------------------------------------------------------------------------------ -- -- -- GNAT 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 -- -- -- -- Copyright (C) 1991-1994, Florida State University -- -- Copyright (C) 1995-2013, AdaCore -- -- -- -- 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 -- -- . -- -- -- -- GNARL was developed by the GNARL team at Florida State University. -- -- Extensive contributions were provided by Ada Core Technologies, Inc. -- -- -- ------------------------------------------------------------------------------ with Ada.Unchecked_Conversion; with System.Task_Primitives.Operations; with System.Tasking.Initialization; package body System.Tasking.Task_Attributes is use Task_Primitives.Operations; use Tasking.Initialization; function To_Access_Address is new Ada.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; Self_Id : constant Task_Id := Self; begin -- Defer abort. Note that we use the nestable versions of Defer_Abort -- and Undefer_Abort, because abort can already deferred when this is -- called during finalization, which would cause an assert failure -- in Defer_Abort. Defer_Abort_Nestable (Self_Id); Lock_RTS; -- 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. 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 RTS_Lock Q.Next := To_Be_Freed; To_Be_Freed := Q; end if; Unlock (C); C := C.Common.All_Tasks_Link; end loop; end; end if; Unlock_RTS; while To_Be_Freed /= null loop Q := To_Be_Freed; To_Be_Freed := To_Be_Freed.Next; X.Deallocate.all (Q); end loop; Undefer_Abort_Nestable (Self_Id); 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.Tasking.Stages.Create_Task procedure Initialize_Attributes (T : Task_Id) is P : Access_Instance; Self_Id : constant Task_Id := Self; begin -- Note: we call [Un]Defer_Abort_Nestable, rather than [Un]Defer_Abort, -- because Abort might already be deferred in Create_Task. Defer_Abort_Nestable (Self_Id); Lock_RTS; -- 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) := Direct_Attribute_Element (System.Storage_Elements.To_Address (P.Initial_Value)); end if; P := P.Next; end loop; Unlock_RTS; Undefer_Abort_Nestable (Self_Id); exception when others => null; pragma Assert (False); end Initialize_Attributes; end System.Tasking.Task_Attributes;