Date: 2022-03-04T17:38:17+00:00

Actual source code: matstash.c

      2: #include <petsc/private/matimpl.h>

      4: #define DEFAULT_STASH_SIZE   10000

      6: static PetscErrorCode MatStashScatterBegin_Ref(Mat,MatStash*,PetscInt*);
      7: PETSC_INTERN PetscErrorCode MatStashScatterGetMesg_Ref(MatStash*,PetscMPIInt*,PetscInt**,PetscInt**,PetscScalar**,PetscInt*);
      8: PETSC_INTERN 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: #endif

     15: /*
     16:   MatStashCreate_Private - Creates a stash,currently used for all the parallel
     17:   matrix implementations. The stash is where elements of a matrix destined
     18:   to be stored on other processors are kept until matrix assembly is done.

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

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

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

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

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

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

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

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

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

    102: /*
    103:    MatStashDestroy_Private - Destroy the stash
    104: */
    105: PetscErrorCode MatStashDestroy_Private(MatStash *stash)
    106: {

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

    113:   stash->space = NULL;

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

    119: /*
    120:    MatStashScatterEnd_Private - This is called as the final stage of
    121:    scatter. The final stages of message passing is done here, and
    122:    all the memory used for message passing is cleaned up. This
    123:    routine also resets the stash, and deallocates the memory used
    124:    for the stash. It also keeps track of the current memory usage
    125:    so that the same value can be used the next time through.
    126: */
    127: PetscErrorCode MatStashScatterEnd_Private(MatStash *stash)
    128: {

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

    136: PETSC_INTERN PetscErrorCode MatStashScatterEnd_Ref(MatStash *stash)
    137: {
    139:   PetscInt       nsends=stash->nsends,bs2,oldnmax,i;
    140:   MPI_Status     *send_status;

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

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

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

    165:   PetscMatStashSpaceDestroy(&stash->space_head);

    167:   stash->space = NULL;

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

    179: /*
    180:    MatStashGetInfo_Private - Gets the relavant statistics of the stash

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

    187: */
    188: PetscErrorCode MatStashGetInfo_Private(MatStash *stash,PetscInt *nstash,PetscInt *reallocs)
    189: {
    190:   PetscInt bs2 = stash->bs*stash->bs;

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

    201: /*
    202:    MatStashSetInitialSize_Private - Sets the initial size of the stash

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

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

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

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

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

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

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

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

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

    292: /*
    293:   MatStashValuesCol_Private - inserts values into the stash. This function
    294:   expects the values to be columnoriented. Multiple columns belong to the same row
    295:   can be inserted with a single call to this function.

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

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

    333: /*
    334:   MatStashValuesRowBlocked_Private - inserts blocks of values into the stash.
    335:   This function expects the values to be roworiented. Multiple columns belong
    336:   to the same block-row can be inserted with a single call to this function.
    337:   This function extracts the sub-block of values based on the dimensions of
    338:   the original input block, and the row,col values corresponding to the blocks.

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

    360:   if (!space || space->local_remaining < n) {
    361:     MatStashExpand_Private(stash,n);
    362:   }
    363:   space = stash->space;
    364:   l     = space->local_used;
    365:   bs2   = bs*bs;
    366:   for (i=0; i<n; i++) {
    367:     space->idx[l] = row;
    368:     space->idy[l] = idxn[i];
    369:     /* Now copy over the block of values. Store the values column oriented.
    370:        This enables inserting multiple blocks belonging to a row with a single
    371:        funtion call */
    372:     array = space->val + bs2*l;
    373:     vals  = values + idx*bs2*n + bs*i;
    374:     for (j=0; j<bs; j++) {
    375:       for (k=0; k<bs; k++) array[k*bs] = values ? vals[k] : 0.0;
    376:       array++;
    377:       vals += cmax*bs;
    378:     }
    379:     l++;
    380:   }
    381:   stash->n               += n;
    382:   space->local_used      += n;
    383:   space->local_remaining -= n;
    384:   return(0);
    385: }

    387: /*
    388:   MatStashValuesColBlocked_Private - inserts blocks of values into the stash.
    389:   This function expects the values to be roworiented. Multiple columns belong
    390:   to the same block-row can be inserted with a single call to this function.
    391:   This function extracts the sub-block of values based on the dimensions of
    392:   the original input block, and the row,col values corresponding to the blocks.

