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-- --
-- --
-- S Y S T E M . I N T E R R U P T S --
-- --
-- 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. --
-- --
-- Note: the compiler generates direct calls to this interface, via Rtsfind.
-- Any changes to this interface may require corresponding compiler changes.
-- This package encapsulates the implementation of interrupt or signal
-- handlers. It is logically an extension of the body of Ada.Interrupts.
-- It is made a child of System to allow visibility of various
-- runtime system internal data and operations.
-- See System.Interrupt_Management for core interrupt/signal interfaces.
-- These two packages are separated in order to allow
-- System.Interrupt_Management to be used without requiring the whole
-- tasking implementation to be linked and elaborated.
with System.Tasking;
-- used for Task_ID
with System.Tasking.Protected_Objects.Entries;
-- used for Protection_Entries
with System.OS_Interface;
-- used for Max_Interrupt
package System.Interrupts is
pragma Elaborate_Body;
-- Comment needed on why this is here ???
-- Constants and types --
Default_Interrupt_Priority : constant System.Interrupt_Priority :=
-- Default value used when a pragma Interrupt_Handler or Attach_Handler is
-- specified without an Interrupt_Priority pragma, see D.3(10).
type Ada_Interrupt_ID is range 0 .. System.OS_Interface.Max_Interrupt;
-- Avoid inheritance by Ada.Interrupts.Interrupt_ID of unwanted operations
type Interrupt_ID is range 0 .. System.OS_Interface.Max_Interrupt;
-- The following renaming is introduced so that the type is accessible
-- through rtsfind, otherwise the name clashes with its homonym in
-- ada.interrupts.
subtype System_Interrupt_Id is Interrupt_ID;
type Parameterless_Handler is access protected procedure;
-- General services --
-- Attempt to attach a Handler to an Interrupt to which an Entry is
-- already bound will raise a Program_Error.
function Is_Reserved (Interrupt : Interrupt_ID) return Boolean;
function Is_Entry_Attached (Interrupt : Interrupt_ID) return Boolean;
function Is_Handler_Attached (Interrupt : Interrupt_ID) return Boolean;
function Current_Handler
(Interrupt : Interrupt_ID)
return Parameterless_Handler;
-- Calling the following procedures with New_Handler = null
-- and Static = true means that we want to modify the current handler
-- regardless of the previous handler's binding status.
-- (i.e. we do not care whether it is a dynamic or static handler)
procedure Attach_Handler
(New_Handler : Parameterless_Handler;
Interrupt : Interrupt_ID;
Static : Boolean := False);
procedure Exchange_Handler
(Old_Handler : out Parameterless_Handler;
New_Handler : Parameterless_Handler;
Interrupt : Interrupt_ID;
Static : Boolean := False);
procedure Detach_Handler
(Interrupt : Interrupt_ID;
Static : Boolean := False);
function Reference
(Interrupt : Interrupt_ID)
return System.Address;
-- Interrupt entries services --
-- Routines needed for Interrupt Entries
-- Attempt to bind an Entry to an Interrupt to which a Handler is
-- already attached will raise a Program_Error.
procedure Bind_Interrupt_To_Entry
(T : System.Tasking.Task_ID;
E : System.Tasking.Task_Entry_Index;
Int_Ref : System.Address);
procedure Detach_Interrupt_Entries (T : System.Tasking.Task_ID);
-- This procedure detaches all the Interrupt Entries bound to a task.
-- POSIX.5 signals services --
-- Routines needed for POSIX dot5 POSIX_Signals
procedure Block_Interrupt (Interrupt : Interrupt_ID);
-- Block the Interrupt on the process level
procedure Unblock_Interrupt (Interrupt : Interrupt_ID);
function Unblocked_By
(Interrupt : Interrupt_ID)
return System.Tasking.Task_ID;
-- It returns the ID of the last Task which Unblocked this Interrupt.
-- It returns Null_Task if no tasks have ever requested the
-- Unblocking operation or the Interrupt is currently Blocked.
function Is_Blocked (Interrupt : Interrupt_ID) return Boolean;
-- Comment needed ???
procedure Ignore_Interrupt (Interrupt : Interrupt_ID);
-- Set the sigacion for the interrupt to SIG_IGN.
procedure Unignore_Interrupt (Interrupt : Interrupt_ID);
-- Comment needed ???
function Is_Ignored (Interrupt : Interrupt_ID) return Boolean;
-- Comment needed ???
