17.2.119. MPI_File_iwrite

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

17.2.119.1. SYNTAX

17.2.119.1.1. C Syntax

#include <mpi.h>

int MPI_File_iwrite(MPI_File fh, const void *buf, int count,
     MPI_Datatype datatype, MPI_Request *request)

17.2.119.1.2. 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

17.2.119.1.3. 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

17.2.119.2. INPUT/OUTPUT PARAMETER

fh: File handle (handle).

17.2.119.3. INPUT PARAMETERS

buf: Initial address of buffer (choice).
count: Number of elements in buffer (integer).
datatype: Data type of each buffer element (handle).

17.2.119.4. OUTPUT PARAMETER

request: Request object (handle).
IERROR: Fortran only: Error status (integer).

17.2.119.5. 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.

17.2.119.6. 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.