MPI_File_write_ordered is a collective routine. This routine 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. 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. MPI_File_write_ordered returns the number of
datatype
elements written in
status.
The shared file pointer is
updated by the amounts of data requested by all processes of the
group.
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.