Date: 2026-06-01T23:13:52+00:00

Actual source code: ex1.c

      1: static const char help[] = "Test star forest communication (PetscSF)\n\n";

      3: /*
      4:     Description: A star is a simple tree with one root and zero or more leaves.
      5:     A star forest is a union of disjoint stars.
      6:     Many common communication patterns can be expressed as updates of rootdata using leafdata and vice-versa.
      7:     This example creates a star forest, communicates values using the graph (see options for types of communication), views the graph, then destroys it.
      8: */

     10: /*
     11:   Include petscsf.h so we can use PetscSF objects. Note that this automatically
     12:   includes petscsys.h.
     13: */
     14: #include <petscsf.h>
     15: #include <petscviewer.h>

     17: /* like PetscSFView() but with alternative array of local indices */
     18: static PetscErrorCode PetscSFViewCustomLocals_Private(PetscSF sf, const PetscInt locals[], PetscViewer viewer)
     19: {
     20:   const PetscSFNode *iremote;
     21:   PetscInt           i, nroots, nleaves;
     22:   PetscMPIInt        rank, nranks;

     24:   PetscFunctionBeginUser;
     25:   PetscCallMPI(MPI_Comm_rank(PetscObjectComm((PetscObject)sf), &rank));
     26:   PetscCall(PetscSFGetGraph(sf, &nroots, &nleaves, NULL, &iremote));
     27:   PetscCall(PetscSFGetRootRanks(sf, &nranks, NULL, NULL, NULL, NULL));
     28:   PetscCall(PetscViewerASCIIPushTab(viewer));
     29:   PetscCall(PetscViewerASCIIPushSynchronized(viewer));
     30:   PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "[%d] Number of roots=%" PetscInt_FMT ", leaves=%" PetscInt_FMT ", remote ranks=%d\n", rank, nroots, nleaves, nranks));
     31:   for (i = 0; i < nleaves; i++) PetscCall(PetscViewerASCIISynchronizedPrintf(viewer, "[%d] %" PetscInt_FMT " <- (%d,%" PetscInt_FMT ")\n", rank, locals[i], (PetscMPIInt)iremote[i].rank, iremote[i].index));
     32:   PetscCall(PetscViewerFlush(viewer));
     33:   PetscCall(PetscViewerASCIIPopTab(viewer));
     34:   PetscCall(PetscViewerASCIIPopSynchronized(viewer));
     35:   PetscFunctionReturn(PETSC_SUCCESS);
     36: }

     38: int main(int argc, char **argv)
     39: {
     40:   PetscInt     i, bs = 2, nroots, nrootsalloc, nleaves, nleavesalloc, *mine, stride;
     41:   PetscSFNode *remote;
     42:   PetscMPIInt  rank, size;
     43:   PetscSF      sf, vsf;
     44:   PetscBool    test_all, test_bcast, test_bcastop, test_reduce, test_degree, test_fetchandop, test_gather, test_scatter, test_embed, test_invert, test_sf_distribute, test_char, test_vector = PETSC_FALSE;
     45:   MPI_Op       mop = MPI_OP_NULL; /* initialize to prevent compiler warnings with cxx_quad build */
     46:   char         opstring[256];
     47:   PetscBool    strflg;

     49:   PetscFunctionBeginUser;
     50:   PetscCall(PetscInitialize(&argc, &argv, NULL, help));
     51:   PetscCallMPI(MPI_Comm_rank(PETSC_COMM_WORLD, &rank));
     52:   PetscCallMPI(MPI_Comm_size(PETSC_COMM_WORLD, &size));

