


MPI_Accumulate(3)            LAM/MPI            MPI_Accumulate(3)


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)

INPUT PARAMETERS
       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 dif-
       ferent 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



LAM/MPI 6.5.9               1/27/2003                           1





MPI_Accumulate(3)            LAM/MPI            MPI_Accumulate(3)


       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 val-
       ues; 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 per-
              formed  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  combi-
              nation  of datatypes and operations are defined, see MPI-1, sec-
              tion 4.9.2) or one-sided operations where the  actions  on  spe-
              cific 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)


MORE INFORMATION
       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  docu-
       ments  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




LAM/MPI 6.5.9               1/27/2003                           2


