Actual source code: viewreg.c

petsc-master 2018-04-20
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  2:  #include <petsc/private/viewerimpl.h>
  3:  #include <petsc/private/hash.h>
  4: #if defined(PETSC_HAVE_SAWS)
  5:  #include <petscviewersaws.h>
  6: #endif

  8: PetscFunctionList PetscViewerList = 0;


 11: PetscOptionsHelpPrinted PetscOptionsHelpPrintedSingleton = NULL;
 12: KHASH_SET_INIT_STR(HTPrinted)
 13: struct  _n_PetscOptionsHelpPrinted{
 14:   khash_t(HTPrinted) *printed;
 15:   PetscSegBuffer     strings;
 16: };

 18: PetscErrorCode PetscOptionsHelpPrintedDestroy(PetscOptionsHelpPrinted *hp)
 19: {

 23:   if (!*hp) return(0);
 24:   kh_destroy(HTPrinted,(*hp)->printed);
 25:   PetscSegBufferDestroy(&(*hp)->strings);
 26:   PetscFree(*hp);
 27:   return(0);
 28: }

 30: /*@C
 31:       PetscOptionsHelpPrintedCreate - Creates an object used to manage tracking which help messages have
 32:          been printed so they will not be printed again.

 34:      Not collective

 36:     Level: developer

 38: .seealso: PetscOptionsHelpPrintedCheck(), PetscOptionsHelpPrintChecked()
 39: @*/
 40: PetscErrorCode PetscOptionsHelpPrintedCreate(PetscOptionsHelpPrinted *hp)
 41: {
 42:   PetscErrorCode             ierr;

 45:   PetscNew(hp);
 46:   (*hp)->printed = kh_init(HTPrinted);
 47:   PetscSegBufferCreate(sizeof(char),10000,&(*hp)->strings);
 48:   return(0);
 49: }

 51: /*@C
 52:       PetscOptionsHelpPrintedCheck - Checks if a particular pre, name pair has previous been entered (meaning the help message was printed)

 54:      Not collective

 56:     Input Parameters:
 57: +     hp - the object used to manage tracking what help messages have been printed
 58: .     pre - the prefix part of the string, many be NULL
 59: -     name - the string to look for (cannot be NULL)

 61:     Output Parameter:
 62: .     found - PETSC_TRUE if the string was already set

 64:     Level: intermediate


 67: .seealso: PetscOptionsHelpPrintedCreate()
 68: @*/
 69: PetscErrorCode PetscOptionsHelpPrintedCheck(PetscOptionsHelpPrinted hp,const char *pre,const char* name,PetscBool *found)
 70: {
 71:   size_t          l1,l2;
 72: #if !defined(PETSC_HAVE_THREADSAFETY)
 73:   char            *both;
 74:   khint_t         newitem;
 75: #endif
 76:   PetscErrorCode  ierr;

 79:   PetscStrlen(pre,&l1);
 80:   PetscStrlen(name,&l2);
 81:   if (l1+l2 == 0) {
 82:     *found = PETSC_FALSE;
 83:     return(0);
 84:   }
 85: #if !defined(PETSC_HAVE_THREADSAFETY)
 86:   PetscSegBufferGet(hp->strings,l1+l2+1,&both);
 87:   PetscStrcpy(both,pre);
 88:   PetscStrcat(both,name);
 89:   kh_put(HTPrinted,hp->printed,both,&newitem);
 90:   if (!newitem) {
 91:     PetscSegBufferUnuse(hp->strings,l1+l2+1);
 92:   }
 93:   *found = newitem ? PETSC_FALSE : PETSC_TRUE;
 94: #else
 95:   *found = PETSC_FALSE;
 96: #endif
 97:   return(0);
 98: }

100: static PetscBool noviewer = PETSC_FALSE;
101: static PetscBool noviewers[PETSCVIEWERGETVIEWEROFFPUSHESMAX];
102: static PetscInt  inoviewers = 0;

104: /*@
105:   PetscOptionsPushGetViewerOff - control whether PetscOptionsGetViewer returns a viewer.

107:   Logically Collective

109:   Input Parameter:
110: . flg - PETSC_TRUE to turn off viewer creation, PETSC_FALSE to turn it on.

