Actual source code: sfgather.c

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

  4: /* Reuse the type. The difference is some fields (i.e., displs, recvcounts) are not used in Gather, which is not a big deal */
  5: typedef PetscSF_Allgatherv PetscSF_Gather;

  7: PETSC_INTERN PetscErrorCode PetscSFBcastBegin_Gather(PetscSF sf, MPI_Datatype unit, PetscMemType rootmtype, const void *rootdata, PetscMemType leafmtype, void *leafdata, MPI_Op op)
  8: {
  9:   PetscSFLink  link;
 10:   PetscMPIInt  sendcount;
 11:   MPI_Comm     comm;
 12:   void        *rootbuf = NULL, *leafbuf = NULL;
 13:   MPI_Request *req;

 15:   PetscSFLinkCreate(sf, unit, rootmtype, rootdata, leafmtype, leafdata, op, PETSCSF_BCAST, &link);
 16:   PetscSFLinkPackRootData(sf, link, PETSCSF_REMOTE, rootdata);
 17:   PetscSFLinkCopyRootBufferInCaseNotUseGpuAwareMPI(sf, link, PETSC_TRUE /* device2host before sending */);
 18:   PetscObjectGetComm((PetscObject)sf, &comm);
 19:   PetscMPIIntCast(sf->nroots, &sendcount);
 20:   PetscSFLinkGetMPIBuffersAndRequests(sf, link, PETSCSF_../../../../../..2LEAF, &rootbuf, &leafbuf, &req, NULL);
 21:   PetscSFLinkSyncStreamBeforeCallMPI(sf, link, PETSCSF_../../../../../..2LEAF);
 22:   MPIU_Igather(rootbuf == leafbuf ? MPI_IN_PLACE : rootbuf, sendcount, unit, leafbuf, sendcount, unit, 0 /*rank 0*/, comm, req);
 23:   return 0;
 24: }

 26: static PetscErrorCode PetscSFReduceBegin_Gather(PetscSF sf, MPI_Datatype unit, PetscMemType leafmtype, const void *leafdata, PetscMemType rootmtype, void *rootdata, MPI_Op op)
 27: {
 28:   PetscSFLink  link;
 29:   PetscMPIInt  recvcount;
 30:   MPI_Comm     comm;
 31:   void        *rootbuf = NULL, *leafbuf = NULL;
 32:   MPI_Request *req;

 34:   PetscSFLinkCreate(sf, unit, rootmtype, rootdata, leafmtype, leafdata, op, PETSCSF_REDUCE, &link);
 35:   PetscSFLinkPackLeafData(sf, link, PETSCSF_REMOTE, leafdata);
 36:   PetscSFLinkCopyLeafBufferInCaseNotUseGpuAwareMPI(sf, link, PETSC_TRUE /* device2host before sending */);
 37:   PetscObjectGetComm((PetscObject)sf, &comm);
 38:   PetscMPIIntCast(sf->nroots, &recvcount);
 39:   PetscSFLinkGetMPIBuffersAndRequests(sf, link, PETSCSF_LEAF2../../../../../.., &rootbuf, &leafbuf, &req, NULL);
 40:   PetscSFLinkSyncStreamBeforeCallMPI(sf, link, PETSCSF_LEAF2../../../../../..);
 41:   MPIU_Iscatter(leafbuf, recvcount, unit, rootbuf == leafbuf ? MPI_IN_PLACE : rootbuf, recvcount, unit, 0 /*rank 0*/, comm, req);
 42:   return 0;
 43: }

 45: PETSC_INTERN PetscErrorCode PetscSFCreate_Gather(PetscSF sf)
 46: {
 47:   PetscSF_Gather *dat = (PetscSF_Gather *)sf->data;

 49:   sf->ops->BcastEnd  = PetscSFBcastEnd_Basic;
 50:   sf->ops->ReduceEnd = PetscSFReduceEnd_Basic;

 52:   /* Inherit from Allgatherv */
 53:   sf->ops->Reset         = PetscSFReset_Allgatherv;
 54:   sf->ops->Destroy       = PetscSFDestroy_Allgatherv;
 55:   sf->ops->GetGraph      = PetscSFGetGraph_Allgatherv;
 56:   sf->ops->GetRootRanks  = PetscSFGetRootRanks_Allgatherv;
 57:   sf->ops->GetLeafRanks  = PetscSFGetLeafRanks_Allgatherv;
 58:   sf->ops->FetchAndOpEnd = PetscSFFetchAndOpEnd_Allgatherv;
 59:   sf->ops->CreateLocalSF = PetscSFCreateLocalSF_Allgatherv;

 61:   /* Inherit from Allgather */
 62:   sf->ops->SetUp = PetscSFSetUp_Allgather;

 64:   /* Inherit from Gatherv */
 65:   sf->ops->FetchAndOpBegin = PetscSFFetchAndOpBegin_Gatherv;

 67:   /* Gather stuff */
 68:   sf->ops->BcastBegin  = PetscSFBcastBegin_Gather;
 69:   sf->ops->ReduceBegin = PetscSFReduceBegin_Gather;

 71:   PetscNew(&dat);
 72:   sf->data = (void *)dat;
 73:   return 0;
 74: }