NAME¶
MPI_Accumulate - Accumulates data into a window
SYNOPSIS¶
#include <mpi.h>
int MPI_Accumulate(void *orgaddr, int orgcnt, MPI_Datatype orgtype, int rank,
MPI_Aint targdisp, int targcnt, MPI_Datatype targtype,
MPI_Op op, MPI_Win win)
- orgaddr
- - initial address of buffer (choice)
- orgcnt
- - number of entries in buffer (nonnegative integer)
- orgtype
- - datatype of each buffer entry (handle)
- rank
- - rank of target (nonnegative integer)
- targdisp
- - displacement from start of window to beginning of target buffer
(nonnegative integer)
- targtype
- - datatype of each entry in target buffer (handle)
- op
- - reduce operation (handle)
- win
- - window object (handle)
NOTES¶
MPI_PUT is a special case of MPI_ACCUMULATE, with the operation MPI_REPLACE.
Note, however, that MPI_PUT and MPI_ACCUMULATE have different constraints on
concurrent updates. ( End of advice to users.)
NOTES FOR FORTRAN¶
All MPI routines in Fortran (except for
MPI_WTIME and
MPI_WTICK )
have an additional argument
ierr at the end of the argument list.
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
call statement.
All MPI objects (e.g.,
MPI_Datatype ,
MPI_Comm ) are of type
INTEGER in Fortran.
ERRORS¶
If an error occurs in an MPI function, the current MPI error handler is called
to handle it. By default, this error handler aborts the MPI job. The error
handler may be changed with
MPI_Errhandler_set ; the predefined error
handler
MPI_ERRORS_RETURN may be used to cause error values to be
returned (in C and Fortran; this error handler is less useful in with the C++
MPI bindings. The predefined error handler
MPI::ERRORS_THROW_EXCEPTIONS
should be used in C++ if the error value needs to be recovered). Note that MPI
does
not guarantee that an MPI program can continue past an error.
All MPI routines (except
MPI_Wtime and
MPI_Wtick ) return an error
value; C routines as the value of the function and Fortran routines in the
last argument. The C++ bindings for MPI do not return error values; instead,
error values are communicated by throwing exceptions of type
MPI::Exception (but not by default). Exceptions are only thrown if the
error value is not
MPI::SUCCESS .
Note that if the
MPI::ERRORS_RETURN handler is set in C++, while MPI
functions will return upon an error, there will be no way to recover what the
actual error value was.
- MPI_SUCCESS
- - No error; MPI routine completed successfully.
- MPI_ERR_WIN
- - Invalid window. A common error is to use a null window in a call.
- MPI_ERR_TYPE
- - Invalid datatype argument. May be an uncommitted MPI_Datatype (see
MPI_Type_commit ).
- MPI_ERR_EPOCH
- - This error indicates than an operation has been attempted on a
"closed" window. Certain one-sided operations can only be
performed on windows whose epoch has been started with MPI_Win_start.
- MPI_ERR_INTERN
- - An internal error has been detected. This is fatal. Please send a bug
report to the LAM mailing list (see
http://www.lam-mpi.org/contact.php ).
- MPI_ERR_TYPENOTSUP
- - Type not supported for this operation. This typically applies to either
reduction operations (for which only a limited combination of datatypes
and operations are defined, see MPI-1, section 4.9.2) or one-sided
operations where the actions on specific datatpyes have not been
implemented yet.
SEE ALSO¶
MPI_Put(3),
MPI_Get(3),
MPI_Win_create(3),
MPI_Win_start(3),
MPI_Win_complete(3),
MPI_Win_fence(3),
MPI_Win_free(3),
MPI_Win_get_group(3),
MPI_Win_get_group(3),
MPI_Win_wait(3)
For more information, please see the official MPI Forum web site, which contains
the text of both the MPI-1 and MPI-2 standards. These documents contain
detailed information about each MPI function (most of which is not duplicated
in these man pages).
http://www.mpi-forum.org/
LOCATION¶
accumulate.c