int MPICH_AlltoAll_medium(
void *sendbuf,
int sendcount,
MPI_Datatype sendtype,
void *recvbuf,
int recvcount,
MPI_Datatype recvtype,
MPI_Comm comm )
{
int comm_size, i, pof2;
MPI_Aint sendtype_extent, recvtype_extent;
int mpi_errno=MPI_SUCCESS, src, dst, rank, nbytes;
MPI_Status status;
int sendtype_size;
MPI_Request *reqarray;
MPI_Status *starray;
if (sendcount == 0) return MPI_SUCCESS;
MPI_Comm_rank (MPI_COMM_WORLD, &rank);
MPI_Comm_size (MPI_COMM_WORLD, &comm_size);
/* Get extent of send and recv types */
MPID_Datatype_get_extent_macro(recvtype, recvtype_extent);
MPID_Datatype_get_extent_macro(sendtype, sendtype_extent);
MPID_Datatype_get_size_macro(sendtype, sendtype_size);
nbytes = sendtype_size * sendcount;
/* Medium-size message. Use isend/irecv with scattered destinations */
reqarray = (MPI_Request *) malloc(2*comm_size*sizeof(MPI_Request));
if (!reqarray)
return MPI_ERR_OTHER;
starray = (MPI_Status *) malloc(2*comm_size*sizeof(MPI_Status));
if (!starray)
return MPI_ERR_OTHER;
/* do the communication -- post all sends and receives: */
for ( i=0; i<comm_size; i++ ) {
dst = (rank+i) % comm_size;
mpi_errno = AMPI_Irecv((char *)recvbuf +
dst*recvcount*recvtype_extent,
recvcount, recvtype, dst,
MPI_ATA_TAG, comm,
&reqarray[i]);
if (mpi_errno)
return MPI_ERR_OTHER;
}
for ( i=0; i<comm_size; i++ ) {
dst = (rank+i) % comm_size;
mpi_errno = AMPI_Isend((char *)sendbuf +
dst*sendcount*sendtype_extent,
sendcount, sendtype, dst,
MPI_ATA_TAG, comm,
&reqarray[i+comm_size]);
if (mpi_errno)
return mpi_errno;
}
/* ... then wait for *all* of them to finish: */
mpi_errno = AMPI_Waitall(2*comm_size,reqarray,starray);
/* --BEGIN ERROR HANDLING-- */
// if (mpi_errno == MPI_ERR_IN_STATUS) {
// for (int j=0; j<2*comm_size; j++) {
// if (starray[j] != MPI_SUCCESS)
// mpi_errno = starray[j];
// }
// }
/* --END ERROR HANDLING-- */
free(starray);
free(reqarray);
return mpi_errno;
}
void mpi_irecv(void *buf, int *count, int *datatype, int *src,
int *tag, int *comm, int *request, int *ierr)
{
*ierr = AMPI_Irecv(buf, *count, *datatype, *src, *tag, *comm, (MPI_Request *)request);
}
