| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S Y S T E M . T A S K _ I N F O -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- $Revision: 1.4 $ |
| -- -- |
| -- 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 SGI (libathread) specific 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 sprocs and sprocs to processors -- |
| --------------------------------------------------------- |
| |
| -- The SGI implementation of the GNU Low-Level Interface (GNULLI) |
| -- implements each Ada task as a Posix thread (Pthread). The SGI |
| -- Pthread library distributes threads across one or more processes |
| -- that are members of a common share group. Irix distributes |
| -- processes across the available CPUs on a given machine. The |
| -- pragma Task_Info provides the mechanism to control the distribution |
| -- of tasks to sprocs, and sprocs to processors. |
| |
| -- Each thread has a number of attributes that dictate it's scheduling. |
| -- These attributes are: |
| -- |
| -- Bound_To_Sproc: whether the thread is bound to a specific sproc |
| -- for its entire lifetime. |
| -- |
| -- Timeslice: Amount of time that a thread is allowed to execute |
| -- before the system yeilds control to another thread |
| -- of equal priority. |
| -- |
| -- Resource_Vector: A bitmask used to control the binding of threads |
| -- to sprocs. |
| -- |
| |
| -- Each share group process (sproc) |
| |
| -- 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). |
| |
| ---------------------- |
| -- Resource Vectors -- |
| ---------------------- |
| |
| -- <discussion> |
| |
| type Resource_Vector_T is array (0 .. 31) of Boolean; |
| pragma Pack (Resource_Vector_T); |
| |
| NO_RESOURCES : constant Resource_Vector_T := (others => False); |
| |
| generic |
| type Resource_T is (<>); -- Discrete type up to 32 entries |
| package Resource_Vector_Functions is |
| function "+"(R : Resource_T) |
| return Resource_Vector_T; |
| function "+"(R1, R2 : Resource_T) |
| return Resource_Vector_T; |
| function "+"(R : Resource_T; S : Resource_Vector_T) |
| return Resource_Vector_T; |
| function "+"(S : Resource_Vector_T; R : Resource_T) |
| return Resource_Vector_T; |
| function "+"(S1, S2 : Resource_Vector_T) |
| return Resource_Vector_T; |
| function "-"(S : Resource_Vector_T; R : Resource_T) |
| return Resource_Vector_T; |
| end Resource_Vector_Functions; |
| |
| ---------------------- |
| -- Sproc Attributes -- |
| ---------------------- |
| |
| subtype sproc_t is System.OS_Interface.sproc_t; |
| |
| subtype CPU_Number is Integer range -1 .. Integer'Last; |
| |
| ANY_CPU : constant CPU_Number := CPU_Number'First; |
| |
| -- |
| -- Specification of IRIX Non Degrading Priorities. |
| -- |
| -- WARNING: IRIX priorities have the reverse meaning of Ada priorities. |
| -- The lower the priority value, the greater the greater the |
| -- scheduling preference. |
| -- |
| -- See the schedctl(2) man page for a complete discussion of non-degrading |
| -- priorities. |
| -- |
| type Non_Degrading_Priority is range 0 .. 255; |
| |
| -- these priorities are higher than ALL normal user process priorities |
| NDPHIMAX : constant Non_Degrading_Priority := 30; |
| NDPHIMIN : constant Non_Degrading_Priority := 39; |
| |
| subtype NDP_High is Non_Degrading_Priority range NDPHIMAX .. NDPHIMIN; |
| |
| -- these priorities overlap normal user process priorities |
| NDPNORMMAX : constant Non_Degrading_Priority := 40; |
| NDPNORMMIN : constant Non_Degrading_Priority := 127; |
| |
| subtype NDP_Norm is Non_Degrading_Priority range NDPNORMMAX .. NDPNORMMIN; |