     54:   PetscOptionsBegin(PETSC_COMM_WORLD, "", "PetscSF Test Options", "none");
     55:   test_all = PETSC_FALSE;
     56:   PetscCall(PetscOptionsBool("-test_all", "Test all SF communications", "", test_all, &test_all, NULL));
     57:   test_bcast = test_all;
     58:   PetscCall(PetscOptionsBool("-test_bcast", "Test broadcast", "", test_bcast, &test_bcast, NULL));
     59:   test_bcastop = test_all;
     60:   PetscCall(PetscOptionsBool("-test_bcastop", "Test broadcast and reduce", "", test_bcastop, &test_bcastop, NULL));
     61:   test_reduce = test_all;
     62:   PetscCall(PetscOptionsBool("-test_reduce", "Test reduction", "", test_reduce, &test_reduce, NULL));
     63:   test_char = test_all;
     64:   PetscCall(PetscOptionsBool("-test_char", "Test signed char, unsigned char, and char", "", test_char, &test_char, NULL));
     65:   mop = MPI_SUM;
     66:   PetscCall(PetscStrncpy(opstring, "sum", sizeof(opstring)));
     67:   PetscCall(PetscOptionsString("-test_op", "Designate which MPI_Op to use", "", opstring, opstring, sizeof(opstring), NULL));
     68:   PetscCall(PetscStrcmp("sum", opstring, &strflg));
     69:   if (strflg) mop = MPIU_SUM;
     70:   PetscCall(PetscStrcmp("prod", opstring, &strflg));
     71:   if (strflg) mop = MPI_PROD;
     72:   PetscCall(PetscStrcmp("max", opstring, &strflg));
     73:   if (strflg) mop = MPI_MAX;
     74:   PetscCall(PetscStrcmp("min", opstring, &strflg));
     75:   if (strflg) mop = MPI_MIN;
     76:   PetscCall(PetscStrcmp("land", opstring, &strflg));
     77:   if (strflg) mop = MPI_LAND;
     78:   PetscCall(PetscStrcmp("band", opstring, &strflg));
     79:   if (strflg) mop = MPI_BAND;
     80:   PetscCall(PetscStrcmp("lor", opstring, &strflg));
     81:   if (strflg) mop = MPI_LOR;
     82:   PetscCall(PetscStrcmp("bor", opstring, &strflg));
     83:   if (strflg) mop = MPI_BOR;
     84:   PetscCall(PetscStrcmp("lxor", opstring, &strflg));
     85:   if (strflg) mop = MPI_LXOR;
     86:   PetscCall(PetscStrcmp("bxor", opstring, &strflg));
     87:   if (strflg) mop = MPI_BXOR;
     88:   test_degree = test_all;
     89:   PetscCall(PetscOptionsBool("-test_degree", "Test computation of vertex degree", "", test_degree, &test_degree, NULL));
     90:   test_fetchandop = test_all;
     91:   PetscCall(PetscOptionsBool("-test_fetchandop", "Test atomic Fetch-And-Op", "", test_fetchandop, &test_fetchandop, NULL));
     92:   test_gather = test_all;
     93:   PetscCall(PetscOptionsBool("-test_gather", "Test point gather", "", test_gather, &test_gather, NULL));
     94:   test_scatter = test_all;
     95:   PetscCall(PetscOptionsBool("-test_scatter", "Test point scatter", "", test_scatter, &test_scatter, NULL));
     96:   test_embed = test_all;
     97:   PetscCall(PetscOptionsBool("-test_embed", "Test point embed", "", test_embed, &test_embed, NULL));
     98:   test_invert = test_all;
     99:   PetscCall(PetscOptionsBool("-test_invert", "Test point invert", "", test_invert, &test_invert, NULL));
    100:   stride = 1;
    101:   PetscCall(PetscOptionsInt("-stride", "Stride for leaf and root data", "", stride, &stride, NULL));
    102:   test_sf_distribute = PETSC_FALSE;
    103:   PetscCall(PetscOptionsBool("-test_sf_distribute", "Create an SF that 'distributes' to each process, like an alltoall", "", test_sf_distribute, &test_sf_distribute, NULL));
    104:   PetscCall(PetscOptionsString("-test_op", "Designate which MPI_Op to use", "", opstring, opstring, sizeof(opstring), NULL));
    105:   PetscCall(PetscOptionsInt("-bs", "Block size for vectorial SF", "", bs, &bs, NULL));
    106:   PetscCall(PetscOptionsBool("-test_vector", "Run tests using the vectorial SF", "", test_vector, &test_vector, NULL));
    107:   PetscOptionsEnd();

    109:   if (test_sf_distribute) {
    110:     nroots       = size;
    111:     nrootsalloc  = size;
    112:     nleaves      = size;
    113:     nleavesalloc = size;
    114:     mine         = NULL;
    115:     PetscCall(PetscMalloc1(nleaves, &remote));
    116:     for (PetscMPIInt ii = 0; ii < size; ii++) {
    117:       remote[ii].rank  = ii;
    118:       remote[ii].index = rank;
    119:     }
    120:   } else {
    121:     nroots       = 2 + (PetscInt)(rank == 0);
    122:     nrootsalloc  = nroots * stride;
    123:     nleaves      = 2 + (PetscInt)(rank > 0);
    124:     nleavesalloc = nleaves * stride;
    125:     mine         = NULL;
    126:     if (stride > 1) {
    127:       PetscInt i;

    129:       PetscCall(PetscMalloc1(nleaves, &mine));
    130:       for (i = 0; i < nleaves; i++) mine[i] = stride * i;
    131:     }
    132:     PetscCall(PetscMalloc1(nleaves, &remote));
    133:     /* Left periodic neighbor */
    134:     remote[0].rank  = (rank + size - 1) % size;
    135:     remote[0].index = 1 * stride;
    136:     /* Right periodic neighbor */
    137:     remote[1].rank  = (rank + 1) % size;
    138:     remote[1].index = 0 * stride;
    139:     if (rank > 0) { /* All processes reference rank 0, index 1 */
    140:       remote[2].rank  = 0;
    141:       remote[2].index = 2 * stride;
    142:     }
    143:   }

    145:   /* Create a star forest for communication */
    146:   PetscCall(PetscSFCreate(PETSC_COMM_WORLD, &sf));
    147:   PetscCall(PetscSFSetFromOptions(sf));
    148:   PetscCall(PetscSFSetGraph(sf, nrootsalloc, nleaves, mine, PETSC_OWN_POINTER, remote, PETSC_OWN_POINTER));
    149:   PetscCall(PetscSFSetUp(sf));

