Ubuntu Manpage: MPI_Put, MPI_Rput - Copies data from the origin memory to the target.

Provided by: openmpi-doc_4.1.6-7ubuntu2_all

NAME

       MPI_Put, MPI_Rput - Copies data from the origin memory to the target.

SYNTAX

C Syntax

       #include <mpi.h>
       MPI_Put(const void *origin_addr, int origin_count, MPI_Datatype
            origin_datatype, int target_rank, MPI_Aint target_disp,
            int target_count, MPI_Datatype target_datatype, MPI_Win win)

       MPI_Rput(const void *origin_addr, int origin_count, MPI_Datatype
             origin_datatype, int target_rank, MPI_Aint target_disp,
             int target_count, MPI_Datatype target_datatype, MPI_Win win,
             MPI_Request *request)

Fortran Syntax (see FORTRAN 77 NOTES)

       USE MPI
       ! or the older form: INCLUDE 'mpif.h'
       MPI_PUT(ORIGIN_ADDR, ORIGIN_COUNT, ORIGIN_DATATYPE, TARGET_RANK,
            TARGET_DISP, TARGET_COUNT, TARGET_DATATYPE, WIN, IERROR)
            <type> ORIGIN_ADDR(*)
            INTEGER(KIND=MPI_ADDRESS_KIND) TARGET_DISP
            INTEGER ORIGIN_COUNT, ORIGIN_DATATYPE, TARGET_RANK, TARGET_COUNT,
            TARGET_DATATYPE, WIN, IERROR

       MPI_RPUT(ORIGIN_ADDR, ORIGIN_COUNT, ORIGIN_DATATYPE, TARGET_RANK,
             TARGET_DISP, TARGET_COUNT, TARGET_DATATYPE, WIN, REQUEST, IERROR)
             <type> ORIGIN_ADDR(*)
             INTEGER(KIND=MPI_ADDRESS_KIND) TARGET_DISP
             INTEGER ORIGIN_COUNT, ORIGIN_DATATYPE, TARGET_RANK, TARGET_COUNT,
             TARGET_DATATYPE, WIN, REQUEST, IERROR

Fortran 2008 Syntax

       USE mpi_f08
       MPI_Put(origin_addr, origin_count, origin_datatype, target_rank,
                 target_disp, target_count, target_datatype, win, ierror)
            TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: origin_addr
            INTEGER, INTENT(IN) :: origin_count, target_rank, target_count
            TYPE(MPI_Datatype), INTENT(IN) :: origin_datatype, target_datatype
            INTEGER(KIND=MPI_ADDRESS_KIND), INTENT(IN) :: target_disp
            TYPE(MPI_Win), INTENT(IN) :: win
            INTEGER, OPTIONAL, INTENT(OUT) :: ierror

       MPI_Rput(origin_addr, origin_count, origin_datatype, target_rank,
            target_disp, target_count, target_datatype, win, request,
                 ierror)
            TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: origin_addr
            INTEGER, INTENT(IN) :: origin_count, target_rank, target_count
            TYPE(MPI_Datatype), INTENT(IN) :: origin_datatype, target_datatype
            INTEGER(KIND=MPI_ADDRESS_KIND), INTENT(IN) :: target_disp
            TYPE(MPI_Win), INTENT(IN) :: win
            TYPE(MPI_Request), INTENT(OUT) :: request
            INTEGER, OPTIONAL, INTENT(OUT) :: ierror

C++ Syntax

       #include <mpi.h>
       void MPI::Win::Put(const void* origin_addr, int origin_count, const
            MPI::Datatype& origin_datatype, int target_rank, MPI::Aint
            target_disp, int target_count, const MPI::Datatype&
            target_datatype) const

INPUT PARAMETERS

       origin_addr
                 Initial address of origin buffer (choice).

       origin_count
                 Number of entries in origin buffer (nonnegative integer).

       origin_datatype
                 Data type of each entry in origin buffer (handle).

       target_rank
                 Rank of target (nonnegative integer).

       target_disp
                 Displacement from start of window to target buffer (nonnegative integer).

       target_count
                 Number of entries in target buffer (nonnegative integer).

       target_datatype
                 Data type of each entry in target buffer (handle).

       win       Window object used for communication (handle).

