| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS -- |
| -- -- |
| -- 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 -- |
| -- -- |
| -- $Revision$ |
| -- -- |
| -- Copyright (C) 1991-2001 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). -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- This package encapsulates and centralizes information about |
| -- all uses of interrupts (or signals), including the |
| -- target-dependent mapping of interrupts (or signals) to exceptions. |
| |
| -- PLEASE DO NOT add any with-clauses to this package. |
| -- This is designed to work for both tasking and non-tasking systems, |
| -- without pulling in any of the tasking support. |
| |
| -- 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-dependences. |
| |
| -- 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 |
| -- below are implemented as visible arrays rather than functions.) |
| |
| with System.OS_Interface; |
| -- used for Signal |
| -- sigset_t |
| |
| package System.Interrupt_Management is |
| |
| pragma Elaborate_Body; |
| |
| type Interrupt_Mask is limited private; |
| |
| type Interrupt_ID is new System.OS_Interface.Signal; |
| |
| 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 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. |
| |
| Keep_Masked : Interrupt_Set := (others => False); |
| -- Keep_Masked (I) is true iff the interrupt I must always be masked. |
| -- Where interrupts are implemented as OS signals, and signal masking |
| -- is per-task, the interrupt should be masked in ALL TASKS. |
| -- There might not be any interrupts in this class, depending on |
| -- the environment. For example, if interrupts are OS signals |
| -- and signal masking is per-task, use of the sigwait operation |
| -- requires the signal be masked in all tasks. |
| |
| 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. |
| |
| private |
| 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; |
