NAME

       MPI_File_iwrite  -  Writes  a  file  starting  at  the  location specified by the individual file pointer
       (nonblocking, noncollective).

SYNTAX

C Syntax

       #include <mpi.h>
       int MPI_File_iwrite(MPI_File fh, const void *buf, int count,
            MPI_Datatype datatype, MPI_Request *request)

Fortran Syntax

       USE MPI
       ! or the older form: INCLUDE 'mpif.h'
       MPI_FILE_IWRITE(FH, BUF, COUNT, DATATYPE, REQUEST, IERROR)
            <type>    BUF(*)
            INTEGER   FH, COUNT, DATATYPE, REQUEST, IERROR

Fortran 2008 Syntax

       USE mpi_f08
       MPI_File_iwrite(fh, buf, count, datatype, request, ierror)
            TYPE(MPI_File), INTENT(IN) :: fh
            TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: buf
            INTEGER, INTENT(IN) :: count
            TYPE(MPI_Datatype), INTENT(IN) :: datatype
            TYPE(MPI_Request), INTENT(OUT) :: request
            INTEGER, OPTIONAL, INTENT(OUT) :: ierror

C++ Syntax

       #include <mpi.h>
       MPI::Request MPI::File::Iwrite(const void* buf, int count,
            const MPI::Datatype& datatype)

INPUT/OUTPUT PARAMETER

       fh        File handle (handle).

INPUT PARAMETERS

       buf       Initial address of buffer (choice).

       count     Number of elements in buffer (integer).

       datatype  Data type of each buffer element (handle).

OUTPUT PARAMETER

       request   Request object (handle).

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       MPI_File_iwrite is a nonblocking version of the MPI_File_write interface. It attempts to write  into  the
       file  associated  with  fh  (at  the current individual file pointer position maintained by the system) a
       total number of count data items having datatype type from the user's buffer buf.  The  data  is  written
       into those parts of the file specified by the current view. MPI_File_iwrite stores the number of datatype
       elements actually written in status.  All other fields of status are undefined.

       It is erroneous to call this function if MPI_MODE_SEQUENTIAL mode was specified when the file was open.

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.