Actual source code: characteristic.c
petsc-3.10.5 2019-03-28
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      2:  #include <petsc/private/characteristicimpl.h>
      3:  #include <petscdmda.h>
      4:  #include <petscviewer.h>

      6: PetscClassId  CHARACTERISTIC_CLASSID;
      7: PetscLogEvent CHARACTERISTIC_SetUp, CHARACTERISTIC_Solve, CHARACTERISTIC_QueueSetup, CHARACTERISTIC_DAUpdate;
      8: PetscLogEvent CHARACTERISTIC_HalfTimeLocal, CHARACTERISTIC_HalfTimeRemote, CHARACTERISTIC_HalfTimeExchange;
      9: PetscLogEvent CHARACTERISTIC_FullTimeLocal, CHARACTERISTIC_FullTimeRemote, CHARACTERISTIC_FullTimeExchange;
     10: /*
     11:    Contains the list of registered characteristic routines
     12: */
     13: PetscFunctionList CharacteristicList              = NULL;
     14: PetscBool         CharacteristicRegisterAllCalled = PETSC_FALSE;

     16: PetscErrorCode DMDAGetNeighborsRank(DM, PetscMPIInt []);
     17: PetscInt       DMDAGetNeighborRelative(DM, PetscReal, PetscReal);
     18: PetscErrorCode DMDAMapToPeriodicDomain(DM, PetscScalar []);

     20: PetscErrorCode CharacteristicHeapSort(Characteristic, Queue, PetscInt);
     21: PetscErrorCode CharacteristicSiftDown(Characteristic, Queue, PetscInt, PetscInt);

     23: PetscErrorCode CharacteristicView(Characteristic c, PetscViewer viewer)
     24: {
     25:   PetscBool      iascii;

     30:   if (!viewer) {
     31:     PetscViewerASCIIGetStdout(PetscObjectComm((PetscObject)c),&viewer);
     32:   }

     36:   PetscObjectTypeCompare((PetscObject) viewer, PETSCVIEWERASCII, &iascii);
     37:   if (!iascii) {
     38:     if (c->ops->view) {
     39:       (*c->ops->view)(c, viewer);
     40:     }
     41:   }
     42:   return(0);
     43: }

     45: PetscErrorCode CharacteristicDestroy(Characteristic *c)
     46: {

     50:   if (!*c) return(0);
     52:   if (--((PetscObject)(*c))->refct > 0) return(0);

     54:   if ((*c)->ops->destroy) {
     55:     (*(*c)->ops->destroy)((*c));
     56:   }
     57:   MPI_Type_free(&(*c)->itemType);
     58:   PetscFree((*c)->queue);
     59:   PetscFree((*c)->queueLocal);
     60:   PetscFree((*c)->queueRemote);
     61:   PetscFree((*c)->neighbors);
     62:   PetscFree((*c)->needCount);
     63:   PetscFree((*c)->localOffsets);
     64:   PetscFree((*c)->fillCount);
     65:   PetscFree((*c)->remoteOffsets);
     66:   PetscFree((*c)->request);
     67:   PetscFree((*c)->status);
     68:   PetscHeaderDestroy(c);
     69:   return(0);
     70: }

     72: PetscErrorCode CharacteristicCreate(MPI_Comm comm, Characteristic *c)
     73: {
     74:   Characteristic newC;

     79:   *c = NULL;
     80:   CharacteristicInitializePackage();

     82:   PetscHeaderCreate(newC, CHARACTERISTIC_CLASSID, "Characteristic", "Characteristic", "Characteristic", comm, CharacteristicDestroy, CharacteristicView);
     83:   *c   = newC;

     85:   newC->structured          = PETSC_TRUE;
     86:   newC->numIds              = 0;
     87:   newC->velocityDA          = NULL;
     88:   newC->velocity            = NULL;
     89:   newC->velocityOld         = NULL;
     90:   newC->numVelocityComp     = 0;
     91:   newC->velocityComp        = NULL;
     92:   newC->velocityInterp      = NULL;
     93:   newC->velocityInterpLocal = NULL;
     94:   newC->velocityCtx         = NULL;
     95:   newC->fieldDA             = NULL;
     96:   newC->field               = NULL;
     97:   newC->numFieldComp        = 0;
     98:   newC->fieldComp           = NULL;
     99:   newC->fieldInterp         = NULL;
    100:   newC->fieldInterpLocal    = NULL;
    101:   newC->fieldCtx            = NULL;
    102:   newC->itemType            = 0;
    103:   newC->queue               = NULL;
    104:   newC->queueSize           = 0;
    105:   newC->queueMax            = 0;
    106:   newC->queueLocal          = NULL;
    107:   newC->queueLocalSize      = 0;
    108:   newC->queueLocalMax       = 0;
    109:   newC->queueRemote         = NULL;
    110:   newC->queueRemoteSize     = 0;
    111:   newC->queueRemoteMax      = 0;
    112:   newC->numNeighbors        = 0;
    113:   newC->neighbors           = NULL;
    114:   newC->needCount           = NULL;
    115:   newC->localOffsets        = NULL;
    116:   newC->fillCount           = NULL;
    117:   newC->remoteOffsets       = NULL;
    118:   newC->request             = NULL;
    119:   newC->status              = NULL;
    120:   return(0);
    121: }

    123: /*@C
    124:    CharacteristicSetType - Builds Characteristic for a particular solver.

