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Diffstat (limited to 'gcc/ada/libgnat/s-atopri.ads')
| -rw-r--r-- | gcc/ada/libgnat/s-atopri.ads | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/gcc/ada/libgnat/s-atopri.ads b/gcc/ada/libgnat/s-atopri.ads new file mode 100644 index 00000000000..b9c9251c3cf --- /dev/null +++ b/gcc/ada/libgnat/s-atopri.ads @@ -0,0 +1,180 @@ +------------------------------------------------------------------------------ +-- -- +-- 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 -- +-- -- +-- S p e c -- +-- -- +-- Copyright (C) 2012-2017, 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 contains both atomic primitives defined from gcc built-in +-- functions and operations used by the compiler to generate the lock-free +-- implementation of protected objects. + +package System.Atomic_Primitives is + pragma Preelaborate; + + type uint is mod 2 ** Long_Integer'Size; + + type uint8 is mod 2**8 + with Size => 8; + + type uint16 is mod 2**16 + with Size => 16; + + type uint32 is mod 2**32 + with Size => 32; + + type uint64 is mod 2**64 + with Size => 64; + + Relaxed : constant := 0; + Consume : constant := 1; + Acquire : constant := 2; + Release : constant := 3; + Acq_Rel : constant := 4; + Seq_Cst : constant := 5; + Last : constant := 6; + + subtype Mem_Model is Integer range Relaxed .. Last; + + ------------------------------------ + -- GCC built-in atomic primitives -- + ------------------------------------ + + function Atomic_Load_8 + (Ptr : Address; + Model : Mem_Model := Seq_Cst) return uint8; + pragma Import (Intrinsic, Atomic_Load_8, "__atomic_load_1"); + + function Atomic_Load_16 + (Ptr : Address; + Model : Mem_Model := Seq_Cst) return uint16; + pragma Import (Intrinsic, Atomic_Load_16, "__atomic_load_2"); + + function Atomic_Load_32 + (Ptr : Address; + Model : Mem_Model := Seq_Cst) return uint32; + pragma Import (Intrinsic, Atomic_Load_32, "__atomic_load_4"); + + function Atomic_Load_64 + (Ptr : Address; + Model : Mem_Model := Seq_Cst) return uint64; + pragma Import (Intrinsic, Atomic_Load_64, "__atomic_load_8"); + + function Sync_Compare_And_Swap_8 + (Ptr : Address; + Expected : uint8; + Desired : uint8) return uint8; + pragma Import (Intrinsic, + Sync_Compare_And_Swap_8, + "__sync_val_compare_and_swap_1"); + + -- ??? Should use __atomic_compare_exchange_1 (doesn't work yet): + -- function Sync_Compare_And_Swap_8 + -- (Ptr : Address; + -- Expected : Address; + -- Desired : uint8; + -- Weak : Boolean := False; + -- Success_Model : Mem_Model := Seq_Cst; + -- Failure_Model : Mem_Model := Seq_Cst) return Boolean; + -- pragma Import (Intrinsic, + -- Sync_Compare_And_Swap_8, + -- "__atomic_compare_exchange_1"); + + function Sync_Compare_And_Swap_16 + (Ptr : Address; + Expected : uint16; + Desired : uint16) return uint16; + pragma Import (Intrinsic, + Sync_Compare_And_Swap_16, + "__sync_val_compare_and_swap_2"); + + function Sync_Compare_And_Swap_32 + (Ptr : Address; + Expected : uint32; + Desired : uint32) return uint32; + pragma Import (Intrinsic, + Sync_Compare_And_Swap_32, + "__sync_val_compare_and_swap_4"); + + function Sync_Compare_And_Swap_64 + (Ptr : Address; + Expected : uint64; + Desired : uint64) return uint64; + pragma Import (Intrinsic, + Sync_Compare_And_Swap_64, + "__sync_val_compare_and_swap_8"); + + -------------------------- + -- Lock-free operations -- + -------------------------- + + -- The lock-free implementation uses two atomic instructions for the + -- expansion of protected operations: + + -- * Lock_Free_Read_N atomically loads the value of the protected component + -- accessed by the current protected operation. + + -- * Lock_Free_Try_Write_N tries to write the Desired value into Ptr only + -- if Expected and Desired mismatch. + + function Lock_Free_Read_8 (Ptr : Address) return uint8; + + function Lock_Free_Read_16 (Ptr : Address) return uint16; + + function Lock_Free_Read_32 (Ptr : Address) return uint32; + + function Lock_Free_Read_64 (Ptr : Address) return uint64; + + function Lock_Free_Try_Write_8 + (Ptr : Address; + Expected : in out uint8; + Desired : uint8) return Boolean; + + function Lock_Free_Try_Write_16 + (Ptr : Address; + Expected : in out uint16; + Desired : uint16) return Boolean; + + function Lock_Free_Try_Write_32 + (Ptr : Address; + Expected : in out uint32; + Desired : uint32) return Boolean; + + function Lock_Free_Try_Write_64 + (Ptr : Address; + Expected : in out uint64; + Desired : uint64) return Boolean; + + pragma Inline (Lock_Free_Read_8); + pragma Inline (Lock_Free_Read_16); + pragma Inline (Lock_Free_Read_32); + pragma Inline (Lock_Free_Read_64); + pragma Inline (Lock_Free_Try_Write_8); + pragma Inline (Lock_Free_Try_Write_16); + pragma Inline (Lock_Free_Try_Write_32); + pragma Inline (Lock_Free_Try_Write_64); +end System.Atomic_Primitives; |