202 lines
6.3 KiB
Ada
202 lines
6.3 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT RUN-TIME COMPONENTS --
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-- --
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-- S Y S T E M . A T O M I C _ P R I M I T I V E S --
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-- --
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-- B o d y --
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-- --
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-- Copyright (C) 2012, Free Software Foundation, Inc. --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. --
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-- --
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-- As a special exception under Section 7 of GPL version 3, you are granted --
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-- additional permissions described in the GCC Runtime Library Exception, --
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-- version 3.1, as published by the Free Software Foundation. --
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-- --
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-- You should have received a copy of the GNU General Public License and --
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-- a copy of the GCC Runtime Library Exception along with this program; --
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-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
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-- <http://www.gnu.org/licenses/>. --
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-- --
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-- GNAT was originally developed by the GNAT team at New York University. --
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-- Extensive contributions were provided by Ada Core Technologies Inc. --
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-- --
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------------------------------------------------------------------------------
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package body System.Atomic_Primitives is
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----------------------
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-- Lock_Free_Read_8 --
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----------------------
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function Lock_Free_Read_8 (Ptr : Address) return uint8 is
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begin
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if uint8'Atomic_Always_Lock_Free then
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return Atomic_Load_8 (Ptr, Acquire);
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else
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raise Program_Error;
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end if;
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end Lock_Free_Read_8;
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-----------------------
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-- Lock_Free_Read_16 --
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-----------------------
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function Lock_Free_Read_16 (Ptr : Address) return uint16 is
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begin
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if uint16'Atomic_Always_Lock_Free then
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return Atomic_Load_16 (Ptr, Acquire);
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else
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raise Program_Error;
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end if;
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end Lock_Free_Read_16;
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-----------------------
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-- Lock_Free_Read_32 --
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-----------------------
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function Lock_Free_Read_32 (Ptr : Address) return uint32 is
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begin
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if uint32'Atomic_Always_Lock_Free then
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return Atomic_Load_32 (Ptr, Acquire);
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else
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raise Program_Error;
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end if;
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end Lock_Free_Read_32;
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-----------------------
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-- Lock_Free_Read_64 --
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-----------------------
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function Lock_Free_Read_64 (Ptr : Address) return uint64 is
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begin
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if uint64'Atomic_Always_Lock_Free then
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return Atomic_Load_64 (Ptr, Acquire);
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else
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raise Program_Error;
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end if;
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end Lock_Free_Read_64;
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---------------------------
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-- Lock_Free_Try_Write_8 --
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---------------------------
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function Lock_Free_Try_Write_8
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(Ptr : Address;
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Expected : in out uint8;
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Desired : uint8) return Boolean
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is
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Actual : uint8;
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begin
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if Expected /= Desired then
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if uint8'Atomic_Always_Lock_Free then
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Actual := Sync_Compare_And_Swap_8 (Ptr, Expected, Desired);
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else
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raise Program_Error;
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end if;
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if Actual /= Expected then
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Expected := Actual;
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return False;
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end if;
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end if;
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return True;
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end Lock_Free_Try_Write_8;
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----------------------------
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-- Lock_Free_Try_Write_16 --
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----------------------------
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function Lock_Free_Try_Write_16
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(Ptr : Address;
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Expected : in out uint16;
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Desired : uint16) return Boolean
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is
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Actual : uint16;
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begin
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if Expected /= Desired then
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if uint16'Atomic_Always_Lock_Free then
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Actual := Sync_Compare_And_Swap_16 (Ptr, Expected, Desired);
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else
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raise Program_Error;
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end if;
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if Actual /= Expected then
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Expected := Actual;
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return False;
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end if;
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end if;
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return True;
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end Lock_Free_Try_Write_16;
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----------------------------
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-- Lock_Free_Try_Write_32 --
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----------------------------
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function Lock_Free_Try_Write_32
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(Ptr : Address;
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Expected : in out uint32;
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Desired : uint32) return Boolean
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is
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Actual : uint32;
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begin
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if Expected /= Desired then
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if uint32'Atomic_Always_Lock_Free then
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Actual := Sync_Compare_And_Swap_32 (Ptr, Expected, Desired);
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else
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raise Program_Error;
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end if;
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if Actual /= Expected then
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Expected := Actual;
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return False;
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end if;
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end if;
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return True;
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end Lock_Free_Try_Write_32;
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----------------------------
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-- Lock_Free_Try_Write_64 --
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----------------------------
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function Lock_Free_Try_Write_64
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(Ptr : Address;
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Expected : in out uint64;
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Desired : uint64) return Boolean
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is
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Actual : uint64;
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begin
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if Expected /= Desired then
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if uint64'Atomic_Always_Lock_Free then
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Actual := Sync_Compare_And_Swap_64 (Ptr, Expected, Desired);
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else
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raise Program_Error;
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end if;
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if Actual /= Expected then
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Expected := Actual;
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return False;
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end if;
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end if;
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return True;
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end Lock_Free_Try_Write_64;
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end System.Atomic_Primitives;
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