    126:    Logically Collective on Characteristic

    128:    Input Parameters:
    129: +  c    - the method of characteristics context
    130: -  type - a known method

    132:    Options Database Key:
    133: .  -characteristic_type <method> - Sets the method; use -help for a list
    134:     of available methods

    136:    Notes:
    137:    See "include/petsccharacteristic.h" for available methods

    139:   Normally, it is best to use the CharacteristicSetFromOptions() command and
    140:   then set the Characteristic type from the options database rather than by using
    141:   this routine.  Using the options database provides the user with
    142:   maximum flexibility in evaluating the many different Krylov methods.
    143:   The CharacteristicSetType() routine is provided for those situations where it
    144:   is necessary to set the iterative solver independently of the command
    145:   line or options database.  This might be the case, for example, when
    146:   the choice of iterative solver changes during the execution of the
    147:   program, and the user's application is taking responsibility for
    148:   choosing the appropriate method.  In other words, this routine is
    149:   not for beginners.

    151:   Level: intermediate

    153: .keywords: Characteristic, set, method

    155: .seealso: CharacteristicType

    157: @*/
    158: PetscErrorCode CharacteristicSetType(Characteristic c, CharacteristicType type)
    159: {
    160:   PetscErrorCode ierr, (*r)(Characteristic);
    161:   PetscBool      match;

    167:   PetscObjectTypeCompare((PetscObject) c, type, &match);
    168:   if (match) return(0);

    170:   if (c->data) {
    171:     /* destroy the old private Characteristic context */
    172:     (*c->ops->destroy)(c);
    173:     c->ops->destroy = NULL;
    174:     c->data         = 0;
    175:   }

    177:    PetscFunctionListFind(CharacteristicList,type,&r);
    178:   if (!r) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_UNKNOWN_TYPE, "Unknown Characteristic type given: %s", type);
    179:   c->setupcalled = 0;
    180:   (*r)(c);
    181:   PetscObjectChangeTypeName((PetscObject) c, type);
    182:   return(0);
    183: }

    185: /*@
    186:    CharacteristicSetUp - Sets up the internal data structures for the
    187:    later use of an iterative solver.

    189:    Collective on Characteristic

    191:    Input Parameter:
    192: .  ksp   - iterative context obtained from CharacteristicCreate()

    194:    Level: developer

    196: .keywords: Characteristic, setup

    198: .seealso: CharacteristicCreate(), CharacteristicSolve(), CharacteristicDestroy()
    199: @*/
    200: PetscErrorCode CharacteristicSetUp(Characteristic c)
    201: {

    207:   if (!((PetscObject)c)->type_name) {
    208:     CharacteristicSetType(c, CHARACTERISTICDA);
    209:   }

    211:   if (c->setupcalled == 2) return(0);

    213:   PetscLogEventBegin(CHARACTERISTIC_SetUp,c,0,0,0);
    214:   if (!c->setupcalled) {
    215:     (*c->ops->setup)(c);
    216:   }
    217:   PetscLogEventEnd(CHARACTERISTIC_SetUp,c,0,0,0);
    218:   c->setupcalled = 2;
    219:   return(0);
    220: }

    222: /*@C
    223:   CharacteristicRegister -  Adds a solver to the method of characteristics package.

    225:    Not Collective

    227:    Input Parameters:
    228: +  name_solver - name of a new user-defined solver
    229: -  routine_create - routine to create method context

    231:   Sample usage:
    232: .vb
    233:     CharacteristicRegister("my_char", MyCharCreate);
    234: .ve

    236:   Then, your Characteristic type can be chosen with the procedural interface via
    237: .vb
    238:     CharacteristicCreate(MPI_Comm, Characteristic* &char);
    239:     CharacteristicSetType(char,"my_char");
    240: .ve
    241:    or at runtime via the option
    242: .vb
    243:     -characteristic_type my_char
    244: .ve

    246:    Notes:
    247:    CharacteristicRegister() may be called multiple times to add several user-defined solvers.

    249: .keywords: Characteristic, register

    251: .seealso: CharacteristicRegisterAll(), CharacteristicRegisterDestroy()

    253:   Level: advanced
    254: @*/
    255: PetscErrorCode CharacteristicRegister(const char sname[],PetscErrorCode (*function)(Characteristic))
    256: {

    260:   CharacteristicInitializePackage();
    261:   PetscFunctionListAdd(&CharacteristicList,sname,function);
    262:   return(0);
    263: }

    265: PetscErrorCode CharacteristicSetVelocityInterpolation(Characteristic c, DM da, Vec v, Vec vOld, PetscInt numComponents, PetscInt components[], PetscErrorCode (*interp)(Vec, PetscReal[], PetscInt, PetscInt[], PetscScalar[], void*), void *ctx)
    266: {
    268:   c->velocityDA      = da;
    269:   c->velocity        = v;
    270:   c->velocityOld     = vOld;
    271:   c->numVelocityComp = numComponents;
    272:   c->velocityComp    = components;
    273:   c->velocityInterp  = interp;
    274:   c->velocityCtx     = ctx;
    275:   return(0);
    276: }