OUTPUT PARAMETER

       request   MPI_Rput: RMA request

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

MPI_Put transfers origin_count successive entries of the type specified by origin_datatype, starting at
address origin_addr on the origin node to the target node specified by the win, target_rank pair. The
data are written in the target buffer at address target_addr = window_base + target_disp x disp_unit,
where window_base and disp_unit are the base address and window displacement unit specified at window
initialization, by the target process.

The target buffer is specified by the arguments target_count and target_datatype.

The data transfer is the same as that which would occur if the origin process executed a send operation
with arguments origin_addr, origin_count, origin_datatype, target_rank, tag, comm, and the target process
executed a receive operation with arguments target_addr, target_count, target_datatype, source, tag,
comm, where target_addr is the target buffer address computed as explained above, and comm is a
communicator for the group of win.

The communication must satisfy the same constraints as for a similar message-passing communication. The
target_datatype may not specify overlapping entries in the target buffer. The message sent must fit,
without truncation, in the target buffer. Furthermore, the target buffer must fit in the target window.
In addition, only processes within the same buffer can access the target window.

The target_datatype argument is a handle to a datatype object defined at the origin process. However,
this object is interpreted at the target process: The outcome is as if the target datatype object were
defined at the target process, by the same sequence of calls used to define it at the origin process. The
target data type must contain only relative displacements, not absolute addresses. The same holds for get
and accumulate.

MPI_Rput is similar to MPI_Put, except that it allocates a communication request object and associates it
with the request handle (the argument request). The completion of an MPI_Rput operation (i.e., after the
corresponding test or wait) indicates that the sender is now free to update the locations in the
origin_addr buffer. It does not indicate that the data is available at the target window. If remote
completion is required, MPI_Win_flush, MPI_Win_flush_all, MPI_Win_unlock, or MPI_Win_unlock_all can be
used.

NOTES

       The target_datatype argument is a handle to a datatype object that is defined at the origin process, even
       though  it  defines  a  data  layout  in  the  target  process  memory. This does not cause problems in a
       homogeneous or heterogeneous environment, as long as only portable data types  are  used  (portable  data
       types are defined in Section 2.4 of the MPI-2 Standard).

       The  performance  of  a  put  transfer can be significantly affected, on some systems, from the choice of
       window location and the shape and location of the origin and target buffer: Transfers to a target  window
       in  memory  allocated  by  MPI_Alloc_mem  may  be  much  faster  on shared memory systems; transfers from
       contiguous buffers will be faster on most, if not  all,  systems;  the  alignment  of  the  communication
       buffers may also impact performance.

FORTRAN 77 NOTES

       The  MPI  standard  prescribes  portable Fortran syntax for the TARGET_DISP argument only for Fortran 90.
       FORTRAN 77 users may use the non-portable syntax

            INTEGER*MPI_ADDRESS_KIND TARGET_DISP

       where MPI_ADDRESS_KIND is a constant defined in mpif.h and gives the length of the  declared  integer  in
       bytes.

ERRORS

       Almost  all  MPI  routines  return  an  error  value; C routines as the value of the function and Fortran
       routines in the last argument. C++ functions do not return errors. If the default error handler is set to
       MPI::ERRORS_THROW_EXCEPTIONS, then on error the  C++  exception  mechanism  will  be  used  to  throw  an
       MPI::Exception object.

       Before  the  error  value  is  returned,  the current MPI error handler is called. By default, this error
       handler aborts the MPI job, except for I/O function  errors.  The  error  handler  may  be  changed  with
       MPI_Comm_set_errhandler; the predefined error handler MPI_ERRORS_RETURN may be used to cause error values
       to be returned. Note that MPI does not guarantee that an MPI program can continue past an error.