* MPI-2 */
787:     MPI_Type_commit(&stash->blocktype);
788:     MPI_Type_free(&stype);
789:   }
790:   return(0);
791: }

793: /* Callback invoked after target rank has initiatied receive of rendezvous message.
794:  * Here we post the main sends.
795:  */
796: static PetscErrorCode MatStashBTSSend_Private(MPI_Comm comm,const PetscMPIInt tag[],PetscMPIInt rankid,PetscMPIInt rank,void *sdata,MPI_Request req[],void *ctx)
797: {
798:   MatStash *stash = (MatStash*)ctx;
799:   MatStashHeader *hdr = (MatStashHeader*)sdata;

803:   if (rank != stash->sendranks[rankid]) SETERRQ3(comm,PETSC_ERR_PLIB,"BTS Send rank %d does not match sendranks[%d] %d",rank,rankid,stash->sendranks[rankid]);
804:   MPI_Isend(stash->sendframes[rankid].buffer,hdr->count,stash->blocktype,rank,tag[0],comm,&req[0]);
805:   stash->sendframes[rankid].count = hdr->count;
806:   stash->sendframes[rankid].pending = 1;
807:   return(0);
808: }

810: /* Callback invoked by target after receiving rendezvous message.
811:  * Here we post the main recvs.
812:  */
813: static PetscErrorCode MatStashBTSRecv_Private(MPI_Comm comm,const PetscMPIInt tag[],PetscMPIInt rank,void *rdata,MPI_Request req[],void *ctx)
814: {
815:   MatStash *stash = (MatStash*)ctx;
816:   MatStashHeader *hdr = (MatStashHeader*)rdata;
817:   MatStashFrame *frame;

821:   PetscSegBufferGet(stash->segrecvframe,1,&frame);
822:   PetscSegBufferGet(stash->segrecvblocks,hdr->count,&frame->buffer);
823:   MPI_Irecv(frame->buffer,hdr->count,stash->blocktype,rank,tag[0],comm,&req[0]);
824:   frame->count = hdr->count;
825:   frame->pending = 1;
826:   return(0);
827: }

829: /*
830:  * owners[] contains the ownership ranges; may be indexed by either blocks or scalars
831:  */
832: static PetscErrorCode MatStashScatterBegin_BTS(Mat mat,MatStash *stash,PetscInt owners[])
833: {
835:   size_t nblocks;
836:   char *sendblocks;

839: #if defined(PETSC_USE_DEBUG)
840:   {                             /* make sure all processors are either in INSERTMODE or ADDMODE */
841:     InsertMode addv;
842:     MPIU_Allreduce((PetscEnum*)&mat->insertmode,(PetscEnum*)&addv,1,MPIU_ENUM,MPI_BOR,PetscObjectComm((PetscObject)mat));
843:     if (addv == (ADD_VALUES|INSERT_VALUES)) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_ARG_WRONGSTATE,"Some processors inserted others added");
844:   }
845: #endif

847:   if (stash->subset_off_proc && !mat->subsetoffprocentries) { /* We won't use the old scatter context. */
848:     MatStashScatterDestroy_BTS(stash);
849:   }

851:   MatStashBlockTypeSetUp(stash);
852:   MatStashSortCompress_Private(stash,mat->insertmode);
853:   PetscSegBufferGetSize(stash->segsendblocks,&nblocks);
854:   PetscSegBufferExtractInPlace(stash->segsendblocks,&sendblocks);
855:   if (stash->subset_off_proc && mat->subsetoffprocentries) { /* Set up sendhdrs and sendframes for each rank that we sent before */
856:     PetscInt i;
857:     size_t b;
858:     for (i=0,b=0; i<stash->nsendranks; i++) {
859:       stash->sendframes[i].buffer = &sendblocks[b*stash->blocktype_size];
860:       /* sendhdr is never actually sent, but the count is used by MatStashBTSSend_Private */
861:       stash->sendhdr[i].count = 0; /* Might remain empty (in which case we send a zero-sized message) if no values are communicated to that process */
862:       for ( ; b<nblocks; b++) {
863:         MatStashBlock *sendblock_b = (MatStashBlock*)&sendblocks[b*stash->blocktype_size];
864:         if (PetscUnlikely(sendblock_b->row < owners[stash->sendranks[i]])) SETERRQ2(stash->comm,PETSC_ERR_ARG_WRONG,"MAT_SUBSET_OFF_PROC_ENTRIES set, but row %D owned by %d not communicated in initial assembly",sendblock_b->row,stash->sendranks[i]);
865:         if (sendblock_b->row >= owners[stash->sendranks[i]+1]) break;
866:         stash->sendhdr[i].count++;
867:       }
868:     }
869:   } else {                      /* Dynamically count and pack (first time) */
870:     PetscInt sendno;
871:     size_t i,rowstart;

