232 lines
5.3 KiB
Groff
232 lines
5.3 KiB
Groff
.TH MPI_Get_accumulate 3 "6/5/2019" " " "MPI"
|
|
.SH NAME
|
|
MPI_Get_accumulate \- Perform an atomic, one-sided read-and-accumulate operation.
|
|
.SH SYNOPSIS
|
|
.nf
|
|
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)
|
|
.fi
|
|
|
|
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
|
|
accumulation.
|
|
|
|
.SH INPUT PARAMETERS
|
|
.PD 0
|
|
.TP
|
|
.B origin_addr
|
|
- initial address of buffer (choice)
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B origin_count
|
|
- number of entries in buffer (nonnegative integer)
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B origin_datatype
|
|
- datatype of each buffer entry (handle)
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B result_addr
|
|
- initial address of result buffer (choice)
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B result_count
|
|
- number of entries in result buffer (non-negative integer)
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B result_datatype
|
|
- datatype of each entry in result buffer (handle)
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B target_rank
|
|
- rank of target (nonnegative integer)
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B target_disp
|
|
- displacement from start of window to beginning of target
|
|
buffer (nonnegative integer)
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B target_count
|
|
- number of entries in target buffer (nonnegative integer)
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B target_datatype
|
|
- datatype of each entry in target buffer (handle)
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B op
|
|
- predefined reduce operation (handle)
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B win
|
|
- window object (handle)
|
|
.PD 1
|
|
|
|
.SH NOTES
|
|
This operations is atomic with respect to other "accumulate" operations.
|
|
|
|
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
|
|
.I MPI_REPLACE
|
|
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
|
|
.I MPI_Reduce
|
|
, as well as
|
|
.I MPI_NO_OP
|
|
or
|
|
.I MPI_REPLACE
|
|
can be specified as op. User-defined functions cannot be used. A
|
|
new predefined operation,
|
|
.I MPI_NO_OP
|
|
, is 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.
|
|
.I MPI_NO_OP
|
|
can be used only in
|
|
.I MPI_Get_accumulate
|
|
,
|
|
.I MPI_Rget_accumulate
|
|
, and
|
|
.I MPI_Fetch_and_op
|
|
\&.
|
|
.I MPI_NO_OP
|
|
cannot be used in
|
|
.I MPI_Accumulate
|
|
,
|
|
.I MPI_Raccumulate
|
|
, or collective reduction operations, such as
|
|
.I MPI_Reduce
|
|
and others.
|
|
|
|
.SH NOTES FOR FORTRAN
|
|
All MPI routines in Fortran (except for
|
|
.I MPI_WTIME
|
|
and
|
|
.I MPI_WTICK
|
|
) have
|
|
an additional argument
|
|
.I ierr
|
|
at the end of the argument list.
|
|
.I ierr
|
|
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 the
|
|
.I call
|
|
statement.
|
|
|
|
All MPI objects (e.g.,
|
|
.I MPI_Datatype
|
|
,
|
|
.I MPI_Comm
|
|
) are of type
|
|
.I INTEGER
|
|
in Fortran.
|
|
|
|
.SH ERRORS
|
|
|
|
All MPI routines (except
|
|
.I MPI_Wtime
|
|
and
|
|
.I MPI_Wtick
|
|
) 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
|
|
.I MPI_Comm_set_errhandler
|
|
(for communicators),
|
|
.I MPI_File_set_errhandler
|
|
(for files), and
|
|
.I MPI_Win_set_errhandler
|
|
(for
|
|
RMA windows). The MPI-1 routine
|
|
.I MPI_Errhandler_set
|
|
may be used but
|
|
its use is deprecated. The predefined error handler
|
|
.I MPI_ERRORS_RETURN
|
|
may be used to cause error values to be returned.
|
|
Note that MPI does
|
|
.B not
|
|
guarentee that an MPI program can continue past
|
|
an error; however, MPI implementations will attempt to continue whenever
|
|
possible.
|
|
|
|
.PD 0
|
|
.TP
|
|
.B MPI_SUCCESS
|
|
- No error; MPI routine completed successfully.
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B MPI_ERR_ARG
|
|
- Invalid argument. Some argument is invalid and is not
|
|
identified by a specific error class (e.g.,
|
|
.I MPI_ERR_RANK
|
|
).
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B MPI_ERR_COUNT
|
|
- Invalid count argument. Count arguments must be
|
|
non-negative; a count of zero is often valid.
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B MPI_ERR_RANK
|
|
- Invalid source or destination rank. Ranks must be between
|
|
zero and the size of the communicator minus one; ranks in a receive
|
|
(
|
|
.I MPI_Recv
|
|
,
|
|
.I MPI_Irecv
|
|
,
|
|
.I MPI_Sendrecv
|
|
, etc.) may also be
|
|
.I MPI_ANY_SOURCE
|
|
\&.
|
|
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B MPI_ERR_TYPE
|
|
- Invalid datatype argument. Additionally, this error can
|
|
occur if an uncommitted MPI_Datatype (see
|
|
.I MPI_Type_commit
|
|
) is used
|
|
in a communication call.
|
|
.PD 1
|
|
.PD 0
|
|
.TP
|
|
.B MPI_ERR_WIN
|
|
- Invalid MPI window object
|
|
.PD 1
|
|
|
|
.SH SEE ALSO
|
|
MPI_Rget_accumulate MPI_Fetch_and_op
|
|
.br
|