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------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S Y S T E M . T A S K _ I N F O --
-- --
-- S p e c --
-- (Compiler Interface) --
-- --
-- Copyright (C) 1998-2009, 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 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 --
-- <http://www.gnu.org/licenses/>. --
-- --
-- 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.
-- This is a DEC Unix 4.0d version of this package
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 Unspecified_Task_Info 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 Thread_Attributes is record
Bind_To_Cpu_Number : Integer;
-- -1: Do nothing
-- 0: Unbind
-- 1-N: Bind all unbound threads to this CPU
Contention_Scope : Scope_Type;
end record;
type Task_Info_Type is access all Thread_Attributes;
-- 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_Thread_Attribute : aliased Thread_Attributes :=
Thread_Attributes'(-1, Default_Scope);
Unspecified_Task_Info : constant Task_Info_Type :=
Unspecified_Thread_Attribute'Access;
-- Value passed to task in the absence of a Task_Info pragma
-- Don't call new here because the tasking run time has not been
-- elaborated yet, so calling Task_Lock is unsafe.
end System.Task_Info;
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