| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT RUN-TIME COMPONENTS -- |
| -- -- |
| -- S Y S T E M . A T O M I C _ P R I M I T I V E S -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 2012-2021, 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. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| package body System.Atomic_Primitives is |
| |
| ---------------------- |
| -- Lock_Free_Read_8 -- |
| ---------------------- |
| |
| function Lock_Free_Read_8 (Ptr : Address) return uint8 is |
| begin |
| if uint8'Atomic_Always_Lock_Free then |
| return Atomic_Load_8 (Ptr, Acquire); |
| else |
| raise Program_Error; |
| end if; |
| end Lock_Free_Read_8; |
| |
| ----------------------- |
| -- Lock_Free_Read_16 -- |
| ----------------------- |
| |
| function Lock_Free_Read_16 (Ptr : Address) return uint16 is |
| begin |
| if uint16'Atomic_Always_Lock_Free then |
| return Atomic_Load_16 (Ptr, Acquire); |
| else |
| raise Program_Error; |
| end if; |
| end Lock_Free_Read_16; |
| |
| ----------------------- |
| -- Lock_Free_Read_32 -- |
| ----------------------- |
| |
| function Lock_Free_Read_32 (Ptr : Address) return uint32 is |
| begin |
| if uint32'Atomic_Always_Lock_Free then |
| return Atomic_Load_32 (Ptr, Acquire); |
| else |
| raise Program_Error; |
| end if; |
| end Lock_Free_Read_32; |
| |
| ----------------------- |
| -- Lock_Free_Read_64 -- |
| ----------------------- |
| |
| function Lock_Free_Read_64 (Ptr : Address) return uint64 is |
| begin |
| if uint64'Atomic_Always_Lock_Free then |
| return Atomic_Load_64 (Ptr, Acquire); |
| else |
| raise Program_Error; |
| end if; |
| end Lock_Free_Read_64; |
| |
| --------------------------- |
| -- Lock_Free_Try_Write_8 -- |
| --------------------------- |
| |
| function Lock_Free_Try_Write_8 |
| (Ptr : Address; |
| Expected : in out uint8; |
| Desired : uint8) return Boolean |
| is |
| Actual : uint8; |
| |
| begin |
| if Expected /= Desired then |
| |
| if uint8'Atomic_Always_Lock_Free then |
| Actual := Sync_Compare_And_Swap_8 (Ptr, Expected, Desired); |
| else |
| raise Program_Error; |
| end if; |
| |
| if Actual /= Expected then |
| Expected := Actual; |
| return False; |
| end if; |
| end if; |
| |
| return True; |
| end Lock_Free_Try_Write_8; |
| |
| ---------------------------- |
| -- Lock_Free_Try_Write_16 -- |
| ---------------------------- |
| |
| function Lock_Free_Try_Write_16 |
| (Ptr : Address; |
| Expected : in out uint16; |
| Desired : uint16) return Boolean |
| is |
| Actual : uint16; |
| |
| begin |
| if Expected /= Desired then |
| |
| if uint16'Atomic_Always_Lock_Free then |
| Actual := Sync_Compare_And_Swap_16 (Ptr, Expected, Desired); |
| else |
| raise Program_Error; |
| end if; |
| |
| if Actual /= Expected then |
| Expected := Actual; |
| return False; |
| end if; |
| end if; |
| |
| return True; |
| end Lock_Free_Try_Write_16; |
| |
| ---------------------------- |
| -- Lock_Free_Try_Write_32 -- |
| ---------------------------- |
| |
| function Lock_Free_Try_Write_32 |
| (Ptr : Address; |
| Expected : in out uint32; |
| Desired : uint32) return Boolean |
| is |
| Actual : uint32; |
| |
| begin |
| if Expected /= Desired then |
| |
| if uint32'Atomic_Always_Lock_Free then |
| Actual := Sync_Compare_And_Swap_32 (Ptr, Expected, Desired); |
| else |
| raise Program_Error; |
| end if; |
| |
| if Actual /= Expected then |
| Expected := Actual; |
| return False; |
| end if; |
| end if; |
| |
| return True; |
| end Lock_Free_Try_Write_32; |
| |
| ---------------------------- |
| -- Lock_Free_Try_Write_64 -- |
| ---------------------------- |
| |
| function Lock_Free_Try_Write_64 |
| (Ptr : Address; |
| Expected : in out uint64; |
| Desired : uint64) return Boolean |
| is |
| Actual : uint64; |
| |
| begin |
| if Expected /= Desired then |
| |
| if uint64'Atomic_Always_Lock_Free then |
| Actual := Sync_Compare_And_Swap_64 (Ptr, Expected, Desired); |
| else |
| raise Program_Error; |
| end if; |
| |
| if Actual /= Expected then |
| Expected := Actual; |
| return False; |
| end if; |
| end if; |
| |
| return True; |
| end Lock_Free_Try_Write_64; |
| end System.Atomic_Primitives; |
