MPIX_Barrier_init(3)
💖 MPIX_Barrier_init(3) — Open MPI 💖
okay bestie, gather round, because this is the Open MPI page for MPIX_Barrier_init(3) and its whole collective-init bestie squad 🫶 no cap, it's a big one, so we're doing this in parts. part 1 is right here, and it's giving iconic reference material. let's go 💅
✨ NAME ✨
MPIX_Allgather_init, MPIX_Allgatherv_init, MPIX_Allreduce_init, MPIX_Alltoall_init, MPIX_Alltoallv_init, MPIX_Alltoallw_init, MPIX_Barrier_init, MPIX_Bcast_init, MPIX_Exscan_init, MPIX_Gather_init, MPIX_Gatherv_init, MPIX_Reduce_init, MPIX_Reduce_scatter_init, MPIX_Reduce_scatter_block_init, MPIX_Scan_init, MPIX_Scatter_init, MPIX_Scatterv_init, MPIX_Neighbor_allgather_init, MPIX_Neighbor_allgatherv_init, MPIX_Neighbor_alltoall_init, MPIX_Neighbor_alltoallv_init, MPIX_Neighbor_alltoallw_init — Builds a handle for a collective communication or neighborhood collective communication 🌈
fr fr, that's the whole roster. one giant friend group of functions whose entire job is building a handle. 🎀
🌸 SYNTAX 🌸
C Syntax 💻
first up, the includes. yes, both of them, don't skip the second one bestie:
#include <mpi.h>
#include <mpi-ext.h>and now, the whole squad, one by one, exactly as written ✨
int MPIX_Allgather_init(const void *sendbuf, int sendcount,
MPI_Datatype sendtype, void *recvbuf, int recvcount,
MPI_Datatype recvtype, MPI_Comm comm, MPI_Info info,
MPI_Request *request)int MPIX_Allgatherv_init(const void *sendbuf, int sendcount,
MPI_Datatype sendtype, void *recvbuf, const int recvcounts[],
const int displs[], MPI_Datatype recvtype, MPI_Comm comm,
MPI_Info info, MPI_Request *request)int MPIX_Allreduce_init(const void *sendbuf, void *recvbuf, int count,
MPI_Datatype datatype, MPI_Op op, MPI_Comm comm, MPI_Info info,
MPI_Request *request)int MPIX_Alltoall_init(const void *sendbuf, int sendcount,
MPI_Datatype sendtype, void *recvbuf, int recvcount,
MPI_Datatype recvtype, MPI_Comm comm, MPI_Info info,
MPI_Request *request)int MPIX_Alltoallv_init(const void *sendbuf, const int sendcounts[],
const int sdispls[], MPI_Datatype sendtype, void *recvbuf,
const int recvcounts[], const int rdispls[], MPI_Datatype recvtype,
MPI_Comm comm, MPI_Info info, MPI_Request *request)int MPIX_Alltoallw_init(const void *sendbuf, const int sendcounts[],
const int sdispls[], const MPI_Datatype sendtypes[], void *recvbuf,
const int recvcounts[], const int rdispls[],
const MPI_Datatype recvtypes[], MPI_Comm comm, MPI_Info info,
MPI_Request *request)int MPIX_Barrier_init(MPI_Comm comm, MPI_Info info,
MPI_Request *request)the main character of this page right here 👑 — yes,MPIX_Barrier_initonly takescomm,info, andrequest. that's it. minimal. slay.
