Actual source code: partitioner.c

petsc-3.14.6 2021-03-30
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  1: #include <petsc/private/partitionerimpl.h>

  3: /*@C
  4:   PetscPartitionerSetType - Builds a particular PetscPartitioner

  6:   Collective on PetscPartitioner

  8:   Input Parameters:
  9: + part - The PetscPartitioner object
 10: - name - The kind of partitioner

 12:   Options Database Key:
 13: . -petscpartitioner_type <type> - Sets the PetscPartitioner type; use -help for a list of available types

 15:   Level: intermediate

 17: .seealso: PetscPartitionerGetType(), PetscPartitionerCreate()
 18: @*/
 19: PetscErrorCode PetscPartitionerSetType(PetscPartitioner part, PetscPartitionerType name)
 20: {
 21:   PetscErrorCode (*r)(PetscPartitioner);
 22:   PetscBool      match;

 27:   PetscObjectTypeCompare((PetscObject) part, name, &match);
 28:   if (match) return(0);

 30:   PetscPartitionerRegisterAll();
 31:   PetscFunctionListFind(PetscPartitionerList, name, &r);
 32:   if (!r) SETERRQ1(PetscObjectComm((PetscObject) part), PETSC_ERR_ARG_UNKNOWN_TYPE, "Unknown PetscPartitioner type: %s", name);

 34:   if (part->ops->destroy) {
 35:     (*part->ops->destroy)(part);
 36:   }
 37:   part->noGraph = PETSC_FALSE;
 38:   PetscMemzero(part->ops, sizeof(*part->ops));
 39:   PetscObjectChangeTypeName((PetscObject) part, name);
 40:   (*r)(part);
 41:   return(0);
 42: }

 44: /*@C
 45:   PetscPartitionerGetType - Gets the PetscPartitioner type name (as a string) from the object.

 47:   Not Collective

 49:   Input Parameter:
 50: . part - The PetscPartitioner

 52:   Output Parameter:
 53: . name - The PetscPartitioner type name

 55:   Level: intermediate

 57: .seealso: PetscPartitionerSetType(), PetscPartitionerCreate()
 58: @*/
 59: PetscErrorCode PetscPartitionerGetType(PetscPartitioner part, PetscPartitionerType *name)
 60: {
 64:   *name = ((PetscObject) part)->type_name;
 65:   return(0);
 66: }

 68: /*@C
 69:    PetscPartitionerViewFromOptions - View from Options

 71:    Collective on PetscPartitioner

 73:    Input Parameters:
 74: +  A - the PetscPartitioner object
 75: .  obj - Optional object
 76: -  name - command line option

 78:    Level: intermediate
 79: .seealso:  PetscPartitionerView(), PetscObjectViewFromOptions()
 80: @*/
 81: PetscErrorCode PetscPartitionerViewFromOptions(PetscPartitioner A,PetscObject obj,const char name[])
 82: {

 87:   PetscObjectViewFromOptions((PetscObject)A,obj,name);
 88:   return(0);
 89: }

 91: /*@
 92:   PetscPartitionerView - Views a PetscPartitioner

 94:   Collective on PetscPartitioner

 96:   Input Parameter:
 97: + part - the PetscPartitioner object to view
 98: - v    - the viewer

100:   Level: developer

102: .seealso: PetscPartitionerDestroy()
103: @*/
104: PetscErrorCode PetscPartitionerView(PetscPartitioner part, PetscViewer v)
105: {
106:   PetscMPIInt    size;
107:   PetscBool      isascii;

