------------------------------------------------------------------------------ -- -- -- 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 -- -- . -- -- -- -- 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;