2:  #include <../src/vec/is/sf/impls/basic/gatherv/sfgatherv.h>

  4: #define PetscSFPackGet_Gatherv PetscSFPackGet_Allgatherv

  6: /* Reuse the type. The difference is some fields (displs, recvcounts) are only significant
  7:    on rank 0 in Gatherv. On other ranks they are harmless NULL.
  8:  */
  9: typedef PetscSF_Allgatherv PetscSF_Gatherv;

 11: PETSC_INTERN PetscErrorCode PetscSFBcastAndOpBegin_Gatherv(PetscSF sf,MPI_Datatype unit,PetscMemType rootmtype,const void *rootdata,PetscMemType leafmtype,void *leafdata,MPI_Op op)
 12: {
 13:   PetscErrorCode       ierr;
 14:   PetscSFPack          link;
 15:   PetscMPIInt          rank,sendcount;
 16:   MPI_Comm             comm;
 17:   char                 *recvbuf;
 18:   PetscSF_Gatherv      *dat = (PetscSF_Gatherv*)sf->data;

 21:   PetscSFPackGet_Gatherv(sf,unit,rootmtype,rootdata,leafmtype,leafdata,&link);
 22:   PetscObjectGetComm((PetscObject)sf,&comm);
 23:   PetscMPIIntCast(sf->nroots,&sendcount);
 24:   MPI_Comm_rank(comm,&rank);

 26:   if (op == MPIU_REPLACE) {
 27:     recvbuf = (char*)leafdata;
 28:   } else {
 29:     if (!link->leafbuf[leafmtype] && !rank) {PetscMallocWithMemType(leafmtype,sf->nleaves*link->unitbytes,(void**)&link->leafbuf[leafmtype]);} /* Alloate leafbuf on rank 0 */
 30:     recvbuf = link->leafbuf[leafmtype];
 31:   }

 33:   MPIU_Igatherv(rootdata,sendcount,unit,recvbuf,dat->recvcounts,dat->displs,unit,0/*rank 0*/,comm,link->rootreqs[PETSCSF_../../../../../..2LEAF_BCAST][rootmtype]);
 34:   return(0);
 35: }

 37: static PetscErrorCode PetscSFReduceBegin_Gatherv(PetscSF sf,MPI_Datatype unit,PetscMemType leafmtype,const void *leafdata,PetscMemType rootmtype,void *rootdata,MPI_Op op)
 38: {
 39:   PetscErrorCode       ierr;
 40:   PetscSFPack          link;
 41:   PetscMPIInt          recvcount;
 42:   MPI_Comm             comm;
 43:   char                 *recvbuf;
 44:   PetscSF_Gatherv      *dat = (PetscSF_Gatherv*)sf->data;

 47:   PetscSFPackGet_Gatherv(sf,unit,rootmtype,rootdata,leafmtype,leafdata,&link);
 48:   PetscObjectGetComm((PetscObject)sf,&comm);

 50:   if (op == MPIU_REPLACE) {
 51:     recvbuf = (char*)rootdata;
 52:   } else {
 53:     if (!link->rootbuf[rootmtype]) {PetscMallocWithMemType(rootmtype,sf->nroots*link->unitbytes,(void**)&link->rootbuf[rootmtype]);}
 54:     recvbuf = link->rootbuf[rootmtype];
 55:   }

 57:   PetscMPIIntCast(sf->nroots,&recvcount);
 58:   MPIU_Iscatterv(leafdata,dat->recvcounts,dat->displs,unit,recvbuf,recvcount,unit,0,comm,link->rootreqs[PETSCSF_LEAF2../../../../../.._REDUCE][rootmtype]);
 59:   return(0);
 60: }

 62: PETSC_INTERN PetscErrorCode PetscSFFetchAndOpBegin_Gatherv(PetscSF sf,MPI_Datatype unit,PetscMemType rootmtype,void *rootdata,PetscMemType leafmtype,const void *leafdata,void *leafupdate,MPI_Op op)
 63: {
 64:   PetscErrorCode      ierr;

 67:   /* In Gatherv, each root only has one leaf. So we just need to bcast rootdata to leafupdate and then reduce leafdata to rootdata */
 68:   PetscSFBcastAndOpBegin(sf,unit,rootdata,leafupdate,MPIU_REPLACE);
 69:   PetscSFBcastAndOpEnd(sf,unit,rootdata,leafupdate,MPIU_REPLACE);
 70:   PetscSFReduceBegin(sf,unit,leafdata,rootdata,op);
 71:   return(0);
 72: }

 74: PETSC_INTERN PetscErrorCode PetscSFCreate_Gatherv(PetscSF sf)
 75: {
 76:   PetscErrorCode  ierr;
 77:   PetscSF_Gatherv *dat = (PetscSF_Gatherv*)sf->data;

 80:   /* Inherit from Allgatherv */
 81:   sf->ops->SetUp           = PetscSFSetUp_Allgatherv;
 82:   sf->ops->Reset           = PetscSFReset_Allgatherv;
 83:   sf->ops->Destroy         = PetscSFDestroy_Allgatherv;
 84:   sf->ops->GetGraph        = PetscSFGetGraph_Allgatherv;
 85:   sf->ops->GetLeafRanks    = PetscSFGetLeafRanks_Allgatherv;
 86:   sf->ops->GetRootRanks    = PetscSFGetRootRanks_Allgatherv;
 87:   sf->ops->BcastAndOpEnd   = PetscSFBcastAndOpEnd_Allgatherv;
 88:   sf->ops->ReduceEnd       = PetscSFReduceEnd_Allgatherv;
 89:   sf->ops->FetchAndOpEnd   = PetscSFFetchAndOpEnd_Allgatherv;
 90:   sf->ops->CreateLocalSF   = PetscSFCreateLocalSF_Allgatherv;

 92:   /* Gatherv stuff */
 93:   sf->ops->BcastAndOpBegin = PetscSFBcastAndOpBegin_Gatherv;
 94:   sf->ops->ReduceBegin     = PetscSFReduceBegin_Gatherv;
 95:   sf->ops->FetchAndOpBegin = PetscSFFetchAndOpBegin_Gatherv;

 97:   PetscNewLog(sf,&dat);
 98:   sf->data = (void*)dat;
 99:   return(0);
100: }