int MPIX_Bcast_init(void *buffer, int count, MPI_Datatype datatype,
int root, MPI_Comm comm, MPI_Info info, MPI_Request *request)int MPIX_Exscan_init(const void *sendbuf, void *recvbuf, int count,
MPI_Datatype datatype, MPI_Op op, MPI_Comm comm, MPI_Info info,
MPI_Request *request)int MPIX_Gather_init(const void *sendbuf, int sendcount,
MPI_Datatype sendtype, void *recvbuf, int recvcount,
MPI_Datatype recvtype, int root, MPI_Comm comm, MPI_Info info,
MPI_Request *request)int MPIX_Gatherv_init(const void *sendbuf, int sendcount,
MPI_Datatype sendtype, void *recvbuf, const int recvcounts[],
const int displs[], MPI_Datatype recvtype, int root, MPI_Comm comm,
MPI_Info info, MPI_Request *request)int MPIX_Reduce_init(const void *sendbuf, void *recvbuf, int count,
MPI_Datatype datatype, MPI_Op op, int root, MPI_Comm comm,
MPI_Info info, MPI_Request *request)int MPIX_Reduce_scatter_init(const void *sendbuf, void *recvbuf,
const int recvcounts[], MPI_Datatype datatype, MPI_Op op,
MPI_Comm comm, MPI_Info info, MPI_Request *request)int MPIX_Reduce_scatter_block_init(const void *sendbuf, void *recvbuf,
int recvcount, MPI_Datatype datatype, MPI_Op op, MPI_Comm comm,
MPI_Info info, MPI_Request *request)int MPIX_Scan_init(const void *sendbuf, void *recvbuf, int count,
MPI_Datatype datatype, MPI_Op op, MPI_Comm comm, MPI_Info info,
MPI_Request *request)int MPIX_Scatter_init(const void *sendbuf, int sendcount,
MPI_Datatype sendtype, void *recvbuf, int recvcount,
MPI_Datatype recvtype, int root, MPI_Comm comm, MPI_Info info,
MPI_Request *request)int MPIX_Scatterv_init(const void *sendbuf, const int sendcounts[],
const int displs[], MPI_Datatype sendtype, void *recvbuf,
int recvcount, MPI_Datatype recvtype, int root, MPI_Comm comm,
MPI_Info info, MPI_Request *request)int MPIX_Neighbor_allgather_init(const void *sendbuf, int sendcount,
MPI_Datatype sendtype, void *recvbuf, int recvcount,
MPI_Datatype recvtype, MPI_Comm comm, MPI_Info info,
MPI_Request *request)int MPIX_Neighbor_allgatherv_init(const void *sendbuf, int sendcount,
MPI_Datatype sendtype, void *recvbuf, const int recvcounts[],
const int displs[], MPI_Datatype recvtype, MPI_Comm comm,
MPI_Info info, MPI_Request *request)int MPIX_Neighbor_alltoall_init(const void *sendbuf, int sendcount,
MPI_Datatype sendtype, void *recvbuf, int recvcount,
MPI_Datatype recvtype, MPI_Comm comm, MPI_Info info,
MPI_Request *request)int MPIX_Neighbor_alltoallv_init(const void *sendbuf,
const int sendcounts[], const int sdispls[], MPI_Datatype sendtype,
void *recvbuf, const int recvcounts[], const int rdispls[],
MPI_Datatype recvtype, MPI_Comm comm, MPI_Info info,
MPI_Request *request)int MPIX_Neighbor_alltoallw_init(const void *sendbuf,
const int sendcounts[], const MPI_Aint sdispls[],
const MPI_Datatype sendtypes[], void *recvbuf,
const int recvcounts[], const MPI_Aint rdispls[],
const MPI_Datatype recvtypes[], MPI_Comm comm, MPI_Info info,
MPI_Request *request)🦋 heads up bestie, peep theMPI_Aintin thewvariants of the neighbor calls —MPIX_Neighbor_alltoallw_inittakesconst MPI_Aint sdispls[]andconst MPI_Aint rdispls[], not plainint. iykyk. don't mix them up 🙈
okay that's the end of part 1 — the roster and the syntax are fully documented, no details skipped, no cap. 💜 more parts coming, so don't go anywhere, bestie 🎀
💖 Fortran Syntax 💖
okay bestie, the Fortran interface is giving classic. you got your USE MPI and USE MPI_EXT, or if you're feeling vintage, the INCLUDE lines. then boom, all the init functions. they're all about that nonblocking collective life. here's the whole squad:
USE MPI
USE MPI_EXT
! or the older form: INCLUDE 'mpif.h'; INCLUDE 'mpif-ext.h'
