Date: 2026-03-01T05:25:11+00:00

Actual source code: inherit.c

      1: /*
      2:      Provides utility routines for manipulating any type of PETSc object.
      3: */
      4: #include <petsc/private/petscimpl.h>
      5: #include <petscviewer.h>

      7: PETSC_INTERN PetscObject *PetscObjects;
      8: PETSC_INTERN PetscInt     PetscObjectsCounts;
      9: PETSC_INTERN PetscInt     PetscObjectsMaxCounts;
     10: PETSC_INTERN PetscBool    PetscObjectsLog;

     12: PetscObject *PetscObjects       = NULL;
     13: PetscInt     PetscObjectsCounts = 0, PetscObjectsMaxCounts = 0;
     14: PetscBool    PetscObjectsLog = PETSC_FALSE;

     16: PetscObjectId PetscObjectNewId_Internal(void)
     17: {
     18:   static PetscObjectId idcnt = 1;
     19:   return idcnt++;
     20: }

     22: PetscErrorCode PetscHeaderCreate_Function(PetscErrorCode ierr, PetscObject *h, PetscClassId classid, const char class_name[], const char descr[], const char mansec[], MPI_Comm comm, PetscObjectDestroyFn *destroy, PetscObjectViewFn *view)
     23: {
     24:   PetscFunctionBegin;
     25:   if (ierr) PetscFunctionReturn(ierr);
     26:   PetscCall(PetscHeaderCreate_Private(*h, classid, class_name, descr, mansec, comm, destroy, view));
     27:   PetscCall(PetscLogObjectCreate(*h));
     28:   PetscFunctionReturn(PETSC_SUCCESS);
     29: }

     31: /*
     32:    PetscHeaderCreate_Private - Fills in the default values.
     33: */
     34: PetscErrorCode PetscHeaderCreate_Private(PetscObject h, PetscClassId classid, const char class_name[], const char descr[], const char mansec[], MPI_Comm comm, PetscObjectDestroyFn *destroy, PetscObjectViewFn *view)
     35: {
     36:   void       *get_tmp;
     37:   PetscInt64 *cidx;
     38:   PetscMPIInt iflg;

     40:   PetscFunctionBegin;
     41:   h->classid               = classid;
     42:   h->class_name            = (char *)class_name;
     43:   h->description           = (char *)descr;
     44:   h->mansec                = (char *)mansec;
     45:   h->refct                 = 1;
     46:   h->non_cyclic_references = NULL;
     47:   h->id                    = PetscObjectNewId_Internal();
     48:   h->bops->destroy         = destroy;
     49:   h->bops->view            = view;

     51:   PetscCall(PetscCommDuplicate(comm, &h->comm, &h->tag));

     53:   /* Increment and store current object creation index */
     54:   PetscCallMPI(MPI_Comm_get_attr(h->comm, Petsc_CreationIdx_keyval, &get_tmp, &iflg));
     55:   PetscCheck(iflg, h->comm, PETSC_ERR_ARG_CORRUPT, "MPI_Comm does not have an object creation index");
     56:   cidx    = (PetscInt64 *)get_tmp;
     57:   h->cidx = (*cidx)++;

     59:   /* Keep a record of object created */
     60:   if (PetscDefined(USE_LOG) && PetscObjectsLog) {
     61:     PetscObject *newPetscObjects;
     62:     PetscInt     newPetscObjectsMaxCounts;

     64:     PetscObjectsCounts++;
     65:     for (PetscInt i = 0; i < PetscObjectsMaxCounts; ++i) {
     66:       if (!PetscObjects[i]) {
     67:         PetscObjects[i] = h;
     68:         PetscFunctionReturn(PETSC_SUCCESS);
     69:       }
     70:     }
     71:     /* Need to increase the space for storing PETSc objects */
     72:     if (!PetscObjectsMaxCounts) newPetscObjectsMaxCounts = 100;
     73:     else newPetscObjectsMaxCounts = 2 * PetscObjectsMaxCounts;
     74:     PetscCall(PetscCalloc1(newPetscObjectsMaxCounts, &newPetscObjects));
     75:     PetscCall(PetscArraycpy(newPetscObjects, PetscObjects, PetscObjectsMaxCounts));
     76:     PetscCall(PetscFree(PetscObjects));

     78:     PetscObjects                        = newPetscObjects;
     79:     PetscObjects[PetscObjectsMaxCounts] = h;
     80:     PetscObjectsMaxCounts               = newPetscObjectsMaxCounts;
     81:   }
     82:   PetscFunctionReturn(PETSC_SUCCESS);
     83: }

     85: PETSC_INTERN PetscBool      PetscMemoryCollectMaximumUsage;
     86: PETSC_INTERN PetscLogDouble PetscMemoryMaximumUsage;

     88: PetscErrorCode PetscHeaderDestroy_Function(PetscObject *h)
     89: {
     90:   PetscFunctionBegin;
     91:   PetscCall(PetscLogObjectDestroy(*h));
     92:   PetscCall(PetscHeaderDestroy_Private(*h, PETSC_FALSE));
     93:   PetscCall(PetscFree(*h));
     94:   PetscFunctionReturn(PETSC_SUCCESS);
     95: }

     97: /*
     98:     PetscHeaderDestroy_Private - Destroys a base PETSc object header. Called by
     99:     the macro PetscHeaderDestroy().
    100: */
    101: PetscErrorCode PetscHeaderDestroy_Private(PetscObject obj, PetscBool clear_for_reuse)
    102: {
    103:   PetscFunctionBegin;
    105:   PetscCall(PetscComposedQuantitiesDestroy(obj));
    106:   if (PetscMemoryCollectMaximumUsage) {
    107:     PetscLogDouble usage;

    109:     PetscCall(PetscMemoryGetCurrentUsage(&usage));
    110:     if (usage > PetscMemoryMaximumUsage) PetscMemoryMaximumUsage = usage;
    111:   }
    112:   /* first destroy things that could execute arbitrary code */
    113:   if (obj->python_destroy) {
    114:     void *python_context                     = obj->python_context;
    115:     PetscErrorCode (*python_destroy)(void *) = obj->python_destroy;

    117:     obj->python_context = NULL;
    118:     obj->python_destroy = NULL;
    119:     PetscCall((*python_destroy)(python_context));
    120:   }
    121:   PetscCall(PetscObjectDestroyOptionsHandlers(obj));
    122:   PetscCall(PetscObjectListDestroy(&obj->olist));

    124:   /* destroy allocated quantities */
    125:   if (PetscPrintFunctionList) PetscCall(PetscFunctionListPrintNonEmpty(obj->qlist));
    126:   PetscCheck(--(obj->refct) <= 0, obj->comm, PETSC_ERR_PLIB, "Destroying a PetscObject (%s) with reference count %" PetscInt_FMT " >= 1", obj->name ? obj->name : "unnamed", obj->refct);
    127:   PetscCall(PetscFree(obj->name));
    128:   PetscCall(PetscFree(obj->prefix));
    129:   PetscCall(PetscFree(obj->type_name));

    131:   if (clear_for_reuse) {
    132:     /* we will assume that obj->bops->view and destroy are safe to leave as-is */

