| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS -- |
| -- -- |
| -- S Y S T E M . I N T E R R U P T S -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- $Revision: 1.18 $ |
| -- -- |
| -- Copyright (C) 1992-2001 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. It is -- |
| -- now maintained by Ada Core Technologies Inc. in cooperation with Florida -- |
| -- State University (http://www.gnat.com). -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- 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 := |
| System.Interrupt_Priority'Last; |
| -- 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; |
| |
| 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 |
| record |
| 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; |