    151:   /* We can also obtain a strided SF to communicate interleaved blocks of data */
    152:   PetscCall(PetscSFCreateStridedSF(sf, bs, PETSC_DECIDE, PETSC_DECIDE, &vsf));
    153:   if (test_vector) { /* perform all tests below using the vectorial SF */
    154:     PetscSF t = sf;

    156:     sf  = vsf;
    157:     vsf = t;

    159:     nroots *= bs;
    160:     nleaves *= bs;
    161:     nrootsalloc *= bs;
    162:     nleavesalloc *= bs;
    163:   }
    164:   PetscCall(PetscSFDestroy(&vsf));

    166:   /* View graph, mostly useful for debugging purposes. */
    167:   PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD, PETSC_VIEWER_ASCII_INFO_DETAIL));
    168:   PetscCall(PetscSFView(sf, PETSC_VIEWER_STDOUT_WORLD));
    169:   PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));

    171:   if (test_bcast) { /* broadcast rootdata into leafdata */
    172:     PetscInt *rootdata, *leafdata;
    173:     /* Allocate space for send and receive buffers. This example communicates PetscInt, but other types, including
    174:      * user-defined structures, could also be used. */
    175:     PetscCall(PetscMalloc2(nrootsalloc, &rootdata, nleavesalloc, &leafdata));
    176:     /* Set rootdata buffer to be broadcast */
    177:     for (i = 0; i < nrootsalloc; i++) rootdata[i] = -1;
    178:     for (i = 0; i < nroots; i++) rootdata[i * stride] = 100 * (rank + 1) + i;
    179:     /* Initialize local buffer, these values are never used. */
    180:     for (i = 0; i < nleavesalloc; i++) leafdata[i] = -1;
    181:     /* Broadcast entries from rootdata to leafdata. Computation or other communication can be performed between the begin and end calls. */
    182:     // test persistent communication code paths by repeated bcast several times
    183:     PetscCall(PetscSFRegisterPersistent(sf, MPIU_INT, rootdata, leafdata));
    184:     for (PetscInt i = 0; i < 10; i++) {
    185:       PetscCall(PetscSFBcastBegin(sf, MPIU_INT, rootdata, leafdata, MPI_REPLACE));
    186:       PetscCall(PetscSFBcastEnd(sf, MPIU_INT, rootdata, leafdata, MPI_REPLACE));
    187:     }
    188:     PetscCall(PetscSFDeregisterPersistent(sf, MPIU_INT, rootdata, leafdata));
    189:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Bcast Rootdata\n"));
    190:     PetscCall(PetscIntView(nrootsalloc, rootdata, PETSC_VIEWER_STDOUT_WORLD));
    191:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Bcast Leafdata\n"));
    192:     PetscCall(PetscIntView(nleavesalloc, leafdata, PETSC_VIEWER_STDOUT_WORLD));
    193:     PetscCall(PetscFree2(rootdata, leafdata));
    194:   }

    196:   if (test_bcast && test_char) { /* Bcast with char */
    197:     PetscInt len;
    198:     char     buf[256];
    199:     char    *rootdata, *leafdata;
    200:     PetscCall(PetscMalloc2(nrootsalloc, &rootdata, nleavesalloc, &leafdata));
    201:     /* Set rootdata buffer to be broadcast */
    202:     for (i = 0; i < nrootsalloc; i++) rootdata[i] = '*';
    203:     for (i = 0; i < nroots; i++) rootdata[i * stride] = (char)('A' + rank * 3 + i); /* rank is very small, so it is fine to compute a char */
    204:     /* Initialize local buffer, these values are never used. */
    205:     for (i = 0; i < nleavesalloc; i++) leafdata[i] = '?';

    207:     PetscCall(PetscSFBcastBegin(sf, MPI_CHAR, rootdata, leafdata, MPI_REPLACE));
    208:     PetscCall(PetscSFBcastEnd(sf, MPI_CHAR, rootdata, leafdata, MPI_REPLACE));

    210:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Bcast Rootdata in type of char\n"));
    211:     len = 0;
    212:     PetscCall(PetscSNPrintf(buf, 256, "%4d:", rank));
    213:     len += 5;
    214:     for (i = 0; i < nrootsalloc; i++) {
    215:       PetscCall(PetscSNPrintf(buf + len, 256 - len, "%5c", rootdata[i]));
    216:       len += 5;
    217:     }
    218:     PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD, "%s\n", buf));
    219:     PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD, PETSC_STDOUT));

    221:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Bcast Leafdata in type of char\n"));
    222:     len = 0;
    223:     PetscCall(PetscSNPrintf(buf, 256, "%4d:", rank));
    224:     len += 5;
    225:     for (i = 0; i < nleavesalloc; i++) {
    226:       PetscCall(PetscSNPrintf(buf + len, 256 - len, "%5c", leafdata[i]));
    227:       len += 5;
    228:     }
    229:     PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD, "%s\n", buf));
    230:     PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD, PETSC_STDOUT));

