1434 lines
50 KiB
Ada
1434 lines
50 KiB
Ada
------------------------------------------------------------------------------
|
|
-- --
|
|
-- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
|
|
-- --
|
|
-- S Y S T E M . I N T E R R U P T S --
|
|
-- --
|
|
-- B o d y --
|
|
-- --
|
|
-- Copyright (C) 1992-2020, 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 3, or (at your option) any later ver- --
|
|
-- sion. GNAT 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. --
|
|
-- --
|
|
-- As a special exception under Section 7 of GPL version 3, you are granted --
|
|
-- additional permissions described in the GCC Runtime Library Exception, --
|
|
-- version 3.1, as published by the Free Software Foundation. --
|
|
-- --
|
|
-- You should have received a copy of the GNU General Public License and --
|
|
-- a copy of the GCC Runtime Library Exception along with this program; --
|
|
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
|
|
-- <http://www.gnu.org/licenses/>. --
|
|
-- --
|
|
-- GNARL was developed by the GNARL team at Florida State University. --
|
|
-- Extensive contributions were provided by Ada Core Technologies, Inc. --
|
|
-- --
|
|
------------------------------------------------------------------------------
|
|
|
|
-- Invariants:
|
|
|
|
-- All user-handleable interrupts are masked at all times in all tasks/threads
|
|
-- except possibly for the Interrupt_Manager task.
|
|
|
|
-- When a user task wants to achieve masking/unmasking an interrupt, it must
|
|
-- call Block_Interrupt/Unblock_Interrupt, which will have the effect of
|
|
-- unmasking/masking the interrupt in the Interrupt_Manager task.
|
|
|
|
-- Note : Direct calls to sigaction, sigprocmask, pthread_sigsetmask or any
|
|
-- other low-level interface that changes the interrupt action or
|
|
-- interrupt mask needs a careful thought.
|
|
|
|
-- One may achieve the effect of system calls first masking RTS blocked
|
|
-- (by calling Block_Interrupt) for the interrupt under consideration.
|
|
-- This will make all the tasks in RTS blocked for the Interrupt.
|
|
|
|
-- Once we associate a Server_Task with an interrupt, the task never goes
|
|
-- away, and we never remove the association.
|
|
|
|
-- There is no more than one interrupt per Server_Task and no more than one
|
|
-- Server_Task per interrupt.
|
|
|
|
with Ada.Exceptions;
|
|
with Ada.Task_Identification;
|
|
|
|
with System.Task_Primitives;
|
|
with System.Interrupt_Management;
|
|
|
|
with System.Interrupt_Management.Operations;
|
|
pragma Elaborate_All (System.Interrupt_Management.Operations);
|
|
|
|
with System.IO;
|
|
|
|
with System.Task_Primitives.Operations;
|
|
with System.Task_Primitives.Interrupt_Operations;
|
|
with System.Storage_Elements;
|
|
with System.Tasking.Utilities;
|
|
|
|
with System.Tasking.Rendezvous;
|
|
pragma Elaborate_All (System.Tasking.Rendezvous);
|
|
|
|
with System.Tasking.Initialization;
|
|
with System.Parameters;
|
|
|
|
with Ada.Unchecked_Conversion;
|
|
|
|
package body System.Interrupts is
|
|
|
|
use Parameters;
|
|
use Tasking;
|
|
|
|
package POP renames System.Task_Primitives.Operations;
|
|
package PIO renames System.Task_Primitives.Interrupt_Operations;
|
|
package IMNG renames System.Interrupt_Management;
|
|
package IMOP renames System.Interrupt_Management.Operations;
|
|
|
|
function To_System is new Ada.Unchecked_Conversion
|
|
(Ada.Task_Identification.Task_Id, Task_Id);
|
|
|
|
-----------------
|
|
-- Local Tasks --
|
|
-----------------
|
|
|
|
-- WARNING: System.Tasking.Stages performs calls to this task with
|
|
-- low-level constructs. Do not change this spec without synchronizing it.