MPIX_ALLGATHER_INIT(SENDBUF, SENDCOUNT, SENDTYPE, RECVBUF, RECVCOUNT,
RECVTYPE, COMM, INFO, REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER SENDCOUNT, SENDTYPE, RECVCOUNT, RECVTYPE, COMM, INFO
INTEGER REQUEST, IERROR
MPIX_ALLGATHERV_INIT(SENDBUF, SENDCOUNT, SENDTYPE, RECVBUF,
RECVCOUNT, DISPLS, RECVTYPE, COMM, INFO, REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER SENDCOUNT, SENDTYPE, RECVCOUNT(*)
INTEGER DISPLS(*), RECVTYPE, COMM, INFO, REQUEST, IERROR
MPIX_ALLREDUCE_INIT(SENDBUF, RECVBUF, COUNT, DATATYPE, OP, COMM, INFO,
REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER COUNT, DATATYPE, OP, COMM, INFO, REQUEST, IERROR
MPIX_ALLTOALL_INIT(SENDBUF, SENDCOUNT, SENDTYPE, RECVBUF, RECVCOUNT,
RECVTYPE, COMM, INFO, REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER SENDCOUNT, SENDTYPE, RECVCOUNT, RECVTYPE
INTEGER COMM, INFO, REQUEST, IERROR
MPIX_ALLTOALLV_INIT(SENDBUF, SENDCOUNTS, SDISPLS, SENDTYPE,
RECVBUF, RECVCOUNTS, RDISPLS, RECVTYPE, COMM, INFO, REQUEST,
IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER SENDCOUNTS(*), SDISPLS(*), SENDTYPE
INTEGER RECVCOUNTS(*), RDISPLS(*), RECVTYPE
INTEGER COMM, INFO, REQUEST, IERROR
MPIX_ALLTOALLW_INIT(SENDBUF, SENDCOUNTS, SDISPLS, SENDTYPES,
RECVBUF, RECVCOUNTS, RDISPLS, RECVTYPES, COMM, INFO, REQUEST,
IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER SENDCOUNTS(*), SDISPLS(*), SENDTYPES(*)
INTEGER RECVCOUNTS(*), RDISPLS(*), RECVTYPES(*)
INTEGER COMM, INFO, REQUEST, IERROR
MPIX_BARRIER_INIT(COMM, INFO, REQUEST, IERROR)
INTEGER COMM, INFO, REQUEST, IERROR
MPIX_BCAST_INIT(BUFFER, COUNT, DATATYPE, ROOT, COMM, INFO, REQUEST,
IERROR)
<type> BUFFER(*)
INTEGER COUNT, DATATYPE, ROOT, COMM, INFO, REQUEST, IERROR
MPIX_EXSCAN_INIT(SENDBUF, RECVBUF, COUNT, DATATYPE, OP, COMM, INFO,
REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER COUNT, DATATYPE, OP, COMM, INFO, REQUEST, IERROR
MPIX_GATHER_INIT(SENDBUF, SENDCOUNT, SENDTYPE, RECVBUF, RECVCOUNT,
RECVTYPE, ROOT, COMM, INFO, REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER SENDCOUNT, SENDTYPE, RECVCOUNT, RECVTYPE, ROOT
INTEGER COMM, INFO, REQUEST, IERROR
MPIX_GATHERV_INIT(SENDBUF, SENDCOUNT, SENDTYPE, RECVBUF, RECVCOUNTS,
DISPLS, RECVTYPE, ROOT, COMM, INFO, REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER SENDCOUNT, SENDTYPE, RECVCOUNTS(*), DISPLS(*)
INTEGER RECVTYPE, ROOT, COMM, INFO, REQUEST, IERROR
MPIX_REDUCE_INIT(SENDBUF, RECVBUF, COUNT, DATATYPE, OP, ROOT, COMM,
INFO, REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER COUNT, DATATYPE, OP, ROOT, COMM, INFO, REQUEST, IERROR
MPIX_REDUCE_SCATTER_INIT(SENDBUF, RECVBUF, RECVCOUNTS, DATATYPE, OP,
COMM, INFO, REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER RECVCOUNTS(*), DATATYPE, OP, COMM, INFO, REQUEST, IERROR
MPIX_REDUCE_SCATTER_BLOCK_INIT(SENDBUF, RECVBUF, RECVCOUNT, DATATYPE,
OP, COMM, INFO, REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER RECVCOUNT, DATATYPE, OP, COMM, INFO, REQUEST, IERROR
MPIX_SCAN_INIT(SENDBUF, RECVBUF, COUNT, DATATYPE, OP, COMM, INFO,
REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER COUNT, DATATYPE, OP, COMM, INFO, REQUEST, IERROR
MPIX_SCATTER_INIT(SENDBUF, SENDCOUNT, SENDTYPE, RECVBUF, RECVCOUNT,
RECVTYPE, ROOT, COMM, INFO, REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER SENDCOUNT, SENDTYPE, RECVCOUNT, RECVTYPE, ROOT
INTEGER COMM, INFO, REQUEST, IERROR
MPIX_SCATTERV_INIT(SENDBUF, SENDCOUNTS, DISPLS, SENDTYPE, RECVBUF,
RECVCOUNT, RECVTYPE, ROOT, COMM, INFO, REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER SENDCOUNTS(*), DISPLS(*), SENDTYPE
INTEGER RECVCOUNT, RECVTYPE, ROOT, COMM, INFO, REQUEST, IERROR
MPIX_NEIGHBOR_ALLGATHER_INIT(SENDBUF, SENDCOUNT, SENDTYPE, RECVBUF,