    232:     PetscCall(PetscFree2(rootdata, leafdata));
    233:   }

    235:   if (test_bcastop) { /* Reduce rootdata into leafdata */
    236:     PetscInt *rootdata, *leafdata;
    237:     /* Allocate space for send and receive buffers. This example communicates PetscInt, but other types, including
    238:      * user-defined structures, could also be used. */
    239:     PetscCall(PetscMalloc2(nrootsalloc, &rootdata, nleavesalloc, &leafdata));
    240:     /* Set rootdata buffer to be broadcast */
    241:     for (i = 0; i < nrootsalloc; i++) rootdata[i] = -1;
    242:     for (i = 0; i < nroots; i++) rootdata[i * stride] = 100 * (rank + 1) + i;
    243:     /* Set leaf values to reduce with */
    244:     for (i = 0; i < nleavesalloc; i++) leafdata[i] = -10 * (rank + 1) - i;
    245:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Pre-BcastAndOp Leafdata\n"));
    246:     PetscCall(PetscIntView(nleavesalloc, leafdata, PETSC_VIEWER_STDOUT_WORLD));
    247:     /* Broadcast entries from rootdata to leafdata. Computation or other communication can be performed between the begin and end calls. */
    248:     PetscCall(PetscSFBcastBegin(sf, MPIU_INT, rootdata, leafdata, mop));
    249:     PetscCall(PetscSFBcastEnd(sf, MPIU_INT, rootdata, leafdata, mop));
    250:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## BcastAndOp Rootdata\n"));
    251:     PetscCall(PetscIntView(nrootsalloc, rootdata, PETSC_VIEWER_STDOUT_WORLD));
    252:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## BcastAndOp Leafdata\n"));
    253:     PetscCall(PetscIntView(nleavesalloc, leafdata, PETSC_VIEWER_STDOUT_WORLD));
    254:     PetscCall(PetscFree2(rootdata, leafdata));
    255:   }

    257:   if (test_reduce) { /* Reduce leafdata into rootdata */
    258:     PetscInt *rootdata, *leafdata;
    259:     PetscCall(PetscMalloc2(nrootsalloc, &rootdata, nleavesalloc, &leafdata));
    260:     /* Initialize rootdata buffer in which the result of the reduction will appear. */
    261:     for (i = 0; i < nrootsalloc; i++) rootdata[i] = -1;
    262:     for (i = 0; i < nroots; i++) rootdata[i * stride] = 100 * (rank + 1) + i;
    263:     /* Set leaf values to reduce. */
    264:     for (i = 0; i < nleavesalloc; i++) leafdata[i] = -1;
    265:     for (i = 0; i < nleaves; i++) leafdata[i * stride] = 1000 * (rank + 1) + 10 * i;
    266:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Pre-Reduce Rootdata\n"));
    267:     PetscCall(PetscIntView(nrootsalloc, rootdata, PETSC_VIEWER_STDOUT_WORLD));
    268:     /* Perform reduction. Computation or other communication can be performed between the begin and end calls.
    269:      * This example sums the values, but other MPI_Ops can be used (e.g MPI_MAX, MPI_PROD). */
    270:     PetscCall(PetscSFReduceBegin(sf, MPIU_INT, leafdata, rootdata, mop));
    271:     PetscCall(PetscSFReduceEnd(sf, MPIU_INT, leafdata, rootdata, mop));
    272:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Reduce Leafdata\n"));
    273:     PetscCall(PetscIntView(nleavesalloc, leafdata, PETSC_VIEWER_STDOUT_WORLD));
    274:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Reduce Rootdata\n"));
    275:     PetscCall(PetscIntView(nrootsalloc, rootdata, PETSC_VIEWER_STDOUT_WORLD));
    276:     PetscCall(PetscFree2(rootdata, leafdata));
    277:   }

    279:   if (test_reduce && test_char) { /* Reduce with signed char */
    280:     PetscInt     len;
    281:     char         buf[256];
    282:     signed char *rootdata, *leafdata;
    283:     PetscCall(PetscMalloc2(nrootsalloc, &rootdata, nleavesalloc, &leafdata));
    284:     /* Initialize rootdata buffer in which the result of the reduction will appear. */
    285:     for (i = 0; i < nrootsalloc; i++) rootdata[i] = -1;
    286:     for (i = 0; i < nroots; i++) rootdata[i * stride] = (signed char)(10 * (rank + 1) + i);
    287:     /* Set leaf values to reduce. */
    288:     for (i = 0; i < nleavesalloc; i++) leafdata[i] = -1;
    289:     for (i = 0; i < nleaves; i++) leafdata[i * stride] = (signed char)(50 * (rank + 1) + 10 * i);
    290:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Pre-Reduce Rootdata in type of signed char\n"));