|
|
|
|
task Interrupt_Manager is
|
|
entry Detach_Interrupt_Entries (T : Task_Id);
|
|
|
|
entry Initialize (Mask : IMNG.Interrupt_Mask);
|
|
|
|
entry Attach_Handler
|
|
(New_Handler : Parameterless_Handler;
|
|
Interrupt : Interrupt_ID;
|
|
Static : Boolean;
|
|
Restoration : Boolean := False);
|
|
|
|
entry Exchange_Handler
|
|
(Old_Handler : out Parameterless_Handler;
|
|
New_Handler : Parameterless_Handler;
|
|
Interrupt : Interrupt_ID;
|
|
Static : Boolean);
|
|
|
|
entry Detach_Handler
|
|
(Interrupt : Interrupt_ID;
|
|
Static : Boolean);
|
|
|
|
entry Bind_Interrupt_To_Entry
|
|
(T : Task_Id;
|
|
E : Task_Entry_Index;
|
|
Interrupt : Interrupt_ID);
|
|
|
|
entry Block_Interrupt (Interrupt : Interrupt_ID);
|
|
|
|
entry Unblock_Interrupt (Interrupt : Interrupt_ID);
|
|
|
|
entry Ignore_Interrupt (Interrupt : Interrupt_ID);
|
|
|
|
entry Unignore_Interrupt (Interrupt : Interrupt_ID);
|
|
|
|
pragma Interrupt_Priority (System.Interrupt_Priority'Last);
|
|
end Interrupt_Manager;
|
|
|
|
task type Server_Task (Interrupt : Interrupt_ID) is
|
|
pragma Priority (System.Interrupt_Priority'Last);
|
|
-- Note: the above pragma Priority is strictly speaking improper since
|
|
-- it is outside the range of allowed priorities, but the compiler
|
|
-- treats system units specially and does not apply this range checking
|
|
-- rule to system units.
|
|
|
|
end Server_Task;
|
|
|
|
type Server_Task_Access is access Server_Task;
|
|
|
|
-------------------------------
|
|
-- Local Types and Variables --
|
|
-------------------------------
|
|
|
|
type Entry_Assoc is record
|
|
T : Task_Id;
|
|
E : Task_Entry_Index;
|
|
end record;
|
|
|
|
type Handler_Assoc is record
|
|
H : Parameterless_Handler;
|
|
Static : Boolean; -- Indicates static binding;
|
|
end record;
|
|
|
|
User_Handler : array (Interrupt_ID'Range) of Handler_Assoc :=
|
|
(others => (null, Static => False));
|
|
pragma Volatile_Components (User_Handler);
|
|
-- Holds the protected procedure handler (if any) and its Static
|
|
-- information for each interrupt. A handler is a Static one if it is
|
|
-- specified through the pragma Attach_Handler. Attach_Handler. Otherwise,
|
|
-- not static)
|
|
|
|
User_Entry : array (Interrupt_ID'Range) of Entry_Assoc :=
|
|
(others => (T => Null_Task, E => Null_Task_Entry));
|
|
pragma Volatile_Components (User_Entry);
|
|
-- Holds the task and entry index (if any) for each interrupt
|
|
|
|
Blocked : array (Interrupt_ID'Range) of Boolean := (others => False);
|
|
pragma Atomic_Components (Blocked);
|
|
-- True iff the corresponding interrupt is blocked in the process level
|
|
|
|
Ignored : array (Interrupt_ID'Range) of Boolean := (others => False);
|
|
pragma Atomic_Components (Ignored);
|
|
-- True iff the corresponding interrupt is blocked in the process level
|
|
|
|
Last_Unblocker :
|
|
array (Interrupt_ID'Range) of Task_Id := (others => Null_Task);
|
|
pragma Atomic_Components (Last_Unblocker);
|
|
-- Holds the ID of the last Task which Unblocked this Interrupt. It
|
|
-- contains Null_Task if no tasks have ever requested the Unblocking
|
|
-- operation or the Interrupt is currently Blocked.
|
|
|
|
Server_ID : array (Interrupt_ID'Range) of Task_Id :=
|
|
(others => Null_Task);
|
|
pragma Atomic_Components (Server_ID);
|
|
-- Holds the Task_Id of the Server_Task for each interrupt. Task_Id is
|
|
-- needed to accomplish locking per Interrupt base. Also is needed to
|
|
-- decide whether to create a new Server_Task.
|
|
|
|
-- Type and Head, Tail of the list containing Registered Interrupt
|
|
-- Handlers. These definitions are used to register the handlers
|
|
-- specified by the pragma Interrupt_Handler.
|
|
|
|
type Registered_Handler;
|
|
type R_Link is access all Registered_Handler;
|
|
|
|
type Registered_Handler is record
|
|
H : System.Address := System.Null_Address;
|
|
Next : R_Link := null;
|
|
end record;
|
|
|
|
Registered_Handler_Head : R_Link := null;
|
|
Registered_Handler_Tail : R_Link := null;
|
|
|
|
Access_Hold : Server_Task_Access;
|
|
-- Variable used to allocate Server_Task using "new"
|
|
|
|
-----------------------
|
|
-- Local Subprograms --
|
|
-----------------------
|
|
|
|
function Is_Registered (Handler : Parameterless_Handler) return Boolean;
|
|
-- See if the Handler has been "pragma"ed using Interrupt_Handler. Always
|
|
-- consider a null handler as registered.