| |
| -- these priorities are below ALL normal user process priorities |
| NDPLOMAX : constant Non_Degrading_Priority := 128; |
| NDPLOMIN : constant Non_Degrading_Priority := 254; |
| |
| NDP_NONE : constant Non_Degrading_Priority := 255; |
| |
| subtype NDP_LOW is Non_Degrading_Priority range NDPLOMAX .. NDPLOMIN; |
| |
| type Page_Locking is |
| (NOLOCK, -- Do not lock pages in memory |
| PROCLOCK, -- Lock text and data segments into memory (process lock) |
| TXTLOCK, -- Lock text segment into memory (text lock) |
| DATLOCK -- Lock data segment into memory (data lock) |
| ); |
| |
| type Sproc_Attributes is |
| record |
| Sproc_Resources : Resource_Vector_T := NO_RESOURCES; |
| CPU : CPU_Number := ANY_CPU; |
| Resident : Page_Locking := NOLOCK; |
| NDPRI : Non_Degrading_Priority := NDP_NONE; |
| -- Sproc_Slice : Duration := 0.0; |
| -- Deadline_Period : Duration := 0.0; |
| -- Deadline_Alloc : Duration := 0.0; |
| |
| end record; |
| |
| Default_Sproc_Attributes : constant Sproc_Attributes := |
| (NO_RESOURCES, ANY_CPU, NOLOCK, NDP_NONE); |
| |
| function New_Sproc (Attr : Sproc_Attributes) return sproc_t; |
| function New_Sproc |
| (Sproc_Resources : Resource_Vector_T := NO_RESOURCES; |
| CPU : CPU_Number := ANY_CPU; |
| Resident : Page_Locking := NOLOCK; |
| NDPRI : Non_Degrading_Priority := NDP_NONE) |
| return sproc_t; |
| -- |
| -- Allocates a sproc_t controll structure and creates the |
| -- corresponding sproc. |
| -- |
| |
| Invalid_CPU_Number : exception; |
| Permission_Error : exception; |
| Sproc_Create_Error : exception; |
| |
| ----------------------- |
| -- Thread Attributes -- |
| ----------------------- |
| |
| type Thread_Attributes (Bound_To_Sproc : Boolean) is |
| record |
| Thread_Resources : Resource_Vector_T := NO_RESOURCES; |
| Thread_Timeslice : Duration := 0.0; |
| case Bound_To_Sproc is |
| when False => |
| null; |
| when True => |
| Sproc : sproc_t; |
| end case; |
| end record; |
| |
| Default_Thread_Attributes : constant Thread_Attributes := |
| (False, NO_RESOURCES, 0.0); |
| |
| function Unbound_Thread_Attributes |
| (Thread_Resources : Resource_Vector_T := NO_RESOURCES; |
| Thread_Timeslice : Duration := 0.0) |
| return Thread_Attributes; |
| |
| function Bound_Thread_Attributes |
| (Thread_Resources : Resource_Vector_T := NO_RESOURCES; |
| Thread_Timeslice : Duration := 0.0; |
| Sproc : sproc_t) |
| return Thread_Attributes; |
| |
| function Bound_Thread_Attributes |
| (Thread_Resources : Resource_Vector_T := NO_RESOURCES; |
| Thread_Timeslice : Duration := 0.0; |
| Sproc_Resources : Resource_Vector_T := NO_RESOURCES; |
| CPU : CPU_Number := ANY_CPU; |
| Resident : Page_Locking := NOLOCK; |
| NDPRI : Non_Degrading_Priority := NDP_NONE) |
| return Thread_Attributes; |
| |
| type Task_Info_Type is access all Thread_Attributes; |
| |
| function New_Unbound_Thread_Attributes |
| (Thread_Resources : Resource_Vector_T := NO_RESOURCES; |
| Thread_Timeslice : Duration := 0.0) |
| return Task_Info_Type; |
| |
| function New_Bound_Thread_Attributes |
| (Thread_Resources : Resource_Vector_T := NO_RESOURCES; |
| Thread_Timeslice : Duration := 0.0; |
| Sproc : sproc_t) |
| return Task_Info_Type; |
| |
| function New_Bound_Thread_Attributes |
| (Thread_Resources : Resource_Vector_T := NO_RESOURCES; |
| Thread_Timeslice : Duration := 0.0; |
| Sproc_Resources : Resource_Vector_T := NO_RESOURCES; |
| CPU : CPU_Number := ANY_CPU; |
| Resident : Page_Locking := NOLOCK; |
| NDPRI : Non_Degrading_Priority := NDP_NONE) |
| 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; |
