------------------------------------------------------------------------------ -- -- -- 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) 1998-2003 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. -- -- 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 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). 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;