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;

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

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

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

     82:   PetscOptionsGetBool(NULL,NULL,"-matstash_reproduce",&stash->reproduce,NULL);
     83: #if !defined(PETSC_HAVE_MPIUNI)
     84:   flg  = PETSC_FALSE;
     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 = NULL;

    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: PETSC_INTERN 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 = NULL;

    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 && values[i] == 0.0) continue;
    281:     space->idx[k] = row;
    282:     space->idy[k] = idxn[i];
    283:     space->val[k] = values ? values[i] : 0.0;
    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 && values[i*stepval] == 0.0) continue;
    322:     space->idx[k] = row;
    323:     space->idy[k] = idxn[i];
    324:     space->val[k] = values ? values[i*stepval] : 0.0;
    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] = values ? vals[k] : 0.0;
    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] = values ? vals[k] : 0.0;
    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:
    453:     The 'owners' array in the cased of the blocked-stash has the
    454:   ranges specified blocked global indices, and for the regular stash in
    455:   the proper global indices.
    456: */
    457: PetscErrorCode MatStashScatterBegin_Private(Mat mat,MatStash *stash,PetscInt *owners)
    458: {

    462:   (*stash->ScatterBegin)(mat,stash,owners);
    463:   return(0);
    464: }

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

    481:   {                             /* make sure all processors are either in INSERTMODE or ADDMODE */
    482:     InsertMode addv;
    483:     MPIU_Allreduce((PetscEnum*)&mat->insertmode,(PetscEnum*)&addv,1,MPIU_ENUM,MPI_BOR,PetscObjectComm((PetscObject)mat));
    484:     if (addv == (ADD_VALUES|INSERT_VALUES)) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_ARG_WRONGSTATE,"Some processors inserted others added");
    485:     mat->insertmode = addv; /* in case this processor had no cache */
    486:   }

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

    490:   /*  first count number of contributors to each processor */
    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:   }

    514:   /* Now check what procs get messages - and compute nsends. */
    515:   PetscCalloc1(size,&sizes);
    516:   for (i=0, nsends=0; i<size; i++) {
    517:     if (nlengths[i]) {
    518:       sizes[i] = 1; nsends++;
    519:     }
    520:   }

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

    535:   /* do sends:
    536:       1) starts[i] gives the starting index in svalues for stuff going to
    537:          the ith processor
    538:   */
    539:   PetscMalloc2(bs2*stash->n,&svalues,2*(stash->n+1),&sindices);
    540:   PetscMalloc1(2*nsends,&send_waits);
    541:   PetscMalloc2(size,&startv,size,&starti);
    542:   /* use 2 sends the first with all_a, the next with all_i and all_j */
    543:   startv[0] = 0; starti[0] = 0;
    544:   for (i=1; i<size; i++) {
    545:     startv[i] = startv[i-1] + nlengths[i-1];
    546:     starti[i] = starti[i-1] + 2*nlengths[i-1];
    547:   }

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

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

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

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

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

    609:   stash->svalues         = svalues;
    610:   stash->sindices        = sindices;
    611:   stash->rvalues         = rvalues;
    612:   stash->rindices        = rindices;
    613:   stash->send_waits      = send_waits;
    614:   stash->nsends          = nsends;
    615:   stash->nrecvs          = nreceives;
    616:   stash->reproduce_count = 0;
    617:   return(0);
    618: }

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

    626:    Input Parameters:
    627:    stash - the stash

    629:    Output Parameters:
    630:    nvals - the number of entries in the current message.
    631:    rows  - an array of row indices (or blocked indices) corresponding to the values
    632:    cols  - an array of columnindices (or blocked indices) corresponding to the values
    633:    vals  - the values
    634:    flg   - 0 indicates no more message left, and the current call has no values associated.
    635:            1 indicates that the current call successfully received a message, and the
    636:              other output parameters nvals,rows,cols,vals are set appropriately.
    637: */
    638: PetscErrorCode MatStashScatterGetMesg_Private(MatStash *stash,PetscMPIInt *nvals,PetscInt **rows,PetscInt **cols,PetscScalar **vals,PetscInt *flg)
    639: {

    643:   (*stash->ScatterGetMesg)(stash,nvals,rows,cols,vals,flg);
    644:   return(0);
    645: }

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

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

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

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

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

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

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

    684:       *nvals = *nvals/2; /* This message has both row indices and col indices */
    685:     }

    687:     /* Check if we have both messages from this proc */
    688:     i1 = flg_v[2*recv_status.MPI_SOURCE];
    689:     i2 = flg_v[2*recv_status.MPI_SOURCE+1];
    690:     if (i1 != -1 && i2 != -1) {
    691:       *rows = stash->rindices[i2];
    692:       *cols = *rows + *nvals;
    693:       *vals = stash->rvalues[i1];
    694:       *flg  = 1;
    695:       stash->nprocessed++;
    696:       match_found = PETSC_TRUE;
    697:     }
    698:   }
    699:   return(0);
    700: }