    278: PetscErrorCode CharacteristicSetVelocityInterpolationLocal(Characteristic c, DM da, Vec v, Vec vOld, PetscInt numComponents, PetscInt components[], PetscErrorCode (*interp)(void*, PetscReal [], PetscInt, PetscInt[], PetscScalar[], void*), void *ctx)
    279: {
    281:   c->velocityDA          = da;
    282:   c->velocity            = v;
    283:   c->velocityOld         = vOld;
    284:   c->numVelocityComp     = numComponents;
    285:   c->velocityComp        = components;
    286:   c->velocityInterpLocal = interp;
    287:   c->velocityCtx         = ctx;
    288:   return(0);
    289: }

    291: PetscErrorCode CharacteristicSetFieldInterpolation(Characteristic c, DM da, Vec v, PetscInt numComponents, PetscInt components[], PetscErrorCode (*interp)(Vec, PetscReal[], PetscInt, PetscInt[], PetscScalar[], void*), void *ctx)
    292: {
    294: #if 0
    295:   if (numComponents > 2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP, "Fields with more than 2 components are not supported. Send mail to petsc-maint@mcs.anl.gov.");
    296: #endif
    297:   c->fieldDA      = da;
    298:   c->field        = v;
    299:   c->numFieldComp = numComponents;
    300:   c->fieldComp    = components;
    301:   c->fieldInterp  = interp;
    302:   c->fieldCtx     = ctx;
    303:   return(0);
    304: }

    306: PetscErrorCode CharacteristicSetFieldInterpolationLocal(Characteristic c, DM da, Vec v, PetscInt numComponents, PetscInt components[], PetscErrorCode (*interp)(void*, PetscReal[], PetscInt, PetscInt[], PetscScalar [], void*), void *ctx)
    307: {
    309: #if 0
    310:   if (numComponents > 2) SETERRQ(PETSC_COMM_SELF,PETSC_ERR_SUP, "Fields with more than 2 components are not supported. Send mail to petsc-maint@mcs.anl.gov.");
    311: #endif
    312:   c->fieldDA          = da;
    313:   c->field            = v;
    314:   c->numFieldComp     = numComponents;
    315:   c->fieldComp        = components;
    316:   c->fieldInterpLocal = interp;
    317:   c->fieldCtx         = ctx;
    318:   return(0);
    319: }

    321: PetscErrorCode CharacteristicSolve(Characteristic c, PetscReal dt, Vec solution)
    322: {
    323:   CharacteristicPointDA2D Qi;
    324:   DM                      da = c->velocityDA;
    325:   Vec                     velocityLocal, velocityLocalOld;
    326:   Vec                     fieldLocal;
    327:   DMDALocalInfo           info;
    328:   PetscScalar             **solArray;
    329:   void                    *velocityArray;
    330:   void                    *velocityArrayOld;
    331:   void                    *fieldArray;
    332:   PetscScalar             *interpIndices;
    333:   PetscScalar             *velocityValues, *velocityValuesOld;
    334:   PetscScalar             *fieldValues;
    335:   PetscMPIInt             rank;
    336:   PetscInt                dim;
    337:   PetscMPIInt             neighbors[9];
    338:   PetscInt                dof;
    339:   PetscInt                gx, gy;
    340:   PetscInt                n, is, ie, js, je, comp;
    341:   PetscErrorCode          ierr;

    344:   c->queueSize = 0;
    345:   MPI_Comm_rank(PetscObjectComm((PetscObject)c), &rank);
    346:   DMDAGetNeighborsRank(da, neighbors);
    347:   CharacteristicSetNeighbors(c, 9, neighbors);
    348:   CharacteristicSetUp(c);
    349:   /* global and local grid info */
    350:   DMDAGetInfo(da, &dim, &gx, &gy, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
    351:   DMDAGetLocalInfo(da, &info);
    352:   is   = info.xs;          ie   = info.xs+info.xm;
    353:   js   = info.ys;          je   = info.ys+info.ym;
    354:   /* Allocation */
    355:   PetscMalloc1(dim,                &interpIndices);
    356:   PetscMalloc1(c->numVelocityComp, &velocityValues);
    357:   PetscMalloc1(c->numVelocityComp, &velocityValuesOld);
    358:   PetscMalloc1(c->numFieldComp,    &fieldValues);
    359:   PetscLogEventBegin(CHARACTERISTIC_Solve,0,0,0,0);

