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-- --
-- --
-- S Y S T E M . I N T E R R U P T _ M A N A G E M E N T --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2003 Free Software Foundation, Inc. --
-- --
-- GNARL 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. GNARL 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 GNARL; 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. --
-- --
-- GNARL was developed by the GNARL team at Florida State University. --
-- Extensive contributions were provided by Ada Core Technologies, Inc. --
-- --
-- This package encapsulates and centralizes information about all
-- uses of interrupts (or signals), including the target-dependent
-- mapping of interrupts (or signals) to exceptions.
-- Unlike the original design, System.Interrupt_Management can only
-- be used for tasking systems.
-- PLEASE DO NOT remove the Elaborate_Body pragma from this package.
-- Elaboration of this package should happen early, as most other
-- initializations depend on it. Forcing immediate elaboration of
-- the body also helps to enforce the design assumption that this
-- is a second-level package, just one level above System.OS_Interface
-- with no cross-dependencies.
-- PLEASE DO NOT put any subprogram declarations with arguments of
-- type Interrupt_ID into the visible part of this package. The type
-- Interrupt_ID is used to derive the type in Ada.Interrupts, and
-- adding more operations to that type would be illegal according
-- to the Ada Reference Manual. This is the reason why the signals
-- sets are implemeneted using visible arrays rather than functions.
with System.OS_Interface;
-- used for sigset_t
with Interfaces.C;
-- used for int
package System.Interrupt_Management is
pragma Elaborate_Body;
type Interrupt_Mask is limited private;
type Interrupt_ID is new
range 0 .. System.OS_Interface.Max_Interrupt;
type Interrupt_Set is array (Interrupt_ID) of Boolean;
-- The following objects serve as constants, but are initialized
-- in the body to aid portability. This permits us to use more
-- portable names for interrupts, where distinct names may map to
-- the same interrupt ID value.
-- For example, suppose SIGRARE is a signal that is not defined on
-- all systems, but is always reserved when it is defined. If we
-- have the convention that ID zero is not used for any "real"
-- signals, and SIGRARE = 0 when SIGRARE is not one of the locally
-- supported signals, we can write
-- Reserved (SIGRARE) := true;
-- and the initialization code will be portable.
Abort_Task_Interrupt : Interrupt_ID;
-- The interrupt that is used to implement task abortion if
-- an interrupt is used for that purpose. This is one of the
-- reserved interrupts.
Keep_Unmasked : Interrupt_Set := (others => False);
-- Keep_Unmasked (I) is true iff the interrupt I is one that must
-- that must be kept unmasked at all times, except (perhaps) for
-- short critical sections. This includes interrupts that are
-- mapped to exceptions (see System.Interrupt_Exceptions.Is_Exception),
-- but may also include interrupts (e.g. timer) that need to be kept
-- unmasked for other reasons. Where interrupts are implemented as
-- OS signals, and signal masking is per-task, the interrupt should
-- be unmasked in ALL TASKS.
Reserve : Interrupt_Set := (others => False);
-- Reserve (I) is true iff the interrupt I is one that cannot be
-- permitted to be attached to a user handler. The possible reasons
-- are many. For example, it may be mapped to an exception used to
-- implement task abortion, or used to implement time delays.
procedure Initialize_Interrupts;
-- On systems where there is no signal inheritance between tasks (e.g
-- VxWorks, GNU/LinuxThreads), this procedure is used to initialize
-- interrupts handling in each task. Otherwise this function should
-- only be called by initialize in this package body.
type Interrupt_Mask is new System.OS_Interface.sigset_t;
-- In some implementation Interrupt_Mask can be represented
-- as a linked list.
end System.Interrupt_Management;