    292:     len = 0;
    293:     PetscCall(PetscSNPrintf(buf, 256, "%4d:", rank));
    294:     len += 5;
    295:     for (i = 0; i < nrootsalloc; i++) {
    296:       PetscCall(PetscSNPrintf(buf + len, 256 - len, "%5d", rootdata[i]));
    297:       len += 5;
    298:     }
    299:     PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD, "%s\n", buf));
    300:     PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD, PETSC_STDOUT));

    302:     /* Using MPI_CHAR should trigger an error since MPI standard does not support reduction on MPI_CHAR.
    303:        Testing with -test_op max, one can see the sign does take effect in MPI_MAX.
    304:      */
    305:     PetscCall(PetscSFReduceBegin(sf, MPI_SIGNED_CHAR, leafdata, rootdata, mop));
    306:     PetscCall(PetscSFReduceEnd(sf, MPI_SIGNED_CHAR, leafdata, rootdata, mop));

    308:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Reduce Leafdata in type of signed char\n"));
    309:     len = 0;
    310:     PetscCall(PetscSNPrintf(buf, 256, "%4d:", rank));
    311:     len += 5;
    312:     for (i = 0; i < nleavesalloc; i++) {
    313:       PetscCall(PetscSNPrintf(buf + len, 256 - len, "%5d", leafdata[i]));
    314:       len += 5;
    315:     }
    316:     PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD, "%s\n", buf));
    317:     PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD, PETSC_STDOUT));

    319:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Reduce Rootdata in type of signed char\n"));
    320:     len = 0;
    321:     PetscCall(PetscSNPrintf(buf, 256, "%4d:", rank));
    322:     len += 5;
    323:     for (i = 0; i < nrootsalloc; i++) {
    324:       PetscCall(PetscSNPrintf(buf + len, 256 - len, "%5d", rootdata[i]));
    325:       len += 5;
    326:     }
    327:     PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD, "%s\n", buf));
    328:     PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD, PETSC_STDOUT));

    330:     PetscCall(PetscFree2(rootdata, leafdata));
    331:   }

    333:   if (test_reduce && test_char) { /* Reduce with unsigned char */
    334:     PetscInt       len;
    335:     char           buf[256];
    336:     unsigned char *rootdata, *leafdata;
    337:     PetscCall(PetscMalloc2(nrootsalloc, &rootdata, nleavesalloc, &leafdata));
    338:     /* Initialize rootdata buffer in which the result of the reduction will appear. */
    339:     for (i = 0; i < nrootsalloc; i++) rootdata[i] = 0;
    340:     for (i = 0; i < nroots; i++) rootdata[i * stride] = (unsigned char)(10 * (rank + 1) + i);
    341:     /* Set leaf values to reduce. */
    342:     for (i = 0; i < nleavesalloc; i++) leafdata[i] = 0;
    343:     for (i = 0; i < nleaves; i++) leafdata[i * stride] = (unsigned char)(50 * (rank + 1) + 10 * i);
    344:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Pre-Reduce Rootdata in type of unsigned char\n"));

    346:     len = 0;
    347:     PetscCall(PetscSNPrintf(buf, 256, "%4d:", rank));
    348:     len += 5;
    349:     for (i = 0; i < nrootsalloc; i++) {
    350:       PetscCall(PetscSNPrintf(buf + len, 256 - len, "%5u", rootdata[i]));
    351:       len += 5;
    352:     }
    353:     PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD, "%s\n", buf));
    354:     PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD, PETSC_STDOUT));

    356:     /* Using MPI_CHAR should trigger an error since MPI standard does not support reduction on MPI_CHAR.
    357:        Testing with -test_op max, one can see the sign does take effect in MPI_MAX.
    358:      */
    359:     PetscCall(PetscSFReduceBegin(sf, MPI_UNSIGNED_CHAR, leafdata, rootdata, mop));
    360:     PetscCall(PetscSFReduceEnd(sf, MPI_UNSIGNED_CHAR, leafdata, rootdata, mop));

    362:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Reduce Leafdata in type of unsigned char\n"));
    363:     len = 0;
    364:     PetscCall(PetscSNPrintf(buf, 256, "%4d:", rank));
    365:     len += 5;
    366:     for (i = 0; i < nleavesalloc; i++) {
    367:       PetscCall(PetscSNPrintf(buf + len, 256 - len, "%5u", leafdata[i]));
    368:       len += 5;
    369:     }
    370:     PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD, "%s\n", buf));
    371:     PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD, PETSC_STDOUT));

    373:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Reduce Rootdata in type of unsigned char\n"));
    374:     len = 0;
    375:     PetscCall(PetscSNPrintf(buf, 256, "%4d:", rank));
    376:     len += 5;
    377:     for (i = 0; i < nrootsalloc; i++) {
    378:       PetscCall(PetscSNPrintf(buf + len, 256 - len, "%5u", rootdata[i]));
    379:       len += 5;
    380:     }
    381:     PetscCall(PetscSynchronizedPrintf(PETSC_COMM_WORLD, "%s\n", buf));
    382:     PetscCall(PetscSynchronizedFlush(PETSC_COMM_WORLD, PETSC_STDOUT));

