| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT 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) 1991-2005 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, 51 Franklin Street, Fifth Floor, -- |
| -- Boston, MA 02110-1301, 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 is the Alpha/VMS version of this package |
| |
| -- 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 |
| |
| -- 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 Preelaborate; |
| |
| 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; |
| |
| -- Then the initialization code will be portable |
| |
| Abort_Task_Interrupt : Interrupt_ID; |
| -- The interrupt that is used to implement task abort, 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 abort. |
| |
| 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; |
| -- Initialize the various variables defined in this package. |
| -- This procedure must be called before accessing any object from this |
| -- package and can be called multiple times. |
| |
| private |
| use type System.OS_Interface.unsigned_long; |
| |
| type Interrupt_Mask is new System.OS_Interface.sigset_t; |
| |
| -- Interrupts on VMS are implemented with a mailbox. A QIO read is |
| -- registered on the Rcv channel and the interrupt occurs by registering |
| -- a QIO write on the Snd channel. The maximum number of pending |
| -- interrupts is arbitrarily set at 1000. One nice feature of using |
| -- a mailbox is that it is trivially extendable to cross process |
| -- interrupts. |
| |
| Rcv_Interrupt_Chan : System.OS_Interface.unsigned_short := 0; |
| Snd_Interrupt_Chan : System.OS_Interface.unsigned_short := 0; |
| Interrupt_Mailbox : Interrupt_ID := 0; |
| Interrupt_Bufquo : System.OS_Interface.unsigned_long := |
| 1000 * (Interrupt_ID'Size / 8); |
| |
| end System.Interrupt_Management; |