MPI_File_write_at_all_begin(3)     Open MPI     MPI_File_write_at_all_begin(3)



NAME
       MPI_File_write_at_all_begin - Writes a file at explicitly specified
       offsets; beginning part of a split collective routine (nonblocking).


SYNTAX
       C Syntax
           #include <mpi.h>
           int MPI_File_write_at_all_begin(MPI_File fh, MPI_Offset offset,
                  void *buf, int count, MPI_Datatype datatype)

       Fortran Syntax (see FORTRAN 77 NOTES)
           INCLUDE 'mpif.h'
           MPI_FILE_WRITE_AT_ALL_BEGIN(FH, OFFSET, BUF, COUNT, DATATYPE, IERROR)
                 <TYPE> BUF(*)
                 INTEGER   FH, COUNT, DATATYPE, IERROR
                 INTEGER(KIND=MPI_OFFSET_KIND) OFFSET


C++ Syntax
       #include <mpi.h>
       void MPI::File::Write_at_all_begin(MPI::Offset offset,
            const void* buf, int count,
            const MPI::Datatype& datatype)


INPUT/OUTPUT PARAMETER
       fh        File handle (handle).


INPUT PARAMETERS
       offset    File offset (handle).

       buf       Initial address of buffer (choice).

       count     Number of elements in buffer (integer).

       datatype  Data type of each buffer element (handle).


OUTPUT PARAMETER
       IERROR    Fortran only: Error status (integer).


DESCRIPTION
       MPI_File_write_at_all_begin is the beginning part of a split
       collective, that is, a nonblocking routine that attempts to write into
       the file associated with fh (at the offset position) a total number of
       count data items having datatype type from the user's buffer buf.  The
       offset is in etype units relative to the current view. That is, holes
       are not counted when locating an offset. The data is written into those
       parts of the file specified by the current view.


FORTRAN 77 NOTES
       The MPI standard prescribes portable Fortran syntax for the OFFSET
       argument only for Fortran 90.  FORTRAN 77 users may use the non-
       portable syntax

            INTEGER*MPI_OFFSET_KIND OFFSET

       where MPI_OFFSET_KIND is a constant defined in mpif.h and gives the
       length of the declared integer in bytes.


NOTES
       All the nonblocking collective routines for data access are "split"
       into two routines, each with _begin or _end as a suffix. These split
       collective routines are subject to the semantic rules described in
       Section 9.4.5 of the MPI-2 standard.


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. For MPI I/O function errors, the default error handler is set
       to MPI_ERRORS_RETURN. The error handler may be changed with
       MPI_File_set_errhandler; the predefined error handler
       MPI_ERRORS_ARE_FATAL may be used to make I/O errors fatal. Note that
       MPI does not guarantee that an MPI program can continue past an error.




1.4.1                            Jan 14, 2010   MPI_File_write_at_all_begin(3)
