95 lines
4.8 KiB
Ada
95 lines
4.8 KiB
Ada
------------------------------------------------------------------------------
|
|
-- --
|
|
-- GNAT COMPILER COMPONENTS --
|
|
-- --
|
|
-- S Y S T E M . T A S K _ I N F O --
|
|
-- --
|
|
-- S p e c --
|
|
-- --
|
|
-- Copyright (C) 1992-2005 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 2, 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. See the GNU General Public License --
|
|
-- for more details. You should have received a copy of the GNU General --
|
|
-- Public License distributed with GNAT; see file COPYING. If not, write --
|
|
-- 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, --
|
|
-- 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. --
|
|
-- --
|
|
-- GNAT was originally developed by the GNAT team at New York University. --
|
|
-- Extensive contributions were provided by Ada Core Technologies Inc. --
|
|
-- --
|
|
------------------------------------------------------------------------------
|
|
|
|
-- This package contains the definitions and routines associated with the
|
|
-- implementation and use of the Task_Info pragma. It is specialized
|
|
-- appropriately for targets that make use of this pragma.
|
|
|
|
-- Note: the compiler generates direct calls to this interface, via Rtsfind.
|
|
-- Any changes to this interface may require corresponding compiler changes.
|
|
|
|
-- This unit may be used directly from an application program by providing
|
|
-- an appropriate WITH, and the interface can be expected to remain stable.
|
|
|
|
package System.Task_Info is
|
|
pragma Preelaborate;
|
|
pragma Elaborate_Body;
|
|
-- To ensure that a body is allowed
|
|
|
|
-----------------------------------------
|
|
-- Implementation of Task_Info Feature --
|
|
-----------------------------------------
|
|
|
|
-- The Task_Info pragma:
|
|
|
|
-- pragma Task_Info (EXPRESSION);
|
|
|
|
-- allows the specification on a task by task basis of a value of type
|
|
-- System.Task_Info.Task_Info_Type to be passed to a task when it is
|
|
-- created. The specification of this type, and the effect on the task
|
|
-- that is created is target dependent.
|
|
|
|
-- The Task_Info pragma appears within a task definition (compare the
|
|
-- definition and implementation of pragma Priority). If no such pragma
|
|
-- appears, then the value Task_Info_Unspecified is passed. If a pragma
|
|
-- is present, then it supplies an alternative value. If the argument of
|
|
-- the pragma is a discriminant reference, then the value can be set on
|
|
-- a task by task basis by supplying the appropriate discriminant value.
|
|
|
|
-- Note that this means that the type used for Task_Info_Type must be
|
|
-- suitable for use as a discriminant (i.e. a scalar or access type).
|
|
|
|
------------------
|
|
-- Declarations --
|
|
------------------
|
|
|
|
type Scope_Type is
|
|
(Process_Scope,
|
|
-- Contend only with threads in same process
|
|
|
|
System_Scope,
|
|
-- Contend with all threads on same CPU
|
|
|
|
Default_Scope);
|
|
|
|
type Task_Info_Type is new Scope_Type;
|
|
-- Type used for passing information to task create call, using the
|
|
-- Task_Info pragma. This type may be specialized for individual
|
|
-- implementations, but it must be a type that can be used as a
|
|
-- discriminant (i.e. a scalar or access type).
|
|
|
|
Unspecified_Task_Info : constant Task_Info_Type := Default_Scope;
|
|
-- Value passed to task in the absence of a Task_Info pragma
|
|
|
|
end System.Task_Info;
|