:ref:`MPI_File_iread_at` - Reads a file at an explicitly specified offset (nonblocking, noncollective).
#include <mpi.h>
int MPI_File_iread_at(MPI_File fh, MPI_Offset offset,
void *buf, int count, MPI_Datatype datatype,
MPI_Request *request)
USE MPI
! or the older form: INCLUDE 'mpif.h'
MPI_FILE_IREAD_AT(FH, OFFSET, BUF, COUNT, DATATYPE, REQUEST, IERROR)
<type> BUF(*)
INTEGER FH, COUNT, DATATYPE, REQUEST, IERROR
INTEGER(KIND=MPI_OFFSET_KIND) OFFSET
USE mpi_f08
MPI_File_iread_at(fh, offset, buf, count, datatype, request, ierror)
TYPE(MPI_File), INTENT(IN) :: fh
INTEGER(KIND=MPI_OFFSET_KIND), INTENT(IN) :: offset
TYPE(*), DIMENSION(..), ASYNCHRONOUS :: buf
INTEGER, INTENT(IN) :: count
TYPE(MPI_Datatype), INTENT(IN) :: datatype
TYPE(MPI_Request), INTENT(OUT) :: request
INTEGER, OPTIONAL, INTENT(OUT) :: ierror
fh
: File handle (handle).offset
: File offset (integer).count
: Number of elements in the buffer (integer).datatype
: Data type of each buffer element (handle).
buf
: Initial address of the buffer (choice).request
: Request object (handle).ierror
: Fortran only: Error status (integer).
:ref:`MPI_File_iread_at` is the nonblocking version of :ref:`MPI_File_read_at`.
:ref:`MPI_File_iread_at` is a nonblocking routine that attempts to read from the file associated with fh at the offset position a total number of count data items having datatype type into 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 taken out of those parts of the file specified by the current view. :ref:`MPI_File_iread_at` stores the number of datatype elements actually read in status. All other fields of status are undefined.