MPI_File_iwrite(3)                 Open MPI                 MPI_File_iwrite(3)



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, void *buf, int count,
                  MPI_Datatype datatype, MPI_Request *request)

       Fortran Syntax
           INCLUDE 'mpif.h'
           MPI_FILE_IWRITE(FH, BUF, COUNT, DATATYPE, REQUEST, IERROR)
                 <TYPE>         BUF(*)
                 INTEGER        FH, COUNT, DATATYPE, REQUEST, 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_SEQENTIAL 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.




1.4.1                            Jan 14, 2010               MPI_File_iwrite(3)
