------------------------------------------------------------------------------ -- -- -- GNU ADA RUNTIME LIBRARY (GNARL) COMPONENTS -- -- -- -- S Y S T E M . T A S K I N G -- -- -- -- S p e c -- -- -- -- $Revision: 1.12 $ -- -- -- -- Copyright (c) 1991,1992,1993, FSU, All Rights Reserved -- -- -- -- GNARL is free software; you can redistribute it and/or modify it under -- -- terms of the GNU Library General Public License as published by the -- -- Free Software Foundation; either version 2, or (at your option) any -- -- later version. GNARL is distributed in the hope that it will be use- -- -- ful, but but WITHOUT ANY WARRANTY; without even the implied warranty of -- -- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Gen- -- -- eral Library Public License for more details. You should have received -- -- a copy of the GNU Library General Public License along with GNARL; see -- -- file COPYING. If not, write to the Free Software Foundation, 675 Mass -- -- Ave, Cambridge, MA 02139, USA. -- -- -- ------------------------------------------------------------------------------ -- This package provides necessary type definitions for compiler interface. with System.Task_Primitives; -- Used for, Task_Primitives.Lock with System.Compiler_Exceptions; -- Used for, Exception_ID package System.Tasking is -- Task_ID related definitions type Task_ID is private; Null_Task : constant Task_ID; function Self return Task_ID; pragma Inline (Self); -- Task size, initial_state and interrupt info. type Task_Procedure_Access is access procedure (Arg : System.Address); type Task_Storage_Size is new integer; type Interrupt_ID is range 0 .. 31; -- Some Constants Null_Entry : constant := 0; Max_Entry : constant := System.Max_Int; Interrupt_Entry : constant := -2; Cancelled_Entry : constant := -1; type Entry_Index is range Interrupt_Entry .. Max_Entry; -- PO related definitions Null_Protected_Entry : constant := Null_Entry; Max_Protected_Entry : constant := Max_Entry; type Protected_Entry_Index is new Entry_Index range Null_Protected_Entry .. Max_Protected_Entry; subtype Positive_Protected_Entry_Index is Protected_Entry_Index range 1 .. Protected_Entry_Index'Last; type Call_Modes is (Simple_Call, Conditional_Call, Asynchronous_Call); -- definition for Protecton has to be private. But, currently -- generates gnat internal error. type Protection (Num_Entries : Protected_Entry_Index) is private; type Protection_Access is access Protection; type Communication_Block is private; type Barrier_Vector is array (Protected_Entry_Index range <>) of Boolean; -- Rendezvous related definitions Null_Task_Entry : constant := Null_Entry; Max_Task_Entry : constant := Max_Entry; type Task_Entry_Index is new Entry_Index range Null_Task_Entry .. Max_Task_Entry; No_Rendezvous : constant := 0; Max_Select : constant Integer := Integer'Last; -- RTS-defined subtype Select_Index is Integer range No_Rendezvous .. Max_Select; -- type Select_Index is range No_Rendezvous .. Max_Select; subtype Positive_Select_Index is Select_Index range 1 .. Select_Index'Last; type Accept_Alternative is record -- should be packed Null_Body : Boolean; S : Task_Entry_Index; end record; type Accept_List is array (Positive_Select_Index range <>) of Accept_Alternative; type Accept_List_Access is access constant Accept_List; type Select_Modes is ( Simple_Mode, Else_Mode, Terminate_Mode); -- Abortion related declarations Max_ATC_Nesting : constant Natural := 20; type Task_List is array (Positive range <>) of Task_ID; -- Task_Stage related types type Master_ID is private; type Access_Boolean is access Boolean; type Size_Type is new Task_Storage_Size; Unspecified_Size : constant Size_Type := Size_Type'First; type Activation_Chain is limited private; type Activation_Chain_Access is access all Activation_Chain; Unspecified_Priority : constant Integer := System.Priority'First - 1; ------------------------------------- -- This part should go to s-taruty.ads when we can move queuing related -- stuffs to s-tasque.ad? subtype ATC_Level_Base