    134:     /* reset quantities, in order of appearance in _p_PetscObject */
    135:     obj->id       = PetscObjectNewId_Internal();
    136:     obj->refct    = 1;
    137:     obj->tablevel = 0;
    138:     obj->state    = 0;
    139:     /* don't deallocate, zero these out instead */
    140:     PetscCall(PetscFunctionListClear(obj->qlist));
    141:     PetscCall(PetscArrayzero(obj->fortran_func_pointers, obj->num_fortran_func_pointers));
    142:     PetscCall(PetscArrayzero(obj->fortrancallback[PETSC_FORTRAN_CALLBACK_CLASS], obj->num_fortrancallback[PETSC_FORTRAN_CALLBACK_CLASS]));
    143:     PetscCall(PetscArrayzero(obj->fortrancallback[PETSC_FORTRAN_CALLBACK_SUBTYPE], obj->num_fortrancallback[PETSC_FORTRAN_CALLBACK_SUBTYPE]));
    144:     obj->optionsprinted = PETSC_FALSE;
    145: #if PetscDefined(HAVE_SAWS)
    146:     obj->amsmem          = PETSC_FALSE;
    147:     obj->amspublishblock = PETSC_FALSE;
    148: #endif
    149:     obj->options                                  = NULL;
    150:     obj->donotPetscObjectPrintClassNamePrefixType = PETSC_FALSE;
    151:   } else {
    152:     PetscCall(PetscFunctionListDestroy(&obj->qlist));
    153:     PetscCall(PetscFree(obj->fortran_func_pointers));
    154:     PetscCall(PetscFree(obj->fortrancallback[PETSC_FORTRAN_CALLBACK_CLASS]));
    155:     PetscCall(PetscFree(obj->fortrancallback[PETSC_FORTRAN_CALLBACK_SUBTYPE]));
    156:     PetscCall(PetscCommDestroy(&obj->comm));
    157:     obj->classid = PETSCFREEDHEADER;

    159:     if (PetscDefined(USE_LOG) && PetscObjectsLog) {
    160:       /* Record object removal from list of all objects */
    161:       for (PetscInt i = 0; i < PetscObjectsMaxCounts; ++i) {
    162:         if (PetscObjects[i] == obj) {
    163:           PetscObjects[i] = NULL;
    164:           --PetscObjectsCounts;
    165:           break;
    166:         }
    167:       }
    168:       if (!PetscObjectsCounts) {
    169:         PetscCall(PetscFree(PetscObjects));
    170:         PetscObjectsMaxCounts = 0;
    171:       }
    172:     }
    173:   }
    174:   PetscFunctionReturn(PETSC_SUCCESS);
    175: }

    177: /*
    178:   PetscHeaderReset_Internal - "Reset" a PetscObject header. This is tantamount to destroying
    179:   the object but does not free all resources. The object retains its:

    181:   - classid
    182:   - bops->view
    183:   - bops->destroy
    184:   - comm
    185:   - tag
    186:   - class_name
    187:   - description
    188:   - mansec
    189:   - cpp

    191:   Note that while subclass information is lost, superclass info remains. Thus this function is
    192:   intended to be used to reuse a PetscObject within the same class to avoid reallocating its
    193:   resources.
    194: */
    195: PetscErrorCode PetscHeaderReset_Internal(PetscObject obj)
    196: {
    197:   PetscFunctionBegin;
    198:   PetscCall(PetscHeaderDestroy_Private(obj, PETSC_TRUE));
    199:   PetscFunctionReturn(PETSC_SUCCESS);
    200: }

    202: /*@
    203:   PetscObjectCopyFortranFunctionPointers - Copy function pointers to another object

    205:   Logically Collective

    207:   Input Parameters:
    208: + src  - source object
    209: - dest - destination object

    211:   Level: developer

    213:   Note:
    214:   Both objects must have the same class.

    216:   This is used to help manage user callback functions that were provided in Fortran

    218: .seealso: `PetscFortranCallbackRegister()`, `PetscFortranCallbackGetSizes()`
    219: @*/
    220: PetscErrorCode PetscObjectCopyFortranFunctionPointers(PetscObject src, PetscObject dest)
    221: {
    222:   PetscFortranCallbackId cbtype, numcb[PETSC_FORTRAN_CALLBACK_MAXTYPE];

    224:   PetscFunctionBegin;
    227:   PetscCheck(src->classid == dest->classid, src->comm, PETSC_ERR_ARG_INCOMP, "Objects must be of the same class");

    229:   PetscCall(PetscFree(dest->fortran_func_pointers));
    230:   PetscCall(PetscMalloc(src->num_fortran_func_pointers * sizeof(PetscFortranCallbackFn *), &dest->fortran_func_pointers));
    231:   PetscCall(PetscMemcpy(dest->fortran_func_pointers, src->fortran_func_pointers, src->num_fortran_func_pointers * sizeof(PetscFortranCallbackFn *)));

    233:   dest->num_fortran_func_pointers = src->num_fortran_func_pointers;

    235:   PetscCall(PetscFortranCallbackGetSizes(src->classid, &numcb[PETSC_FORTRAN_CALLBACK_CLASS], &numcb[PETSC_FORTRAN_CALLBACK_SUBTYPE]));
    236:   for (cbtype = PETSC_FORTRAN_CALLBACK_CLASS; cbtype < PETSC_FORTRAN_CALLBACK_MAXTYPE; cbtype++) {
    237:     PetscCall(PetscFree(dest->fortrancallback[cbtype]));
    238:     PetscCall(PetscCalloc1(numcb[cbtype], &dest->fortrancallback[cbtype]));
    239:     PetscCall(PetscMemcpy(dest->fortrancallback[cbtype], src->fortrancallback[cbtype], src->num_fortrancallback[cbtype] * sizeof(PetscFortranCallback)));
    240:     dest->num_fortrancallback[cbtype] = src->num_fortrancallback[cbtype];
    241:   }
    242:   PetscFunctionReturn(PETSC_SUCCESS);
    243: }

    245: /*@C
    246:   PetscObjectSetFortranCallback - set Fortran callback function pointer and context

    248:   Logically Collective, No Fortran Support

    250:   Input Parameters:
    251: + obj    - object on which to set callback
    252: . cbtype - callback type (class or subtype)
    253: . cid    - address of callback Id, updated if not yet initialized (zero)
    254: . func   - Fortran function
    255: - ctx    - Fortran context

    257:   Level: developer

    259:   Note:
    260:   This is used to help manage user callback functions that were provided in Fortran

    262: .seealso: `PetscObjectGetFortranCallback()`, `PetscFortranCallbackRegister()`, `PetscFortranCallbackGetSizes()`
    263: @*/
    264: PetscErrorCode PetscObjectSetFortranCallback(PetscObject obj, PetscFortranCallbackType cbtype, PetscFortranCallbackId *cid, PetscFortranCallbackFn *func, void *ctx)
    265: {
    266:   const char *subtype = NULL;

    268:   PetscFunctionBegin;
    270:   if (cbtype == PETSC_FORTRAN_CALLBACK_SUBTYPE) subtype = obj->type_name;
    271:   if (!*cid) PetscCall(PetscFortranCallbackRegister(obj->classid, subtype, cid));
    272:   if (*cid >= PETSC_SMALLEST_FORTRAN_CALLBACK + obj->num_fortrancallback[cbtype]) {
    273:     PetscFortranCallbackId oldnum = obj->num_fortrancallback[cbtype];
    274:     PetscFortranCallbackId newnum = PetscMax(*cid - PETSC_SMALLEST_FORTRAN_CALLBACK + 1, 2 * oldnum);
    275:     PetscFortranCallback  *callback;
    276:     PetscCall(PetscMalloc1(newnum, &callback));
    277:     PetscCall(PetscMemcpy(callback, obj->fortrancallback[cbtype], oldnum * sizeof(*obj->fortrancallback[cbtype])));
    278:     PetscCall(PetscFree(obj->fortrancallback[cbtype]));