-- Note : Direct calls to sigaction, sigprocmask, thr_sigsetmask or any
-- other low-level interface that changes the signal action or signal mask
-- needs a careful thought.
-- One may acheive the effect of system calls first making RTS blocked
-- (by calling Block_Interrupt) for the signal under consideration.
-- This will make all the tasks in RTS blocked for the Interrupt.
-- Protection types --
-- Routines and types needed to implement Interrupt_Handler and
-- Attach_Handler.
-- There are two kinds of protected objects that deal with interrupts:
-- (1) Only Interrupt_Handler pragmas are used. We need to be able to
-- tell if an Interrupt_Handler applies to a given procedure, so
-- Register_Interrupt_Handler has to be called for all the potential
-- handlers, it should be done by calling Register_Interrupt_Handler
-- with the handler code address. On finalization, which can happen only
-- has part of library level finalization since PO with
-- Interrupt_Handler pragmas can only be declared at library level,
-- nothing special needs to be done since the default handlers have been
-- restored as part of task completion which is done just before global
-- finalization. Dynamic_Interrupt_Protection should be used in this
-- case.
-- (2) Attach_Handler pragmas are used, and possibly Interrupt_Handler
-- pragma. We need to attach the handlers to the given interrupts when
-- the objet is elaborated. This should be done by constructing an array
-- of pairs (interrupt, handler) from the pragmas and calling
-- Install_Handlers with it (types to be used are New_Handler_Item and
-- New_Handler_Array). On finalization, we need to restore the handlers
-- that were installed before the elaboration of the PO, so we need to
-- store these previous handlers. This is also done by Install_Handlers,
-- the room for these informations is provided by adding a discriminant
-- which is the number of Attach_Handler pragmas and an array of this
-- size in the protection type, Static_Interrupt_Protection.
procedure Register_Interrupt_Handler
(Handler_Addr : System.Address);
-- This routine should be called by the compiler to allow the
-- handler be used as an Interrupt Handler. That means call this
-- procedure for each pragma Interrup_Handler providing the
-- address of the handler (not including the pointer to the
-- actual PO, this way this routine is called only once for
-- each type definition of PO).
type Static_Handler_Index is range 0 .. Integer'Last;
subtype Positive_Static_Handler_Index is
Static_Handler_Index range 1 .. Static_Handler_Index'Last;
-- Comment needed ???
type Previous_Handler_Item is record
Interrupt : Interrupt_ID;
Handler : Parameterless_Handler;
Static : Boolean;
end record;
-- Contains all the information needed to restore a previous handler.
type Previous_Handler_Array is array
(Positive_Static_Handler_Index range <>) of Previous_Handler_Item;
type New_Handler_Item is record
Interrupt : Interrupt_ID;
Handler : Parameterless_Handler;
end record;
-- Contains all the information from an Attach_Handler pragma.
type New_Handler_Array is
array (Positive_Static_Handler_Index range <>) of New_Handler_Item;
-- Comment needed ???
-- Case (1)
type Dynamic_Interrupt_Protection is new
Tasking.Protected_Objects.Entries.Protection_Entries with null record;
-- ??? Finalize is not overloaded since we currently have no
-- way to detach the handlers during library level finalization.
function Has_Interrupt_Or_Attach_Handler
(Object : access Dynamic_Interrupt_Protection) return Boolean;
-- Returns True.
-- Case (2)
type Static_Interrupt_Protection
(Num_Entries : Tasking.Protected_Objects.Protected_Entry_Index;
Num_Attach_Handler : Static_Handler_Index)
is new
Tasking.Protected_Objects.Entries.Protection_Entries (Num_Entries) with
Previous_Handlers : Previous_Handler_Array (1 .. Num_Attach_Handler);
end record;
function Has_Interrupt_Or_Attach_Handler
(Object : access Static_Interrupt_Protection)
return Boolean;
-- Returns True.
procedure Finalize (Object : in out Static_Interrupt_Protection);
-- Restore previous handlers as required by C.3.1(12) then call
-- Finalize (Protection).
procedure Install_Handlers
(Object : access Static_Interrupt_Protection;
New_Handlers : in New_Handler_Array);
-- Store the old handlers in Object.Previous_Handlers and install
-- the new static handlers.
end System.Interrupts;