    361:   /* -----------------------------------------------------------------------
    362:      PART 1, AT t-dt/2
    363:      -----------------------------------------------------------------------*/
    364:   PetscLogEventBegin(CHARACTERISTIC_QueueSetup,0,0,0,0);
    365:   /* GET POSITION AT HALF TIME IN THE PAST */
    366:   if (c->velocityInterpLocal) {
    367:     DMGetLocalVector(c->velocityDA, &velocityLocal);
    368:     DMGetLocalVector(c->velocityDA, &velocityLocalOld);
    369:     DMGlobalToLocalBegin(c->velocityDA, c->velocity, INSERT_VALUES, velocityLocal);
    370:     DMGlobalToLocalEnd(c->velocityDA, c->velocity, INSERT_VALUES, velocityLocal);
    371:     DMGlobalToLocalBegin(c->velocityDA, c->velocityOld, INSERT_VALUES, velocityLocalOld);
    372:     DMGlobalToLocalEnd(c->velocityDA, c->velocityOld, INSERT_VALUES, velocityLocalOld);
    373:     DMDAVecGetArray(c->velocityDA, velocityLocal,    &velocityArray);
    374:     DMDAVecGetArray(c->velocityDA, velocityLocalOld, &velocityArrayOld);
    375:   }
    376:   PetscInfo(NULL, "Calculating position at t_{n - 1/2}\n");
    377:   for (Qi.j = js; Qi.j < je; Qi.j++) {
    378:     for (Qi.i = is; Qi.i < ie; Qi.i++) {
    379:       interpIndices[0] = Qi.i;
    380:       interpIndices[1] = Qi.j;
    381:       if (c->velocityInterpLocal) {c->velocityInterpLocal(velocityArray, interpIndices, c->numVelocityComp, c->velocityComp, velocityValues, c->velocityCtx);}
    382:       else {c->velocityInterp(c->velocity, interpIndices, c->numVelocityComp, c->velocityComp, velocityValues, c->velocityCtx);}
    383:       Qi.x = Qi.i - velocityValues[0]*dt/2.0;
    384:       Qi.y = Qi.j - velocityValues[1]*dt/2.0;

    386:       /* Determine whether the position at t - dt/2 is local */
    387:       Qi.proc = DMDAGetNeighborRelative(da, Qi.x, Qi.y);

    389:       /* Check for Periodic boundaries and move all periodic points back onto the domain */
    390:       DMDAMapCoordsToPeriodicDomain(da,&(Qi.x),&(Qi.y));
    391:       CharacteristicAddPoint(c, &Qi);
    392:     }
    393:   }
    394:   PetscLogEventEnd(CHARACTERISTIC_QueueSetup,0,0,0,0);

    396:   PetscLogEventBegin(CHARACTERISTIC_HalfTimeExchange,0,0,0,0);
    397:   CharacteristicSendCoordinatesBegin(c);
    398:   PetscLogEventEnd(CHARACTERISTIC_HalfTimeExchange,0,0,0,0);

    400:   PetscLogEventBegin(CHARACTERISTIC_HalfTimeLocal,0,0,0,0);
    401:   /* Calculate velocity at t_n+1/2 (local values) */
    402:   PetscInfo(NULL, "Calculating local velocities at t_{n - 1/2}\n");
    403:   for (n = 0; n < c->queueSize; n++) {
    404:     Qi = c->queue[n];
    405:     if (c->neighbors[Qi.proc] == rank) {
    406:       interpIndices[0] = Qi.x;
    407:       interpIndices[1] = Qi.y;
    408:       if (c->velocityInterpLocal) {
    409:         c->velocityInterpLocal(velocityArray,    interpIndices, c->numVelocityComp, c->velocityComp, velocityValues, c->velocityCtx);
    410:         c->velocityInterpLocal(velocityArrayOld, interpIndices, c->numVelocityComp, c->velocityComp, velocityValuesOld, c->velocityCtx);
    411:       } else {
    412:         c->velocityInterp(c->velocity,    interpIndices, c->numVelocityComp, c->velocityComp, velocityValues, c->velocityCtx);
    413:         c->velocityInterp(c->velocityOld, interpIndices, c->numVelocityComp, c->velocityComp, velocityValuesOld, c->velocityCtx);
    414:       }
    415:       Qi.x = 0.5*(velocityValues[0] + velocityValuesOld[0]);
    416:       Qi.y = 0.5*(velocityValues[1] + velocityValuesOld[1]);
    417:     }
    418:     c->queue[n] = Qi;
    419:   }
    420:   PetscLogEventEnd(CHARACTERISTIC_HalfTimeLocal,0,0,0,0);

    422:   PetscLogEventBegin(CHARACTERISTIC_HalfTimeExchange,0,0,0,0);
    423:   CharacteristicSendCoordinatesEnd(c);
    424:   PetscLogEventEnd(CHARACTERISTIC_HalfTimeExchange,0,0,0,0);

    427:   /* Calculate velocity at t_n+1/2 (fill remote requests) */
    428:   PetscLogEventBegin(CHARACTERISTIC_HalfTimeRemote,0,0,0,0);
    429:   PetscInfo1(NULL, "Calculating %d remote velocities at t_{n - 1/2}\n", c->queueRemoteSize);
    430:   for (n = 0; n < c->queueRemoteSize; n++) {
    431:     Qi = c->queueRemote[n];
    432:     interpIndices[0] = Qi.x;
    433:     interpIndices[1] = Qi.y;
    434:     if (c->velocityInterpLocal) {
    435:       c->velocityInterpLocal(velocityArray,    interpIndices, c->numVelocityComp, c->velocityComp, velocityValues,    c->velocityCtx);
    436:       c->velocityInterpLocal(velocityArrayOld, interpIndices, c->numVelocityComp, c->velocityComp, velocityValuesOld, c->velocityCtx);
    437:     } else {
    438:       c->velocityInterp(c->velocity,    interpIndices, c->numVelocityComp, c->velocityComp, velocityValues,    c->velocityCtx);
    439:       c->velocityInterp(c->velocityOld, interpIndices, c->numVelocityComp, c->velocityComp, velocityValuesOld, c->velocityCtx);
    440:     }
    441:     Qi.x = 0.5*(velocityValues[0] + velocityValuesOld[0]);
    442:     Qi.y = 0.5*(velocityValues[1] + velocityValuesOld[1]);
    443:     c->queueRemote[n] = Qi;
    444:   }
    445:   PetscLogEventEnd(CHARACTERISTIC_HalfTimeRemote,0,0,0,0);
    446:   PetscLogEventBegin(CHARACTERISTIC_HalfTimeExchange,0,0,0,0);
    447:   CharacteristicGetValuesBegin(c);
    448:   CharacteristicGetValuesEnd(c);
    449:   if (c->velocityInterpLocal) {
    450:     DMDAVecRestoreArray(c->velocityDA, velocityLocal,    &velocityArray);
    451:     DMDAVecRestoreArray(c->velocityDA, velocityLocalOld, &velocityArrayOld);
    452:     DMRestoreLocalVector(c->velocityDA, &velocityLocal);
    453:     DMRestoreLocalVector(c->velocityDA, &velocityLocalOld);
    454:   }
    455:   PetscLogEventEnd(CHARACTERISTIC_HalfTimeExchange,0,0,0,0);