    280:     obj->fortrancallback[cbtype]     = callback;
    281:     obj->num_fortrancallback[cbtype] = newnum;
    282:   }
    283:   obj->fortrancallback[cbtype][*cid - PETSC_SMALLEST_FORTRAN_CALLBACK].func = func;
    284:   obj->fortrancallback[cbtype][*cid - PETSC_SMALLEST_FORTRAN_CALLBACK].ctx  = ctx;
    285:   PetscFunctionReturn(PETSC_SUCCESS);
    286: }

    288: /*@C
    289:   PetscObjectGetFortranCallback - get Fortran callback function pointer and context

    291:   Logically Collective, No Fortran Support

    293:   Input Parameters:
    294: + obj    - object on which to get callback
    295: . cbtype - callback type
    296: - cid    - address of callback Id

    298:   Output Parameters:
    299: + func - Fortran function (or `NULL` if not needed)
    300: - ctx  - Fortran context (or `NULL` if not needed)

    302:   Level: developer

    304:   Note:
    305:   This is used to help manage user callback functions that were provided in Fortran

    307: .seealso: `PetscObjectSetFortranCallback()`, `PetscFortranCallbackRegister()`, `PetscFortranCallbackGetSizes()`
    308: @*/
    309: PetscErrorCode PetscObjectGetFortranCallback(PetscObject obj, PetscFortranCallbackType cbtype, PetscFortranCallbackId cid, PetscFortranCallbackFn **func, void **ctx)
    310: {
    311:   PetscFortranCallback *cb;

    313:   PetscFunctionBegin;
    315:   PetscCheck(cid >= PETSC_SMALLEST_FORTRAN_CALLBACK, obj->comm, PETSC_ERR_ARG_CORRUPT, "Fortran callback Id invalid");
    316:   PetscCheck(cid < PETSC_SMALLEST_FORTRAN_CALLBACK + obj->num_fortrancallback[cbtype], obj->comm, PETSC_ERR_ARG_CORRUPT, "Fortran callback not set on this object");
    317:   cb = &obj->fortrancallback[cbtype][cid - PETSC_SMALLEST_FORTRAN_CALLBACK];
    318:   if (func) *func = cb->func;
    319:   if (ctx) *ctx = cb->ctx;
    320:   PetscFunctionReturn(PETSC_SUCCESS);
    321: }

    323: #if defined(PETSC_USE_LOG)
    324: /*@C
    325:   PetscObjectsDump - Prints all the currently existing objects.

    327:   Input Parameters:
    328: + fd  - file pointer
    329: - all - by default only tries to display objects created explicitly by the user, if all is `PETSC_TRUE` then lists all outstanding objects

    331:   Options Database Key:
    332: . -objects_dump <all> - print information about all the objects that exist at the end of the programs run

    334:   Level: advanced

    336:   Note:
    337:   Only MPI rank 0 of `PETSC_COMM_WORLD` prints the values

    339: .seealso: `PetscObject`
    340: @*/
    341: PetscErrorCode PetscObjectsDump(FILE *fd, PetscBool all)
    342: {
    343:   PetscInt    i, j, k = 0;
    344:   PetscObject h;

    346:   PetscFunctionBegin;
    347:   if (PetscObjectsCounts) {
    348:     PetscCall(PetscFPrintf(PETSC_COMM_WORLD, fd, "The following objects were never freed\n"));
    349:     PetscCall(PetscFPrintf(PETSC_COMM_WORLD, fd, "-----------------------------------------\n"));
    350:     for (i = 0; i < PetscObjectsMaxCounts; i++) {
    351:       if ((h = PetscObjects[i])) {
    352:         PetscCall(PetscObjectName(h));
    353:         {
    354:           PetscStack *stack  = NULL;
    355:           char       *create = NULL, *rclass = NULL;

    357:           /* if the PETSc function the user calls is not a create then this object was NOT directly created by them */
    358:           PetscCall(PetscMallocGetStack(h, &stack));
    359:           if (stack) {
    360:             k = stack->currentsize - 2;
    361:             if (!all) {
    362:               k = 0;
    363:               while (!stack->petscroutine[k]) k++;
    364:               PetscCall(PetscStrstr(stack->function[k], "Create", &create));
    365:               if (!create) PetscCall(PetscStrstr(stack->function[k], "Get", &create));
    366:               PetscCall(PetscStrstr(stack->function[k], h->class_name, &rclass));
    367:               if (!create) continue;
    368:               if (!rclass) continue;
    369:             }
    370:           }

    372:           PetscCall(PetscFPrintf(PETSC_COMM_WORLD, fd, "[%d] %s %s %s\n", PetscGlobalRank, h->class_name, h->type_name, h->name));

    374:           PetscCall(PetscMallocGetStack(h, &stack));
    375:           if (stack) {
    376:             for (j = k; j >= 0; j--) fprintf(fd, "      [%d]  %s() in %s\n", PetscGlobalRank, stack->function[j], stack->file[j]);
    377:           }
    378:         }
    379:       }
    380:     }
    381:   }
    382:   PetscFunctionReturn(PETSC_SUCCESS);
    383: }

    385: /*@
    386:   PetscObjectsView - Prints the currently existing objects.

    388:   Logically Collective

    390:   Input Parameter:
    391: . viewer - must be an `PETSCVIEWERASCII` viewer

    393:   Level: advanced

    395: .seealso: `PetscObject`
    396: @*/
    397: PetscErrorCode PetscObjectsView(PetscViewer viewer)
    398: {
    399:   PetscBool isascii;
    400:   FILE     *fd;

    402:   PetscFunctionBegin;
    403:   if (!viewer) viewer = PETSC_VIEWER_STDOUT_WORLD;
    404:   PetscCall(PetscObjectTypeCompare((PetscObject)viewer, PETSCVIEWERASCII, &isascii));
    405:   PetscCheck(isascii, PetscObjectComm((PetscObject)viewer), PETSC_ERR_SUP, "Only supports ASCII viewer");
    406:   PetscCall(PetscViewerASCIIGetPointer(viewer, &fd));
    407:   PetscCall(PetscObjectsDump(fd, PETSC_TRUE));
    408:   PetscFunctionReturn(PETSC_SUCCESS);
    409: }

    411: /*@
    412:   PetscObjectsGetObject - Get a pointer to a named object

    414:   Not Collective

    416:   Input Parameter:
    417: . name - the name of an object

    419:   Output Parameters:
    420: + obj       - the object or `NULL` if there is no object, optional, pass in `NULL` if not needed
    421: - classname - the name of the class of the object, optional, pass in `NULL` if not needed

    423:   Level: advanced

    425: .seealso: `PetscObject`
    426: @*/
    427: PetscErrorCode PetscObjectsGetObject(const char name[], PetscObject *obj, const char *classname[])
    428: {
    429:   PetscInt    i;
    430:   PetscObject h;
    431:   PetscBool   flg;