|
|
|
|
--------------------
|
|
-- Attach_Handler --
|
|
--------------------
|
|
|
|
-- Calling this procedure with New_Handler = null and Static = True means
|
|
-- we want to detach the current handler regardless of the previous
|
|
-- handler's binding status (i.e. do not care if it is a dynamic or static
|
|
-- handler).
|
|
|
|
-- This option is needed so that during the finalization of a PO, we can
|
|
-- detach handlers attached through pragma Attach_Handler.
|
|
|
|
procedure Attach_Handler
|
|
(New_Handler : Parameterless_Handler;
|
|
Interrupt : Interrupt_ID;
|
|
Static : Boolean := False)
|
|
is
|
|
begin
|
|
if Is_Reserved (Interrupt) then
|
|
raise Program_Error with
|
|
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
|
|
end if;
|
|
|
|
Interrupt_Manager.Attach_Handler (New_Handler, Interrupt, Static);
|
|
|
|
end Attach_Handler;
|
|
|
|
-----------------------------
|
|
-- Bind_Interrupt_To_Entry --
|
|
-----------------------------
|
|
|
|
-- This procedure raises a Program_Error if it tries to bind an interrupt
|
|
-- to which an Entry or a Procedure is already bound.
|
|
|
|
procedure Bind_Interrupt_To_Entry
|
|
(T : Task_Id;
|
|
E : Task_Entry_Index;
|
|
Int_Ref : System.Address)
|
|
is
|
|
Interrupt : constant Interrupt_ID :=
|
|
Interrupt_ID (Storage_Elements.To_Integer (Int_Ref));
|
|
|
|
begin
|
|
if Is_Reserved (Interrupt) then
|
|
raise Program_Error with
|
|
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
|
|
end if;
|
|
|
|
Interrupt_Manager.Bind_Interrupt_To_Entry (T, E, Interrupt);
|
|
end Bind_Interrupt_To_Entry;
|
|
|
|
---------------------
|
|
-- Block_Interrupt --
|
|
---------------------
|
|
|
|
procedure Block_Interrupt (Interrupt : Interrupt_ID) is
|
|
begin
|
|
if Is_Reserved (Interrupt) then
|
|
raise Program_Error with
|
|
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
|
|
end if;
|
|
|
|
Interrupt_Manager.Block_Interrupt (Interrupt);
|
|
end Block_Interrupt;
|
|
|
|
---------------------
|
|
-- Current_Handler --
|
|
---------------------
|
|
|
|
function Current_Handler
|
|
(Interrupt : Interrupt_ID) return Parameterless_Handler
|
|
is
|
|
begin
|
|
if Is_Reserved (Interrupt) then
|
|
raise Program_Error with
|
|
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
|
|
end if;
|
|
|
|
-- ??? Since Parameterless_Handler is not Atomic, the current
|
|
-- implementation is wrong. We need a new service in Interrupt_Manager
|
|
-- to ensure atomicity.
|
|
|
|
return User_Handler (Interrupt).H;
|
|
end Current_Handler;
|
|
|
|
--------------------
|
|
-- Detach_Handler --
|
|
--------------------
|
|
|
|
-- Calling this procedure with Static = True means we want to Detach the
|
|
-- current handler regardless of the previous handler's binding status
|
|
-- (i.e. do not care if it is a dynamic or static handler).
|
|
|
|
-- This option is needed so that during the finalization of a PO, we can
|
|
-- detach handlers attached through pragma Attach_Handler.
|
|
|
|
procedure Detach_Handler
|
|
(Interrupt : Interrupt_ID;
|
|
Static : Boolean := False)
|
|
is
|
|
begin
|
|
if Is_Reserved (Interrupt) then
|
|
raise Program_Error with
|
|
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
|
|
end if;
|
|
|
|
Interrupt_Manager.Detach_Handler (Interrupt, Static);
|
|
end Detach_Handler;
|
|
|
|
------------------------------
|
|
-- Detach_Interrupt_Entries --
|
|
------------------------------
|
|
|
|
procedure Detach_Interrupt_Entries (T : Task_Id) is
|
|
begin
|
|
Interrupt_Manager.Detach_Interrupt_Entries (T);
|
|
end Detach_Interrupt_Entries;
|
|
|
|
----------------------
|
|
-- Exchange_Handler --
|
|
----------------------
|
|
|
|
-- Calling this procedure with New_Handler = null and Static = True means
|
|
-- we want to detach the current handler regardless of the previous
|
|
-- handler's binding status (i.e. do not care if it is a dynamic or static
|
|
-- handler).
