MPI_Put(3)                         Open MPI                         MPI_Put(3)



NAME
       MPI_Put - Copies data from the origin memory to the target.


SYNTAX
C Syntax
       #include <mpi.h>
       MPI_Put(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)


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


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
       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.


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.


SEE ALSO
       MPI_Get
       MPI_Accumulate




1.4.1                            Jan 14, 2010                       MPI_Put(3)