112:   if (!v) {PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject) part), &v);}
113:   PetscObjectTypeCompare((PetscObject) v, PETSCVIEWERASCII, &isascii);
114:   if (isascii) {
115:     MPI_Comm_size(PetscObjectComm((PetscObject) part), &size);
116:     PetscViewerASCIIPrintf(v, "Graph Partitioner: %d MPI Process%s\n", size, size > 1 ? "es" : "");
117:     PetscViewerASCIIPrintf(v, "  type: %s\n", ((PetscObject)part)->type_name);
118:     PetscViewerASCIIPrintf(v, "  edge cut: %D\n", part->edgeCut);
119:     PetscViewerASCIIPrintf(v, "  balance: %.2g\n", part->balance);
120:     PetscViewerASCIIPrintf(v, "  use vertex weights: %d\n", part->usevwgt);
121:   }
122:   if (part->ops->view) {(*part->ops->view)(part, v);}
123:   return(0);
124: }

126: static PetscErrorCode PetscPartitionerGetDefaultType(MPI_Comm comm, const char **defaultType)
127: {
128:   PetscMPIInt    size;

132:   MPI_Comm_size(comm, &size);
133:   if (size == 1) {
134:     *defaultType = PETSCPARTITIONERSIMPLE;
135:   } else {
136: #if defined(PETSC_HAVE_PARMETIS)
137:     *defaultType = PETSCPARTITIONERPARMETIS;
138: #elif defined(PETSC_HAVE_PTSCOTCH)
139:     *defaultType = PETSCPARTITIONERPTSCOTCH;
140: #elif defined(PETSC_HAVE_CHACO)
141:     *defaultType = PETSCPARTITIONERCHACO;
142: #else
143:     *defaultType = PETSCPARTITIONERSIMPLE;
144: #endif
145:   }
146:   return(0);
147: }

149: /*@
150:   PetscPartitionerSetFromOptions - sets parameters in a PetscPartitioner from the options database

152:   Collective on PetscPartitioner

154:   Input Parameter:
155: . part - the PetscPartitioner object to set options for

157:   Options Database Keys:
158: +  -petscpartitioner_type <type> - Sets the PetscPartitioner type; use -help for a list of available types
159: .  -petscpartitioner_use_vertex_weights - Uses weights associated with the graph vertices
160: -  -petscpartitioner_view_graph - View the graph each time PetscPartitionerPartition is called. Viewer can be customized, see PetscOptionsGetViewer()

162:   Level: developer

164: .seealso: PetscPartitionerView(), PetscPartitionerSetType(), PetscPartitionerPartition()
165: @*/
166: PetscErrorCode PetscPartitionerSetFromOptions(PetscPartitioner part)
167: {
168:   const char    *currentType = NULL;
169:   char           name[256];
170:   PetscBool      flg;

175:   PetscObjectOptionsBegin((PetscObject) part);
176:   PetscPartitionerGetType(part, &currentType);
177:   PetscOptionsFList("-petscpartitioner_type", "Graph partitioner", "PetscPartitionerSetType", PetscPartitionerList, currentType, name, sizeof(name), &flg);
178:   if (flg) {
179:     PetscPartitionerSetType(part, name);
180:   }
181:   PetscOptionsBool("-petscpartitioner_use_vertex_weights","Use vertex weights","",part->usevwgt,&part->usevwgt,NULL);
182:   if (part->ops->setfromoptions) {
183:     (*part->ops->setfromoptions)(PetscOptionsObject,part);
184:   }
185:   PetscViewerDestroy(&part->viewer);
186:   PetscViewerDestroy(&part->viewerGraph);
187:   PetscOptionsGetViewer(((PetscObject) part)->comm, ((PetscObject) part)->options, ((PetscObject) part)->prefix, "-petscpartitioner_view", &part->viewer, NULL, NULL);
188:   PetscOptionsGetViewer(((PetscObject) part)->comm, ((PetscObject) part)->options, ((PetscObject) part)->prefix, "-petscpartitioner_view_graph", &part->viewerGraph, NULL, &part->viewGraph);
189:   /* process any options handlers added with PetscObjectAddOptionsHandler() */
190:   PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject) part);
191:   PetscOptionsEnd();
192:   return(0);
193: }

195: /*@
196:   PetscPartitionerSetUp - Construct data structures for the PetscPartitioner

