| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S Y S T E M . P O O L _ L O C A L -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 1992-2021, 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. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| with System.Memory; |
| |
| with Ada.Unchecked_Conversion; |
| |
| package body System.Pool_Local is |
| |
| package SSE renames System.Storage_Elements; |
| use type SSE.Storage_Offset; |
| |
| Pointer_Size : constant SSE.Storage_Offset := Address'Size / Storage_Unit; |
| Pointers_Size : constant SSE.Storage_Offset := 2 * Pointer_Size; |
| |
| type Acc_Address is access all Address; |
| function To_Acc_Address is |
| new Ada.Unchecked_Conversion (Address, Acc_Address); |
| |
| ----------------------- |
| -- Local Subprograms -- |
| ----------------------- |
| |
| function Next (A : Address) return Acc_Address; |
| pragma Inline (Next); |
| -- Given an address of a block, return an access to the next block |
| |
| function Prev (A : Address) return Acc_Address; |
| pragma Inline (Prev); |
| -- Given an address of a block, return an access to the previous block |
| |
| -------------- |
| -- Allocate -- |
| -------------- |
| |
| procedure Allocate |
| (Pool : in out Unbounded_Reclaim_Pool; |
| Address : out System.Address; |
| Storage_Size : SSE.Storage_Count; |
| Alignment : SSE.Storage_Count) |
| is |
| pragma Warnings (Off, Alignment); |
| |
| Allocated : constant System.Address := |
| Memory.Alloc |
| (Memory.size_t (Storage_Size + Pointers_Size)); |
| |
| begin |
| -- The call to Alloc returns an address whose alignment is compatible |
| -- with the worst case alignment requirement for the machine; thus the |
| -- Alignment argument can be safely ignored. |
| |
| if Allocated = Null_Address then |
| raise Storage_Error; |
| else |
| Address := Allocated + Pointers_Size; |
| Next (Allocated).all := Pool.First; |
| Prev (Allocated).all := Null_Address; |
| |
| if Pool.First /= Null_Address then |
| Prev (Pool.First).all := Allocated; |
| end if; |
| |
| Pool.First := Allocated; |
| end if; |
| end Allocate; |
| |
| ---------------- |
| -- Deallocate -- |
| ---------------- |
| |
| procedure Deallocate |
| (Pool : in out Unbounded_Reclaim_Pool; |
| Address : System.Address; |
| Storage_Size : SSE.Storage_Count; |
| Alignment : SSE.Storage_Count) |
| is |
| pragma Warnings (Off, Storage_Size); |
| pragma Warnings (Off, Alignment); |
| |
| Allocated : constant System.Address := Address - Pointers_Size; |
| |
| begin |
| if Prev (Allocated).all = Null_Address then |
| Pool.First := Next (Allocated).all; |
| |
| -- Comment needed |
| |
| if Pool.First /= Null_Address then |
| Prev (Pool.First).all := Null_Address; |
| end if; |
| else |
| Next (Prev (Allocated).all).all := Next (Allocated).all; |
| end if; |
| |
| if Next (Allocated).all /= Null_Address then |
| Prev (Next (Allocated).all).all := Prev (Allocated).all; |
| end if; |
| |
| Memory.Free (Allocated); |
| end Deallocate; |
| |
| -------------- |
| -- Finalize -- |
| -------------- |
| |
| procedure Finalize (Pool : in out Unbounded_Reclaim_Pool) is |
| N : System.Address := Pool.First; |
| Allocated : System.Address; |
| |
| begin |
| while N /= Null_Address loop |
| Allocated := N; |
| N := Next (N).all; |
| Memory.Free (Allocated); |
| end loop; |
| end Finalize; |
| |
| ---------- |
| -- Next -- |
| ---------- |
| |
| function Next (A : Address) return Acc_Address is |
| begin |
| return To_Acc_Address (A); |
| end Next; |
| |
| ---------- |
| -- Prev -- |
| ---------- |
| |
| function Prev (A : Address) return Acc_Address is |
| begin |
| return To_Acc_Address (A + Pointer_Size); |
| end Prev; |
| |
| end System.Pool_Local; |
