MPI_Get_accumulate - Perform an atomic, one-sided read-and-accumulate operation.
int MPI_Get_accumulate(const void *origin_addr, int origin_count,
MPI_Datatype origin_datatype, void *result_addr, int result_count,
MPI_Datatype result_datatype, int target_rank, MPI_Aint target_disp,
int target_count, MPI_Datatype target_datatype, MPI_Op op, MPI_Win win)
Accumulate origin_count elements of type origin_datatype from the origin buffer
(origin_addr) to the buffer at offset target_disp, in the target window
specified by target_rank and win, using the operation op and return in the
result buffer result_addr the content of the target buffer before the
- - initial address of buffer (choice)
- - number of entries in buffer (nonnegative integer)
- - datatype of each buffer entry (handle)
- - initial address of result buffer (choice)
- - number of entries in result buffer (non-negative integer)
- - datatype of each entry in result buffer (handle)
- - rank of target (nonnegative integer)
- - displacement from start of window to beginning of target buffer
- - number of entries in target buffer (nonnegative integer)
- - datatype of each entry in target buffer (handle)
- - predefined reduce operation (handle)
- - window object (handle)
This operations is atomic with respect to other "accumulate"
The get and accumulate steps are executed atomically for each basic element in
the datatype (see MPI 3.0 Section 11.7 for details). The predefined operation
provides fetch-and-set behavior.
The origin and result buffers (origin_addr and result_addr) must be disjoint.
Each datatype argument must be a predefined datatype or a derived datatype
where all basic components are of the same predefined datatype. All datatype
arguments must be constructed from the same predefined datatype. The operation
op applies to elements of that predefined type. target_datatype must not
specify overlapping entries, and the target buffer must fit in the target
window or in attached memory in a dynamic window.
Any of the predefined operations for MPI_Reduce
, as well as
can be specified as op. User-defined
functions cannot be used. A new predefined operation, MPI_NO_OP
defined. It corresponds to the associative function f (a, b) = a; i.e., the
current value in the target memory is returned in the result buffer at the
origin and no operation is performed on the target buffer. MPI_NO_OP
can be used only in MPI_Get_accumulate
cannot be used in
, or collective reduction
operations, such as MPI_Reduce
All MPI routines in Fortran (except for MPI_WTIME
have an additional argument ierr
at the end of the argument list.
is an integer and has the same meaning as the return value of the
routine in C. In Fortran, MPI routines are subroutines, and are invoked with
All MPI objects (e.g., MPI_Datatype
) are of type
All MPI routines (except MPI_Wtime
) return an error
value; C routines as the value of the function and Fortran routines in the
last argument. Before the value is returned, the current MPI error handler is
called. By default, this error handler aborts the MPI job. The error handler
may be changed with MPI_Comm_set_errhandler
(for files), and MPI_Win_set_errhandler
(for RMA windows). The MPI-1 routine MPI_Errhandler_set
may be used but
its use is deprecated. The predefined error handler MPI_ERRORS_RETURN
may be used to cause error values to be returned. Note that MPI does
guarentee that an MPI program can continue past an error; however,
MPI implementations will attempt to continue whenever possible.
- - No error; MPI routine completed successfully.
- - Invalid argument. Some argument is invalid and is not identified by a
specific error class (e.g., MPI_ERR_RANK ).
- - Invalid count argument. Count arguments must be non-negative; a count of
zero is often valid.
- - Invalid source or destination rank. Ranks must be between zero and the
size of the communicator minus one; ranks in a receive ( MPI_Recv ,
MPI_Irecv , MPI_Sendrecv , etc.) may also be
- - Invalid datatype argument. Additionally, this error can occur if an
uncommitted MPI_Datatype (see MPI_Type_commit ) is used in a
- - Invalid MPI window object