+++ /dev/null
-------------------------------------------------------------------------------
--- --
--- GNAT COMPILER COMPONENTS --
--- --
--- S Y S T E M . T A S K _ I N F O --
--- --
--- S p e c --
--- --
--- $Revision: 1.1.16.1 $
--- --
--- 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 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;