198:   Collective on PetscPartitioner

200:   Input Parameter:
201: . part - the PetscPartitioner object to setup

203:   Level: developer

205: .seealso: PetscPartitionerView(), PetscPartitionerDestroy()
206: @*/
207: PetscErrorCode PetscPartitionerSetUp(PetscPartitioner part)
208: {

213:   if (part->ops->setup) {(*part->ops->setup)(part);}
214:   return(0);
215: }

217: /*@
218:   PetscPartitionerReset - Resets data structures for the PetscPartitioner

220:   Collective on PetscPartitioner

222:   Input Parameter:
223: . part - the PetscPartitioner object to reset

225:   Level: developer

227: .seealso: PetscPartitionerSetUp(), PetscPartitionerDestroy()
228: @*/
229: PetscErrorCode PetscPartitionerReset(PetscPartitioner part)
230: {

235:   if (part->ops->reset) {(*part->ops->reset)(part);}
236:   return(0);
237: }

239: /*@
240:   PetscPartitionerDestroy - Destroys a PetscPartitioner object

242:   Collective on PetscPartitioner

244:   Input Parameter:
245: . part - the PetscPartitioner object to destroy

247:   Level: developer

249: .seealso: PetscPartitionerView()
250: @*/
251: PetscErrorCode PetscPartitionerDestroy(PetscPartitioner *part)
252: {

256:   if (!*part) return(0);

259:   if (--((PetscObject)(*part))->refct > 0) {*part = NULL; return(0);}
260:   ((PetscObject) (*part))->refct = 0;

262:   PetscPartitionerReset(*part);

264:   PetscViewerDestroy(&(*part)->viewer);
265:   PetscViewerDestroy(&(*part)->viewerGraph);
266:   if ((*part)->ops->destroy) {(*(*part)->ops->destroy)(*part);}
267:   PetscHeaderDestroy(part);
268:   return(0);
269: }

271: /*@
272:   PetscPartitionerPartition - Partition a graph

274:   Collective on PetscPartitioner

276:   Input Parameters:
277: + part    - The PetscPartitioner
278: . nparts  - Number of partitions
279: . numVertices - Number of vertices in the local part of the graph
280: . start - row pointers for the local part of the graph (CSR style)
281: . adjacency - adjacency list (CSR style)
282: . vertexSection - PetscSection describing the absolute weight of each local vertex (can be NULL)
283: - targetSection - PetscSection describing the absolute weight of each partition (can be NULL)

285:   Output Parameters:
286: + partSection     - The PetscSection giving the division of points by partition
287: - partition       - The list of points by partition

289:   Options Database:
290: + -petscpartitioner_view - View the partitioner information
291: - -petscpartitioner_view_graph - View the graph we are partitioning

293:   Notes:
294:     The chart of the vertexSection (if present) must contain [0,numVertices), with the number of dofs in the section specifying the absolute weight for each vertex.
295:     The chart of the targetSection (if present) must contain [0,nparts), with the number of dofs in the section specifying the absolute weight for each partition. This information must be the same across processes, PETSc does not check it.

297:   Level: developer

299: .seealso PetscPartitionerCreate(), PetscSectionCreate(), PetscSectionSetChart(), PetscSectionSetDof()
300: @*/
301: PetscErrorCode PetscPartitionerPartition(PetscPartitioner part, PetscInt nparts, PetscInt numVertices, PetscInt start[], PetscInt adjacency[], PetscSection vertexSection, PetscSection targetSection, PetscSection partSection, IS *partition)
302: {

308:   if (nparts <= 0) SETERRQ(PetscObjectComm((PetscObject) part), PETSC_ERR_ARG_OUTOFRANGE, "Number of parts must be positive");
309:   if (numVertices < 0) SETERRQ(PETSC_COMM_SELF, PETSC_ERR_ARG_OUTOFRANGE, "Number of vertices must be non-negative");
310:   if (numVertices && !part->noGraph) {
314:   }
315:   if (vertexSection) {
316:     PetscInt s,e;

