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

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.