873:     /* Count number of send ranks and allocate for sends */
874:     stash->nsendranks = 0;
875:     for (rowstart=0; rowstart<nblocks; ) {
876:       PetscInt owner;
877:       MatStashBlock *sendblock_rowstart = (MatStashBlock*)&sendblocks[rowstart*stash->blocktype_size];
878:       PetscFindInt(sendblock_rowstart->row,stash->size+1,owners,&owner);
879:       if (owner < 0) owner = -(owner+2);
880:       for (i=rowstart+1; i<nblocks; i++) { /* Move forward through a run of blocks with the same owner */
881:         MatStashBlock *sendblock_i = (MatStashBlock*)&sendblocks[i*stash->blocktype_size];
882:         if (sendblock_i->row >= owners[owner+1]) break;
883:       }
884:       stash->nsendranks++;
885:       rowstart = i;
886:     }
887:     PetscMalloc3(stash->nsendranks,&stash->sendranks,stash->nsendranks,&stash->sendhdr,stash->nsendranks,&stash->sendframes);

889:     /* Set up sendhdrs and sendframes */
890:     sendno = 0;
891:     for (rowstart=0; rowstart<nblocks; ) {
892:       PetscInt owner;
893:       MatStashBlock *sendblock_rowstart = (MatStashBlock*)&sendblocks[rowstart*stash->blocktype_size];
894:       PetscFindInt(sendblock_rowstart->row,stash->size+1,owners,&owner);
895:       if (owner < 0) owner = -(owner+2);
896:       stash->sendranks[sendno] = owner;
897:       for (i=rowstart+1; i<nblocks; i++) { /* Move forward through a run of blocks with the same owner */
898:         MatStashBlock *sendblock_i = (MatStashBlock*)&sendblocks[i*stash->blocktype_size];
899:         if (sendblock_i->row >= owners[owner+1]) break;
900:       }
901:       stash->sendframes[sendno].buffer = sendblock_rowstart;
902:       stash->sendframes[sendno].pending = 0;
903:       stash->sendhdr[sendno].count = i - rowstart;
904:       sendno++;
905:       rowstart = i;
906:     }
907:     if (sendno != stash->nsendranks) SETERRQ2(stash->comm,PETSC_ERR_PLIB,"BTS counted %D sendranks, but %D sends",stash->nsendranks,sendno);
908:   }

910:   /* Encode insertmode on the outgoing messages. If we want to support more than two options, we would need a new
911:    * message or a dummy entry of some sort. */
912:   if (mat->insertmode == INSERT_VALUES) {
913:     size_t i;
914:     for (i=0; i<nblocks; i++) {
915:       MatStashBlock *sendblock_i = (MatStashBlock*)&sendblocks[i*stash->blocktype_size];
916:       sendblock_i->row = -(sendblock_i->row+1);
917:     }
918:   }

920:   if (stash->subset_off_proc && mat->subsetoffprocentries) {
921:     PetscMPIInt i,tag;
922:     PetscCommGetNewTag(stash->comm,&tag);
923:     for (i=0; i<stash->nrecvranks; i++) {
924:       MatStashBTSRecv_Private(stash->comm,&tag,stash->recvranks[i],&stash->recvhdr[i],&stash->recvreqs[i],stash);
925:     }
926:     for (i=0; i<stash->nsendranks; i++) {
927:       MatStashBTSSend_Private(stash->comm,&tag,i,stash->sendranks[i],&stash->sendhdr[i],&stash->sendreqs[i],stash);
928:     }
929:     stash->use_status = PETSC_TRUE; /* Use count from message status. */
930:   } else {
931:     PetscCommBuildTwoSidedFReq(stash->comm,1,MPIU_INT,stash->nsendranks,stash->sendranks,(PetscInt*)stash->sendhdr,
932:                                       &stash->nrecvranks,&stash->recvranks,(PetscInt*)&stash->recvhdr,1,&stash->sendreqs,&stash->recvreqs,
933:                                       MatStashBTSSend_Private,MatStashBTSRecv_Private,stash);
934:     PetscMalloc2(stash->nrecvranks,&stash->some_indices,stash->nrecvranks,&stash->some_statuses);
935:     stash->use_status = PETSC_FALSE; /* Use count from header instead of from message. */
936:   }

938:   PetscSegBufferExtractInPlace(stash->segrecvframe,&stash->recvframes);
939:   stash->recvframe_active = NULL;
940:   stash->recvframe_i      = 0;
941:   stash->some_i           = 0;
942:   stash->some_count       = 0;
943:   stash->recvcount        = 0;
944:   stash->subset_off_proc  = mat->subsetoffprocentries;
945:   stash->insertmode       = &mat->insertmode;
946:   return(0);
947: }

949: static PetscErrorCode MatStashScatterGetMesg_BTS(MatStash *stash,PetscMPIInt *n,PetscInt **row,PetscInt **col,PetscScalar **val,PetscInt *flg)
950: {
952:   MatStashBlock *block;