112:   Level: developer

114:   Notes:
115:     Calling XXXViewFromOptions in an inner loop can be very expensive.  This can appear, for example, when using
116:    many small subsolves.  Call this function to control viewer creation in PetscOptionsGetViewer, thus removing the expensive XXXViewFromOptions calls.

118: .seealso: PetscOptionsGetViewer(), PetscOptionsPopGetViewerOff()
119: @*/
120: PetscErrorCode  PetscOptionsPushGetViewerOff(PetscBool flg)
121: {
123:   if (inoviewers > PETSCVIEWERGETVIEWEROFFPUSHESMAX - 1) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many PetscOptionsPushGetViewerOff(), perhaps you forgot PetscOptionsPopGetViewerOff()?");

125:   noviewers[inoviewers++] = noviewer;
126:   noviewer = flg;
127:   return(0);
128: }

130: /*@
131:   PetscOptionsPopGetViewerOff - reset whether PetscOptionsGetViewer returns a viewer.

133:   Logically Collective

135:   Level: developer

137:   Notes:
138:     Calling XXXViewFromOptions in an inner loop can be very expensive.  This can appear, for example, when using
139:    many small subsolves.  Call this function to control viewer creation in PetscOptionsGetViewer, thus removing the expensive XXXViewFromOptions calls.

141: .seealso: PetscOptionsGetViewer(), PetscOptionsPushGetViewerOff()
142: @*/
143: PetscErrorCode  PetscOptionsPopGetViewerOff(void)
144: {
146:   if (!inoviewers) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE,"Too many PetscOptionsPopGetViewerOff(), perhaps you forgot PetscOptionsPushGetViewerOff()?");
147:   noviewer = noviewers[--inoviewers];
148:   return(0);
149: }

151: /*@
152:   PetscOptionsGetViewerOff - does PetscOptionsGetViewer return a viewer?

154:   Logically Collective

156:   Output Parameter:
157: . flg - whether viewers are returned.

159:   Level: developer

161:   Notes:
162:     Calling XXXViewFromOptions in an inner loop can be very expensive.  This can appear, for example, when using
163:    many small subsolves.

165: .seealso: PetscOptionsGetViewer(), PetscOptionsPushGetViewerOff(), PetscOptionsPopGetViewerOff()
166: @*/
167: PetscErrorCode  PetscOptionsGetViewerOff(PetscBool *flg)
168: {
171:   *flg = noviewer;
172:   return(0);
173: }

175: /*@C
176:    PetscOptionsGetViewer - Gets a viewer appropriate for the type indicated by the user

178:    Collective on MPI_Comm

180:    Input Parameters:
181: +  comm - the communicator to own the viewer
182: .  pre - the string to prepend to the name or NULL
183: -  name - the option one is seeking

185:    Output Parameter:
186: +  viewer - the viewer, pass NULL if not needed
187: .  format - the PetscViewerFormat requested by the user, pass NULL if not needed
188: -  set - PETSC_TRUE if found, else PETSC_FALSE

190:    Level: intermediate

192:    Notes:
193:     If no value is provided ascii:stdout is used
194: $       ascii[:[filename][:[format][:append]]]    defaults to stdout - format can be one of ascii_info, ascii_info_detail, or ascii_matlab, 
195:                                                   for example ascii::ascii_info prints just the information about the object not all details
196:                                                   unless :append is given filename opens in write mode, overwriting what was already there
197: $       binary[:[filename][:[format][:append]]]   defaults to the file binaryoutput
198: $       draw[:drawtype[:filename]]                for example, draw:tikz, draw:tikz:figure.tex  or draw:x 
199: $       socket[:port]                             defaults to the standard output port
200: $       saws[:communicatorname]                    publishes object to the Scientific Application Webserver (SAWs)

202:    Use PetscViewerDestroy() after using the viewer, otherwise a memory leak will occur

204:    You can control whether calls to this function create a viewer (or return early with *set of PETSC_FALSE) with
205:    PetscOptionsPushGetViewerOff.  This is useful if calling many small subsolves, in which case XXXViewFromOptions can take
206:    an appreciable fraction of the runtime.