    433:   PetscFunctionBegin;
    434:   PetscAssertPointer(name, 1);
    435:   if (obj) *obj = NULL;
    436:   for (i = 0; i < PetscObjectsMaxCounts; i++) {
    437:     if ((h = PetscObjects[i])) {
    438:       PetscCall(PetscObjectName(h));
    439:       PetscCall(PetscStrcmp(h->name, name, &flg));
    440:       if (flg) {
    441:         if (obj) *obj = h;
    442:         if (classname) *classname = h->class_name;
    443:         PetscFunctionReturn(PETSC_SUCCESS);
    444:       }
    445:     }
    446:   }
    447:   PetscFunctionReturn(PETSC_SUCCESS);
    448: }
    449: #else
    450: PetscErrorCode PetscObjectsView(PetscViewer viewer)
    451: {
    452:   PetscFunctionReturn(PETSC_SUCCESS);
    453: }

    455: PetscErrorCode PetscObjectsGetObject(const char name[], PetscObject *obj, const char *classname[])
    456: {
    457:   PetscFunctionReturn(PETSC_SUCCESS);
    458: }
    459: #endif

    461: /*@
    462:   PetscObjectSetPrintedOptions - indicate to an object that it should behave as if it has already printed the help for its options so it will not display the help message

    464:   Input Parameter:
    465: . obj - the `PetscObject`

    467:   Level: developer

    469:   Developer Notes:
    470:   This is used, for example to prevent sequential objects that are created from a parallel object; such as the `KSP` created by
    471:   `PCBJACOBI` from all printing the same help messages to the screen

    473: .seealso: `PetscOptionsInsert()`, `PetscObject`
    474: @*/
    475: PetscErrorCode PetscObjectSetPrintedOptions(PetscObject obj)
    476: {
    477:   PetscFunctionBegin;
    478:   PetscAssertPointer(obj, 1);
    479:   obj->optionsprinted = PETSC_TRUE;
    480:   PetscFunctionReturn(PETSC_SUCCESS);
    481: }

    483: /*@
    484:   PetscObjectInheritPrintedOptions - If the child object is not on the MPI rank 0 process of the parent object and the child is sequential then the child gets it set.

    486:   Input Parameters:
    487: + pobj - the parent object
    488: - obj  - the `PetscObject`

    490:   Level: developer

    492:   Developer Notes:
    493:   This is used, for example to prevent sequential objects that are created from a parallel object; such as the `KSP` created by
    494:   `PCBJACOBI` from all printing the same help messages to the screen

    496:   This will not handle more complicated situations like with `PCGASM` where children may live on any subset of the parent's processes and overlap

    498: .seealso: `PetscOptionsInsert()`, `PetscObjectSetPrintedOptions()`, `PetscObject`
    499: @*/
    500: PetscErrorCode PetscObjectInheritPrintedOptions(PetscObject pobj, PetscObject obj)
    501: {
    502:   PetscMPIInt prank, size;

    504:   PetscFunctionBegin;
    507:   PetscCallMPI(MPI_Comm_rank(pobj->comm, &prank));
    508:   PetscCallMPI(MPI_Comm_size(obj->comm, &size));
    509:   if (size == 1 && prank > 0) obj->optionsprinted = PETSC_TRUE;
    510:   PetscFunctionReturn(PETSC_SUCCESS);
    511: }

    513: /*@C
    514:   PetscObjectAddOptionsHandler - Adds an additional function to check for options when `XXXSetFromOptions()` is called.

    516:   Not Collective

    518:   Input Parameters:
    519: + obj     - the PETSc object
    520: . handle  - function that checks for options
    521: . destroy - function to destroy `ctx` if provided
    522: - ctx     - optional context for check function

    524:   Calling sequence of `handle`:
    525: + obj                - the PETSc object
    526: . PetscOptionsObject - the `PetscOptionItems` object
    527: - ctx                - optional context for `handle`

    529:   Calling sequence of `destroy`:
    530: + obj - the PETSc object
    531: - ctx - optional context for `handle`

    533:   Level: developer

    535: .seealso: `KSPSetFromOptions()`, `PCSetFromOptions()`, `SNESSetFromOptions()`, `PetscObjectProcessOptionsHandlers()`, `PetscObjectDestroyOptionsHandlers()`,
    536:           `PetscObject`
    537: @*/
    538: PetscErrorCode PetscObjectAddOptionsHandler(PetscObject obj, PetscErrorCode (*handle)(PetscObject obj, PetscOptionItems PetscOptionsObject, void *ctx), PetscErrorCode (*destroy)(PetscObject obj, void *ctx), void *ctx)
    539: {
    540:   PetscFunctionBegin;
    542:   for (PetscInt i = 0; i < obj->noptionhandler; i++) {
    543:     PetscBool identical = (PetscBool)(obj->optionhandler[i] == handle && obj->optiondestroy[i] == destroy && obj->optionctx[i] == ctx);
    544:     if (identical) PetscFunctionReturn(PETSC_SUCCESS);
    545:   }
    546:   PetscCheck(obj->noptionhandler < PETSC_MAX_OPTIONS_HANDLER, obj->comm, PETSC_ERR_ARG_OUTOFRANGE, "Too many options handlers added");
    547:   obj->optionhandler[obj->noptionhandler] = handle;
    548:   obj->optiondestroy[obj->noptionhandler] = destroy;
    549:   obj->optionctx[obj->noptionhandler++]   = ctx;
    550:   PetscFunctionReturn(PETSC_SUCCESS);
    551: }

    553: /*@C
    554:   PetscObjectProcessOptionsHandlers - Calls all the options handlers attached to an object

    556:   Not Collective

    558:   Input Parameters:
    559: + obj                - the PETSc object
    560: - PetscOptionsObject - the options context

    562:   Level: developer

    564: .seealso: `KSPSetFromOptions()`, `PCSetFromOptions()`, `SNESSetFromOptions()`, `PetscObjectAddOptionsHandler()`, `PetscObjectDestroyOptionsHandlers()`,
    565:           `PetscObject`
    566: @*/
    567: PetscErrorCode PetscObjectProcessOptionsHandlers(PetscObject obj, PetscOptionItems PetscOptionsObject)
    568: {
    569:   PetscFunctionBegin;
    571:   for (PetscInt i = 0; i < obj->noptionhandler; i++) PetscCall((*obj->optionhandler[i])(obj, PetscOptionsObject, obj->optionctx[i]));
    572:   PetscFunctionReturn(PETSC_SUCCESS);
    573: }

    575: /*@
    576:   PetscObjectDestroyOptionsHandlers - Destroys all the option handlers attached to an object

    578:   Not Collective

    580:   Input Parameter:
    581: . obj - the PETSc object

    583:   Level: developer

    585: .seealso: `KSPSetFromOptions()`, `PCSetFromOptions()`, `SNESSetFromOptions()`, `PetscObjectAddOptionsHandler()`, `PetscObjectProcessOptionsHandlers()`,
    586:           `PetscObject`
    587: @*/
    588: PetscErrorCode PetscObjectDestroyOptionsHandlers(PetscObject obj)
    589: {
    590:   PetscFunctionBegin;
    592:   for (PetscInt i = 0; i < obj->noptionhandler; i++) {
    593:     if (obj->optiondestroy[i]) PetscCall((*obj->optiondestroy[i])(obj, obj->optionctx[i]));
    594:   }
    595:   obj->noptionhandler = 0;
    596:   PetscFunctionReturn(PETSC_SUCCESS);
    597: }

    599: /*@
    600:   PetscObjectReference - Indicates to a `PetscObject` that it is being
    601:   referenced by another `PetscObject`. This increases the reference
    602:   count for that object by one.

