------------------------------------------------------------------------------ -- -- -- 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 -- -- -- -- -- -- 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. -- -- 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. -- 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;