    457:   /* -----------------------------------------------------------------------
    458:      PART 2, AT t-dt
    459:      -----------------------------------------------------------------------*/

    461:   /* GET POSITION AT t_n (local values) */
    462:   PetscLogEventBegin(CHARACTERISTIC_FullTimeLocal,0,0,0,0);
    463:   PetscInfo(NULL, "Calculating position at t_{n}\n");
    464:   for (n = 0; n < c->queueSize; n++) {
    465:     Qi   = c->queue[n];
    466:     Qi.x = Qi.i - Qi.x*dt;
    467:     Qi.y = Qi.j - Qi.y*dt;

    469:     /* Determine whether the position at t-dt is local */
    470:     Qi.proc = DMDAGetNeighborRelative(da, Qi.x, Qi.y);

    472:     /* Check for Periodic boundaries and move all periodic points back onto the domain */
    473:     DMDAMapCoordsToPeriodicDomain(da,&(Qi.x),&(Qi.y));

    475:     c->queue[n] = Qi;
    476:   }
    477:   PetscLogEventEnd(CHARACTERISTIC_FullTimeLocal,0,0,0,0);

    479:   PetscLogEventBegin(CHARACTERISTIC_FullTimeExchange,0,0,0,0);
    480:   CharacteristicSendCoordinatesBegin(c);
    481:   PetscLogEventEnd(CHARACTERISTIC_FullTimeExchange,0,0,0,0);

    483:   /* GET VALUE AT FULL TIME IN THE PAST (LOCAL REQUESTS) */
    484:   PetscLogEventBegin(CHARACTERISTIC_FullTimeLocal,0,0,0,0);
    485:   if (c->fieldInterpLocal) {
    486:     DMGetLocalVector(c->fieldDA, &fieldLocal);
    487:     DMGlobalToLocalBegin(c->fieldDA, c->field, INSERT_VALUES, fieldLocal);
    488:     DMGlobalToLocalEnd(c->fieldDA, c->field, INSERT_VALUES, fieldLocal);
    489:     DMDAVecGetArray(c->fieldDA, fieldLocal, &fieldArray);
    490:   }
    491:   PetscInfo(NULL, "Calculating local field at t_{n}\n");
    492:   for (n = 0; n < c->queueSize; n++) {
    493:     if (c->neighbors[c->queue[n].proc] == rank) {
    494:       interpIndices[0] = c->queue[n].x;
    495:       interpIndices[1] = c->queue[n].y;
    496:       if (c->fieldInterpLocal) {c->fieldInterpLocal(fieldArray, interpIndices, c->numFieldComp, c->fieldComp, fieldValues, c->fieldCtx);}
    497:       else {c->fieldInterp(c->field, interpIndices, c->numFieldComp, c->fieldComp, fieldValues, c->fieldCtx);}
    498:       for (comp = 0; comp < c->numFieldComp; comp++) c->queue[n].field[comp] = fieldValues[comp];
    499:     }
    500:   }
    501:   PetscLogEventEnd(CHARACTERISTIC_FullTimeLocal,0,0,0,0);

    503:   PetscLogEventBegin(CHARACTERISTIC_FullTimeExchange,0,0,0,0);
    504:   CharacteristicSendCoordinatesEnd(c);
    505:   PetscLogEventEnd(CHARACTERISTIC_FullTimeExchange,0,0,0,0);

    507:   /* GET VALUE AT FULL TIME IN THE PAST (REMOTE REQUESTS) */
    508:   PetscLogEventBegin(CHARACTERISTIC_FullTimeRemote,0,0,0,0);
    509:   PetscInfo1(NULL, "Calculating %d remote field points at t_{n}\n", c->queueRemoteSize);
    510:   for (n = 0; n < c->queueRemoteSize; n++) {
    511:     interpIndices[0] = c->queueRemote[n].x;
    512:     interpIndices[1] = c->queueRemote[n].y;

    514:     /* for debugging purposes */
    515:     if (1) { /* hacked bounds test...let's do better */
    516:       PetscScalar im = interpIndices[0]; PetscScalar jm = interpIndices[1];

    518:       if ((im < (PetscScalar) is - 1.) || (im > (PetscScalar) ie) || (jm < (PetscScalar)  js - 1.) || (jm > (PetscScalar) je)) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_LIB, "Nonlocal point: (%g,%g)", im, jm);
    519:     }