319:     PetscSectionGetChart(vertexSection, &s, &e);
320:     if (s > 0 || e < numVertices) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Invalid vertexSection chart [%D,%D)",s,e);
321:   }
322:   if (targetSection) {
323:     PetscInt s,e;

326:     PetscSectionGetChart(targetSection, &s, &e);
327:     if (s > 0 || e < nparts) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Invalid targetSection chart [%D,%D)",s,e);
328:   }

332:   PetscSectionReset(partSection);
333:   PetscSectionSetChart(partSection, 0, nparts);
334:   if (nparts == 1) { /* quick */
335:     PetscSectionSetDof(partSection, 0, numVertices);
336:     ISCreateStride(PetscObjectComm((PetscObject)part),numVertices,0,1,partition);
337:   } else {
338:     if (!part->ops->partition) SETERRQ1(PetscObjectComm((PetscObject) part), PETSC_ERR_SUP, "PetscPartitioner %s has no partitioning method", ((PetscObject)part)->type_name);
339:     (*part->ops->partition)(part, nparts, numVertices, start, adjacency, vertexSection, targetSection, partSection, partition);
340:   }
341:   PetscSectionSetUp(partSection);
342:   if (part->viewerGraph) {
343:     PetscViewer viewer = part->viewerGraph;
344:     PetscBool   isascii;
345:     PetscInt    v, i;
346:     PetscMPIInt rank;

348:     MPI_Comm_rank(PetscObjectComm((PetscObject) viewer), &rank);
349:     PetscObjectTypeCompare((PetscObject) viewer, PETSCVIEWERASCII, &isascii);
350:     if (isascii) {
351:       PetscViewerASCIIPushSynchronized(viewer);
352:       PetscViewerASCIISynchronizedPrintf(viewer, "[%d]Nv: %D\n", rank, numVertices);
353:       for (v = 0; v < numVertices; ++v) {
354:         const PetscInt s = start[v];
355:         const PetscInt e = start[v+1];

357:         PetscViewerASCIISynchronizedPrintf(viewer, "[%d]  ", rank);
358:         for (i = s; i < e; ++i) {PetscViewerASCIISynchronizedPrintf(viewer, "%D ", adjacency[i]);}
359:         PetscViewerASCIISynchronizedPrintf(viewer, "[%D-%D)\n", s, e);
360:       }
361:       PetscViewerFlush(viewer);
362:       PetscViewerASCIIPopSynchronized(viewer);
363:     }
364:   }
365:   if (part->viewer) {
366:     PetscPartitionerView(part,part->viewer);
367:   }
368:   return(0);
369: }

371: /*@
372:   PetscPartitionerCreate - Creates an empty PetscPartitioner object. The type can then be set with PetscPartitionerSetType().

374:   Collective

376:   Input Parameter:
377: . comm - The communicator for the PetscPartitioner object

379:   Output Parameter:
380: . part - The PetscPartitioner object

382:   Level: beginner

384: .seealso: PetscPartitionerSetType(), PETSCPARTITIONERCHACO, PETSCPARTITIONERPARMETIS, PETSCPARTITIONERSHELL, PETSCPARTITIONERSIMPLE, PETSCPARTITIONERGATHER
385: @*/
386: PetscErrorCode PetscPartitionerCreate(MPI_Comm comm, PetscPartitioner *part)
387: {
388:   PetscPartitioner p;
389:   const char       *partitionerType = NULL;
390:   PetscErrorCode   ierr;

394:   *part = NULL;
395:   PetscPartitionerInitializePackage();

397:   PetscHeaderCreate(p, PETSCPARTITIONER_CLASSID, "PetscPartitioner", "Graph Partitioner", "PetscPartitioner", comm, PetscPartitionerDestroy, PetscPartitionerView);
398:   PetscPartitionerGetDefaultType(comm, &partitionerType);
399:   PetscPartitionerSetType(p, partitionerType);

401:   p->edgeCut = 0;
402:   p->balance = 0.0;
403:   p->usevwgt = PETSC_TRUE;

405:   *part = p;
406:   return(0);
407: }