bionic (3) MPI_File_iwrite_at_all.openmpi.3.gz

NAME

       MPI_File_iwrite_at_all - Writes a file at an explicitly specified offset (nonblocking, collective).

SYNTAX

C Syntax

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

Fortran Syntax (see FORTRAN 77 NOTES)

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

INPUT/OUTPUT PARAMETER

       fh        File handle (handle).

INPUT PARAMETERS

       offset    File offset (integer).

       buf       Initial address of buffer (choice).

       count     Number of elements in buffer (integer).

       datatype  Data type of each buffer element (handle).

OUTPUT PARAMETERS

       request   Request object (handle).

       IERROR    Fortran only: Error status (integer).

DESCRIPTION

       MPI_File_iwrite_at_all is a nonblocking version of MPI_File_write_at_all. It 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. MPI_File_iwrite_at_all stores the number  of  datatype  elements  actually  written  in
       status.   All  other  fields  of status are undefined. The request structure can be passed to MPI_Wait or
       MPI_Test, which will return a status with the number of bytes actually accessed.

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

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.

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.