------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S Y S T E M . T A S K _ I N F O -- -- -- -- S p e c -- -- -- -- -- -- Copyright (C) 1992-2000 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. -- -- Extensive contributions were provided by Ada Core Technologies Inc. -- -- -- ------------------------------------------------------------------------------ -- This package contains the definitions and routines associated with the -- implementation of the Task_Info pragma. -- This is the Solaris (native) version of this module. with System.OS_Interface; with Unchecked_Deallocation; package System.Task_Info is pragma Elaborate_Body; -- To ensure that a body is allowed ----------------------------------------------------- -- Binding of Tasks to LWPs and LWPs to processors -- ----------------------------------------------------- -- The Solaris implementation of the GNU Low-Level Interface (GNULLI) -- implements each Ada task as a Solaris thread. The Solaris thread -- library distributes threads across one or more LWPs (Light Weight -- Process) that are members of the same process. Solaris distributes -- processes and LWPs across the available CPUs on a given machine. The -- pragma Task_Info provides the mechanism to control the distribution -- of tasks to LWPs, and LWPs to processors. -- Each thread has a number of attributes that dictate it's scheduling. -- These attributes are: -- -- New_LWP: whether a new LWP is created for this thread. -- -- Bound_To_LWP: whether the thread is bound to a specific LWP -- for its entire lifetime. -- -- CPU: the CPU number associated to the LWP -- -- 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). ----------------------- -- Thread Attributes -- ----------------------- subtype CPU_Number is System.OS_Interface.processorid_t; CPU_UNCHANGED : constant CPU_Number := System.OS_Interface.PBIND_QUERY; -- Do not bind the LWP to a specific processor ANY_CPU : constant CPU_Number := System.OS_Interface.PBIND_NONE; -- Bind the LWP to any processor Invalid_CPU_Number : exception; type Thread_Attributes (New_LWP : Boolean) is record Bound_To_LWP : Boolean := True; case New_LWP is when False => null; when True => CPU : CPU_Number := CPU_UNCHANGED; end case; end record; Default_Thread_Attributes : constant Thread_Attributes := (False, True); function Unbound_Thread_Attributes return Thread_Attributes; function Bound_Thread_Attributes return Thread_Attributes; function Bound_Thread_Attributes (CPU : CPU_Number) return Thread_Attributes; type Task_Info_Type is access all Thread_Attributes; function New_Unbound_Thread_Attributes return Task_Info_Type; function New_Bound_Thread_Attributes return Task_Info_Type; function New_Bound_Thread_Attributes (CPU : CPU_Number) return Task_Info_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_Task_Info : constant Task_Info_Type := null; end System.Task_Info;