    521:     if (c->fieldInterpLocal) {c->fieldInterpLocal(fieldArray, interpIndices, c->numFieldComp, c->fieldComp, fieldValues, c->fieldCtx);}
    522:     else {c->fieldInterp(c->field, interpIndices, c->numFieldComp, c->fieldComp, fieldValues, c->fieldCtx);}
    523:     for (comp = 0; comp < c->numFieldComp; comp++) c->queueRemote[n].field[comp] = fieldValues[comp];
    524:   }
    525:   PetscLogEventEnd(CHARACTERISTIC_FullTimeRemote,0,0,0,0);

    527:   PetscLogEventBegin(CHARACTERISTIC_FullTimeExchange,0,0,0,0);
    528:   CharacteristicGetValuesBegin(c);
    529:   CharacteristicGetValuesEnd(c);
    530:   if (c->fieldInterpLocal) {
    531:     DMDAVecRestoreArray(c->fieldDA, fieldLocal, &fieldArray);
    532:     DMRestoreLocalVector(c->fieldDA, &fieldLocal);
    533:   }
    534:   PetscLogEventEnd(CHARACTERISTIC_FullTimeExchange,0,0,0,0);

    536:   /* Return field of characteristics at t_n-1 */
    537:   PetscLogEventBegin(CHARACTERISTIC_DAUpdate,0,0,0,0);
    538:   DMDAGetInfo(c->fieldDA,0,0,0,0,0,0,0,&dof,0,0,0,0,0);
    539:   DMDAVecGetArray(c->fieldDA, solution, &solArray);
    540:   for (n = 0; n < c->queueSize; n++) {
    541:     Qi = c->queue[n];
    542:     for (comp = 0; comp < c->numFieldComp; comp++) solArray[Qi.j][Qi.i*dof+c->fieldComp[comp]] = Qi.field[comp];
    543:   }
    544:   DMDAVecRestoreArray(c->fieldDA, solution, &solArray);
    545:   PetscLogEventEnd(CHARACTERISTIC_DAUpdate,0,0,0,0);
    546:   PetscLogEventEnd(CHARACTERISTIC_Solve,0,0,0,0);

    548:   /* Cleanup */
    549:   PetscFree(interpIndices);
    550:   PetscFree(velocityValues);
    551:   PetscFree(velocityValuesOld);
    552:   PetscFree(fieldValues);
    553:   return(0);
    554: }

    556: PetscErrorCode CharacteristicSetNeighbors(Characteristic c, PetscInt numNeighbors, PetscMPIInt neighbors[])
    557: {

    561:   c->numNeighbors = numNeighbors;
    562:   PetscFree(c->neighbors);
    563:   PetscMalloc1(numNeighbors, &c->neighbors);
    564:   PetscMemcpy(c->neighbors, neighbors, numNeighbors * sizeof(PetscMPIInt));
    565:   return(0);
    566: }

    568: PetscErrorCode CharacteristicAddPoint(Characteristic c, CharacteristicPointDA2D *point)
    569: {
    571:   if (c->queueSize >= c->queueMax) SETERRQ1(PETSC_COMM_SELF,PETSC_ERR_ARG_OUTOFRANGE, "Exceeeded maximum queue size %d", c->queueMax);
    572:   c->queue[c->queueSize++] = *point;
    573:   return(0);
    574: }

    576: int CharacteristicSendCoordinatesBegin(Characteristic c)
    577: {
    578:   PetscMPIInt    rank, tag = 121;
    579:   PetscInt       i, n;

    583:   MPI_Comm_rank(PetscObjectComm((PetscObject)c), &rank);
    584:   CharacteristicHeapSort(c, c->queue, c->queueSize);
    585:   PetscMemzero(c->needCount, c->numNeighbors * sizeof(PetscInt));
    586:   for (i = 0;  i < c->queueSize; i++) c->needCount[c->queue[i].proc]++;
    587:   c->fillCount[0] = 0;
    588:   for (n = 1; n < c->numNeighbors; n++) {
    589:     MPI_Irecv(&(c->fillCount[n]), 1, MPIU_INT, c->neighbors[n], tag, PetscObjectComm((PetscObject)c), &(c->request[n-1]));
    590:   }
    591:   for (n = 1; n < c->numNeighbors; n++) {
    592:     MPI_Send(&(c->needCount[n]), 1, MPIU_INT, c->neighbors[n], tag, PetscObjectComm((PetscObject)c));
    593:   }
    594:   MPI_Waitall(c->numNeighbors-1, c->request, c->status);
    595:   /* Initialize the remote queue */
    596:   c->queueLocalMax  = c->localOffsets[0]  = 0;
    597:   c->queueRemoteMax = c->remoteOffsets[0] = 0;
    598:   for (n = 1; n < c->numNeighbors; n++) {
    599:     c->remoteOffsets[n] = c->queueRemoteMax;
    600:     c->queueRemoteMax  += c->fillCount[n];
    601:     c->localOffsets[n]  = c->queueLocalMax;
    602:     c->queueLocalMax   += c->needCount[n];
    603:   }
    604:   /* HACK BEGIN */
    605:   for (n = 1; n < c->numNeighbors; n++) c->localOffsets[n] += c->needCount[0];
    606:   c->needCount[0] = 0;
    607:   /* HACK END */
    608:   if (c->queueRemoteMax) {
    609:     PetscMalloc1(c->queueRemoteMax, &c->queueRemote);
    610:   } else c->queueRemote = NULL;
    611:   c->queueRemoteSize = c->queueRemoteMax;

