1------------------------------------------------------------------------------ 2-- -- 3-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS -- 4-- -- 5-- 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 -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 1992-2020, Free Software Foundation, Inc. -- 10-- -- 11-- GNARL is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- GNARL was developed by the GNARL team at Florida State University. -- 28-- Extensive contributions were provided by Ada Core Technologies, Inc. -- 29-- -- 30------------------------------------------------------------------------------ 31 32-- This package encapsulates and centralizes information about all uses of 33-- interrupts (or signals), including the target-dependent mapping of 34-- interrupts (or signals) to exceptions. 35 36-- Unlike the original design, System.Interrupt_Management can only be used 37-- for tasking systems. 38 39-- PLEASE DO NOT put any subprogram declarations with arguments of type 40-- Interrupt_ID into the visible part of this package. The type Interrupt_ID 41-- is used to derive the type in Ada.Interrupts, and adding more operations 42-- to that type would be illegal according to the Ada Reference Manual. This 43-- is the reason why the signals sets are implemented using visible arrays 44-- rather than functions. 45 46with System.OS_Interface; 47 48with Interfaces.C; 49 50package System.Interrupt_Management is 51 pragma Preelaborate; 52 53 type Interrupt_Mask is limited private; 54 55 type Interrupt_ID is new Interfaces.C.int 56 range 0 .. System.OS_Interface.Max_Interrupt; 57 58 type Interrupt_Set is array (Interrupt_ID) of Boolean; 59 60 -- The following objects serve as constants, but are initialized in the 61 -- body to aid portability. This permits us to use more portable names for 62 -- interrupts, where distinct names may map to the same interrupt ID 63 -- value. 64 65 -- For example, suppose SIGRARE is a signal that is not defined on all 66 -- systems, but is always reserved when it is defined. If we have the 67 -- convention that ID zero is not used for any "real" signals, and SIGRARE 68 -- = 0 when SIGRARE is not one of the locally supported signals, we can 69 -- write: 70 -- Reserved (SIGRARE) := True; 71 -- and the initialization code will be portable. 72 73 Abort_Task_Interrupt : Interrupt_ID; 74 -- The interrupt that is used to implement task abort if an interrupt is 75 -- used for that purpose. This is one of the reserved interrupts. 76 77 Keep_Unmasked : Interrupt_Set := (others => False); 78 -- Keep_Unmasked (I) is true iff the interrupt I is one that must be kept 79 -- unmasked at all times, except (perhaps) for short critical sections. 80 -- This includes interrupts that are mapped to exceptions (see 81 -- System.Interrupt_Exceptions.Is_Exception), but may also include 82 -- interrupts (e.g. timer) that need to be kept unmasked for other 83 -- reasons. Where interrupts are implemented as OS signals, and signal 84 -- masking is per-task, the interrupt should be unmasked in ALL TASKS. 85 86 Reserve : Interrupt_Set := (others => False); 87 -- Reserve (I) is true iff the interrupt I is one that cannot be permitted 88 -- to be attached to a user handler. The possible reasons are many. For 89 -- example, it may be mapped to an exception used to implement task abort, 90 -- or used to implement time delays. 91 92 procedure Initialize; 93 -- Initialize the various variables defined in this package. This procedure 94 -- must be called before accessing any object from this package, and can be 95 -- called multiple times. 96 97private 98 type Interrupt_Mask is new System.OS_Interface.sigset_t; 99 -- In some implementations Interrupt_Mask is represented as a linked list 100 101 procedure Adjust_Context_For_Raise 102 (Signo : System.OS_Interface.Signal; 103 Ucontext : System.Address); 104 pragma Import 105 (C, Adjust_Context_For_Raise, "__gnat_adjust_context_for_raise"); 106 -- Target specific hook performing adjustments to the signal's machine 107 -- context, to be called before an exception may be raised from a signal 108 -- handler. This service is provided by init.c, together with the 109 -- non-tasking signal handler. 110 111end System.Interrupt_Management; 112