208:    If PETSc is configured with --with-viewfromoptions=0 this function always returns with *set of PETSC_FALSE

210: .seealso: PetscOptionsGetReal(), PetscOptionsHasName(), PetscOptionsGetString(),
211:           PetscOptionsGetIntArray(), PetscOptionsGetRealArray(), PetscOptionsBool()
212:           PetscOptionsInt(), PetscOptionsString(), PetscOptionsReal(), PetscOptionsBool(),
213:           PetscOptionsName(), PetscOptionsBegin(), PetscOptionsEnd(), PetscOptionsHead(),
214:           PetscOptionsStringArray(),PetscOptionsRealArray(), PetscOptionsScalar(),
215:           PetscOptionsBoolGroupBegin(), PetscOptionsBoolGroup(), PetscOptionsBoolGroupEnd(),
216:           PetscOptionsFList(), PetscOptionsEList(), PetscOptionsPushGetViewerOff(), PetscOptionsPopGetViewerOff(),
217:           PetscOptionsGetViewerOff()
218: @*/
219: PetscErrorCode  PetscOptionsGetViewer(MPI_Comm comm,const char pre[],const char name[],PetscViewer *viewer,PetscViewerFormat *format,PetscBool  *set)
220: {
221:   char                           *value;
222:   PetscErrorCode                 ierr;
223:   PetscBool                      flag,hashelp;


228:   if (set) *set = PETSC_FALSE;
229: #if defined(PETSC_SKIP_VIEWFROMOPTIONS)
230:   return(0);
231: #endif
232:   PetscOptionsGetViewerOff(&flag);
233:   if (flag) return(0);

235:   PetscOptionsHasName(NULL,NULL,"-help",&hashelp);
236:   if (hashelp) {
237:     PetscBool found;

239:     if (!PetscOptionsHelpPrintedSingleton) {
240:       PetscOptionsHelpPrintedCreate(&PetscOptionsHelpPrintedSingleton);
241:     }
242:     PetscOptionsHelpPrintedCheck(PetscOptionsHelpPrintedSingleton,pre,name,&found);
243:     if (!found) {
244:       if (viewer) {
245:         (*PetscHelpPrintf)(comm,"\n  -%s%s ascii[:[filename][:[format][:append]]]: %s (%s)\n",pre ? pre : "",name+1,"Prints object to stdout or ASCII file","PetscOptionsGetViewer");
246:         (*PetscHelpPrintf)(comm,"    -%s%s binary[:[filename][:[format][:append]]]: %s (%s)\n",pre ? pre : "",name+1,"Saves object to a binary file","PetscOptionsGetViewer");
247:         (*PetscHelpPrintf)(comm,"    -%s%s draw[:[drawtype][:filename|format]] %s (%s)\n",pre ? pre : "",name+1,"Draws object","PetscOptionsGetViewer");
248:         (*PetscHelpPrintf)(comm,"    -%s%s socket[:port]: %s (%s)\n",pre ? pre : "",name+1,"Pushes object to a Unix socket","PetscOptionsGetViewer");
249:         (*PetscHelpPrintf)(comm,"    -%s%s saws[:communicatorname]: %s (%s)\n\n",pre ? pre : "",name+1,"Publishes object to SAWs","PetscOptionsGetViewer");
250:       } else {
251:         (*PetscHelpPrintf)(comm,"    -%s%s\n",pre ? pre : "",name+1);
252:       }
253:     }
254:   }

256:   if (format) *format = PETSC_VIEWER_DEFAULT;
257:   PetscOptionsFindPair_Private(NULL,pre,name,&value,&flag);
258:   if (flag) {
259:     if (set) *set = PETSC_TRUE;
260:     if (!value) {
261:       if (viewer) {
262:         PetscViewerASCIIGetStdout(comm,viewer);
263:         PetscObjectReference((PetscObject)*viewer);
264:       }
265:     } else {
266:       char       *loc0_vtype,*loc1_fname,*loc2_fmt = NULL,*loc3_fmode = NULL;
267:       PetscInt   cnt;
268:       const char *viewers[] = {PETSCVIEWERASCII,PETSCVIEWERBINARY,PETSCVIEWERDRAW,PETSCVIEWERSOCKET,PETSCVIEWERMATLAB,PETSCVIEWERSAWS,PETSCVIEWERVTK,PETSCVIEWERHDF5,PETSCVIEWERGLVIS,0};