    613:   /* Send and Receive requests for values at t_n+1/2, giving the coordinates for interpolation */
    614:   for (n = 1; n < c->numNeighbors; n++) {
    615:     PetscInfo2(NULL, "Receiving %d requests for values from proc %d\n", c->fillCount[n], c->neighbors[n]);
    616:     MPI_Irecv(&(c->queueRemote[c->remoteOffsets[n]]), c->fillCount[n], c->itemType, c->neighbors[n], tag, PetscObjectComm((PetscObject)c), &(c->request[n-1]));
    617:   }
    618:   for (n = 1; n < c->numNeighbors; n++) {
    619:     PetscInfo2(NULL, "Sending %d requests for values from proc %d\n", c->needCount[n], c->neighbors[n]);
    620:     MPI_Send(&(c->queue[c->localOffsets[n]]), c->needCount[n], c->itemType, c->neighbors[n], tag, PetscObjectComm((PetscObject)c));
    621:   }
    622:   return(0);
    623: }

    625: PetscErrorCode CharacteristicSendCoordinatesEnd(Characteristic c)
    626: {
    627: #if 0
    628:   PetscMPIInt rank;
    629:   PetscInt    n;
    630: #endif

    634:   MPI_Waitall(c->numNeighbors-1, c->request, c->status);
    635: #if 0
    636:   MPI_Comm_rank(PetscObjectComm((PetscObject)c), &rank);
    637:   for (n = 0; n < c->queueRemoteSize; n++) {
    638:     if (c->neighbors[c->queueRemote[n].proc] == rank) SETERRQ2(PETSC_COMM_SELF,PETSC_ERR_PLIB, "This is messed up, n = %d proc = %d", n, c->queueRemote[n].proc);
    639:   }
    640: #endif
    641:   return(0);
    642: }

    644: PetscErrorCode CharacteristicGetValuesBegin(Characteristic c)
    645: {
    646:   PetscMPIInt    tag = 121;
    647:   PetscInt       n;

    651:   /* SEND AND RECIEVE FILLED REQUESTS for velocities at t_n+1/2 */
    652:   for (n = 1; n < c->numNeighbors; n++) {
    653:     MPI_Irecv(&(c->queue[c->localOffsets[n]]), c->needCount[n], c->itemType, c->neighbors[n], tag, PetscObjectComm((PetscObject)c), &(c->request[n-1]));
    654:   }
    655:   for (n = 1; n < c->numNeighbors; n++) {
    656:     MPI_Send(&(c->queueRemote[c->remoteOffsets[n]]), c->fillCount[n], c->itemType, c->neighbors[n], tag, PetscObjectComm((PetscObject)c));
    657:   }
    658:   return(0);
    659: }

    661: PetscErrorCode CharacteristicGetValuesEnd(Characteristic c)
    662: {

    666:   MPI_Waitall(c->numNeighbors-1, c->request, c->status);
    667:   /* Free queue of requests from other procs */
    668:   PetscFree(c->queueRemote);
    669:   return(0);
    670: }

    672: /*---------------------------------------------------------------------*/
    673: /*
    674:   Based on code from http://linux.wku.edu/~lamonml/algor/sort/heap.html
    675: */
    676: PetscErrorCode CharacteristicHeapSort(Characteristic c, Queue queue, PetscInt size)
    677: /*---------------------------------------------------------------------*/
    678: {
    679:   PetscErrorCode          ierr;
    680:   CharacteristicPointDA2D temp;
    681:   PetscInt                n;

    684:   if (0) { /* Check the order of the queue before sorting */
    685:     PetscInfo(NULL, "Before Heap sort\n");
    686:     for (n=0; n<size; n++) {
    687:       PetscInfo2(NULL,"%d %d\n",n,queue[n].proc);
    688:     }
    689:   }

    691:   /* SORTING PHASE */
    692:   for (n = (size / 2)-1; n >= 0; n--) {
    693:     CharacteristicSiftDown(c, queue, n, size-1); /* Rich had size-1 here, Matt had size*/
    694:   }
    695:   for (n = size-1; n >= 1; n--) {
    696:     temp     = queue[0];
    697:     queue[0] = queue[n];
    698:     queue[n] = temp;
    699:     CharacteristicSiftDown(c, queue, 0, n-1);
    700:   }
    701:   if (0) { /* Check the order of the queue after sorting */
    702:     PetscInfo(NULL, "Avter  Heap sort\n");
    703:     for (n=0; n<size; n++) {
    704:       PetscInfo2(NULL,"%d %d\n",n,queue[n].proc);
    705:     }
    706:   }
    707:   return(0);
    708: }

    710: /*---------------------------------------------------------------------*/
    711: /*
    712:   Based on code from http://linux.wku.edu/~lamonml/algor/sort/heap.html
    713: */
    714: PetscErrorCode CharacteristicSiftDown(Characteristic c, Queue queue, PetscInt root, PetscInt bottom)
    715: /*---------------------------------------------------------------------*/
    716: {
    717:   PetscBool               done = PETSC_FALSE;
    718:   PetscInt                maxChild;
    719:   CharacteristicPointDA2D temp;