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

    414:   if (!space || space->local_remaining < n) {
    415:     MatStashExpand_Private(stash,n);
    416:   }
    417:   space = stash->space;
    418:   l     = space->local_used;
    419:   bs2   = bs*bs;
    420:   for (i=0; i<n; i++) {
    421:     space->idx[l] = row;
    422:     space->idy[l] = idxn[i];
    423:     /* Now copy over the block of values. Store the values column oriented.
    424:      This enables inserting multiple blocks belonging to a row with a single
    425:      funtion call */
    426:     array = space->val + bs2*l;
    427:     vals  = values + idx*bs2*n + bs*i;
    428:     for (j=0; j<bs; j++) {
    429:       for (k=0; k<bs; k++) array[k] = values ? vals[k] : 0.0;
    430:       array += bs;
    431:       vals  += rmax*bs;
    432:     }
    433:     l++;
    434:   }
    435:   stash->n               += n;
    436:   space->local_used      += n;
    437:   space->local_remaining -= n;
    438:   return(0);
    439: }
    440: /*
    441:   MatStashScatterBegin_Private - Initiates the transfer of values to the
    442:   correct owners. This function goes through the stash, and check the
    443:   owners of each stashed value, and sends the values off to the owner
    444:   processors.

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

    451:   Notes:
    452:     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,&nlengths);
    491:   PetscMalloc1(stash->n+1,&owner);

    493:   i       = j    = 0;
    494:   lastidx = -1;
    495:   space   = stash->space_head;
    496:   while (space) {
    497:     space_next = space->next;
    498:     sp_idx     = space->idx;
    499:     for (l=0; l<space->local_used; l++) {
    500:       /* if indices are NOT locally sorted, need to start search at the beginning */
    501:       if (lastidx > (idx = sp_idx[l])) j = 0;
    502:       lastidx = idx;
    503:       for (; j<size; j++) {
    504:         if (idx >= owners[j] && idx < owners[j+1]) {
    505:           nlengths[j]++; owner[i] = j; break;
    506:         }
    507:       }
    508:       i++;
    509:     }
    510:     space = space_next;
    511:   }

    513:   /* Now check what procs get messages - and compute nsends. */
    514:   PetscCalloc1(size,&sizes);
    515:   for (i=0, nsends=0; i<size; i++) {
    516:     if (nlengths[i]) {
    517:       sizes[i] = 1; nsends++;
    518:     }
    519:   }

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

    534:   /* do sends:
    535:       1) starts[i] gives the starting index in svalues for stuff going to
    536:          the ith processor
    537:   */
    538:   PetscMalloc2(bs2*stash->n,&svalues,2*(stash->n+1),&sindices);
    539:   PetscMalloc1(2*nsends,&send_waits);
    540:   PetscMalloc2(size,&startv,size,&starti);
    541:   /* use 2 sends the first with all_a, the next with all_i and all_j */
    542:   startv[0] = 0; starti[0] = 0;
    543:   for (i=1; i<size; i++) {
    544:     startv[i] = startv[i-1] + nlengths[i-1];
    545:     starti[i] = starti[i-1] + 2*nlengths[i-1];
    546:   }

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

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

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

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

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

    608:   stash->svalues         = svalues;
    609:   stash->sindices        = sindices;
    610:   stash->rvalues         = rvalues;
    611:   stash->rindices        = rindices;
    612:   stash->send_waits      = send_waits;
    613:   stash->nsends          = nsends;
    614:   stash->nrecvs          = nreceives;
    615:   stash->reproduce_count = 0;
    616:   return(0);
    617: }