270:       PetscStrallocpy(value,&loc0_vtype);
271:       PetscStrchr(loc0_vtype,':',&loc1_fname);
272:       if (loc1_fname) {
273:         *loc1_fname++ = 0;
274:         PetscStrchr(loc1_fname,':',&loc2_fmt);
275:       }
276:       if (loc2_fmt) {
277:         *loc2_fmt++ = 0;
278:         PetscStrchr(loc2_fmt,':',&loc3_fmode);
279:       }
280:       if (loc3_fmode) *loc3_fmode++ = 0;
281:       PetscStrendswithwhich(*loc0_vtype ? loc0_vtype : "ascii",viewers,&cnt);
282:       if (cnt > (PetscInt) sizeof(viewers)-1) SETERRQ1(comm,PETSC_ERR_ARG_OUTOFRANGE,"Unknown viewer type: %s",loc0_vtype);
283:       if (viewer) {
284:         if (!loc1_fname) {
285:           switch (cnt) {
286:           case 0:
287:             PetscViewerASCIIGetStdout(comm,viewer);
288:             break;
289:           case 1:
290:             if (!(*viewer = PETSC_VIEWER_BINARY_(comm))) CHKERRQ(PETSC_ERR_PLIB);
291:             break;
292:           case 2:
293:             if (!(*viewer = PETSC_VIEWER_DRAW_(comm))) CHKERRQ(PETSC_ERR_PLIB);
294:             break;
295: #if defined(PETSC_USE_SOCKET_VIEWER)
296:           case 3:
297:             if (!(*viewer = PETSC_VIEWER_SOCKET_(comm))) CHKERRQ(PETSC_ERR_PLIB);
298:             break;
299: #endif
300: #if defined(PETSC_HAVE_MATLAB_ENGINE)
301:           case 4:
302:             if (!(*viewer = PETSC_VIEWER_MATLAB_(comm))) CHKERRQ(PETSC_ERR_PLIB);
303:             break;
304: #endif
305: #if defined(PETSC_HAVE_SAWS)
306:           case 5:
307:             if (!(*viewer = PETSC_VIEWER_SAWS_(comm))) CHKERRQ(PETSC_ERR_PLIB);
308:             break;
309: #endif
310: #if defined(PETSC_HAVE_HDF5)
311:           case 7:
312:             if (!(*viewer = PETSC_VIEWER_HDF5_(comm))) CHKERRQ(PETSC_ERR_PLIB);
313:             break;
314: #endif
315:           case 8:
316:             if (!(*viewer = PETSC_VIEWER_GLVIS_(comm))) CHKERRQ(PETSC_ERR_PLIB);
317:             break;
318:           default: SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Unsupported viewer %s",loc0_vtype);
319:           }
320:           PetscObjectReference((PetscObject)*viewer);
321:         } else {
322:           if (loc2_fmt && !*loc1_fname && (cnt == 0)) { /* ASCII format without file name */
323:             PetscViewerASCIIGetStdout(comm,viewer);
324:             PetscObjectReference((PetscObject)*viewer);
325:           } else {
326:             PetscFileMode fmode;
327:             PetscViewerCreate(comm,viewer);
328:             PetscViewerSetType(*viewer,*loc0_vtype ? loc0_vtype : "ascii");
329:             fmode = FILE_MODE_WRITE;
330:             if (loc3_fmode && *loc3_fmode) { /* Has non-empty file mode ("write" or "append") */
331:               PetscEnumFind(PetscFileModes,loc3_fmode,(PetscEnum*)&fmode,&flag);
332:               if (!flag) SETERRQ1(comm,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unknown file mode: %s",loc3_fmode);
333:             }
334:             if (loc2_fmt) {
335:               PetscBool tk,im;
336:               PetscStrcmp(loc1_fname,"tikz",&tk);
337:               PetscStrcmp(loc1_fname,"image",&im);
338:               if (tk || im) {
339:                 PetscViewerDrawSetInfo(*viewer,NULL,loc2_fmt,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE,PETSC_DECIDE);
340:                 *loc2_fmt = 0;
341:               }
342:             }
343:             PetscViewerFileSetMode(*viewer,flag?fmode:FILE_MODE_WRITE);
344:             PetscViewerFileSetName(*viewer,loc1_fname);
345:             if (*loc1_fname) {
346:               PetscViewerDrawSetDrawType(*viewer,loc1_fname);
347:             }
348:           }
349:         }
350:       }
351:       if (viewer) {
352:         PetscViewerSetUp(*viewer);
353:       }
354:       if (loc2_fmt && *loc2_fmt) {
355:         PetscEnumFind(PetscViewerFormats,loc2_fmt,(PetscEnum*)format,&flag);
356:         if (!flag) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_SUP,"Unknown viewer format %s",loc2_fmt);
357:       } else if (viewer && (cnt == 6)) { /* Get format from VTK viewer */
358:         PetscViewerGetFormat(*viewer,format);
359:       }
360:       PetscFree(loc0_vtype);
361:     }
362:   }
363:   return(0);
364: }