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

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

    717:   PetscMalloc4(n,&row,n,&col,n,&valptr,n,&perm);
    718:   for (space=stash->space_head,cnt=0; space; space=space->next) {
    719:     for (i=0; i<space->local_used; i++) {
    720:       row[cnt] = space->idx[i];
    721:       col[cnt] = space->idy[i];
    722:       valptr[cnt] = &space->val[i*bs2];
    723:       perm[cnt] = cnt;          /* Will tell us where to find valptr after sorting row[] and col[] */
    724:       cnt++;
    725:     }
    726:   }
    727:   if (cnt != n) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB,"MatStash n %D, but counted %D entries",n,cnt);
    728:   PetscSortIntWithArrayPair(n,row,col,perm);
    729:   /* Scan through the rows, sorting each one, combining duplicates, and packing send buffers */
    730:   for (rowstart=0,cnt=0,i=1; i<=n; i++) {
    731:     if (i == n || row[i] != row[rowstart]) {         /* Sort the last row. */
    732:       PetscInt colstart;
    733:       PetscSortIntWithArray(i-rowstart,&col[rowstart],&perm[rowstart]);
    734:       for (colstart=rowstart; colstart<i;) { /* Compress multiple insertions to the same location */
    735:         PetscInt j,l;
    736:         MatStashBlock *block;
    737:         PetscSegBufferGet(stash->segsendblocks,1,&block);
    738:         block->row = row[rowstart];
    739:         block->col = col[colstart];
    740:         PetscArraycpy(block->vals,valptr[perm[colstart]],bs2);
    741:         for (j=colstart+1; j<i && col[j] == col[colstart]; j++) { /* Add any extra stashed blocks at the same (row,col) */
    742:           if (insertmode == ADD_VALUES) {
    743:             for (l=0; l<bs2; l++) block->vals[l] += valptr[perm[j]][l];
    744:           } else {
    745:             PetscArraycpy(block->vals,valptr[perm[j]],bs2);
    746:           }
    747:         }
    748:         colstart = j;
    749:       }
    750:       rowstart = i;
    751:     }
    752:   }
    753:   PetscFree4(row,col,valptr,perm);
    754:   return(0);
    755: }

    757: static PetscErrorCode MatStashBlockTypeSetUp(MatStash *stash)
    758: {

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

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

    785:     stash->blocktype_size = offsetof(struct DummyBlock,vals) + bs2*sizeof(PetscScalar);
    786:     if (stash->blocktype_size % sizeof(PetscInt)) { /* Implies that PetscInt is larger and does not satisfy alignment without padding */
    787:       stash->blocktype_size += sizeof(PetscInt) - stash->blocktype_size % sizeof(PetscInt);
    788:     }
    789:     PetscSegBufferCreate(stash->blocktype_size,1,&stash->segsendblocks);
    790:     PetscSegBufferCreate(stash->blocktype_size,1,&stash->segrecvblocks);
    791:     PetscSegBufferCreate(sizeof(MatStashFrame),1,&stash->segrecvframe);
    792:     blocklens[0] = 2;
    793:     blocklens[1] = bs2;
    794:     displs[0] = offsetof(struct DummyBlock,row);
    795:     displs[1] = offsetof(struct DummyBlock,vals);
    796:     types[0] = MPIU_INT;
    797:     types[1] = MPIU_SCALAR;
    798:     MPI_Type_create_struct(2,blocklens,displs,types,&stype);
    799:     MPI_Type_commit(&stype);
    800:     MPI_Type_create_resized(stype,0,stash->blocktype_size,&stash->blocktype);
    801:     MPI_Type_commit(&stash->blocktype);
    802:     MPI_Type_free(&stype);
    803:   }
    804:   return(0);
    805: }

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

    817:   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]);
    818:   MPI_Isend(stash->sendframes[rankid].buffer,hdr->count,stash->blocktype,rank,tag[0],comm,&req[0]);
    819:   stash->sendframes[rankid].count = hdr->count;
    820:   stash->sendframes[rankid].pending = 1;
    821:   return(0);
    822: }

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

    835:   PetscSegBufferGet(stash->segrecvframe,1,&frame);
    836:   PetscSegBufferGet(stash->segrecvblocks,hdr->count,&frame->buffer);
    837:   MPI_Irecv(frame->buffer,hdr->count,stash->blocktype,rank,tag[0],comm,&req[0]);
    838:   frame->count = hdr->count;
    839:   frame->pending = 1;
    840:   return(0);
    841: }