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

    625:    Input Parameters:
    626:    stash - the stash

    628:    Output Parameters:
    629:    nvals - the number of entries in the current message.
    630:    rows  - an array of row indices (or blocked indices) corresponding to the values
    631:    cols  - an array of columnindices (or blocked indices) corresponding to the values
    632:    vals  - the values
    633:    flg   - 0 indicates no more message left, and the current call has no values associated.
    634:            1 indicates that the current call successfully received a message, and the
    635:              other output parameters nvals,rows,cols,vals are set appropriately.
    636: */
    637: PetscErrorCode MatStashScatterGetMesg_Private(MatStash *stash,PetscMPIInt *nvals,PetscInt **rows,PetscInt **cols,PetscScalar **vals,PetscInt *flg)
    638: {

    642:   (*stash->ScatterGetMesg)(stash,nvals,rows,cols,vals,flg);
    643:   return(0);
    644: }

    646: PETSC_INTERN PetscErrorCode MatStashScatterGetMesg_Ref(MatStash *stash,PetscMPIInt *nvals,PetscInt **rows,PetscInt **cols,PetscScalar **vals,PetscInt *flg)
    647: {
    649:   PetscMPIInt    i,*flg_v = stash->flg_v,i1,i2;
    650:   PetscInt       bs2;
    651:   MPI_Status     recv_status;
    652:   PetscBool      match_found = PETSC_FALSE;

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

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

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

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

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

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

    683:       *nvals = *nvals/2; /* This message has both row indices and col indices */
    684:     }

    686:     /* Check if we have both messages from this proc */
    687:     i1 = flg_v[2*recv_status.MPI_SOURCE];
    688:     i2 = flg_v[2*recv_status.MPI_SOURCE+1];
    689:     if (i1 != -1 && i2 != -1) {
    690:       *rows = stash->rindices[i2];
    691:       *cols = *rows + *nvals;
    692:       *vals = stash->rvalues[i1];
    693:       *flg  = 1;
    694:       stash->nprocessed++;
    695:       match_found = PETSC_TRUE;
    696:     }
    697:   }
    698:   return(0);
    699: }

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

    708: static PetscErrorCode MatStashSortCompress_Private(MatStash *stash,InsertMode insertmode)
    709: {
    711:   PetscMatStashSpace space;
    712:   PetscInt n = stash->n,bs = stash->bs,bs2 = bs*bs,cnt,*row,*col,*perm,rowstart,i;
    713:   PetscScalar **valptr;

    716:   PetscMalloc4(n,&row,n,&col,n,&valptr,n,&perm);
    717:   for (space=stash->space_head,cnt=0; space; space=space->next) {
    718:     for (i=0; i<space->local_used; i++) {
    719:       row[cnt] = space->idx[i];
    720:       col[cnt] = space->idy[i];
    721:       valptr[cnt] = &space->val[i*bs2];
    722:       perm[cnt] = cnt;          /* Will tell us where to find valptr after sorting row[] and col[] */
    723:       cnt++;
    724:     }
    725:   }
    726:   if (cnt != n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"MatStash n %D, but counted %D entries",n,cnt);
    727:   PetscSortIntWithArrayPair(n,row,col,perm);
    728:   /* Scan through the rows, sorting each one, combining duplicates, and packing send buffers */
    729:   for (rowstart=0,cnt=0,i=1; i<=n; i++) {
    730:     if (i == n || row[i] != row[rowstart]) {         /* Sort the last row. */
    731:       PetscInt colstart;
    732:       PetscSortIntWithArray(i-rowstart,&col[rowstart],&perm[rowstart]);
    733:       for (colstart=rowstart; colstart<i;) { /* Compress multiple insertions to the same location */
    734:         PetscInt j,l;
    735:         MatStashBlock *block;
    736:         PetscSegBufferGet(stash->segsendblocks,1,&block);
    737:         block->row = row[rowstart];
    738:         block->col = col[colstart];
    739:         PetscArraycpy(block->vals,valptr[perm[colstart]],bs2);
    740:         for (j=colstart+1; j<i && col[j] == col[colstart]; j++) { /* Add any extra stashed blocks at the same (row,col) */
    741:           if (insertmode == ADD_VALUES) {
    742:             for (l=0; l<bs2; l++) block->vals[l] += valptr[perm[j]][l];
    743:           } else {
    744:             PetscArraycpy(block->vals,valptr[perm[j]],bs2);
    745:           }
    746:         }
    747:         colstart = j;
    748:       }
    749:       rowstart = i;
    750:     }
    751:   }
    752:   PetscFree4(row,col,valptr,perm);
    753:   return(0);
    754: }

