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Diffstat (limited to 'gcc-4.9/gcc/ada/s-atocou.ads')
| -rw-r--r-- | gcc-4.9/gcc/ada/s-atocou.ads | 83 |
1 files changed, 83 insertions, 0 deletions
diff --git a/gcc-4.9/gcc/ada/s-atocou.ads b/gcc-4.9/gcc/ada/s-atocou.ads new file mode 100644 index 000000000..55d6bf0ec --- /dev/null +++ b/gcc-4.9/gcc/ada/s-atocou.ads @@ -0,0 +1,83 @@ +------------------------------------------------------------------------------ +-- -- +-- GNAT RUN-TIME COMPONENTS -- +-- -- +-- S Y S T E M . A T O M I C _ C O U N T E R S -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 2011-2013, Free Software Foundation, Inc. -- +-- -- +-- GNAT is free software; you can redistribute it and/or modify it under -- +-- terms of the GNU General Public License as published by the Free Soft- -- +-- ware Foundation; either version 3, or (at your option) any later ver- -- +-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- +-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- +-- or FITNESS FOR A PARTICULAR PURPOSE. -- +-- -- +-- As a special exception under Section 7 of GPL version 3, you are granted -- +-- additional permissions described in the GCC Runtime Library Exception, -- +-- version 3.1, as published by the Free Software Foundation. -- +-- -- +-- You should have received a copy of the GNU General Public License and -- +-- a copy of the GCC Runtime Library Exception along with this program; -- +-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- +-- <http://www.gnu.org/licenses/>. -- +-- -- +-- GNAT was originally developed by the GNAT team at New York University. -- +-- Extensive contributions were provided by Ada Core Technologies Inc. -- +-- -- +------------------------------------------------------------------------------ + +-- This package provides atomic counter on platforms where it is supported: +-- - all Alpha platforms +-- - all ia64 platforms +-- - all PowerPC platforms +-- - all SPARC V9 platforms +-- - all x86 platforms +-- - all x86_64 platforms + +-- Why isn't this package available to application programs??? + +package System.Atomic_Counters is + + pragma Preelaborate; + + type Atomic_Counter is limited private; + -- Type for atomic counter objects. Note, initial value of the counter is + -- one. This allows using an atomic counter as member of record types when + -- object of these types are created at library level in preelaborable + -- compilation units. + -- + -- Atomic_Counter is declared as private limited type to provide highest + -- level of protection from unexpected use. All available operations are + -- declared below, and this set should be as small as possible. + + procedure Increment (Item : in out Atomic_Counter); + pragma Inline_Always (Increment); + -- Increments value of atomic counter. + + function Decrement (Item : in out Atomic_Counter) return Boolean; + pragma Inline_Always (Decrement); + -- Decrements value of atomic counter, returns True when value reach zero. + + function Is_One (Item : Atomic_Counter) return Boolean; + pragma Inline_Always (Is_One); + -- Returns True when value of the atomic counter is one. + + procedure Initialize (Item : out Atomic_Counter); + pragma Inline_Always (Initialize); + -- Initialize counter by setting its value to one. This subprogram is + -- intended to be used in special cases when counter object can't be + -- initialized in standard way. + +private + + type Unsigned_32 is mod 2 ** 32; + + type Atomic_Counter is limited record + Value : aliased Unsigned_32 := 1; + pragma Atomic (Value); + end record; + +end System.Atomic_Counters; |