    843: /*
    844:  * owners[] contains the ownership ranges; may be indexed by either blocks or scalars
    845:  */
    846: static PetscErrorCode MatStashScatterBegin_BTS(Mat mat,MatStash *stash,PetscInt owners[])
    847: {
    849:   size_t nblocks;
    850:   char *sendblocks;

    853:   if (PetscDefined(USE_DEBUG)) { /* make sure all processors are either in INSERTMODE or ADDMODE */
    854:     InsertMode addv;
    855:     MPIU_Allreduce((PetscEnum*)&mat->insertmode,(PetscEnum*)&addv,1,MPIU_ENUM,MPI_BOR,PetscObjectComm((PetscObject)mat));
    856:     if (addv == (ADD_VALUES|INSERT_VALUES)) SETERRQ(PetscObjectComm((PetscObject)mat),PETSC_ERR_ARG_WRONGSTATE,"Some processors inserted others added");
    857:   }

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

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

    897:     /* Set up sendhdrs and sendframes */
    898:     sendno = 0;
    899:     for (rowstart=0; rowstart<nblocks;) {
    900:       PetscInt owner;
    901:       MatStashBlock *sendblock_rowstart = (MatStashBlock*)&sendblocks[rowstart*stash->blocktype_size];
    902:       PetscFindInt(sendblock_rowstart->row,stash->size+1,owners,&owner);
    903:       if (owner < 0) owner = -(owner+2);
    904:       stash->sendranks[sendno] = owner;
    905:       for (i=rowstart+1; i<nblocks; i++) { /* Move forward through a run of blocks with the same owner */
    906:         MatStashBlock *sendblock_i = (MatStashBlock*)&sendblocks[i*stash->blocktype_size];
    907:         if (sendblock_i->row >= owners[owner+1]) break;
    908:       }
    909:       stash->sendframes[sendno].buffer = sendblock_rowstart;
    910:       stash->sendframes[sendno].pending = 0;
    911:       stash->sendhdr[sendno].count = i - rowstart;
    912:       sendno++;
    913:       rowstart = i;
    914:     }
    915:     if (sendno != stash->nsendranks) SETERRQ2(stash->comm,PETSC_ERR_PLIB,"BTS counted %D sendranks, but %D sends",stash->nsendranks,sendno);
    916:   }

    918:   /* Encode insertmode on the outgoing messages. If we want to support more than two options, we would need a new
    919:    * message or a dummy entry of some sort. */
    920:   if (mat->insertmode == INSERT_VALUES) {
    921:     size_t i;
    922:     for (i=0; i<nblocks; i++) {
    923:       MatStashBlock *sendblock_i = (MatStashBlock*)&sendblocks[i*stash->blocktype_size];
    924:       sendblock_i->row = -(sendblock_i->row+1);
    925:     }
    926:   }

    928:   if (stash->first_assembly_done) {
    929:     PetscMPIInt i,tag;
    930:     PetscCommGetNewTag(stash->comm,&tag);
    931:     for (i=0; i<stash->nrecvranks; i++) {
    932:       MatStashBTSRecv_Private(stash->comm,&tag,stash->recvranks[i],&stash->recvhdr[i],&stash->recvreqs[i],stash);
    933:     }
    934:     for (i=0; i<stash->nsendranks; i++) {
    935:       MatStashBTSSend_Private(stash->comm,&tag,i,stash->sendranks[i],&stash->sendhdr[i],&stash->sendreqs[i],stash);
    936:     }
    937:     stash->use_status = PETSC_TRUE; /* Use count from message status. */
    938:   } else {
    939:     PetscCommBuildTwoSidedFReq(stash->comm,1,MPIU_INT,stash->nsendranks,stash->sendranks,(PetscInt*)stash->sendhdr,
    940:                                       &stash->nrecvranks,&stash->recvranks,(PetscInt*)&stash->recvhdr,1,&stash->sendreqs,&stash->recvreqs,
    941:                                       MatStashBTSSend_Private,MatStashBTSRecv_Private,stash);
    942:     PetscMalloc2(stash->nrecvranks,&stash->some_indices,stash->nrecvranks,&stash->some_statuses);
    943:     stash->use_status = PETSC_FALSE; /* Use count from header instead of from message. */
    944:   }

    946:   PetscSegBufferExtractInPlace(stash->segrecvframe,&stash->recvframes);
    947:   stash->recvframe_active     = NULL;
    948:   stash->recvframe_i          = 0;
    949:   stash->some_i               = 0;
    950:   stash->some_count           = 0;
    951:   stash->recvcount            = 0;
    952:   stash->first_assembly_done  = mat->assembly_subset; /* See the same logic in VecAssemblyBegin_MPI_BTS */
    953:   stash->insertmode           = &mat->insertmode;
    954:   return(0);
    955: }

