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

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)

       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

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.