RECVCOUNT, RECVTYPE, COMM, INFO, REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER SENDCOUNT, SENDTYPE, RECVCOUNT, RECVTYPE, COMM,
INTEGER INFO, REQUEST, IERROR
MPIX_NEIGHBOR_ALLGATHERV_INIT(SENDBUF, SENDCOUNT, SENDTYPE, RECVBUF,
RECVCOUNT, DISPLS, RECVTYPE, COMM, INFO, REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER SENDCOUNT, SENDTYPE, RECVCOUNT(*),
INTEGER DISPLS(*), RECVTYPE, COMM, INFO, REQUEST, IERROR
MPIX_NEIGHBOR_ALLTOALL_INIT(SENDBUF, SENDCOUNT, SENDTYPE, RECVBUF,
RECVCOUNT, RECVTYPE, COMM, INFO, REQUEST, IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER SENDCOUNT, SENDTYPE, RECVCOUNT, RECVTYPE
INTEGER COMM, INFO, REQUEST, IERROR
MPIX_NEIGHBOR_ALLTOALLV_INIT(SENDBUF, SENDCOUNTS, SDISPLS, SENDTYPE,
RECVBUF, RECVCOUNTS, RDISPLS, RECVTYPE, COMM, INFO, REQUEST,
IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER SENDCOUNTS(*), SDISPLS(*), SENDTYPE
INTEGER RECVCOUNTS(*), RDISPLS(*), RECVTYPE
INTEGER COMM, INFO, REQUEST, IERROR
MPIX_NEIGHBOR_ALLTOALLW_INIT(SENDBUF, SENDCOUNTS, SDISPLS, SENDTYPES,
RECVBUF, RECVCOUNTS, RDISPLS, RECVTYPES, COMM, INFO, REQUEST,
IERROR)
<type> SENDBUF(*), RECVBUF(*)
INTEGER SENDCOUNTS(*), SENDTYPES(*)
INTEGER RECVCOUNTS(*), RECVTYPES(*)
INTEGER(KIND=MPI_ADDRESS_KIND) SDISPLS(*), RDISPLS(*)
INTEGER COMM, INFO, REQUEST, IERRORthat's a lot of init functions, bestie. it's giving "I have options" energy. ✨
🌸 Fortran 2008 Syntax 🌸
now for the modern Fortran 2008 tea. USE mpi_f08 and USE mpi_f08_ext, and then the same init functions but with TYPE(MPI_*) and ASYNCHRONOUS attributes. it's lowkey iconic. here's what we got:
USE mpi_f08
USE mpi_f08_ext
MPIX_Allgather_init(sendbuf, sendcount, sendtype, recvbuf, recvcount,
recvtype, comm, info, request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN) :: sendcount, recvcount
TYPE(MPI_Datatype), INTENT(IN) :: sendtype, recvtype
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Allgatherv_init(sendbuf, sendcount, sendtype, recvbuf, recvcounts,
displs, recvtype, comm, info, request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN) :: sendcount
INTEGER, INTENT(IN), ASYNCHRONOUS :: recvcounts(*), displs(*)
TYPE(MPI_Datatype), INTENT(IN) :: sendtype, recvtype
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Allreduce_init(sendbuf, recvbuf, count, datatype, op, comm, info,
request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN) :: count
TYPE(MPI_Datatype), INTENT(IN) :: datatype
TYPE(MPI_Op), INTENT(IN) :: op
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Alltoall_init(sendbuf, sendcount, sendtype, recvbuf, recvcount,
recvtype, comm, info, request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN) :: sendcount, recvcount
TYPE(MPI_Datatype), INTENT(IN) :: sendtype, recvtype
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Alltoallv_init(sendbuf, sendcounts, sdispls, sendtype, recvbuf,
recvcounts, rdispls, recvtype, comm, info, request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN), ASYNCHRONOUS :: sendcounts(*), sdispls(*),
recvcounts(*), rdispls(*)
TYPE(MPI_Datatype), INTENT(IN) :: sendtype, recvtype
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Alltoallw_init(sendbuf, sendcounts, sdispls, sendtypes, recvbuf,
recvcounts, rdispls, recvtypes, comm, info, request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN), ASYNCHRONOUS :: sendcounts(*), sdispls(*),
recvcounts(*), rdispls(*)
TYPE(MPI_Datatype), INTENT(IN), ASYNCHRONOUS :: sendtypes(*),
recvtypes(*)
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Barrier_init(comm, info, request, ierror)
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Bcast_init(buffer, count, datatype, root, comm, info, request,
