17.2.155. MPI_File_write_ordered_begin
MPI_File_write_ordered_begin - Writes a file at a location specified by a shared file pointer; beginning part of a split collective routine (nonblocking).
17.2.155.1. Syntax
17.2.155.1.1. C Syntax
#include <mpi.h>
int MPI_File_write_ordered_begin(MPI_File fh, const void *buf,
int count, MPI_Datatype datatype)
17.2.155.1.2. Fortran Syntax
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_FILE_WRITE_ORDERED_BEGIN(FH, BUF, COUNT, DATATYPE, IERROR)
<type> BUF(*)
INTEGER FH, COUNT, DATATYPE, IERROR
17.2.155.1.3. Fortran 2008 Syntax
USE mpi_f08
MPI_File_write_ordered_begin(fh, buf, count, datatype, ierror)
TYPE(MPI_File), INTENT(IN) :: fh
TYPE(*), DIMENSION(..), INTENT(IN), ASYNCHRONOUS :: buf
INTEGER, INTENT(IN) :: count
TYPE(MPI_Datatype), INTENT(IN) :: datatype
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
17.2.155.2. Input/Output Parameter
fh
: File handle (handle).
17.2.155.3. Input Parameters
buf
: Initial address of buffer (choice).count
: Number of elements in buffer (integer).datatype
: Data type of each buffer element (handle).
17.2.155.4. Output Parameter
IERROR
: Fortran only: Error status (integer).
17.2.155.5. Description
MPI_File_write_ordered_begin is the beginning part of a split
collective, nonblocking routine that must be called by all processes in
the communicator group associated with the file handle fh
. Each
process may pass different argument values for the datatype
and
count
arguments. After all processes of the group have issued their
respective calls, each process attempts to write, into the file
associated with fh
, a total number of count
data items having
datatype
type contained in the user’s buffer buf
. For each
process, the location in the file at which data is written is the
position at which the shared file pointer would be after all processes
whose ranks within the group are less than that of this process had
written their data.
17.2.155.6. 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.
17.2.155.7. Errors
Almost all MPI routines return an error value; C routines as the value of the function and Fortran routines in the last argument.
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.