|
|
|
|
-- This option is needed so that during the finalization of a PO, we can
|
|
-- detach handlers attached through pragma Attach_Handler.
|
|
|
|
procedure Exchange_Handler
|
|
(Old_Handler : out Parameterless_Handler;
|
|
New_Handler : Parameterless_Handler;
|
|
Interrupt : Interrupt_ID;
|
|
Static : Boolean := False)
|
|
is
|
|
begin
|
|
if Is_Reserved (Interrupt) then
|
|
raise Program_Error with
|
|
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
|
|
end if;
|
|
|
|
Interrupt_Manager.Exchange_Handler
|
|
(Old_Handler, New_Handler, Interrupt, Static);
|
|
end Exchange_Handler;
|
|
|
|
--------------
|
|
-- Finalize --
|
|
--------------
|
|
|
|
procedure Finalize (Object : in out Static_Interrupt_Protection) is
|
|
function State
|
|
(Int : System.Interrupt_Management.Interrupt_ID) return Character;
|
|
pragma Import (C, State, "__gnat_get_interrupt_state");
|
|
-- Get interrupt state for interrupt number Int. Defined in init.c
|
|
|
|
Default : constant Character := 's';
|
|
-- 's' Interrupt_State pragma set state to System (use "default"
|
|
-- system handler)
|
|
|
|
begin
|
|
-- ??? loop to be executed only when we're not doing library level
|
|
-- finalization, since in this case all interrupt tasks are gone.
|
|
|
|
-- If the Abort_Task signal is set to system, it means that we cannot
|
|
-- reset interrupt handlers since this would require sending the abort
|
|
-- signal to the Server_Task
|
|
|
|
if not Interrupt_Manager'Terminated
|
|
and then
|
|
State (System.Interrupt_Management.Abort_Task_Interrupt) /= Default
|
|
then
|
|
for N in reverse Object.Previous_Handlers'Range loop
|
|
Interrupt_Manager.Attach_Handler
|
|
(New_Handler => Object.Previous_Handlers (N).Handler,
|
|
Interrupt => Object.Previous_Handlers (N).Interrupt,
|
|
Static => Object.Previous_Handlers (N).Static,
|
|
Restoration => True);
|
|
end loop;
|
|
end if;
|
|
|
|
Tasking.Protected_Objects.Entries.Finalize
|
|
(Tasking.Protected_Objects.Entries.Protection_Entries (Object));
|
|
end Finalize;
|
|
|
|
-------------------------------------
|
|
-- Has_Interrupt_Or_Attach_Handler --
|
|
-------------------------------------
|
|
|
|
-- Need comments as to why these always return True ???
|
|
|
|
function Has_Interrupt_Or_Attach_Handler
|
|
(Object : access Dynamic_Interrupt_Protection) return Boolean
|
|
is
|
|
pragma Unreferenced (Object);
|
|
begin
|
|
return True;
|
|
end Has_Interrupt_Or_Attach_Handler;
|
|
|
|
function Has_Interrupt_Or_Attach_Handler
|
|
(Object : access Static_Interrupt_Protection) return Boolean
|
|
is
|
|
pragma Unreferenced (Object);
|
|
begin
|
|
return True;
|
|
end Has_Interrupt_Or_Attach_Handler;
|
|
|
|
----------------------
|
|
-- Ignore_Interrupt --
|
|
----------------------
|
|
|
|
procedure Ignore_Interrupt (Interrupt : Interrupt_ID) is
|
|
begin
|
|
if Is_Reserved (Interrupt) then
|
|
raise Program_Error with
|
|
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
|
|
end if;
|
|
|
|
Interrupt_Manager.Ignore_Interrupt (Interrupt);
|
|
end Ignore_Interrupt;
|
|
|
|
----------------------
|
|
-- Install_Handlers --
|
|
----------------------
|
|
|
|
procedure Install_Handlers
|
|
(Object : access Static_Interrupt_Protection;
|
|
New_Handlers : New_Handler_Array)
|
|
is
|
|
begin
|
|
for N in New_Handlers'Range loop
|
|
|
|
-- We need a lock around this ???