    756: static PetscErrorCode MatStashBlockTypeSetUp(MatStash *stash)
    757: {

    761:   if (stash->blocktype == MPI_DATATYPE_NULL) {
    762:     PetscInt     bs2 = PetscSqr(stash->bs);
    763:     PetscMPIInt  blocklens[2];
    764:     MPI_Aint     displs[2];
    765:     MPI_Datatype types[2],stype;
    766:     /* Note that DummyBlock is a type having standard layout, even when PetscScalar is C++ std::complex.
    767:        std::complex itself has standard layout, so does DummyBlock, recursively.
    768:        To be compatible with C++ std::complex, complex implementations on GPUs must also have standard layout,
    769:        though they can have different alignment, e.g, 16 bytes for double complex, instead of 8 bytes as in GCC stdlibc++.
    770:        offsetof(type, member) only requires type to have standard layout. Ref. https://en.cppreference.com/w/cpp/types/offsetof.

    772:        We can test if std::complex has standard layout with the following code:
    773:        #include <iostream>
    774:        #include <type_traits>
    775:        #include <complex>
    776:        int main() {
    777:          std::cout << std::boolalpha;
    778:          std::cout << std::is_standard_layout<std::complex<double> >::value << '\n';
    779:        }
    780:        Output: true
    781:      */
    782:     struct DummyBlock {PetscInt row,col; PetscScalar vals;};

    784:     stash->blocktype_size = offsetof(struct DummyBlock,vals) + bs2*sizeof(PetscScalar);
    785:     if (stash->blocktype_size % sizeof(PetscInt)) { /* Implies that PetscInt is larger and does not satisfy alignment without padding */
    786:       stash->blocktype_size += sizeof(PetscInt) - stash->blocktype_size % sizeof(PetscInt);
    787:     }
    788:     PetscSegBufferCreate(stash->blocktype_size,1,&stash->segsendblocks);
    789:     PetscSegBufferCreate(stash->blocktype_size,1,&stash->segrecvblocks);
    790:     PetscSegBufferCreate(sizeof(MatStashFrame),1,&stash->segrecvframe);
    791:     blocklens[0] = 2;
    792:     blocklens[1] = bs2;
    793:     displs[0] = offsetof(struct DummyBlock,row);
    794:     displs[1] = offsetof(struct DummyBlock,vals);
    795:     types[0] = MPIU_INT;
    796:     types[1] = MPIU_SCALAR;
    797:     MPI_Type_create_struct(2,blocklens,displs,types,&stype);
    798:     MPI_Type_commit(&stype);
    799:     MPI_Type_create_resized(stype,0,stash->blocktype_size,&stash->blocktype);
    800:     MPI_Type_commit(&stash->blocktype);
    801:     MPI_Type_free(&stype);
    802:   }
    803:   return(0);
    804: }

    806: /* Callback invoked after target rank has initiatied receive of rendezvous message.
    807:  * Here we post the main sends.
    808:  */
    809: static PetscErrorCode MatStashBTSSend_Private(MPI_Comm comm,const PetscMPIInt tag[],PetscMPIInt rankid,PetscMPIInt rank,void *sdata,MPI_Request req[],void *ctx)
    810: {
    811:   MatStash *stash = (MatStash*)ctx;
    812:   MatStashHeader *hdr = (MatStashHeader*)sdata;

    816:   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]);
    817:   MPI_Isend(stash->sendframes[rankid].buffer,hdr->count,stash->blocktype,rank,tag[0],comm,&req[0]);
    818:   stash->sendframes[rankid].count = hdr->count;
    819:   stash->sendframes[rankid].pending = 1;
    820:   return(0);
    821: }

    823: /* Callback invoked by target after receiving rendezvous message.
    824:  * Here we post the main recvs.
    825:  */
    826: static PetscErrorCode MatStashBTSRecv_Private(MPI_Comm comm,const PetscMPIInt tag[],PetscMPIInt rank,void *rdata,MPI_Request req[],void *ctx)
    827: {
    828:   MatStash *stash = (MatStash*)ctx;
    829:   MatStashHeader *hdr = (MatStashHeader*)rdata;
    830:   MatStashFrame *frame;