    604:   Logically Collective

    606:   Input Parameter:
    607: . obj - the PETSc object. This must be cast with (`PetscObject`), for example, `PetscObjectReference`((`PetscObject`)mat);

    609:   Level: advanced

    611:   Note:
    612:   If `obj` is `NULL` this function returns without doing anything.

    614: .seealso: `PetscObjectCompose()`, `PetscObjectDereference()`, `PetscObject`
    615: @*/
    616: PetscErrorCode PetscObjectReference(PetscObject obj)
    617: {
    618:   PetscFunctionBegin;
    619:   if (!obj) PetscFunctionReturn(PETSC_SUCCESS);
    621:   obj->refct++;
    622:   PetscFunctionReturn(PETSC_SUCCESS);
    623: }

    625: /*@
    626:   PetscObjectGetReference - Gets the current reference count for a PETSc object.

    628:   Not Collective

    630:   Input Parameter:
    631: . obj - the PETSc object; this must be cast with (`PetscObject`), for example,
    632:         `PetscObjectGetReference`((`PetscObject`)mat,&cnt); `obj` cannot be `NULL`

    634:   Output Parameter:
    635: . cnt - the reference count

    637:   Level: advanced

    639: .seealso: `PetscObjectCompose()`, `PetscObjectDereference()`, `PetscObjectReference()`, `PetscObject`
    640: @*/
    641: PetscErrorCode PetscObjectGetReference(PetscObject obj, PetscInt *cnt)
    642: {
    643:   PetscFunctionBegin;
    645:   PetscAssertPointer(cnt, 2);
    646:   *cnt = obj->refct;
    647:   PetscFunctionReturn(PETSC_SUCCESS);
    648: }

    650: /*@
    651:   PetscObjectDereference - Indicates to any `PetscObject` that it is being
    652:   referenced by one less `PetscObject`. This decreases the reference
    653:   count for that object by one.

    655:   Collective on `obj` if reference reaches 0 otherwise Logically Collective

    657:   Input Parameter:
    658: . obj - the PETSc object; this must be cast with (`PetscObject`), for example,
    659:         `PetscObjectDereference`((`PetscObject`)mat);

    661:   Level: advanced

    663:   Notes:
    664:   `PetscObjectDestroy()` sets the `obj` pointer to `NULL` after the call, this routine does not.

    666:   If `obj` is `NULL` this function returns without doing anything.

    668: .seealso: `PetscObjectCompose()`, `PetscObjectReference()`, `PetscObjectDestroy()`, `PetscObject`
    669: @*/
    670: PetscErrorCode PetscObjectDereference(PetscObject obj)
    671: {
    672:   PetscFunctionBegin;
    673:   if (!obj) PetscFunctionReturn(PETSC_SUCCESS);
    675:   if (obj->bops->destroy) PetscCall((*obj->bops->destroy)(&obj));
    676:   else PetscCheck(--(obj->refct), PETSC_COMM_SELF, PETSC_ERR_SUP, "This PETSc object does not have a generic destroy routine");
    677:   PetscFunctionReturn(PETSC_SUCCESS);
    678: }

    680: /*
    681:      The following routines are the versions private to the PETSc object
    682:      data structures.
    683: */
    684: PetscErrorCode PetscObjectRemoveReference(PetscObject obj, const char name[])
    685: {
    686:   PetscFunctionBegin;
    688:   PetscCall(PetscObjectListRemoveReference(&obj->olist, name));
    689:   PetscFunctionReturn(PETSC_SUCCESS);
    690: }

    692: /*@
    693:   PetscObjectCompose - Associates another PETSc object with a given PETSc object.

    695:   Not Collective

    697:   Input Parameters:
    698: + obj  - the PETSc object; this must be cast with (`PetscObject`), for example,
    699:          `PetscObjectCompose`((`PetscObject`)mat,...);
    700: . name - name associated with the child object
    701: - ptr  - the other PETSc object to associate with the PETSc object; this must also be
    702:          cast with (`PetscObject`)

    704:   Level: advanced

    706:   Notes:
    707:   The second objects reference count is automatically increased by one when it is
    708:   composed.

    710:   Replaces any previous object that had been composed with the same name.

    712:   If `ptr` is `NULL` and `name` has previously been composed using an object, then that
    713:   entry is removed from `obj`.

    715:   `PetscObjectCompose()` can be used with any PETSc object (such as
    716:   `Mat`, `Vec`, `KSP`, `SNES`, etc.) or any user-provided object.

    718:   `PetscContainerCreate()` or `PetscObjectContainerCompose()` can be used to create an object from a
    719:   user-provided pointer that may then be composed with PETSc objects using `PetscObjectCompose()`

    721:   Fortran Note:
    722:   Use
    723: .vb
    724:   call PetscObjectCompose(obj, name, PetscObjectCast(ptr), ierr)
    725: .ve

    727: .seealso: `PetscObjectQuery()`, `PetscContainerCreate()`, `PetscObjectComposeFunction()`, `PetscObjectQueryFunction()`, `PetscContainer`,
    728:           `PetscContainerSetPointer()`, `PetscObject`, `PetscObjectContainerCompose()`
    729: @*/
    730: PetscErrorCode PetscObjectCompose(PetscObject obj, const char name[], PetscObject ptr)
    731: {
    732:   PetscFunctionBegin;
    734:   PetscAssertPointer(name, 2);
    736:   PetscCheck(obj != ptr, PetscObjectComm(obj), PETSC_ERR_SUP, "Cannot compose object with itself");
    737:   if (ptr) {
    738:     const char *tname;
    739:     PetscBool   skipreference;

    741:     PetscCall(PetscObjectListReverseFind(ptr->olist, obj, &tname, &skipreference));
    742:     if (tname) PetscCheck(skipreference, PETSC_COMM_SELF, PETSC_ERR_ARG_INCOMP, "An object cannot be composed with an object that was composed with it");
    743:   }
    744:   PetscCall(PetscObjectListAdd(&obj->olist, name, ptr));
    745:   PetscFunctionReturn(PETSC_SUCCESS);
    746: }

    748: /*@
    749:   PetscObjectQuery - Gets a PETSc object associated with a given object that was composed with `PetscObjectCompose()`

    751:   Not Collective

    753:   Input Parameters:
    754: + obj  - the PETSc object. It must be cast with a (`PetscObject`), for example,
    755:          `PetscObjectCompose`((`PetscObject`)mat,...);
    756: . name - name associated with child object
    757: - ptr  - the other PETSc object associated with the PETSc object, this must be
    758:          cast with (`PetscObject`*)

    760:   Level: advanced

    762:   Note:
    763:   The reference count of neither object is increased in this call

    765:   Fortran Note:
    766:   Use
    767: .vb
    768:   call PetscObjectQuery(PetscObjectCast(obj), name, ptr, ierr)
    769: .ve

    771: .seealso: `PetscObjectCompose()`, `PetscObjectComposeFunction()`, `PetscObjectQueryFunction()`, `PetscContainer`
    772:           `PetscContainerGetPointer()`, `PetscObject`
    773: @*/
    774: PetscErrorCode PetscObjectQuery(PetscObject obj, const char name[], PetscObject *ptr)
    775: {
    776:   PetscFunctionBegin;
    778:   PetscAssertPointer(name, 2);
    779:   PetscAssertPointer(ptr, 3);
    780:   PetscCall(PetscObjectListFind(obj->olist, name, ptr));
    781:   PetscFunctionReturn(PETSC_SUCCESS);
    782: }

    784: /*MC
    785:   PetscObjectComposeFunction - Associates a function with a given PETSc object.