ierror)
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: buffer
INTEGER, INTENT(IN) :: count, root
TYPE(MPI_Datatype), INTENT(IN) :: datatype
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Exscan_init(sendbuf, recvbuf, count, datatype, op, comm, info,
request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN) :: count
TYPE(MPI_Datatype), INTENT(IN) :: datatype
TYPE(MPI_Op), INTENT(IN) :: op
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierrorand that's the Fortran 2008 glow-up 💅 stay tuned for more, bestie.
MPIX_Gather_init(sendbuf, sendcount, sendtype, recvbuf,
recvcount, recvtype, root, comm, info, request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN) :: sendcount, recvcount, root
TYPE(MPI_Datatype), INTENT(IN) :: sendtype, recvtype
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Gatherv_init(sendbuf, sendcount, sendtype, recvbuf, recvcounts,
displs, recvtype, root, comm, info, request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN) :: sendcount, root
INTEGER, INTENT(IN), ASYNCHRONOUS :: recvcounts(*), displs(*)
TYPE(MPI_Datatype), INTENT(IN) :: sendtype, recvtype
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Reduce_init(sendbuf, recvbuf, count, datatype, op, root, comm,
info, request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN) :: count, root
TYPE(MPI_Datatype), INTENT(IN) :: datatype
TYPE(MPI_Op), INTENT(IN) :: op
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Reduce_scatter_init(sendbuf, recvbuf, recvcounts, datatype, op,
comm, info, request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN), ASYNCHRONOUS :: recvcounts(*)
TYPE(MPI_Datatype), INTENT(IN) :: datatype
TYPE(MPI_Op), INTENT(IN) :: op
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Reduce_scatter_block_init(sendbuf, recvbuf, recvcount, datatype,
op, comm, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN) :: recvcount
TYPE(MPI_Datatype), INTENT(IN) :: datatype
TYPE(MPI_Op), INTENT(IN) :: op
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Reduce_scatter_block_init(sendbuf, recvbuf, recvcount, datatype, op,
comm, info, request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN) :: recvcount
TYPE(MPI_Datatype), INTENT(IN) :: datatype
TYPE(MPI_Op), INTENT(IN) :: op
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Scan_init(sendbuf, recvbuf, count, datatype, op, comm, info,
request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN) :: count
TYPE(MPI_Datatype), INTENT(IN) :: datatype
TYPE(MPI_Op), INTENT(IN) :: op
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Scatter_init(sendbuf, sendcount, sendtype, recvbuf, recvcount,
recvtype, root, comm, info, request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN) :: sendcount, recvcount, root
TYPE(MPI_Datatype), INTENT(IN) :: sendtype, recvtype
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Scatterv_init(sendbuf, sendcounts, displs, sendtype, recvbuf,
recvcount, recvtype, root, comm, info, request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN), ASYNCHRONOUS :: sendcounts(*), displs(*)
INTEGER, INTENT(IN) :: recvcount, root
TYPE(MPI_Datatype), INTENT(IN) :: sendtype, recvtype
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Neighbor_allgather_init(sendbuf, sendcount, sendtype, recvbuf,
recvcount, recvtype, comm, info, request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN) :: sendcount, recvcount
TYPE(MPI_Datatype), INTENT(IN) :: sendtype, recvtype
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Neighbor_allgatherv_init(sendbuf, sendcount, sendtype, recvbuf,
recvcounts, displs, recvtype, comm, info, request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN) :: sendcount