366: /*@
367:    PetscViewerCreate - Creates a viewing context

369:    Collective on MPI_Comm

371:    Input Parameter:
372: .  comm - MPI communicator

374:    Output Parameter:
375: .  inviewer - location to put the PetscViewer context

377:    Level: advanced

379:    Concepts: graphics^creating PetscViewer
380:    Concepts: file input/output^creating PetscViewer
381:    Concepts: sockets^creating PetscViewer

383: .seealso: PetscViewerDestroy(), PetscViewerSetType(), PetscViewerType

385: @*/
386: PetscErrorCode  PetscViewerCreate(MPI_Comm comm,PetscViewer *inviewer)
387: {
388:   PetscViewer    viewer;

392:   *inviewer = 0;
393:   PetscViewerInitializePackage();
394:   PetscHeaderCreate(viewer,PETSC_VIEWER_CLASSID,"PetscViewer","PetscViewer","Viewer",comm,PetscViewerDestroy,NULL);
395:   *inviewer    = viewer;
396:   viewer->data = 0;
397:   return(0);
398: }

400: /*@C
401:    PetscViewerSetType - Builds PetscViewer for a particular implementation.

403:    Collective on PetscViewer

405:    Input Parameter:
406: +  viewer      - the PetscViewer context
407: -  type        - for example, PETSCVIEWERASCII

409:    Options Database Command:
410: .  -draw_type  <type> - Sets the type; use -help for a list
411:     of available methods (for instance, ascii)

413:    Level: advanced

415:    Notes:
416:    See "include/petscviewer.h" for available methods (for instance,
417:    PETSCVIEWERSOCKET)

419: .seealso: PetscViewerCreate(), PetscViewerGetType(), PetscViewerType, PetscViewerPushFormat()
420: @*/
421: PetscErrorCode  PetscViewerSetType(PetscViewer viewer,PetscViewerType type)
422: {
423:   PetscErrorCode ierr,(*r)(PetscViewer);
424:   PetscBool      match;

429:   PetscObjectTypeCompare((PetscObject)viewer,type,&match);
430:   if (match) return(0);

432:   /* cleanup any old type that may be there */
433:   if (viewer->data) {
434:     (*viewer->ops->destroy)(viewer);

436:     viewer->ops->destroy = NULL;
437:     viewer->data         = 0;
438:   }
439:   PetscMemzero(viewer->ops,sizeof(struct _PetscViewerOps));

441:    PetscFunctionListFind(PetscViewerList,type,&r);
442:   if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE,"Unknown PetscViewer type given: %s",type);

444:   PetscObjectChangeTypeName((PetscObject)viewer,type);
445:   (*r)(viewer);
446:   return(0);
447: }

449: /*@C
450:    PetscViewerRegister - Adds a viewer

452:    Not Collective

454:    Input Parameters:
455: +  name_solver - name of a new user-defined viewer
456: -  routine_create - routine to create method context

458:    Level: developer
459:    Notes:
460:    PetscViewerRegister() may be called multiple times to add several user-defined viewers.

462:    Sample usage:
463: .vb
464:    PetscViewerRegister("my_viewer_type",MyViewerCreate);
465: .ve

467:    Then, your solver can be chosen with the procedural interface via
468: $     PetscViewerSetType(viewer,"my_viewer_type")
469:    or at runtime via the option
470: $     -viewer_type my_viewer_type

472:   Concepts: registering^Viewers

474: .seealso: PetscViewerRegisterAll(), PetscViewerRegisterDestroy()
475:  @*/
476: PetscErrorCode  PetscViewerRegister(const char *sname,PetscErrorCode (*function)(PetscViewer))
477: {

481:   PetscFunctionListAdd(&PetscViewerList,sname,function);
482:   return(0);
483: }

485: /*@C
486:    PetscViewerSetFromOptions - Sets the graphics type from the options database.
487:       Defaults to a PETSc X windows graphics.