    787:   Synopsis:
    788: #include <petscsys.h>
    789:   PetscErrorCode PetscObjectComposeFunction(PetscObject obj, const char name[], PetscErrorCodeFn *fptr)

    791:   Logically Collective

    793:   Input Parameters:
    794: + obj  - the PETSc object; this must be cast with a (`PetscObject`), for example,
    795:          `PetscObjectCompose`((`PetscObject`)mat,...);
    796: . name - name associated with the child function
    797: - fptr - function pointer

    799:   Level: advanced

    801:   Notes:
    802:   When the first argument of `fptr` is (or is derived from) a `PetscObject` then `PetscTryMethod()` and `PetscUseMethod()`
    803:   can be used to call the function directly with error checking.

    805:   To remove a registered routine, pass in `NULL` for `fptr`.

    807:   `PetscObjectComposeFunction()` can be used with any PETSc object (such as
    808:   `Mat`, `Vec`, `KSP`, `SNES`, etc.) or any user-provided object.

    810:   `PetscUseTypeMethod()` and `PetscTryTypeMethod()` are used to call a function that is stored in the objects `obj->ops` table.

    812: .seealso: `PetscObjectQueryFunction()`, `PetscContainerCreate()` `PetscObjectCompose()`, `PetscObjectQuery()`, `PetscTryMethod()`, `PetscUseMethod()`,
    813:           `PetscUseTypeMethod()`, `PetscTryTypeMethod()`, `PetscObject`
    814: M*/
    815: PetscErrorCode PetscObjectComposeFunction_Private(PetscObject obj, const char name[], PetscErrorCodeFn *fptr)
    816: {
    817:   PetscFunctionBegin;
    819:   PetscAssertPointer(name, 2);
    820:   PetscCall(PetscFunctionListAdd_Private(&obj->qlist, name, fptr));
    821:   PetscFunctionReturn(PETSC_SUCCESS);
    822: }

    824: /*MC
    825:   PetscObjectQueryFunction - Gets a function associated with a given object.

    827:   Synopsis:
    828: #include <petscsys.h>
    829:   PetscErrorCode PetscObjectQueryFunction(PetscObject obj, const char name[], PetscErrorCodeFn **fptr)

    831:   Logically Collective

    833:   Input Parameters:
    834: + obj  - the PETSc object; this must be cast with (`PetscObject`), for example,
    835:          `PetscObjectQueryFunction`((`PetscObject`)ksp,...);
    836: - name - name associated with the child function

    838:   Output Parameter:
    839: . fptr - function pointer

    841:   Level: advanced

    843: .seealso: `PetscObjectComposeFunction()`, `PetscFunctionListFind()`, `PetscObjectCompose()`, `PetscObjectQuery()`, `PetscObject`
    844: M*/
    845: PETSC_EXTERN PetscErrorCode PetscObjectQueryFunction_Private(PetscObject obj, const char name[], PetscErrorCodeFn **fptr)
    846: {
    847:   PetscFunctionBegin;
    849:   PetscAssertPointer(name, 2);
    850:   PetscCall(PetscFunctionListFind_Private(obj->qlist, name, fptr));
    851:   PetscFunctionReturn(PETSC_SUCCESS);
    852: }

    854: /*@
    855:   PetscObjectHasFunction - Query if a function is associated with a given object.

    857:   Logically Collective

    859:   Input Parameters:
    860: + obj  - the PETSc object
    861: - name - name associated with the child function

    863:   Output Parameter:
    864: . has - the boolean value

    866:   Level: advanced

    868: .seealso: `PetscObject`, `PetscObjectComposeFunction()`, `PetscObjectQueryFunction()`
    869: @*/
    870: PetscErrorCode PetscObjectHasFunction(PetscObject obj, const char name[], PetscBool *has)
    871: {
    872:   PetscErrorCodeFn *fptr = NULL;

    874:   PetscFunctionBegin;
    875:   PetscAssertPointer(has, 3);
    876:   PetscCall(PetscObjectQueryFunction(obj, name, &fptr));
    877:   *has = fptr ? PETSC_TRUE : PETSC_FALSE;
    878:   PetscFunctionReturn(PETSC_SUCCESS);
    879: }

    881: struct _p_PetscContainer {
    882:   PETSCHEADER(int);
    883:   void              *ctx;
    884:   PetscCtxDestroyFn *ctxdestroy;
    885:   PetscErrorCode (*userdestroy_deprecated)(void *);
    886: };

    888: /*@C
    889:   PetscContainerGetPointer - Gets the pointer value contained in the container that was provided with `PetscContainerSetPointer()`

    891:   Not Collective, No Fortran Support

    893:   Input Parameter:
    894: . obj - the object created with `PetscContainerCreate()`

    896:   Output Parameter:
    897: . ptr - the pointer value

    899:   Level: advanced

    901: .seealso: `PetscContainerCreate()`, `PetscContainerDestroy()`, `PetscObject`,
    902:           `PetscContainerSetPointer()`, `PetscObjectContainerCompose()`, `PetscObjectContainerQuery()`
    903: @*/
    904: PetscErrorCode PetscContainerGetPointer(PetscContainer obj, PeCtx ptr)
    905: {
    906:   PetscFunctionBegin;
    908:   PetscAssertPointer(ptr, 2);
    909:   *(void **)ptr = obj->ctx;
    910:   PetscFunctionReturn(PETSC_SUCCESS);
    911: }

    913: /*@C
    914:   PetscContainerSetPointer - Sets the pointer value contained in the container.

    916:   Logically Collective, No Fortran Support

    918:   Input Parameters:
    919: + obj - the object created with `PetscContainerCreate()`
    920: - ptr - the pointer value

    922:   Level: advanced

    924: .seealso: `PetscContainerCreate()`, `PetscContainerDestroy()`, `PetscObjectCompose()`, `PetscObjectQuery()`, `PetscObject`,
    925:           `PetscContainerGetPointer()`, `PetscObjectContainerCompose()`, `PetscObjectContainerQuery()`
    926: @*/
    927: PetscErrorCode PetscContainerSetPointer(PetscContainer obj, void *ptr)
    928: {
    929:   PetscFunctionBegin;
    931:   if (ptr) PetscAssertPointer(ptr, 2);
    932:   obj->ctx = ptr;
    933:   PetscFunctionReturn(PETSC_SUCCESS);
    934: }

    936: /*@C
    937:   PetscContainerDestroy - Destroys a PETSc container object.

    939:   Collective, No Fortran Support

    941:   Input Parameter:
    942: . obj - an object that was created with `PetscContainerCreate()`

    944:   Level: advanced

    946:   Note:
    947:   If `PetscContainerSetCtxDestroy()` was used to provide a user destroy object for the data provided with `PetscContainerSetPointer()`
    948:   then that function is called to destroy the data.