is Integer range 0 .. Max_ATC_Nesting; ATC_Level_Infinity : constant ATC_Level_Base := ATC_Level_Base'Last; subtype ATC_Level is ATC_Level_Base range ATC_Level_Base'First .. ATC_Level_Base'Last - 1; subtype ATC_Level_Index is ATC_Level range ATC_Level'First + 1 .. ATC_Level'Last; ----------------------------------------- -- This part should go to private part right before the type Protection. Priority_Not_Boosted : constant Integer := System.Priority'First - 1; subtype Rendezvous_Priority is Integer range Priority_Not_Boosted .. System.Priority'Last; type Entry_Call_Record; type Entry_Call_Link is access Entry_Call_Record; type Entry_Queue is record Head : Entry_Call_Link; Tail : Entry_Call_Link; end record; type Entry_Call_Record is record Prev : Entry_Call_Link; Next : Entry_Call_Link; Call_Claimed : Boolean; -- This flag is True if the call has been queued -- and subsequently claimed -- for service or cancellation. -- Protection : Test_And_Set/gloabal update or some similar mechanism -- (e.g. global mutex). -- Caution : on machines were we use Test_And_Set, we may not want this -- field packed. For example, the SPARC atomic ldsub instruction -- effects a whole byte. Self : Task_ID; Level : ATC_Level; -- One of Self and Level are redundent in this implementation, since -- each Entry_Call_Record is at Self.Entry_Calls (Level). Since we must -- have access to the entry call record to be reading this, we could -- get Self from Level, or Level from Self. However, this requires -- non-portable address arithmetic. Mode : Call_Modes; Abortable : Boolean; Done : Boolean; -- Protection : Self.L. E : Entry_Index; Prio : System.Any_Priority; -- The above fields are those that there may be some hope of packing. -- They are gathered together to allow for compilers that lay records -- out contigously, to allow for such packing. Uninterpreted_Data : System.Address; Exception_To_Raise : Compiler_Exceptions.Exception_ID; -- The exception to raise once this call has been completed without -- being aborted. -- Server : Server_Record; Called_Task : Task_ID; -- For task entry calls only. Acceptor_Prev_Call : Entry_Call_Link; -- For task entry calls only. Acceptor_Prev_Priority : Rendezvous_Priority; -- For task entry calls only. -- The priority of the most recent prior call being serviced. -- For protected entry calls, this function should be performed by -- GNULLI ceiling locking. -- Called_PO : Protection_Access; -- Compiler bug when compiler queue package as child. -- Work-around: declare access type as System.Address cast types. Called_PO : System.Address; -- For protected entry calls only. end record; type Protected_Entry_Queue_Array is array (Protected_Entry_Index range <>) of Entry_Queue; ---------------------------------- private type Dummy is new Integer; type Task_ID is access Dummy; Null_Task : constant Task_ID := null; type Activation_Chain is new Task_ID; type Master_ID is new Integer; type Communication_Block is record Self : Task_ID; end record; type Protection (Num_Entries : Protected_Entry_Index) is record L : Task_Primitives.Lock; Pending_Call : Entry_Call_Link; Call_In_Progress : Entry_Call_Link; Ceiling : System.Priority; Old_Base_Priority : System.Priority; Pending_Action : Boolean; Entry_Queues : Protected_Entry_Queue_Array (1 .. Num_Entries); end record; end System.Tasking; ---------------------- -- REVISION HISTORY -- ---------------------- -- ---------------------------- -- revision 1.10 -- date: Fri Jul 15 17:54:13 1994; author: giering -- Name Change: Init_State => Task_Procedure_Access -- Checked in from FSU by doh. -- ---------------------------- -- revision 1.11 -- date: Fri Jul 22 08:54:30 1994; author: giering -- Made Protection private type. -- Checked in from FSU by doh. -- ---------------------------- -- revision 1.12 -- date: Wed Aug 3 14:55:02 1994; author: giering -- Definition of Activation_Chain_Access type -- Checked in from FSU by doh. -- ---------------------------- -- New changes after this line. Each line starts with: "-- "