Actual source code: mpilong.c
petsc-3.7.7 2017-09-25
2: #include <petscsys.h> /*I "petscsys.h" I*/
4: /*
5: Allows sending/receiving larger messages then 2 gigabytes in a single call
6: */
8: PetscErrorCode MPIULong_Send(void *mess,PetscInt cnt, MPI_Datatype type,PetscMPIInt to, PetscMPIInt tag, MPI_Comm comm)
9: {
10: PetscErrorCode ierr;
11: static PetscInt CHUNKSIZE = 250000000; /* 250,000,000 */
12: PetscInt i,numchunks;
13: PetscMPIInt icnt;
16: numchunks = cnt/CHUNKSIZE + 1;
17: for (i=0; i<numchunks; i++) {
18: PetscMPIIntCast((i < numchunks-1) ? CHUNKSIZE : cnt - (numchunks-1)*CHUNKSIZE,&icnt);
19: MPI_Send(mess,icnt,type,to,tag,comm);
20: if (type == MPIU_INT) mess = (void*) (((PetscInt*)mess) + CHUNKSIZE);
21: else if (type == MPIU_SCALAR) mess = (void*) (((PetscScalar*)mess) + CHUNKSIZE);
22: else SETERRQ(comm,PETSC_ERR_SUP,"No support for this datatype");
23: }
24: return(0);
25: }
27: PetscErrorCode MPIULong_Recv(void *mess,PetscInt cnt, MPI_Datatype type,PetscMPIInt from, PetscMPIInt tag, MPI_Comm comm)
28: {
29: int ierr;
30: static PetscInt CHUNKSIZE = 250000000; /* 250,000,000 */
31: MPI_Status status;
32: PetscInt i,numchunks;
33: PetscMPIInt icnt;
36: numchunks = cnt/CHUNKSIZE + 1;
37: for (i=0; i<numchunks; i++) {
38: PetscMPIIntCast((i < numchunks-1) ? CHUNKSIZE : cnt - (numchunks-1)*CHUNKSIZE,&icnt);
39: MPI_Recv(mess,icnt,type,from,tag,comm,&status);
40: if (type == MPIU_INT) mess = (void*) (((PetscInt*)mess) + CHUNKSIZE);
41: else if (type == MPIU_SCALAR) mess = (void*) (((PetscScalar*)mess) + CHUNKSIZE);
42: else SETERRQ(comm,PETSC_ERR_SUP,"No support for this datatype");
43: }
44: return(0);
45: }