| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S Y S T E M . T A S K _ I N F O -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1992-2009, 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. |
| |
| 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 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; |