    834:   PetscSegBufferGet(stash->segrecvframe,1,&frame);
    835:   PetscSegBufferGet(stash->segrecvblocks,hdr->count,&frame->buffer);
    836:   MPI_Irecv(frame->buffer,hdr->count,stash->blocktype,rank,tag[0],comm,&req[0]);
    837:   frame->count = hdr->count;
    838:   frame->pending = 1;
    839:   return(0);
    840: }

    842: /*
    843:  * owners[] contains the ownership ranges; may be indexed by either blocks or scalars
    844:  */
    845: static PetscErrorCode MatStashScatterBegin_BTS(Mat mat,MatStash *stash,PetscInt owners[])
    846: {
    848:   size_t nblocks;
    849:   char *sendblocks;

    852:   if (PetscDefined(USE_DEBUG)) { /* make sure all processors are either in INSERTMODE or ADDMODE */
    853:     InsertMode addv;
    854:     MPIU_Allreduce((PetscEnum*)&mat->insertmode,(PetscEnum*)&addv,1,MPIU_ENUM,MPI_BOR,PetscObjectComm((PetscObject)mat));
    855:     if (addv == (ADD_VALUES|INSERT_VALUES)) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_ARG_WRONGSTATE,"Some processors inserted others added");
    856:   }

    858:   MatStashBlockTypeSetUp(stash);
    859:   MatStashSortCompress_Private(stash,mat->insertmode);
    860:   PetscSegBufferGetSize(stash->segsendblocks,&nblocks);
    861:   PetscSegBufferExtractInPlace(stash->segsendblocks,&sendblocks);
    862:   if (stash->first_assembly_done) { /* Set up sendhdrs and sendframes for each rank that we sent before */
    863:     PetscInt i;
    864:     size_t b;
    865:     for (i=0,b=0; i<stash->nsendranks; i++) {
    866:       stash->sendframes[i].buffer = &sendblocks[b*stash->blocktype_size];
    867:       /* sendhdr is never actually sent, but the count is used by MatStashBTSSend_Private */
    868:       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 */
    869:       for (; b<nblocks; b++) {
    870:         MatStashBlock *sendblock_b = (MatStashBlock*)&sendblocks[b*stash->blocktype_size];
    871:         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]);
    872:         if (sendblock_b->row >= owners[stash->sendranks[i]+1]) break;
    873:         stash->sendhdr[i].count++;
    874:       }
    875:     }
    876:   } else {                      /* Dynamically count and pack (first time) */
    877:     PetscInt sendno;
    878:     size_t i,rowstart;

    880:     /* Count number of send ranks and allocate for sends */
    881:     stash->nsendranks = 0;
    882:     for (rowstart=0; rowstart<nblocks;) {
    883:       PetscInt owner;
    884:       MatStashBlock *sendblock_rowstart = (MatStashBlock*)&sendblocks[rowstart*stash->blocktype_size];
    885:       PetscFindInt(sendblock_rowstart->row,stash->size+1,owners,&owner);
    886:       if (owner < 0) owner = -(owner+2);
    887:       for (i=rowstart+1; i<nblocks; i++) { /* Move forward through a run of blocks with the same owner */
    888:         MatStashBlock *sendblock_i = (MatStashBlock*)&sendblocks[i*stash->blocktype_size];
    889:         if (sendblock_i->row >= owners[owner+1]) break;
    890:       }
    891:       stash->nsendranks++;
    892:       rowstart = i;
    893:     }
    894:     PetscMalloc3(stash->nsendranks,&stash->sendranks,stash->nsendranks,&stash->sendhdr,stash->nsendranks,&stash->sendframes);