|
|
|
|
Object.Previous_Handlers (N).Interrupt := New_Handlers (N).Interrupt;
|
|
Object.Previous_Handlers (N).Static := User_Handler
|
|
(New_Handlers (N).Interrupt).Static;
|
|
|
|
-- We call Exchange_Handler and not directly Interrupt_Manager.
|
|
-- Exchange_Handler so we get the Is_Reserved check.
|
|
|
|
Exchange_Handler
|
|
(Old_Handler => Object.Previous_Handlers (N).Handler,
|
|
New_Handler => New_Handlers (N).Handler,
|
|
Interrupt => New_Handlers (N).Interrupt,
|
|
Static => True);
|
|
end loop;
|
|
end Install_Handlers;
|
|
|
|
---------------------------------
|
|
-- Install_Restricted_Handlers --
|
|
---------------------------------
|
|
|
|
procedure Install_Restricted_Handlers
|
|
(Prio : Any_Priority;
|
|
Handlers : New_Handler_Array)
|
|
is
|
|
pragma Unreferenced (Prio);
|
|
begin
|
|
for N in Handlers'Range loop
|
|
Attach_Handler (Handlers (N).Handler, Handlers (N).Interrupt, True);
|
|
end loop;
|
|
end Install_Restricted_Handlers;
|
|
|
|
----------------
|
|
-- Is_Blocked --
|
|
----------------
|
|
|
|
function Is_Blocked (Interrupt : Interrupt_ID) return Boolean is
|
|
begin
|
|
if Is_Reserved (Interrupt) then
|
|
raise Program_Error with
|
|
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
|
|
end if;
|
|
|
|
return Blocked (Interrupt);
|
|
end Is_Blocked;
|
|
|
|
-----------------------
|
|
-- Is_Entry_Attached --
|
|
-----------------------
|
|
|
|
function Is_Entry_Attached (Interrupt : Interrupt_ID) return Boolean is
|
|
begin
|
|
if Is_Reserved (Interrupt) then
|
|
raise Program_Error with
|
|
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
|
|
end if;
|
|
|
|
return User_Entry (Interrupt).T /= Null_Task;
|
|
end Is_Entry_Attached;
|
|
|
|
-------------------------
|
|
-- Is_Handler_Attached --
|
|
-------------------------
|
|
|
|
function Is_Handler_Attached (Interrupt : Interrupt_ID) return Boolean is
|
|
begin
|
|
if Is_Reserved (Interrupt) then
|
|
raise Program_Error with
|
|
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
|
|
end if;
|
|
|
|
return User_Handler (Interrupt).H /= null;
|
|
end Is_Handler_Attached;
|
|
|
|
----------------
|
|
-- Is_Ignored --
|
|
----------------
|
|
|
|
function Is_Ignored (Interrupt : Interrupt_ID) return Boolean is
|
|
begin
|
|
if Is_Reserved (Interrupt) then
|
|
raise Program_Error with
|
|
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
|
|
end if;
|
|
|
|
return Ignored (Interrupt);
|
|
end Is_Ignored;
|
|
|
|
-------------------
|
|
-- Is_Registered --
|
|
-------------------
|
|
|
|
function Is_Registered (Handler : Parameterless_Handler) return Boolean is
|
|
|
|
type Acc_Proc is access procedure;
|
|
|
|
type Fat_Ptr is record
|
|
Object_Addr : System.Address;
|
|
Handler_Addr : Acc_Proc;
|
|
end record;
|
|
|
|
function To_Fat_Ptr is new Ada.Unchecked_Conversion
|
|
(Parameterless_Handler, Fat_Ptr);
|
|
|
|
Ptr : R_Link;
|
|
Fat : Fat_Ptr;
|
|
|
|
begin
|
|
if Handler = null then
|
|
return True;
|
|
end if;
|
|
|
|
Fat := To_Fat_Ptr (Handler);
|
|
|
|
Ptr := Registered_Handler_Head;
|
|
while Ptr /= null loop
|
|
if Ptr.H = Fat.Handler_Addr.all'Address then
|
|
return True;
|
|
end if;
|
|
|
|
Ptr := Ptr.Next;
|
|
end loop;
|
|
|
|
return False;
|
|
end Is_Registered;
|
|
|
|
-----------------
|
|
-- Is_Reserved --
|
|
-----------------
|
|
|
|
function Is_Reserved (Interrupt : Interrupt_ID) return Boolean is
|
|
begin
|
|
return IMNG.Reserve (IMNG.Interrupt_ID (Interrupt));
|
|
end Is_Reserved;
|
|
|
|
---------------
|
|
-- Reference --
|
|
---------------
|
|
|
|
function Reference (Interrupt : Interrupt_ID) return System.Address is
|
|
begin
|
|
if Is_Reserved (Interrupt) then
|
|
raise Program_Error with
|
|
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
|
|
end if;
|
|
|
|
return Storage_Elements.To_Address
|
|
(Storage_Elements.Integer_Address (Interrupt));
|
|
end Reference;
|
|
|
|
---------------------------------
|
|
-- Register_Interrupt_Handler --
|
|
---------------------------------
|
|
|
|
procedure Register_Interrupt_Handler (Handler_Addr : System.Address) is
|
|
New_Node_Ptr : R_Link;
|
|
|
|
begin
|
|
-- This routine registers the Handler as usable for Dynamic Interrupt
|
|
-- Handler. Routines attaching and detaching Handler dynamically should
|
|
-- first consult if the Handler is registered. A Program Error should
|
|
-- be raised if it is not registered.
