------------------------------------------------------------------------------
-- --
--- 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) 1992-1999, 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, --
-- covered by the GNU Public License. --
-- --
-- GNARL was developed by the GNARL team at Florida State University. --
--- Extensive contributions were provided by Ada Core Technologies Inc. --
+-- Extensive contributions were provided by Ada Core Technologies, Inc. --
-- --
------------------------------------------------------------------------------
pragma Elaborate_Body;
-- The compiler will expand in the GNAT tree the following construct:
- --
+
-- task type T (Discr : Integer);
- --
+
-- task body T is
-- ...declarations, possibly some controlled...
-- begin
-- ...B...;
-- end T;
- --
+
-- T1 : T (1);
- --
+
-- as follows:
- --
+
-- enter_master.all;
- --
+
-- _chain : aliased activation_chain;
- -- _init_proc (_chain);
- --
+ -- activation_chainIP (_chain);
+
-- task type t (discr : integer);
-- tE : aliased boolean := false;
-- tZ : size_type := unspecified_size;
-- end record;
-- procedure tB (_task : access tV);
-- freeze tV [
- -- procedure _init_proc (_init : in out tV; _master : master_id;
+ -- procedure tVIP (_init : in out tV; _master : master_id;
-- _chain : in out activation_chain; _task_id : in task_image_type;
-- discr : integer) is
-- begin
-- _init'address, tE'unchecked_access, _chain, _task_id, _init.
-- _task_id);
-- return;
- -- end _init_proc;
+ -- end tVIP;
-- ]
- --
+
-- procedure tB (_task : access tV) is
-- discr : integer renames _task.discr;
- --
+
-- procedure _clean is
-- begin
-- abort_defer.all;
-- at end
-- _clean;
-- end tB;
- --
+
-- tE := true;
-- t1 : t (1);
- -- master : constant master_id := current_master.all;
- -- t1I : task_image_type := new string'"t1";
- -- _init_proc (t1, _master, _chain, t1I, 1);
- --
+ -- _master : constant master_id := current_master.all;
+ -- t1S : task_image_type := new string'"t1";
+ -- task_image_typeIP (t1, _master, _chain, t1S, 1);
+
-- activate_tasks (_chain'unchecked_access);
procedure Abort_Tasks (Tasks : Task_List);
- -- Compiler interface only. Do not call from within the RTS.
- -- Initiate abortion, however, the actual abortion is done by abortee by
- -- means of Abort_Handler and Abort_Undefer
+ -- Compiler interface only. Do not call from within the RTS. Initiate
+ -- abort, however, the actual abort is done by abortee by means of
+ -- Abort_Handler and Abort_Undefer
--
-- source code:
-- Abort T1, T2;
-- 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.
Discriminants : System.Address;
Elaborated : Access_Boolean;
Chain : in out Activation_Chain;
- Task_Image : System.Task_Info.Task_Image_Type;
- Created_Task : out Task_ID);
+ Task_Image : String;
+ Created_Task : out Task_Id);
-- Compiler interface only. Do not call from within the RTS.
-- This must be called to create a new task.
--
-- are those of the task to create. This parameter should be passed as
-- the single argument to State.
-- Elaborated is a pointer to a Boolean that must be set to true on exit
- -- if the task could be successfully elaborated.
+ -- if the task could be sucessfully elaborated.
-- Chain is a linked list of task that needs to be created. On exit,
-- Created_Task.Activation_Link will be Chain.T_ID, and Chain.T_ID
-- will be Created_Task (e.g the created task will be linked at the front
-- of Chain).
- -- Task_Image is a pointer to a string created by the compiler that the
+ -- Task_Image is a string created by the compiler that the
-- run time can store to ease the debugging and the
-- Ada.Task_Identification facility.
-- Created_Task is the resulting task.
-- declared.
procedure Expunge_Unactivated_Tasks (Chain : in out Activation_Chain);
- -- Compiler interface only. Do not call from within the RTS.
+ -- Compiler interface only. Do not call from within the RTS.
-- This must be called by the compiler-generated code for an allocator if
-- the allocated object contains tasks, if the allocator exits without
-- calling Activate_Tasks for a given activation chains, as can happen if
-- It currently also executes the global finalization list, and then resets
-- the "soft links".
- procedure Free_Task (T : Task_ID);
+ procedure Free_Task (T : Task_Id);
-- Recover all runtime system storage associated with the task T, but only
-- if T has terminated. Do nothing in the other case. It is called from
-- Unchecked_Deallocation, for objects that are or contain tasks.
- function Terminated (T : Task_ID) return Boolean;
+ 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
-- with the task's ATCB, so that this is more useful for polling the state
-- code expansion:
-- terminated (t1._task_id)
+ procedure Terminate_Task (Self_ID : Task_Id);
+ -- Terminate the calling task.
+ -- This should only be called by the Task_Wrapper procedure, and to
+ -- deallocate storage associate with foreign tasks.
+
end System.Tasking.Stages;
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