    722:   while ((root*2 <= bottom) && (!done)) {
    723:     if (root*2 == bottom) maxChild = root * 2;
    724:     else if (queue[root*2].proc > queue[root*2+1].proc) maxChild = root * 2;
    725:     else maxChild = root * 2 + 1;

    727:     if (queue[root].proc < queue[maxChild].proc) {
    728:       temp            = queue[root];
    729:       queue[root]     = queue[maxChild];
    730:       queue[maxChild] = temp;
    731:       root            = maxChild;
    732:     } else done = PETSC_TRUE;
    733:   }
    734:   return(0);
    735: }

    737: /* [center, left, top-left, top, top-right, right, bottom-right, bottom, bottom-left] */
    738: PetscErrorCode DMDAGetNeighborsRank(DM da, PetscMPIInt neighbors[])
    739: {
    740:   DMBoundaryType   bx, by;
    741:   PetscBool        IPeriodic = PETSC_FALSE, JPeriodic = PETSC_FALSE;
    742:   MPI_Comm         comm;
    743:   PetscMPIInt      rank;
    744:   PetscInt         **procs,pi,pj,pim,pip,pjm,pjp,PI,PJ;
    745:   PetscErrorCode   ierr;

    748:   PetscObjectGetComm((PetscObject) da, &comm);
    749:   MPI_Comm_rank(comm, &rank);
    750:   DMDAGetInfo(da, 0, 0, 0, 0, &PI,&PJ, 0, 0, 0, &bx, &by,0, 0);

    752:   if (bx == DM_BOUNDARY_PERIODIC) IPeriodic = PETSC_TRUE;
    753:   if (by == DM_BOUNDARY_PERIODIC) JPeriodic = PETSC_TRUE;

    755:   neighbors[0] = rank;
    756:   rank = 0;
    757:   PetscMalloc1(PJ,&procs);
    758:   for (pj=0; pj<PJ; pj++) {
    759:     PetscMalloc1(PI,&(procs[pj]));
    760:     for (pi=0; pi<PI; pi++) {
    761:       procs[pj][pi] = rank;
    762:       rank++;
    763:     }
    764:   }

    766:   pi  = neighbors[0] % PI;
    767:   pj  = neighbors[0] / PI;
    768:   pim = pi-1;  if (pim<0) pim=PI-1;
    769:   pip = (pi+1)%PI;
    770:   pjm = pj-1;  if (pjm<0) pjm=PJ-1;
    771:   pjp = (pj+1)%PJ;

    773:   neighbors[1] = procs[pj] [pim];
    774:   neighbors[2] = procs[pjp][pim];
    775:   neighbors[3] = procs[pjp][pi];
    776:   neighbors[4] = procs[pjp][pip];
    777:   neighbors[5] = procs[pj] [pip];
    778:   neighbors[6] = procs[pjm][pip];
    779:   neighbors[7] = procs[pjm][pi];
    780:   neighbors[8] = procs[pjm][pim];

    782:   if (!IPeriodic) {
    783:     if (pi==0)    neighbors[1]=neighbors[2]=neighbors[8]=neighbors[0];
    784:     if (pi==PI-1) neighbors[4]=neighbors[5]=neighbors[6]=neighbors[0];
    785:   }

    787:   if (!JPeriodic) {
    788:     if (pj==0)    neighbors[6]=neighbors[7]=neighbors[8]=neighbors[0];
    789:     if (pj==PJ-1) neighbors[2]=neighbors[3]=neighbors[4]=neighbors[0];
    790:   }

    792:   for (pj = 0; pj < PJ; pj++) {
    793:     PetscFree(procs[pj]);
    794:   }
    795:   PetscFree(procs);
    796:   return(0);
    797: }

    799: /*
    800:   SUBDOMAIN NEIGHBORHOOD PROCESS MAP:
    801:     2 | 3 | 4
    802:     __|___|__
    803:     1 | 0 | 5
    804:     __|___|__
    805:     8 | 7 | 6
    806:       |   |
    807: */
    808: PetscInt DMDAGetNeighborRelative(DM da, PetscReal ir, PetscReal jr)
    809: {
    810:   DMDALocalInfo  info;
    811:   PetscReal      is,ie,js,je;

    814:   DMDAGetLocalInfo(da, &info);
    815:   is   = (PetscReal) info.xs - 0.5; ie = (PetscReal) info.xs + info.xm - 0.5;
    816:   js   = (PetscReal) info.ys - 0.5; je = (PetscReal) info.ys + info.ym - 0.5;

    818:   if (ir >= is && ir <= ie) { /* center column */
    819:     if (jr >= js && jr <= je) return 0;
    820:     else if (jr < js)         return 7;
    821:     else                      return 3;
    822:   } else if (ir < is) {     /* left column */
    823:     if (jr >= js && jr <= je) return 1;
    824:     else if (jr < js)         return 8;
    825:     else                      return 2;
    826:   } else {                  /* right column */
    827:     if (jr >= js && jr <= je) return 5;
    828:     else if (jr < js)         return 6;
    829:     else                      return 4;
    830:   }
    831: }