------------------------------------------------------------------------------
-- --
--- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
+-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
-- --
-- S Y S T E M . T A S K I N G . S T A G E S --
-- --
-- S p e c --
-- --
--- Copyright (C) 1992-2005, Free Software Foundation, Inc. --
+-- Copyright (C) 1992-2006, Free Software Foundation, Inc. --
-- --
-- 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- --
-- 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. --
+-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
+-- Boston, MA 02110-1301, 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, --
-- it is not needed if priority-based scheduling is supported, since all
-- the activated tasks synchronize on the activators lock before they
-- start activating and so they should start activating in priority order.
+ -- ??? Actually, the body of this package DOES reverse the chain, so I
+ -- don't understand the above comment.
procedure Complete_Activation;
-- Compiler interface only. Do not call from within the RTS.
-- if T has terminated. Do nothing in the other case. It is called from
-- Unchecked_Deallocation, for objects that are or contain tasks.
+ procedure Move_Activation_Chain
+ (From, To : Activation_Chain_Access;
+ New_Master : Master_ID);
+ -- Compiler interface only. Do not call from within the RTS.
+ -- Move all tasks on From list to To list, and change their Master_of_Task
+ -- to be New_Master. This is used to implement build-in-place function
+ -- returns. Tasks that are part of the return object are initially placed
+ -- on an activation chain local to the return statement, and their master
+ -- is the return statement, in case the return statement is left
+ -- prematurely (due to raising an exception, being aborted, or a goto or
+ -- exit statement). Once the return statement has completed successfully,
+ -- Move_Activation_Chain is called to move them to the caller's activation
+ -- chain, and change their master to the one passed in by the caller. If
+ -- that doesn't happen, they will never be activated, and will become
+ -- terminated on leaving the return statement.
+
function Terminated (T : Task_Id) return Boolean;
-- This is called by the compiler to implement the 'Terminated attribute.
-- Though is not required to be so by the ARM, we choose to synchronize
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