| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S Y S T E M . T A S K _ I N F O -- |
| -- -- |
| -- S p e c -- |
| -- (Compiler Interface) -- |
| -- -- |
| -- $Revision: 1.5 $ |
| -- -- |
| -- Copyright (C) 1998-2000 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, 59 Temple Place - Suite 330, Boston, -- |
| -- MA 02111-1307, 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. -- |
| -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- This is a DEC Unix 4.0d version of this package. |
| |
| -- This package contains the definitions and routines associated with the |
| -- implementation of the Task_Info pragma. |
| |
| -- Note: the compiler generates direct calls to this interface, via Rtsfind. |
| -- Any changes to this interface may require corresponding compiler changes. |
| |
| with Unchecked_Deallocation; |
| package System.Task_Info is |
| 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 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). |
| |
| type Task_Image_Type is access String; |
| -- Used to generate a meaningful identifier for tasks that are variables |
| -- and components of variables. |
| |
| procedure Free_Task_Image is new |
| Unchecked_Deallocation (String, Task_Image_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; |
