gcc/fortran/doc/gfortran/intrinsic-procedures/atomicdefine.rst

   1 ..
   2   Copyright 1988-2022 Free Software Foundation, Inc.
   3   This is part of the GCC manual.
   4   For copying conditions, see the copyright.rst file.
   5
   6 .. index:: ATOMIC_DEFINE, Atomic subroutine, define
   7
   8 .. _atomic_define:
   9
  10 ATOMIC_DEFINE --- Setting a variable atomically
  11 ***********************************************
  12
  13 .. function:: ATOMIC_DEFINE(ATOM, VALUE)
  14
  15   ``ATOMIC_DEFINE(ATOM, VALUE)`` defines the variable :samp:`{ATOM}` with the value
  16   :samp:`{VALUE}` atomically. When :samp:`{STAT}` is present and the invocation was
  17   successful, it is assigned the value 0. If it is present and the invocation
  18   has failed, it is assigned a positive value; in particular, for a coindexed
  19   :samp:`{ATOM}`, if the remote image has stopped, it is assigned the value of
  20   ``ISO_FORTRAN_ENV`` 's ``STAT_STOPPED_IMAGE`` and if the remote image has
  21   failed, the value ``STAT_FAILED_IMAGE``.
  22
  23   :param ATOM:
  24     Scalar coarray or coindexed variable of either integer
  25     type with ``ATOMIC_INT_KIND`` kind or logical type with
  26     ``ATOMIC_LOGICAL_KIND`` kind.
  27
  28   :param VALUE:
  29     Scalar of the same type as :samp:`{ATOM}`. If the kind
  30     is different, the value is converted to the kind of :samp:`{ATOM}`.
  31
  32   :param STAT:
  33     (optional) Scalar default-kind integer variable.
  34
  35   Standard:
  36     Fortran 2008 and later; with :samp:`{STAT}`, TS 18508 or later
  37
  38   Class:
  39     Atomic subroutine
  40
  41   Syntax:
  42     .. code-block:: fortran
  43
  44       CALL ATOMIC_DEFINE (ATOM, VALUE [, STAT])
  45
  46   Example:
  47     .. code-block:: fortran
  48
  49       program atomic
  50         use iso_fortran_env
  51         integer(atomic_int_kind) :: atom[*]
  52         call atomic_define (atom[1], this_image())
  53       end program atomic
  54
  55   See also:
  56     :ref:`ATOMIC_REF`,
  57     :ref:`ATOMIC_CAS`,
  58     :ref:`ISO_FORTRAN_ENV`,
  59     :ref:`ATOMIC_ADD`,
  60     :ref:`ATOMIC_AND`,
  61     :ref:`ATOMIC_OR`,
  62     :ref:`ATOMIC_XOR`