| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S Y S T E M . T A S K _ I N F O -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- $Revision: 1.3 $ |
| -- -- |
| -- 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. -- |
| -- It is now maintained by Ada Core Technologies Inc (http://www.gnat.com). -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- 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; |