    384:     PetscCall(PetscFree2(rootdata, leafdata));
    385:   }

    387:   if (test_degree) {
    388:     const PetscInt *degree;
    389:     PetscCall(PetscSFComputeDegreeBegin(sf, &degree));
    390:     PetscCall(PetscSFComputeDegreeEnd(sf, &degree));
    391:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Root degrees\n"));
    392:     PetscCall(PetscIntView(nrootsalloc, degree, PETSC_VIEWER_STDOUT_WORLD));
    393:   }

    395:   if (test_fetchandop) {
    396:     /* Cannot use text compare here because token ordering is not deterministic */
    397:     PetscInt *leafdata, *leafupdate, *rootdata;
    398:     PetscCall(PetscMalloc3(nleavesalloc, &leafdata, nleavesalloc, &leafupdate, nrootsalloc, &rootdata));
    399:     for (i = 0; i < nleavesalloc; i++) leafdata[i] = -1;
    400:     for (i = 0; i < nleaves; i++) leafdata[i * stride] = 1;
    401:     for (i = 0; i < nrootsalloc; i++) rootdata[i] = -1;
    402:     for (i = 0; i < nroots; i++) rootdata[i * stride] = 0;
    403:     PetscCall(PetscSFFetchAndOpBegin(sf, MPIU_INT, rootdata, leafdata, leafupdate, mop));
    404:     PetscCall(PetscSFFetchAndOpEnd(sf, MPIU_INT, rootdata, leafdata, leafupdate, mop));
    405:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Rootdata (sum of 1 from each leaf)\n"));
    406:     PetscCall(PetscIntView(nrootsalloc, rootdata, PETSC_VIEWER_STDOUT_WORLD));
    407:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Leafupdate (value at roots prior to my atomic update)\n"));
    408:     PetscCall(PetscIntView(nleavesalloc, leafupdate, PETSC_VIEWER_STDOUT_WORLD));
    409:     PetscCall(PetscFree3(leafdata, leafupdate, rootdata));
    410:   }

    412:   if (test_gather) {
    413:     const PetscInt *degree;
    414:     PetscInt        inedges, *indata, *outdata;
    415:     PetscCall(PetscSFComputeDegreeBegin(sf, &degree));
    416:     PetscCall(PetscSFComputeDegreeEnd(sf, &degree));
    417:     for (i = 0, inedges = 0; i < nrootsalloc; i++) inedges += degree[i];
    418:     PetscCall(PetscMalloc2(inedges, &indata, nleavesalloc, &outdata));
    419:     for (i = 0; i < nleavesalloc; i++) outdata[i] = -1;
    420:     for (i = 0; i < nleaves; i++) outdata[i * stride] = 1000 * (rank + 1) + i;
    421:     PetscCall(PetscSFGatherBegin(sf, MPIU_INT, outdata, indata));
    422:     PetscCall(PetscSFGatherEnd(sf, MPIU_INT, outdata, indata));
    423:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Gathered data at multi-roots from leaves\n"));
    424:     PetscCall(PetscIntView(inedges, indata, PETSC_VIEWER_STDOUT_WORLD));
    425:     PetscCall(PetscFree2(indata, outdata));
    426:   }

    428:   if (test_scatter) {
    429:     const PetscInt *degree;
    430:     PetscInt        j, count, inedges, *indata, *outdata;
    431:     PetscCall(PetscSFComputeDegreeBegin(sf, &degree));
    432:     PetscCall(PetscSFComputeDegreeEnd(sf, &degree));
    433:     for (i = 0, inedges = 0; i < nrootsalloc; i++) inedges += degree[i];
    434:     PetscCall(PetscMalloc2(inedges, &indata, nleavesalloc, &outdata));
    435:     for (i = 0; i < nleavesalloc; i++) outdata[i] = -1;
    436:     for (i = 0, count = 0; i < nrootsalloc; i++) {
    437:       for (j = 0; j < degree[i]; j++) indata[count++] = 1000 * (rank + 1) + 100 * i + j;
    438:     }
    439:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Data at multi-roots, to scatter to leaves\n"));
    440:     PetscCall(PetscIntView(inedges, indata, PETSC_VIEWER_STDOUT_WORLD));

    442:     PetscCall(PetscSFScatterBegin(sf, MPIU_INT, indata, outdata));
    443:     PetscCall(PetscSFScatterEnd(sf, MPIU_INT, indata, outdata));
    444:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Scattered data at leaves\n"));
    445:     PetscCall(PetscIntView(nleavesalloc, outdata, PETSC_VIEWER_STDOUT_WORLD));
    446:     PetscCall(PetscFree2(indata, outdata));
    447:   }

    449:   if (test_embed) {
    450:     const PetscInt nroots = 1 + (PetscInt)(rank == 0);
    451:     PetscInt       selected[2];
    452:     PetscSF        esf;

