gcc/fortran/doc/gfortran/intrinsic-procedures/atomicadd.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_ADD, Atomic subroutine, add
   7
   8 .. _atomic_add:
   9
  10 ATOMIC_ADD --- Atomic ADD operation
  11 ***********************************
  12
  13 .. function:: ATOMIC_ADD(ATOM, VALUE)
  14
  15   ``ATOMIC_ADD(ATOM, VALUE)`` atomically adds the value of :samp:`{VALUE}` to the
  16   variable :samp:`{ATOM}`. 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 integer
  25     type with ``ATOMIC_INT_KIND`` kind.
  26
  27   :param VALUE:
  28     Scalar of the same type as :samp:`{ATOM}`. If the kind
  29     is different, the value is converted to the kind of :samp:`{ATOM}`.
  30
  31   :param STAT:
  32     (optional) Scalar default-kind integer variable.
  33
  34   Standard:
  35     TS 18508 or later
  36
  37   Class:
  38     Atomic subroutine
  39
  40   Syntax:
  41     .. code-block:: fortran
  42
  43       CALL ATOMIC_ADD (ATOM, VALUE [, STAT])
  44
  45   Example:
  46     .. code-block:: fortran
  47
  48       program atomic
  49         use iso_fortran_env
  50         integer(atomic_int_kind) :: atom[*]
  51         call atomic_add (atom[1], this_image())
  52       end program atomic
  53
  54   See also:
  55     :ref:`ATOMIC_DEFINE`,
  56     :ref:`ATOMIC_FETCH_ADD`,
  57     :ref:`ISO_FORTRAN_ENV`,
  58     :ref:`ATOMIC_AND`,
  59     :ref:`ATOMIC_OR`,
  60     :ref:`ATOMIC_XOR`