------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S Y S T E M . T A S K _ I N F O -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992-2004 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 the SGI (libathread) specific version of this module. with System.OS_Interface; 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 : Resource_T; 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 : Resource_Vector_T; 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; type Non_Degrading_Priority is range 0 .. 255; -- 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. NDPHIMAX : constant Non_Degrading_Priority := 30; NDPHIMIN : constant Non_Degrading_Priority := 39; -- These priorities are higher than ALL normal user process priorities subtype NDP_High is Non_Degrading_Priority range NDPHIMAX .. NDPHIMIN; NDPNORMMAX : constant Non_Degrading_Priority := 40; NDPNORMMIN : constant Non_Degrading_Priority := 127; -- These priorities overlap normal user process priorities subtype NDP_Norm is Non_Degrading_Priority range NDPNORMMAX .. NDPNORMMIN; NDPLOMAX : constant Non_Degrading_Priority := 128; NDPLOMIN : constant Non_Degrading_Priority := 254; -- These priorities are below ALL normal user process priorities 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; -- ??? why is that commented out, should it be removed ? -- 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 control 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; Unspecified_Task_Info : constant Task_Info_Type := null; end System.Task_Info;