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------------------------------------------------------------------------------
-- --
-- GNAT LIBRARY COMPONENTS --
-- --
-- A D A . C O N T A I N E R S . H E L P E R S --
-- --
-- B o d y --
-- --
-- Copyright (C) 2015-2022, 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/>. --
------------------------------------------------------------------------------
package body Ada.Containers.Helpers is
Max_Count : constant := 2**31 - 1;
-- Used in assertions below, to make sure the counts don't wrap around.
-- This can help detect bugs in which Adjust and Finalize calls are
-- improperly generated. An extra Decrement could otherwise cause
-- wraparound from 0 to 2**32-1. The highest count seen so far is
-- around 25, so this should be plenty.
package body Generic_Implementation is
use type SAC.Atomic_Unsigned;
------------
-- Adjust --
------------
procedure Adjust (Control : in out Reference_Control_Type) is
begin
if Control.T_Counts /= null then
Busy (Control.T_Counts.all);
end if;
end Adjust;
----------
-- Busy --
----------
procedure Busy (T_Counts : in out Tamper_Counts) is
begin
if T_Check then
SAC.Increment (T_Counts.Busy);
pragma Assert (T_Counts.Busy <= Max_Count);
end if;
end Busy;
--------------
-- Finalize --
--------------
procedure Finalize (Control : in out Reference_Control_Type) is
begin
if Control.T_Counts /= null then
Unbusy (Control.T_Counts.all);
Control.T_Counts := null;
end if;
end Finalize;
-- No need to protect against double Finalize here, because these types
-- are limited.
procedure Finalize (Busy : in out With_Busy) is
pragma Warnings (Off);
pragma Assert (T_Check); -- not called if check suppressed
pragma Warnings (On);
begin
Unbusy (Busy.T_Counts.all);
end Finalize;
procedure Finalize (Lock : in out With_Lock) is
pragma Warnings (Off);
pragma Assert (T_Check); -- not called if check suppressed
pragma Warnings (On);
begin
Unlock (Lock.T_Counts.all);
end Finalize;
----------------
-- Initialize --
----------------
procedure Initialize (Busy : in out With_Busy) is
pragma Warnings (Off);
pragma Assert (T_Check); -- not called if check suppressed
pragma Warnings (On);
begin
Generic_Implementation.Busy (Busy.T_Counts.all);
end Initialize;
procedure Initialize (Lock : in out With_Lock) is
pragma Warnings (Off);
pragma Assert (T_Check); -- not called if check suppressed
pragma Warnings (On);
begin
Generic_Implementation.Lock (Lock.T_Counts.all);
end Initialize;
----------
-- Lock --
----------
procedure Lock (T_Counts : in out Tamper_Counts) is
begin
if T_Check then
SAC.Increment (T_Counts.Lock);
pragma Assert (T_Counts.Lock <= Max_Count);
SAC.Increment (T_Counts.Busy);
pragma Assert (T_Counts.Busy <= Max_Count);
end if;
end Lock;
--------------
-- TC_Check --
--------------
procedure TC_Check (T_Counts : Tamper_Counts) is
begin
if T_Check then
if T_Counts.Busy > 0 then
raise Program_Error with
"attempt to tamper with cursors";
end if;
-- The lock status (which monitors "element tampering") always
-- implies that the busy status (which monitors "cursor
-- tampering") is set too; this is a representation invariant.
-- Thus if the busy count is zero, then the lock count
-- must also be zero.
pragma Assert (T_Counts.Lock = 0);
end if;
end TC_Check;
--------------
-- TE_Check --
--------------
procedure TE_Check (T_Counts : Tamper_Counts) is
begin
if T_Check and then T_Counts.Lock > 0 then
raise Program_Error with
"attempt to tamper with elements";
end if;
end TE_Check;
------------
-- Unbusy --
------------
procedure Unbusy (T_Counts : in out Tamper_Counts) is
begin
if T_Check then
SAC.Decrement (T_Counts.Busy);
pragma Assert (T_Counts.Busy <= Max_Count);
end if;
end Unbusy;
------------
-- Unlock --
------------
procedure Unlock (T_Counts : in out Tamper_Counts) is
begin
if T_Check then
SAC.Decrement (T_Counts.Lock);
pragma Assert (T_Counts.Lock <= Max_Count);
SAC.Decrement (T_Counts.Busy);
pragma Assert (T_Counts.Busy <= Max_Count);
end if;
end Unlock;
-----------------
-- Zero_Counts --
-----------------
procedure Zero_Counts (T_Counts : out Tamper_Counts) is
begin
if T_Check then
T_Counts := (others => <>);
end if;
end Zero_Counts;
end Generic_Implementation;
end Ada.Containers.Helpers;