INTEGER, INTENT(IN), ASYNCHRONOUS :: recvcounts(*), displs(*)
TYPE(MPI_Datatype), INTENT(IN) :: sendtype, recvtype
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Neighbor_alltoall_init(sendbuf, sendcount, sendtype, recvbuf,
recvcount, recvtype, comm, info, request, ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN) :: sendcount, recvcount
TYPE(MPI_Datatype), INTENT(IN) :: sendtype, recvtype
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Neighbor_alltoallv_init(sendbuf, sendcounts, sdispls, sendtype,
recvbuf, recvcounts, rdispls, recvtype, comm, info, request,
ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN), ASYNCHRONOUS :: sendcounts(*), sdispls(*),
recvcounts(*), rdispls(*)
TYPE(MPI_Datatype), INTENT(IN) :: sendtype, recvtype
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
MPIX_Neighbor_alltoallw_init(sendbuf, sendcounts, sdispls, sendtypes,
recvbuf, recvcounts, rdispls, recvtypes, comm, info, request,
ierror)
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: sendbuf
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: recvbuf
INTEGER, INTENT(IN), ASYNCHRONOUS :: sendcounts(*), recvcounts(*)
INTEGER(KIND=MPI_ADDRESS_KIND), INTENT(IN), ASYNCHRONOUS ::
sdispls(*), rdispls(*)
TYPE(MPI_Datatype), INTENT(IN), ASYNCHRONOUS :: sendtypes(*),
recvtypes(*)
TYPE(MPI_Comm), INTENT(IN) :: comm
TYPE(MPI_Info), INTENT(IN) :: info
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror✨ DESCRIPTION ✨
okay bestie, deep breath, because this is the whole point of the page 🫶
This builds you a persistent communication request for a collective operation or a neighborhood collective operation. That's it. That's the girl. 💅
So as of Nov. 2018, the whole persistent-collective-communication-operations thing — and the persistent collective neighborhood communication operations too — is planned to be included in the next MPI Standard after MPI-3.1. Planned! Like, it's on the vision board. 📌
https://github.com/mpi-forum/mpi-issues/issues/25Open MPI implements the 2018 Draft Specification of the MPI standard, which lives at this URL right here:
https://www.mpi-forum.org/docs/drafts/mpi-2018-draft-report.pdf⚠️ and here's the part you actually need to clock: the interface may still change in the standard. That's the whole reason the prefix isMPIX_instead ofMPI_for these request creation routines — the X is literally the "this could still move, don't @ me" flag. 🚩
To start, complete, and free the request you just created, you use the usual MPI routines — MPI_Start etc. Nothing new to learn there, you already ate that. 👑
And listen, future versions of Open MPI are gonna switch to the MPI_ prefix and will not require the C header file mpi-ext.h, the Fortran modules mpi_ext and mpi_f08_ext, and the Fortran header file mpif-ext.h — but only once the MPI Standard that includes this feature is actually published. So like, glow-up pending. ✨
🌸 EXAMPLE 🌸
here's the vibe, look how clean:
MPI_Request req;
MPIX_Barrier_init(MPI_COMM_WORLD, MPI_INFO_NULL, &req);
MPI_Start(&req);
MPI_Wait(&req, MPI_STATUS_IGNORE);
MPI_Request_free(&req);init it, start it, wait on it, free it. four lines and you're done, no cap. 🎀
🦋 SEE ALSO 🦋
MPI_StartMPI_StartallMPI_Request_free
and that's the whole page, bestie!! 🫶💖 you just read version 4.1.6 of this man page, dated Sep 30, 2023 — shoutout to that little footer, iconic of it honestly. go forth and persist your collectives. slay. 💅✨🌈
📦 where this page comes from
- ubuntu noble: openmpi-doc 4.1.6-7ubuntu2
- Copyright (c) 2018 FUJITSU LIMITED. All rights reserved
- 💖 girlified by deepseek-ai/DeepSeek-V4.1-Flash on : a language model's rewrite of the original, under its terms