|
|
|
|
-- The pragma Interrupt_Handler can only appear in the library level PO
|
|
-- definition and instantiation. Therefore, we do not need to implement
|
|
-- Unregistering operation. Neither we need to protect the queue
|
|
-- structure using a Lock.
|
|
|
|
pragma Assert (Handler_Addr /= System.Null_Address);
|
|
|
|
New_Node_Ptr := new Registered_Handler;
|
|
New_Node_Ptr.H := Handler_Addr;
|
|
|
|
if Registered_Handler_Head = null then
|
|
Registered_Handler_Head := New_Node_Ptr;
|
|
Registered_Handler_Tail := New_Node_Ptr;
|
|
|
|
else
|
|
Registered_Handler_Tail.Next := New_Node_Ptr;
|
|
Registered_Handler_Tail := New_Node_Ptr;
|
|
end if;
|
|
end Register_Interrupt_Handler;
|
|
|
|
-----------------------
|
|
-- Unblock_Interrupt --
|
|
-----------------------
|
|
|
|
procedure Unblock_Interrupt (Interrupt : Interrupt_ID) is
|
|
begin
|
|
if Is_Reserved (Interrupt) then
|
|
raise Program_Error with
|
|
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
|
|
end if;
|
|
|
|
Interrupt_Manager.Unblock_Interrupt (Interrupt);
|
|
end Unblock_Interrupt;
|
|
|
|
------------------
|
|
-- Unblocked_By --
|
|
------------------
|
|
|
|
function Unblocked_By
|
|
(Interrupt : Interrupt_ID) return System.Tasking.Task_Id
|
|
is
|
|
begin
|
|
if Is_Reserved (Interrupt) then
|
|
raise Program_Error with
|
|
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
|
|
end if;
|
|
|
|
return Last_Unblocker (Interrupt);
|
|
end Unblocked_By;
|
|
|
|
------------------------
|
|
-- Unignore_Interrupt --
|
|
------------------------
|
|
|
|
procedure Unignore_Interrupt (Interrupt : Interrupt_ID) is
|
|
begin
|
|
if Is_Reserved (Interrupt) then
|
|
raise Program_Error with
|
|
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
|
|
end if;
|
|
|
|
Interrupt_Manager.Unignore_Interrupt (Interrupt);
|
|
end Unignore_Interrupt;
|
|
|
|
-----------------------
|
|
-- Interrupt_Manager --
|
|
-----------------------
|
|
|
|
task body Interrupt_Manager is
|
|
-- By making this task independent of master, when the process
|
|
-- goes away, the Interrupt_Manager will terminate gracefully.
|
|
|
|
Ignore : constant Boolean := System.Tasking.Utilities.Make_Independent;
|
|
|
|
---------------------
|
|
-- Local Variables --
|
|
---------------------
|
|
|
|
Intwait_Mask : aliased IMNG.Interrupt_Mask;
|
|
Ret_Interrupt : Interrupt_ID;
|
|
Old_Mask : aliased IMNG.Interrupt_Mask;
|
|
Old_Handler : Parameterless_Handler;
|
|
|
|
--------------------
|
|
-- Local Routines --
|
|
--------------------
|
|
|
|
procedure Bind_Handler (Interrupt : Interrupt_ID);
|
|
-- This procedure does not do anything if the Interrupt is blocked.
|
|
-- Otherwise, we have to interrupt Server_Task for status change through
|
|
-- Wakeup interrupt.
|
|
|
|
procedure Unbind_Handler (Interrupt : Interrupt_ID);
|
|
-- This procedure does not do anything if the Interrupt is blocked.