    454:     selected[0] = stride;
    455:     selected[1] = 2 * stride;
    456:     PetscCall(PetscSFCreateEmbeddedRootSF(sf, nroots, selected, &esf));
    457:     PetscCall(PetscSFSetUp(esf));
    458:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Embedded PetscSF\n"));
    459:     PetscCall(PetscViewerPushFormat(PETSC_VIEWER_STDOUT_WORLD, PETSC_VIEWER_ASCII_INFO_DETAIL));
    460:     PetscCall(PetscSFView(esf, PETSC_VIEWER_STDOUT_WORLD));
    461:     PetscCall(PetscViewerPopFormat(PETSC_VIEWER_STDOUT_WORLD));
    462:     PetscCall(PetscSFDestroy(&esf));
    463:   }

    465:   if (test_invert) {
    466:     const PetscInt *degree;
    467:     PetscInt       *mRootsOrigNumbering;
    468:     PetscInt        inedges;
    469:     PetscSF         msf, imsf;

    471:     PetscCall(PetscSFGetMultiSF(sf, &msf));
    472:     PetscCall(PetscSFCreateInverseSF(msf, &imsf));
    473:     PetscCall(PetscSFSetUp(msf));
    474:     PetscCall(PetscSFSetUp(imsf));
    475:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Multi-SF\n"));
    476:     PetscCall(PetscSFView(msf, PETSC_VIEWER_STDOUT_WORLD));
    477:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Multi-SF roots indices in original SF roots numbering\n"));
    478:     PetscCall(PetscSFComputeDegreeBegin(sf, &degree));
    479:     PetscCall(PetscSFComputeDegreeEnd(sf, &degree));
    480:     PetscCall(PetscSFComputeMultiRootOriginalNumbering(sf, degree, &inedges, &mRootsOrigNumbering));
    481:     PetscCall(PetscIntView(inedges, mRootsOrigNumbering, PETSC_VIEWER_STDOUT_WORLD));
    482:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Inverse of Multi-SF\n"));
    483:     PetscCall(PetscSFView(imsf, PETSC_VIEWER_STDOUT_WORLD));
    484:     PetscCall(PetscViewerASCIIPrintf(PETSC_VIEWER_STDOUT_WORLD, "## Inverse of Multi-SF, original numbering\n"));
    485:     PetscCall(PetscSFViewCustomLocals_Private(imsf, mRootsOrigNumbering, PETSC_VIEWER_STDOUT_WORLD));
    486:     PetscCall(PetscSFDestroy(&imsf));
    487:     PetscCall(PetscFree(mRootsOrigNumbering));
    488:   }

    490:   /* Clean storage for star forest. */
    491:   PetscCall(PetscSFDestroy(&sf));
    492:   PetscCall(PetscFinalize());
    493:   return 0;
    494: }

    496: /*TEST

    498:    test:
    499:       nsize: 4
    500:       filter: grep -v "type" | grep -v "sort"
    501:       args: -test_bcast -sf_type window -sf_window_sync {{fence active lock}} -sf_window_flavor {{create dynamic allocate}}
    502:       requires: defined(PETSC_HAVE_MPI_ONE_SIDED) defined(PETSC_HAVE_MPI_FEATURE_DYNAMIC_WINDOW)

    504:    test:
    505:       suffix: 2
    506:       nsize: 4
    507:       filter: grep -v "type" | grep -v "sort"
    508:       args: -test_reduce -sf_type window -sf_window_sync {{fence active lock}} -sf_window_flavor {{create dynamic allocate}}
    509:       requires: defined(PETSC_HAVE_MPI_ONE_SIDED) defined(PETSC_HAVE_MPI_FEATURE_DYNAMIC_WINDOW)

    511:    test:
    512:       suffix: 2_basic
    513:       nsize: 4
    514:       args: -test_reduce -sf_type basic

    516:    test:
    517:       suffix: 3
    518:       nsize: 4
    519:       filter: grep -v "type" | grep -v "sort"
    520:       args: -test_degree -sf_type window -sf_window_sync {{fence active lock}} -sf_window_flavor {{create dynamic allocate}}
    521:       requires: defined(PETSC_HAVE_MPI_ONE_SIDED) defined(PETSC_HAVE_MPI_FEATURE_DYNAMIC_WINDOW)

    523:    test:
    524:       suffix: 3_basic
    525:       nsize: 4
    526:       args: -test_degree -sf_type basic

    528:    test:
    529:       suffix: 4
    530:       nsize: 4
    531:       filter: grep -v "type" | grep -v "sort"
    532:       args: -test_gather -sf_type window -sf_window_sync {{fence active lock}} -sf_window_flavor {{create dynamic allocate}}
    533:       requires: defined(PETSC_HAVE_MPI_ONE_SIDED) defined(PETSC_HAVE_MPI_FEATURE_DYNAMIC_WINDOW)

    535:    test:
    536:       suffix: 4_basic
    537:       nsize: 4
    538:       args: -test_gather -sf_type basic

    540:    test:
    541:       suffix: 4_stride
    542:       nsize: 4
    543:       args: -test_gather -sf_type basic -stride 2