489:    Collective on PetscViewer

491:    Input Parameter:
492: .     PetscViewer - the graphics context

494:    Level: intermediate

496:    Notes:
497:     Must be called after PetscViewerCreate() before the PetscViewer is used.

499:   Concepts: PetscViewer^setting options

501: .seealso: PetscViewerCreate(), PetscViewerSetType(), PetscViewerType

503: @*/
504: PetscErrorCode  PetscViewerSetFromOptions(PetscViewer viewer)
505: {
506:   PetscErrorCode    ierr;
507:   char              vtype[256];
508:   PetscBool         flg;


513:   if (!PetscViewerList) {
514:     PetscViewerRegisterAll();
515:   }
516:   PetscObjectOptionsBegin((PetscObject)viewer);
517:   PetscOptionsFList("-viewer_type","Type of PetscViewer","None",PetscViewerList,(char*)(((PetscObject)viewer)->type_name ? ((PetscObject)viewer)->type_name : PETSCVIEWERASCII),vtype,256,&flg);
518:   if (flg) {
519:     PetscViewerSetType(viewer,vtype);
520:   }
521:   /* type has not been set? */
522:   if (!((PetscObject)viewer)->type_name) {
523:     PetscViewerSetType(viewer,PETSCVIEWERASCII);
524:   }
525:   if (viewer->ops->setfromoptions) {
526:     (*viewer->ops->setfromoptions)(PetscOptionsObject,viewer);
527:   }

529:   /* process any options handlers added with PetscObjectAddOptionsHandler() */
530:   PetscObjectProcessOptionsHandlers(PetscOptionsObject,(PetscObject)viewer);
531:   PetscViewerViewFromOptions(viewer,NULL,"-viewer_view");
532:   PetscOptionsEnd();
533:   return(0);
534: }

536: PetscErrorCode PetscViewerFlowControlStart(PetscViewer viewer,PetscInt *mcnt,PetscInt *cnt)
537: {
540:   PetscViewerBinaryGetFlowControl(viewer,mcnt);
541:   PetscViewerBinaryGetFlowControl(viewer,cnt);
542:   return(0);
543: }

545: PetscErrorCode PetscViewerFlowControlStepMaster(PetscViewer viewer,PetscInt i,PetscInt *mcnt,PetscInt cnt)
546: {
548:   MPI_Comm       comm;

551:   PetscObjectGetComm((PetscObject)viewer,&comm);
552:   if (i >= *mcnt) {
553:     *mcnt += cnt;
554:     MPI_Bcast(mcnt,1,MPIU_INT,0,comm);
555:   }
556:   return(0);
557: }

559: PetscErrorCode PetscViewerFlowControlEndMaster(PetscViewer viewer,PetscInt *mcnt)
560: {
562:   MPI_Comm       comm;
564:   PetscObjectGetComm((PetscObject)viewer,&comm);
565:   *mcnt = 0;
566:   MPI_Bcast(mcnt,1,MPIU_INT,0,comm);
567:   return(0);
568: }

570: PetscErrorCode PetscViewerFlowControlStepWorker(PetscViewer viewer,PetscMPIInt rank,PetscInt *mcnt)
571: {
573:   MPI_Comm       comm;
575:   PetscObjectGetComm((PetscObject)viewer,&comm);
576:   while (PETSC_TRUE) {
577:     if (rank < *mcnt) break;
578:     MPI_Bcast(mcnt,1,MPIU_INT,0,comm);
579:   }
580:   return(0);
581: }

583: PetscErrorCode PetscViewerFlowControlEndWorker(PetscViewer viewer,PetscInt *mcnt)
584: {
586:   MPI_Comm       comm;
588:   PetscObjectGetComm((PetscObject)viewer,&comm);
589:   while (PETSC_TRUE) {
590:     MPI_Bcast(mcnt,1,MPIU_INT,0,comm);
591:     if (!*mcnt) break;
592:   }
593:   return(0);
594: }