955:   *flg = 0;
956:   while (!stash->recvframe_active || stash->recvframe_i == stash->recvframe_count) {
957:     if (stash->some_i == stash->some_count) {
958:       if (stash->recvcount == stash->nrecvranks) return(0); /* Done */
959:       MPI_Waitsome(stash->nrecvranks,stash->recvreqs,&stash->some_count,stash->some_indices,stash->use_status?stash->some_statuses:MPI_STATUSES_IGNORE);
960:       stash->some_i = 0;
961:     }
962:     stash->recvframe_active = &stash->recvframes[stash->some_indices[stash->some_i]];
963:     stash->recvframe_count = stash->recvframe_active->count; /* From header; maximum count */
964:     if (stash->use_status) { /* Count what was actually sent */
965:       MPI_Get_count(&stash->some_statuses[stash->some_i],stash->blocktype,&stash->recvframe_count);
966:     }
967:     if (stash->recvframe_count > 0) { /* Check for InsertMode consistency */
968:       block = (MatStashBlock*)&((char*)stash->recvframe_active->buffer)[0];
969:       if (PetscUnlikely(*stash->insertmode == NOT_SET_VALUES)) *stash->insertmode = block->row < 0 ? INSERT_VALUES : ADD_VALUES;
970:       if (PetscUnlikely(*stash->insertmode == INSERT_VALUES && block->row >= 0)) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Assembling INSERT_VALUES, but rank %d requested ADD_VALUES",stash->recvranks[stash->some_indices[stash->some_i]]);
971:       if (PetscUnlikely(*stash->insertmode == ADD_VALUES && block->row < 0)) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_WRONGSTATE,"Assembling ADD_VALUES, but rank %d requested INSERT_VALUES",stash->recvranks[stash->some_indices[stash->some_i]]);
972:     }
973:     stash->some_i++;
974:     stash->recvcount++;
975:     stash->recvframe_i = 0;
976:   }
977:   *n = 1;
978:   block = (MatStashBlock*)&((char*)stash->recvframe_active->buffer)[stash->recvframe_i*stash->blocktype_size];
979:   if (block->row < 0) block->row = -(block->row + 1);
980:   *row = &block->row;
981:   *col = &block->col;
982:   *val = block->vals;
983:   stash->recvframe_i++;
984:   *flg = 1;
985:   return(0);
986: }

988: static PetscErrorCode MatStashScatterEnd_BTS(MatStash *stash)
989: {

993:   MPI_Waitall(stash->nsendranks,stash->sendreqs,MPI_STATUSES_IGNORE);
994:   if (stash->subset_off_proc) { /* Reuse the communication contexts, so consolidate and reset segrecvblocks  */
995:     void *dummy;
996:     PetscSegBufferExtractInPlace(stash->segrecvblocks,&dummy);
997:   } else {                      /* No reuse, so collect everything. */
998:     MatStashScatterDestroy_BTS(stash);
999:   }

1001:   /* Now update nmaxold to be app 10% more than max n used, this way the
1002:      wastage of space is reduced the next time this stash is used.
1003:      Also update the oldmax, only if it increases */
1004:   if (stash->n) {
1005:     PetscInt bs2     = stash->bs*stash->bs;
1006:     PetscInt oldnmax = ((int)(stash->n * 1.1) + 5)*bs2;
1007:     if (oldnmax > stash->oldnmax) stash->oldnmax = oldnmax;
1008:   }

1010:   stash->nmax       = 0;
1011:   stash->n          = 0;
1012:   stash->reallocs   = -1;
1013:   stash->nprocessed = 0;

1015:   PetscMatStashSpaceDestroy(&stash->space_head);

1017:   stash->space = 0;

1019:   return(0);
1020: }

1022: static PetscErrorCode MatStashScatterDestroy_BTS(MatStash *stash)
1023: {

1027:   PetscSegBufferDestroy(&stash->segsendblocks);
1028:   PetscSegBufferDestroy(&stash->segrecvframe);
1029:   stash->recvframes = NULL;
1030:   PetscSegBufferDestroy(&stash->segrecvblocks);
1031:   if (stash->blocktype != MPI_DATATYPE_NULL) {
1032:     MPI_Type_free(&stash->blocktype);
1033:   }
1034:   stash->nsendranks = 0;
1035:   stash->nrecvranks = 0;
1036:   PetscFree3(stash->sendranks,stash->sendhdr,stash->sendframes);
1037:   PetscFree(stash->sendreqs);
1038:   PetscFree(stash->recvreqs);
1039:   PetscFree(stash->recvranks);
1040:   PetscFree(stash->recvhdr);
1041:   PetscFree2(stash->some_indices,stash->some_statuses);
1042:   return(0);
1043: }
1044: #endif