Skip to content

Latest commit

 

History

History
95 lines (64 loc) · 2.24 KB

MPI_File_read_at_all_begin.3.rst

File metadata and controls

95 lines (64 loc) · 2.24 KB
Raw

MPI_File_read_at_all_begin

:ref:`MPI_File_read_at_all_begin` |mdash| Reads a file at explicitly specified offsets; beginning part of a split collective routine (nonblocking).

SYNTAX

C Syntax

#include <mpi.h>

int MPI_File_read_at_all_begin(MPI_File fh, MPI_Offset
     offset, void *buf, int count, MPI_Datatype
     datatype)

Fortran Syntax

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

Fortran 2008 Syntax

USE mpi_f08
MPI_File_read_at_all_begin(fh, offset, buf, count, datatype, 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
     INTEGER, OPTIONAL, INTENT(OUT) :: ierror

INPUT PARAMETERS

  • fh: File handle (handle).
  • offset: File offset (integer).
  • count: Number of elements in buffer (integer).
  • datatype: Data type of each buffer element.

OUTPUT PARAMETERS

  • buf: Initial address of buffer (choice).
  • ierror: Fortran only: Error status (integer).

DESCRIPTION

:ref:`MPI_File_read_at_all_begin` is the beginning part of a split collective 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.

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.

ERRORS