|
|
-- Otherwise, we have to interrupt Server_Task for status change
|
|
-- through abort interrupt.
|
|
|
|
procedure Unprotected_Exchange_Handler
|
|
(Old_Handler : out Parameterless_Handler;
|
|
New_Handler : Parameterless_Handler;
|
|
Interrupt : Interrupt_ID;
|
|
Static : Boolean;
|
|
Restoration : Boolean := False);
|
|
|
|
procedure Unprotected_Detach_Handler
|
|
(Interrupt : Interrupt_ID;
|
|
Static : Boolean);
|
|
|
|
------------------
|
|
-- Bind_Handler --
|
|
------------------
|
|
|
|
procedure Bind_Handler (Interrupt : Interrupt_ID) is
|
|
begin
|
|
if not Blocked (Interrupt) then
|
|
|
|
-- Mask this task for the given Interrupt so that all tasks
|
|
-- are masked for the Interrupt and the actual delivery of the
|
|
-- Interrupt will be caught using "sigwait" by the
|
|
-- corresponding Server_Task.
|
|
|
|
IMOP.Thread_Block_Interrupt (IMNG.Interrupt_ID (Interrupt));
|
|
|
|
-- We have installed a Handler or an Entry before we called
|
|
-- this procedure. If the Handler Task is waiting to be awakened,
|
|
-- do it here. Otherwise, the interrupt will be discarded.
|
|
|
|
POP.Wakeup (Server_ID (Interrupt), Interrupt_Server_Idle_Sleep);
|
|
end if;
|
|
end Bind_Handler;
|
|
|
|
--------------------
|
|
-- Unbind_Handler --
|
|
--------------------
|
|
|
|
procedure Unbind_Handler (Interrupt : Interrupt_ID) is
|
|
Server : System.Tasking.Task_Id;
|
|
|
|
begin
|
|
if not Blocked (Interrupt) then
|
|
|
|
-- Currently, there is a Handler or an Entry attached and
|
|
-- corresponding Server_Task is waiting on "sigwait." We have to
|
|
-- wake up the Server_Task and make it wait on condition variable
|
|
-- by sending an Abort_Task_Interrupt
|
|
|
|
Server := Server_ID (Interrupt);
|
|
|
|
case Server.Common.State is
|
|
when Interrupt_Server_Blocked_Interrupt_Sleep
|
|
| Interrupt_Server_Idle_Sleep
|
|
=>
|
|
POP.Wakeup (Server, Server.Common.State);
|
|
|
|
when Interrupt_Server_Blocked_On_Event_Flag =>
|
|
POP.Abort_Task (Server);
|
|
|
|
-- Make sure corresponding Server_Task is out of its
|
|
-- own sigwait state.
|
|
|
|
Ret_Interrupt :=
|
|
Interrupt_ID (IMOP.Interrupt_Wait (Intwait_Mask'Access));
|
|
pragma Assert
|
|
(Ret_Interrupt = Interrupt_ID (IMNG.Abort_Task_Interrupt));
|
|
|
|
when Runnable =>
|
|
null;
|
|
|
|
when others =>
|
|
pragma Assert (False);
|
|
null;
|
|
end case;
|
|
|
|
IMOP.Install_Default_Action (IMNG.Interrupt_ID (Interrupt));
|
|
|
|
-- Unmake the Interrupt for this task in order to allow default
|
|
-- action again.
|
|
|
|
IMOP.Thread_Unblock_Interrupt (IMNG.Interrupt_ID (Interrupt));
|
|
|
|
else
|
|
IMOP.Install_Default_Action (IMNG.Interrupt_ID (Interrupt));
|
|
end if;
|
|
end Unbind_Handler;
|
|
|
|
--------------------------------
|
|
-- Unprotected_Detach_Handler --
|
|
--------------------------------
|
|
|
|
procedure Unprotected_Detach_Handler
|
|
(Interrupt : Interrupt_ID;
|
|
Static : Boolean)
|
|
is
|
|
Old_Handler : Parameterless_Handler;
|
|
|
|
begin
|
|
if User_Entry (Interrupt).T /= Null_Task then
|
|
|
|
-- In case we have an Interrupt Entry installed, raise a program
|
|
-- error, (propagate it to the caller).
|
|
|
|
raise Program_Error with
|
|
"an interrupt entry is already installed";
|
|
end if;
|
|
|
|
-- Note : Static = True will pass the following check. That is the
|
|
-- case when we want to detach a handler regardless of the static
|
|
-- status of the current_Handler.
|
|
|
|
if not Static and then User_Handler (Interrupt).Static then
|
|
|
|
-- Tries to detach a static Interrupt Handler.