    545:    test:
    546:       suffix: 5
    547:       nsize: 4
    548:       filter: grep -v "type" | grep -v "sort"
    549:       args: -test_scatter -sf_type window -sf_window_sync {{fence active lock}} -sf_window_flavor {{create dynamic allocate}}
    550:       requires: defined(PETSC_HAVE_MPI_ONE_SIDED) defined(PETSC_HAVE_MPI_FEATURE_DYNAMIC_WINDOW)

    552:    test:
    553:       suffix: 5_basic
    554:       nsize: 4
    555:       args: -test_scatter -sf_type basic

    557:    test:
    558:       suffix: 5_stride
    559:       nsize: 4
    560:       args: -test_scatter -sf_type basic -stride 2

    562:    test:
    563:       suffix: 6
    564:       nsize: 4
    565:       filter: grep -v "type" | grep -v "sort"
    566:       # No -sf_window_flavor dynamic due to bug https://gitlab.com/petsc/petsc/issues/555
    567:       args: -test_embed -sf_type window -sf_window_sync {{fence active lock}} -sf_window_flavor {{create allocate}}
    568:       requires: defined(PETSC_HAVE_MPI_ONE_SIDED) defined(PETSC_HAVE_MPI_FEATURE_DYNAMIC_WINDOW)

    570:    test:
    571:       suffix: 6_basic
    572:       nsize: 4
    573:       args: -test_embed -sf_type basic

    575:    test:
    576:       suffix: 7
    577:       nsize: 4
    578:       filter: grep -v "type" | grep -v "sort"
    579:       args: -test_invert -sf_type window -sf_window_sync {{fence active lock}} -sf_window_flavor {{create dynamic allocate}}
    580:       requires: defined(PETSC_HAVE_MPI_ONE_SIDED) defined(PETSC_HAVE_MPI_FEATURE_DYNAMIC_WINDOW)

    582:    test:
    583:       suffix: 7_basic
    584:       nsize: 4
    585:       args: -test_invert -sf_type basic

    587:    test:
    588:       suffix: basic
    589:       nsize: 4
    590:       args: -test_bcast -sf_type basic
    591:       output_file: output/ex1_1_basic.out

    593:    test:
    594:       suffix: bcastop_basic
    595:       nsize: 4
    596:       args: -test_bcastop -sf_type basic
    597:       output_file: output/ex1_bcastop_basic.out

    599:    test:
    600:       suffix: 8
    601:       nsize: 3
    602:       filter: grep -v "type" | grep -v "sort"
    603:       args: -test_bcast -test_sf_distribute -sf_type window -sf_window_sync {{fence active lock}} -sf_window_flavor {{create dynamic allocate}}
    604:       requires: defined(PETSC_HAVE_MPI_ONE_SIDED) defined(PETSC_HAVE_MPI_FEATURE_DYNAMIC_WINDOW)

    606:    test:
    607:       suffix: 8_basic
    608:       nsize: 3
    609:       args: -test_bcast -test_sf_distribute -sf_type basic

    611:    test:
    612:       suffix: 9_char
    613:       nsize: 4
    614:       args: -sf_type basic -test_bcast -test_reduce -test_op max -test_char

    616:    # Here we do not test -sf_window_flavor dynamic since it is designed for repeated SFs with few different rootdata pointers
    617:    test:
    618:       suffix: 10
    619:       filter: grep -v "type" | grep -v "sort"
    620:       nsize: 4
    621:       args: -sf_type window -sf_window_sync {{fence active lock}} -sf_window_flavor {{create allocate}} -test_all -test_bcastop 0 -test_fetchandop 0
    622:       requires: defined(PETSC_HAVE_MPI_ONE_SIDED) defined(PETSC_HAVE_MPI_FEATURE_DYNAMIC_WINDOW)

    624:    # The nightly test suite with MPICH uses ch3:sock, which is broken when winsize == 0 in some of the processes
    625:    test:
    626:       suffix: 10_shared
    627:       output_file: output/ex1_10.out
    628:       filter: grep -v "type" | grep -v "sort"
    629:       nsize: 4
    630:       args: -sf_type window -sf_window_sync {{fence active lock}} -sf_window_flavor shared -test_all -test_bcastop 0 -test_fetchandop 0
    631:       requires: defined(PETSC_HAVE_MPI_PROCESS_SHARED_MEMORY) !defined(PETSC_HAVE_MPICH) defined(PETSC_HAVE_MPI_ONE_SIDED) defined(PETSC_HAVE_MPI_FEATURE_DYNAMIC_WINDOW)

    633:    test:
    634:       suffix: 10_basic
    635:       nsize: 4
    636:       args: -sf_type basic -test_all -test_bcastop 0 -test_fetchandop 0

    638:    test:
    639:       suffix: 10_basic_vector
    640:       nsize: 4
    641:       args: -sf_type basic -test_all -test_bcastop 0 -test_fetchandop 0 -test_vector

    643: TEST*/