    896:     /* Set up sendhdrs and sendframes */
    897:     sendno = 0;
    898:     for (rowstart=0; rowstart<nblocks;) {
    899:       PetscInt owner;
    900:       MatStashBlock *sendblock_rowstart = (MatStashBlock*)&sendblocks[rowstart*stash->blocktype_size];
    901:       PetscFindInt(sendblock_rowstart->row,stash->size+1,owners,&owner);
    902:       if (owner < 0) owner = -(owner+2);
    903:       stash->sendranks[sendno] = owner;
    904:       for (i=rowstart+1; i<nblocks; i++) { /* Move forward through a run of blocks with the same owner */
    905:         MatStashBlock *sendblock_i = (MatStashBlock*)&sendblocks[i*stash->blocktype_size];
    906:         if (sendblock_i->row >= owners[owner+1]) break;
    907:       }
    908:       stash->sendframes[sendno].buffer = sendblock_rowstart;
    909:       stash->sendframes[sendno].pending = 0;
    910:       stash->sendhdr[sendno].count = i - rowstart;
    911:       sendno++;
    912:       rowstart = i;
    913:     }
    914:     if (sendno != stash->nsendranks) SETERRQ2(stash->comm,PETSC_ERR_PLIB,"BTS counted %D sendranks, but %D sends",stash->nsendranks,sendno);
    915:   }

    917:   /* Encode insertmode on the outgoing messages. If we want to support more than two options, we would need a new
    918:    * message or a dummy entry of some sort. */
    919:   if (mat->insertmode == INSERT_VALUES) {
    920:     size_t i;
    921:     for (i=0; i<nblocks; i++) {
    922:       MatStashBlock *sendblock_i = (MatStashBlock*)&sendblocks[i*stash->blocktype_size];
    923:       sendblock_i->row = -(sendblock_i->row+1);
    924:     }
    925:   }

    927:   if (stash->first_assembly_done) {
    928:     PetscMPIInt i,tag;
    929:     PetscCommGetNewTag(stash->comm,&tag);
    930:     for (i=0; i<stash->nrecvranks; i++) {
    931:       MatStashBTSRecv_Private(stash->comm,&tag,stash->recvranks[i],&stash->recvhdr[i],&stash->recvreqs[i],stash);
    932:     }
    933:     for (i=0; i<stash->nsendranks; i++) {
    934:       MatStashBTSSend_Private(stash->comm,&tag,i,stash->sendranks[i],&stash->sendhdr[i],&stash->sendreqs[i],stash);
    935:     }
    936:     stash->use_status = PETSC_TRUE; /* Use count from message status. */
    937:   } else {
    938:     PetscCommBuildTwoSidedFReq(stash->comm,1,MPIU_INT,stash->nsendranks,stash->sendranks,(PetscInt*)stash->sendhdr,
    939:                                       &stash->nrecvranks,&stash->recvranks,(PetscInt*)&stash->recvhdr,1,&stash->sendreqs,&stash->recvreqs,
    940:                                       MatStashBTSSend_Private,MatStashBTSRecv_Private,stash);
    941:     PetscMalloc2(stash->nrecvranks,&stash->some_indices,stash->nrecvranks,&stash->some_statuses);
    942:     stash->use_status = PETSC_FALSE; /* Use count from header instead of from message. */
    943:   }

    945:   PetscSegBufferExtractInPlace(stash->segrecvframe,&stash->recvframes);
    946:   stash->recvframe_active     = NULL;
    947:   stash->recvframe_i          = 0;
    948:   stash->some_i               = 0;
    949:   stash->some_count           = 0;
    950:   stash->recvcount            = 0;
    951:   stash->first_assembly_done  = mat->assembly_subset; /* See the same logic in VecAssemblyBegin_MPI_BTS */
    952:   stash->insertmode           = &mat->insertmode;
    953:   return(0);
    954: }

    956: static PetscErrorCode MatStashScatterGetMesg_BTS(MatStash *stash,PetscMPIInt *n,PetscInt **row,PetscInt **col,PetscScalar **val,PetscInt *flg)
    957: {
    959:   MatStashBlock *block;