    950: .seealso: `PetscContainerCreate()`, `PetscContainerSetCtxDestroy()`, `PetscObject`, `PetscObjectContainerCompose()`, `PetscObjectContainerQuery()`
    951: @*/
    952: PetscErrorCode PetscContainerDestroy(PetscContainer *obj)
    953: {
    954:   PetscFunctionBegin;
    955:   if (!*obj) PetscFunctionReturn(PETSC_SUCCESS);
    957:   if (--((PetscObject)*obj)->refct > 0) {
    958:     *obj = NULL;
    959:     PetscFunctionReturn(PETSC_SUCCESS);
    960:   }
    961:   if ((*obj)->ctxdestroy) PetscCall((*(*obj)->ctxdestroy)(&(*obj)->ctx));
    962:   else if ((*obj)->userdestroy_deprecated) PetscCall((*(*obj)->userdestroy_deprecated)((*obj)->ctx));
    963:   PetscCall(PetscHeaderDestroy(obj));
    964:   PetscFunctionReturn(PETSC_SUCCESS);
    965: }

    967: /*@C
    968:   PetscContainerSetCtxDestroy - Sets the destroy function for the data provided to the `PetscContainer` with `PetscContainerSetPointer()`

    970:   Logically Collective, No Fortran Support

    972:   Input Parameters:
    973: + obj - an object that was created with `PetscContainerCreate()`
    974: - des - name of the ctx destroy function, see `PetscCtxDestroyFn` for its calling sequence

    976:   Level: advanced

    978:   Note:
    979:   Use `PetscCtxDestroyDefault()` if the memory was obtained by calling `PetscMalloc()` or one of its variants for single memory allocation.

    981: .seealso: `PetscContainerDestroy()`, `PetscContainerUserDestroyDefault()`, `PetscMalloc()`, `PetscMalloc1()`, `PetscCalloc()`, `PetscCalloc1()`, `PetscObject`,
    982:           `PetscObjectContainerCompose()`, `PetscObjectContainerQuery()`
    983: @*/
    984: PetscErrorCode PetscContainerSetCtxDestroy(PetscContainer obj, PetscCtxDestroyFn *des)
    985: {
    986:   PetscFunctionBegin;
    988:   obj->ctxdestroy = des;
    989:   PetscFunctionReturn(PETSC_SUCCESS);
    990: }

    992: /*@C
    993:   PetscContainerSetUserDestroy - Sets the destroy function for the data provided to the `PetscContainer` with `PetscContainerSetPointer()`

    995:   Logically Collective, No Fortran Support

    997:   Input Parameters:
    998: + obj - an object that was created with `PetscContainerCreate()`
    999: - des - name of the ctx destroy function

    1001:   Level: advanced

    1003:   Notes:
    1004:   Deprecated, use `PetscContainerSetCtxDestroy()`

    1006: .seealso: `PetscContainerSetCtxDestroy()`, `PetscContainerDestroy()`, `PetscContainerUserDestroyDefault()`, `PetscMalloc()`, `PetscMalloc1()`, `PetscCalloc()`, `PetscCalloc1()`, `PetscObject`,
    1007:           `PetscObjectContainerCompose()`, `PetscObjectContainerQuery()`
    1008: @*/
    1009: PetscErrorCode PetscContainerSetUserDestroy(PetscContainer obj, PetscErrorCode (*des)(void *))
    1010: {
    1011:   PetscFunctionBegin;
    1013:   obj->userdestroy_deprecated = des;
    1014:   PetscFunctionReturn(PETSC_SUCCESS);
    1015: }

    1017: PetscClassId PETSC_CONTAINER_CLASSID;

    1019: /*@C
    1020:   PetscContainerCreate - Creates a PETSc object that has room to hold a single pointer.

    1022:   Collective, No Fortran Support

    1024:   Input Parameter:
    1025: . comm - MPI communicator that shares the object

    1027:   Output Parameter:
    1028: . container - the container created

    1030:   Level: advanced

    1032:   Notes:
    1033:   This allows one to attach any type of data (accessible through a pointer) with the
    1034:   `PetscObjectCompose()` function to a `PetscObject`. The data item itself is attached by a
    1035:   call to `PetscContainerSetPointer()`.

    1037: .seealso: `PetscContainerDestroy()`, `PetscContainerSetPointer()`, `PetscContainerGetPointer()`, `PetscObjectCompose()`, `PetscObjectQuery()`,
    1038:           `PetscContainerSetCtxDestroy()`, `PetscObject`, `PetscObjectContainerCompose()`, `PetscObjectContainerQuery()`
    1039: @*/
    1040: PetscErrorCode PetscContainerCreate(MPI_Comm comm, PetscContainer *container)
    1041: {
    1042:   PetscFunctionBegin;
    1043:   PetscAssertPointer(container, 2);
    1044:   PetscCall(PetscSysInitializePackage());
    1045:   PetscCall(PetscHeaderCreate(*container, PETSC_CONTAINER_CLASSID, "PetscContainer", "Container", "Sys", comm, PetscContainerDestroy, NULL));
    1046:   PetscFunctionReturn(PETSC_SUCCESS);
    1047: }

    1049: /*@C
    1050:   PetscObjectContainerCompose - Creates a `PetscContainer`, provides all of its values and composes it with a `PetscObject`

    1052:   Collective

    1054:   Input Parameters:
    1055: + obj     - the `PetscObject`
    1056: . name    - the name for the composed container
    1057: . pointer - the pointer to the data
    1058: - destroy - the routine to destroy the container's data, see `PetscCtxDestroyFn` for its calling sequence; use `PetscCtxDestroyDefault()` if a `PetscFree()` frees the data

    1060:   Level: advanced

    1062:   Notes:
    1063:   This allows one to attach any type of data (accessible through a pointer) with the
    1064:   `PetscObjectCompose()` function to a `PetscObject`. The data item itself is attached by a
    1065:   call to `PetscContainerSetPointer()`.

    1067: .seealso: `PetscContainerCreate()`, `PetscContainerDestroy()`, `PetscContainerSetPointer()`, `PetscContainerGetPointer()`, `PetscObjectCompose()`, `PetscObjectQuery()`,
    1068:           `PetscContainerSetCtxDestroy()`, `PetscObject`, `PetscObjectContainerQuery()`
    1069: @*/
    1070: PetscErrorCode PetscObjectContainerCompose(PetscObject obj, const char *name, void *pointer, PetscCtxDestroyFn *destroy)
    1071: {
    1072:   PetscContainer container;

    1074:   PetscFunctionBegin;
    1075:   PetscCall(PetscContainerCreate(PetscObjectComm(obj), &container));
    1076:   PetscCall(PetscContainerSetPointer(container, pointer));
    1077:   if (destroy) PetscCall(PetscContainerSetCtxDestroy(container, destroy));
    1078:   PetscCall(PetscObjectCompose(obj, name, (PetscObject)container));
    1079:   PetscCall(PetscContainerDestroy(&container));
    1080:   PetscFunctionReturn(PETSC_SUCCESS);
    1081: }

    1083: /*@C
    1084:   PetscObjectContainerQuery - Accesses the pointer in a container composed to a `PetscObject` with `PetscObjectContainerCompose()`

    1086:   Collective

    1088:   Input Parameters:
    1089: + obj  - the `PetscObject`
    1090: - name - the name for the composed container

    1092:   Output Parameter:
    1093: . pointer - the pointer to the data

    1095:   Level: advanced

    1097: .seealso: `PetscContainerCreate()`, `PetscContainerDestroy()`, `PetscContainerSetPointer()`, `PetscContainerGetPointer()`, `PetscObjectCompose()`, `PetscObjectQuery()`,
    1098:           `PetscContainerSetCtxDestroy()`, `PetscObject`, `PetscObjectContainerCompose()`
    1099: @*/
    1100: PetscErrorCode PetscObjectContainerQuery(PetscObject obj, const char *name, PeCtx pointer)
    1101: {
    1102:   PetscContainer container;

    1104:   PetscFunctionBegin;
    1105:   PetscCall(PetscObjectQuery(obj, name, (PetscObject *)&container));
    1106:   if (container) PetscCall(PetscContainerGetPointer(container, pointer));
    1107:   else *(void **)pointer = NULL;
    1108:   PetscFunctionReturn(PETSC_SUCCESS);
    1109: }

    1111: /*@
    1112:   PetscObjectSetFromOptions - Sets generic parameters from user options.

