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------------------------------------------------------------------------------
-- --
-- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
-- --
-- S Y S T E M . T A S K I N G . T A S K _ A T T R I B U T E S --
-- --
-- B o d y --
-- --
-- $Revision: 1.14 $
-- --
-- Copyright (C) 1995-1999 Florida State University --
-- --
-- GNARL 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 2, or (at your option) any later ver- --
-- sion. GNARL 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. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNARL; see file COPYING. If not, write --
-- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
-- MA 02111-1307, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- GNARL was developed by the GNARL team at Florida State University. It is --
-- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
-- State University (http://www.gnat.com). --
-- --
------------------------------------------------------------------------------
with System.Storage_Elements;
-- used for To_Address
with System.Task_Primitives.Operations;
-- used for Write_Lock
-- Unlock
-- Lock/Unlock_All_Tasks_List
with System.Tasking.Initialization;
-- used for Defer_Abort
-- Undefer_Abort
with Unchecked_Conversion;
package body System.Tasking.Task_Attributes is
use Task_Primitives.Operations,
System.Tasking.Initialization;
function To_Access_Node is new Unchecked_Conversion
(Access_Address, Access_Node);
-- Tetch pointer to indirect attribute list
function To_Access_Address is new Unchecked_Conversion
(Access_Node, Access_Address);
-- Store pointer to indirect attribute list
--------------
-- Finalize --
--------------
procedure Finalize (X : in out Instance) is
Q, To_Be_Freed : Access_Node;
begin
Defer_Abortion;
Write_Lock (All_Attrs_L'Access);
-- Remove this instantiation from the list of all instantiations.
declare
P : Access_Instance;
Q : Access_Instance := All_Attributes;
begin
while Q /= null and then Q /= X'Unchecked_Access loop
P := Q; Q := Q.Next;
end loop;
pragma Assert (Q /= null);
if P = null then
All_Attributes := Q.Next;
else
P.Next := Q.Next;
end if;
end;
if X.Index /= 0 then
-- Free location of this attribute, for reuse.
In_Use := In_Use and not (2**Natural (X.Index));
-- There is no need for finalization in this case,
-- since controlled types are too big to fit in the TCB.
else
-- Remove nodes for this attribute from the lists of
-- all tasks, and deallocate the nodes.
-- Deallocation does finalization, if necessary.
Lock_All_Tasks_List;
declare
C : System.Tasking.Task_ID := All_Tasks_List;
P : Access_Node;
begin
while C /= null loop
Write_Lock (C);
Q := To_Access_Node (C.Indirect_Attributes);
while Q /= null
and then Q.Instance /= X'Unchecked_Access
loop
P := Q;
Q := Q.Next;
end loop;
if Q /= null then
if P = null then
C.Indirect_Attributes := To_Access_Address (Q.Next);
else
P.Next := Q.Next;
end if;
-- Can't Deallocate now since we are holding the All_Tasks_L
-- lock.
Q.Next := To_Be_Freed;
To_Be_Freed := Q;
end if;
Unlock (C);
C := C.Common.All_Tasks_Link;
end loop;
end;
Unlock_All_Tasks_List;
end if;
Unlock (All_Attrs_L'Access);
while To_Be_Freed /= null loop
Q := To_Be_Freed;
To_Be_Freed := To_Be_Freed.Next;
X.Deallocate.all (Q);
end loop;
Undefer_Abortion;
exception
when others => null;
pragma Assert (False,
"Exception in task attribute instance finalization");
end Finalize;
-------------------------
-- Finalize Attributes --
-------------------------
-- This is to be called just before the ATCB is deallocated.
-- It relies on the caller holding T.L write-lock on entry.
procedure Finalize_Attributes (T : Task_ID) is
P : Access_Node;
Q : Access_Node := To_Access_Node (T.Indirect_Attributes);
begin
-- Deallocate all the indirect attributes of this task.
while Q /= null loop
P := Q;
Q := Q.Next; P.Instance.Deallocate.all (P);
end loop;
T.Indirect_Attributes := null;
exception
when others => null;
pragma Assert (False,
"Exception in per-task attributes finalization");
end Finalize_Attributes;
---------------------------
-- Initialize Attributes --
---------------------------
-- This is to be called by System.Task_Stages.Create_Task.
-- It relies on their being no concurrent access to this TCB,
-- so it does not defer abortion or lock T.L.
procedure Initialize_Attributes (T : Task_ID) is
P : Access_Instance;
begin
Write_Lock (All_Attrs_L'Access);
-- Initialize all the direct-access attributes of this task.
P := All_Attributes;
while P /= null loop
if P.Index /= 0 then
T.Direct_Attributes (P.Index) :=
System.Storage_Elements.To_Address (P.Initial_Value);
end if;
P := P.Next;
end loop;
Unlock (All_Attrs_L'Access);
exception
when others => null;
pragma Assert (False);
end Initialize_Attributes;
end System.Tasking.Task_Attributes;
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