    962:   *flg = 0;
    963:   while (!stash->recvframe_active || stash->recvframe_i == stash->recvframe_count) {
    964:     if (stash->some_i == stash->some_count) {
    965:       if (stash->recvcount == stash->nrecvranks) return(0); /* Done */
    966:       MPI_Waitsome(stash->nrecvranks,stash->recvreqs,&stash->some_count,stash->some_indices,stash->use_status?stash->some_statuses:MPI_STATUSES_IGNORE);
    967:       stash->some_i = 0;
    968:     }
    969:     stash->recvframe_active = &stash->recvframes[stash->some_indices[stash->some_i]];
    970:     stash->recvframe_count = stash->recvframe_active->count; /* From header; maximum count */
    971:     if (stash->use_status) { /* Count what was actually sent */
    972:       MPI_Get_count(&stash->some_statuses[stash->some_i],stash->blocktype,&stash->recvframe_count);
    973:     }
    974:     if (stash->recvframe_count > 0) { /* Check for InsertMode consistency */
    975:       block = (MatStashBlock*)&((char*)stash->recvframe_active->buffer)[0];
    976:       if (PetscUnlikely(*stash->insertmode == NOT_SET_VALUES)) *stash->insertmode = block->row < 0 ? INSERT_VALUES : ADD_VALUES;
    977:       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]]);
    978:       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]]);
    979:     }
    980:     stash->some_i++;
    981:     stash->recvcount++;
    982:     stash->recvframe_i = 0;
    983:   }
    984:   *n = 1;
    985:   block = (MatStashBlock*)&((char*)stash->recvframe_active->buffer)[stash->recvframe_i*stash->blocktype_size];
    986:   if (block->row < 0) block->row = -(block->row + 1);
    987:   *row = &block->row;
    988:   *col = &block->col;
    989:   *val = block->vals;
    990:   stash->recvframe_i++;
    991:   *flg = 1;
    992:   return(0);
    993: }

    995: static PetscErrorCode MatStashScatterEnd_BTS(MatStash *stash)
    996: {

    1000:   MPI_Waitall(stash->nsendranks,stash->sendreqs,MPI_STATUSES_IGNORE);
    1001:   if (stash->first_assembly_done) { /* Reuse the communication contexts, so consolidate and reset segrecvblocks  */
    1002:     void *dummy;
    1003:     PetscSegBufferExtractInPlace(stash->segrecvblocks,&dummy);
    1004:   } else {                      /* No reuse, so collect everything. */
    1005:     MatStashScatterDestroy_BTS(stash);
    1006:   }

    1008:   /* Now update nmaxold to be app 10% more than max n used, this way the
    1009:      wastage of space is reduced the next time this stash is used.
    1010:      Also update the oldmax, only if it increases */
    1011:   if (stash->n) {
    1012:     PetscInt bs2     = stash->bs*stash->bs;
    1013:     PetscInt oldnmax = ((int)(stash->n * 1.1) + 5)*bs2;
    1014:     if (oldnmax > stash->oldnmax) stash->oldnmax = oldnmax;
    1015:   }

    1017:   stash->nmax       = 0;
    1018:   stash->n          = 0;
    1019:   stash->reallocs   = -1;
    1020:   stash->nprocessed = 0;

    1022:   PetscMatStashSpaceDestroy(&stash->space_head);

    1024:   stash->space = NULL;

    1026:   return(0);
    1027: }

    1029: PetscErrorCode MatStashScatterDestroy_BTS(MatStash *stash)
    1030: {

    1034:   PetscSegBufferDestroy(&stash->segsendblocks);
    1035:   PetscSegBufferDestroy(&stash->segrecvframe);
    1036:   stash->recvframes = NULL;
    1037:   PetscSegBufferDestroy(&stash->segrecvblocks);
    1038:   if (stash->blocktype != MPI_DATATYPE_NULL) {
    1039:     MPI_Type_free(&stash->blocktype);
    1040:   }
    1041:   stash->nsendranks = 0;
    1042:   stash->nrecvranks = 0;
    1043:   PetscFree3(stash->sendranks,stash->sendhdr,stash->sendframes);
    1044:   PetscFree(stash->sendreqs);
    1045:   PetscFree(stash->recvreqs);
    1046:   PetscFree(stash->recvranks);
    1047:   PetscFree(stash->recvhdr);
    1048:   PetscFree2(stash->some_indices,stash->some_statuses);
    1049:   return(0);
    1050: }
    1051: #endif