    1114:   Collective

    1116:   Input Parameter:
    1117: . obj - the `PetscObject`

    1119:   Level: beginner

    1121:   Note:
    1122:   We have no generic options at present, so this does nothing.

    1124: .seealso: `PetscObjectSetOptionsPrefix()`, `PetscObjectGetOptionsPrefix()`, `PetscObject`
    1125: @*/
    1126: PetscErrorCode PetscObjectSetFromOptions(PetscObject obj)
    1127: {
    1128:   PetscFunctionBegin;
    1130:   PetscFunctionReturn(PETSC_SUCCESS);
    1131: }

    1133: /*@
    1134:   PetscObjectSetUp - Sets up the internal data structures for later use of the object

    1136:   Collective

    1138:   Input Parameter:
    1139: . obj - the `PetscObject`

    1141:   Level: advanced

    1143:   Note:
    1144:   This does nothing at present.

    1146: .seealso: `PetscObjectDestroy()`, `PetscObject`
    1147: @*/
    1148: PetscErrorCode PetscObjectSetUp(PetscObject obj)
    1149: {
    1150:   PetscFunctionBegin;
    1152:   PetscFunctionReturn(PETSC_SUCCESS);
    1153: }

    1155: /*MC
    1156:   PetscObjectIsNull - returns true if the given PETSc object is a null object

    1158:   Fortran only

    1160:   Synopsis:
    1161:   #include <petsc/finclude/petscsys.h>
    1162:   PetscBool PetscObjectIsNull(PetscObject obj)

    1164:   Logically Collective

    1166:   Input Parameter:
    1167: . obj  - the PETSc object

    1169:   Level: beginner

    1171:   Example Usage:
    1172: .vb
    1173:   if (PetscObjectIsNull(dm)) then
    1174:   if (.not. PetscObjectIsNull(dm)) then
    1175: .ve

    1177:   Note:
    1178:   Code such as
    1179: .vb
    1180:   if (dm == PETSC_NULL_DM) then
    1181: .ve
    1182:   is not allowed.

    1184: .seealso: `PetscObject`, `PETSC_NULL_OBJECT`, `PETSC_NULL_VEC`, `PETSC_NULL_VEC_ARRAY`, `PetscObjectNullify()`
    1185: M*/

    1187: /*MC
    1188:   PetscObjectNullify - sets a PETSc object, such as `Vec`, back to the state it had when it was declared, so it
    1189:   can be used in a creation routine, such as `VecCreate()`

    1191:   Fortran only

    1193:   Synopsis:
    1194:   #include <petsc/finclude/petscsys.h>
    1195:   PetscObjectNullify(PetscObject obj)

    1197:   Logically Collective

    1199:   Input Parameter:
    1200: . obj  - the PETSc object

    1202:   Level: beginner

    1204:   Example Usage:
    1205: .vb
    1206:   Vec x, y

    1208:   VecCreate(PETSC_COMM_WORLD, x, ierr)
    1209:   ...
    1210:   y = x
    1211:   ...
    1212:   PetscObjectNullify(y)
    1213: .ve
    1214:   You should not call `VecDestroy()` on `y` because that will destroy `x` since the assignment `y = x` does
    1215:   not increase the reference count of `x`

    1217:   Note:
    1218:   Code such as
    1219: .vb
    1220:   y = PETSC_NULL_VEC
    1221: .ve
    1222:   is not allowed.

    1224: .seealso: `PetscObject`, `PETSC_NULL_OBJECT`, `PETSC_NULL_VEC`, `PETSC_NULL_VEC_ARRAY`, `PetscObjectIsNull()`
    1225: M*/

    1227: /*MC
    1228:   PetscObjectCast - Casts a `PetscObject` to the base `PetscObject` type in function calls

    1230:   Fortran only

    1232:   Synopsis:
    1233:   use petscsys

    1235:   Level: beginner

    1237:   Example Usage:
    1238:   PetscFE fe
    1239: .vb
    1240:   PetscCallA(DMAddField(dm, 0, PetscObjectCast(fe),ierr)
    1241: .ve

    1243: .seealso: `PetscObject`, `PetscObjectSpecificCast()`
    1244: M*/

    1246: /*MC
    1247:   PetscObjectSpecificCast - Casts a `PetscObject` to any specific `PetscObject`

    1249:   Fortran only

    1251:   Synopsis:
    1252:   use petscsys

    1254:   Level: beginner

    1256:   Example Usage:
    1257:   PetscObject obj
    1258:   PetscFE     fe
    1259: .vb
    1260:   PetscCallA(PetscDSGetDiscretization(ds, 0, obj, ierr)
    1261:   PetscObjectSpecificCast(fe,obj)
    1262: .ve

    1264: .seealso: `PetscObject`, `PetscObjectCast()`
    1265: M*/

    1267: /*MC
    1268:   PetscEnumCase - `case()` statement for a PETSc enum variable or value

    1270:   Fortran only

    1272:   Synopsis:
    1273:   #include <petsc/finclude/petscsys.h>
    1274:   PetscEnumCase(PetscObject enm)

    1276:   Input Parameters:
    1277: . enum  - the PETSc enum value or variable

    1279:   Level: beginner

    1281:   Example Usage:
    1282: .vb
    1283:   DMPolytopeType cellType
    1284:   select PetscEnumCase(cellType)
    1285:     PetscEnumCase(DM_POLYTOPE_TRIANGLE)
    1286:       write(*,*) 'cell is a triangle'
    1287:     PetscEnumCase(DM_POLYTOPE_TETRAHEDRON)
    1288:       write(*,*) 'cell is a tetrahedron'
    1289:     case default
    1290:       write(*,*) 'cell is a something else'
    1291:   end select
    1292: .ve
    1293:   is equivalent to
    1294: .vb
    1295:   DMPolytopeType cellType
    1296:   select case(cellType%v)
    1297:     case(DM_POLYTOPE_TRIANGLE%v)
    1298:       write(*,*) 'cell is a triangle'
    1299:     case(DM_POLYTOPE_TETRAHEDRON%v)
    1300:       write(*,*) 'cell is a tetrahedron'
    1301:     case default
    1302:       write(*,*) 'cell is a something else'
    1303:   end select
    1304: .ve

    1306: .seealso: `PetscObject`
    1307: M*/