    957: static PetscErrorCode MatStashScatterGetMesg_BTS(MatStash *stash,PetscMPIInt *n,PetscInt **row,PetscInt **col,PetscScalar **val,PetscInt *flg)
    958: {
    960:   MatStashBlock *block;

    963:   *flg = 0;
    964:   while (!stash->recvframe_active || stash->recvframe_i == stash->recvframe_count) {
    965:     if (stash->some_i == stash->some_count) {
    966:       if (stash->recvcount == stash->nrecvranks) return(0); /* Done */
    967:       MPI_Waitsome(stash->nrecvranks,stash->recvreqs,&stash->some_count,stash->some_indices,stash->use_status?stash->some_statuses:MPI_STATUSES_IGNORE);
    968:       stash->some_i = 0;
    969:     }
    970:     stash->recvframe_active = &stash->recvframes[stash->some_indices[stash->some_i]];
    971:     stash->recvframe_count = stash->recvframe_active->count; /* From header; maximum count */
    972:     if (stash->use_status) { /* Count what was actually sent */
    973:       MPI_Get_count(&stash->some_statuses[stash->some_i],stash->blocktype,&stash->recvframe_count);
    974:     }
    975:     if (stash->recvframe_count > 0) { /* Check for InsertMode consistency */
    976:       block = (MatStashBlock*)&((char*)stash->recvframe_active->buffer)[0];
    977:       if (PetscUnlikely(*stash->insertmode == NOT_SET_VALUES)) *stash->insertmode = block->row < 0 ? INSERT_VALUES : ADD_VALUES;
    978:       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]]);
    979:       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]]);
    980:     }
    981:     stash->some_i++;
    982:     stash->recvcount++;
    983:     stash->recvframe_i = 0;
    984:   }
    985:   *n = 1;
    986:   block = (MatStashBlock*)&((char*)stash->recvframe_active->buffer)[stash->recvframe_i*stash->blocktype_size];
    987:   if (block->row < 0) block->row = -(block->row + 1);
    988:   *row = &block->row;
    989:   *col = &block->col;
    990:   *val = block->vals;
    991:   stash->recvframe_i++;
    992:   *flg = 1;
    993:   return(0);
    994: }

    996: static PetscErrorCode MatStashScatterEnd_BTS(MatStash *stash)
    997: {

    1001:   MPI_Waitall(stash->nsendranks,stash->sendreqs,MPI_STATUSES_IGNORE);
    1002:   if (stash->first_assembly_done) { /* Reuse the communication contexts, so consolidate and reset segrecvblocks  */
    1003:     void *dummy;
    1004:     PetscSegBufferExtractInPlace(stash->segrecvblocks,&dummy);
    1005:   } else {                      /* No reuse, so collect everything. */
    1006:     MatStashScatterDestroy_BTS(stash);
    1007:   }

    1009:   /* Now update nmaxold to be app 10% more than max n used, this way the
    1010:      wastage of space is reduced the next time this stash is used.
    1011:      Also update the oldmax, only if it increases */
    1012:   if (stash->n) {
    1013:     PetscInt bs2     = stash->bs*stash->bs;
    1014:     PetscInt oldnmax = ((int)(stash->n * 1.1) + 5)*bs2;
    1015:     if (oldnmax > stash->oldnmax) stash->oldnmax = oldnmax;
    1016:   }

    1018:   stash->nmax       = 0;
    1019:   stash->n          = 0;
    1020:   stash->reallocs   = -1;
    1021:   stash->nprocessed = 0;

    1023:   PetscMatStashSpaceDestroy(&stash->space_head);

    1025:   stash->space = NULL;

    1027:   return(0);
    1028: }

    1030: PetscErrorCode MatStashScatterDestroy_BTS(MatStash *stash)
    1031: {

    1035:   PetscSegBufferDestroy(&stash->segsendblocks);
    1036:   PetscSegBufferDestroy(&stash->segrecvframe);
    1037:   stash->recvframes = NULL;
    1038:   PetscSegBufferDestroy(&stash->segrecvblocks);
    1039:   if (stash->blocktype != MPI_DATATYPE_NULL) {
    1040:     MPI_Type_free(&stash->blocktype);
    1041:   }
    1042:   stash->nsendranks = 0;
    1043:   stash->nrecvranks = 0;
    1044:   PetscFree3(stash->sendranks,stash->sendhdr,stash->sendframes);
    1045:   PetscFree(stash->sendreqs);
    1046:   PetscFree(stash->recvreqs);
    1047:   PetscFree(stash->recvranks);
    1048:   PetscFree(stash->recvhdr);
    1049:   PetscFree2(stash->some_indices,stash->some_statuses);
    1050:   return(0);
    1051: }
    1052: #endif