|
|
-- raise a program error.
|
|
|
|
raise Program_Error with
|
|
"trying to detach a static interrupt handler";
|
|
end if;
|
|
|
|
-- The interrupt should no longer be ignored if
|
|
-- it was ever ignored.
|
|
|
|
Ignored (Interrupt) := False;
|
|
|
|
Old_Handler := User_Handler (Interrupt).H;
|
|
|
|
-- The new handler
|
|
|
|
User_Handler (Interrupt).H := null;
|
|
User_Handler (Interrupt).Static := False;
|
|
|
|
if Old_Handler /= null then
|
|
Unbind_Handler (Interrupt);
|
|
end if;
|
|
end Unprotected_Detach_Handler;
|
|
|
|
----------------------------------
|
|
-- Unprotected_Exchange_Handler --
|
|
----------------------------------
|
|
|
|
procedure Unprotected_Exchange_Handler
|
|
(Old_Handler : out Parameterless_Handler;
|
|
New_Handler : Parameterless_Handler;
|
|
Interrupt : Interrupt_ID;
|
|
Static : Boolean;
|
|
Restoration : Boolean := False)
|
|
is
|
|
begin
|
|
if User_Entry (Interrupt).T /= Null_Task then
|
|
|
|
-- In case we have an Interrupt Entry already installed, raise a
|
|
-- program error, (propagate it to the caller).
|
|
|
|
raise Program_Error with
|
|
"an interrupt is already installed";
|
|
end if;
|
|
|
|
-- Note : A null handler with Static = True will pass the following
|
|
-- check. That is the case when we want to Detach a handler
|
|
-- regardless of the Static status of the current_Handler.
|
|
|
|
-- We don't check anything if Restoration is True, since we may be
|
|
-- detaching a static handler to restore a dynamic one.
|
|
|
|
if not Restoration and then not Static
|
|
|
|
-- Tries to overwrite a static Interrupt Handler with a dynamic
|
|
-- Handler
|
|
|
|
and then (User_Handler (Interrupt).Static
|
|
|
|
-- The new handler is not specified as an
|
|
-- Interrupt Handler by a pragma.
|
|
|
|
or else not Is_Registered (New_Handler))
|
|
then
|
|
raise Program_Error with
|
|
"trying to overwrite a static Interrupt Handler with a " &
|
|
"dynamic handler";
|
|
end if;
|
|
|
|
-- The interrupt should no longer be ignored if
|
|
-- it was ever ignored.
|
|
|
|
Ignored (Interrupt) := False;
|
|
|
|
-- Save the old handler
|
|
|
|
Old_Handler := User_Handler (Interrupt).H;
|
|
|
|
-- The new handler
|
|
|
|
User_Handler (Interrupt).H := New_Handler;
|
|
|
|
if New_Handler = null then
|
|
|
|
-- The null handler means we are detaching the handler
|
|
|
|
User_Handler (Interrupt).Static := False;
|
|
|
|
else
|
|
User_Handler (Interrupt).Static := Static;
|
|
end if;
|
|
|
|
-- Invoke a corresponding Server_Task if not yet created.
|
|
-- Place Task_Id info in Server_ID array.
|
|
|
|
if Server_ID (Interrupt) = Null_Task then
|
|
|
|
-- When a new Server_Task is created, it should have its
|
|
-- signal mask set to the All_Tasks_Mask.
|
|
|
|
IMOP.Set_Interrupt_Mask
|
|
(IMOP.All_Tasks_Mask'Access, Old_Mask'Access);
|
|
Access_Hold := new Server_Task (Interrupt);
|
|
IMOP.Set_Interrupt_Mask (Old_Mask'Access);
|
|
|
|
Server_ID (Interrupt) := To_System (Access_Hold.all'Identity);
|
|
end if;
|
|
|
|
if New_Handler = null then
|
|
if Old_Handler /= null then
|
|
Unbind_Handler (Interrupt);
|
|
end if;
|
|
|
|
return;
|
|
end if;
|
|
|
|
if Old_Handler = null then
|
|
Bind_Handler (Interrupt);
|
|
end if;
|
|
end Unprotected_Exchange_Handler;
|
|
|
|
-- Start of processing for Interrupt_Manager
|
|
|
|
begin
|
|
-- Environment task gets its own interrupt mask, saves it, and then
|
|
-- masks all interrupts except the Keep_Unmasked set.
|
|
|
|
-- During rendezvous, the Interrupt_Manager receives the old interrupt
|
|
-- mask of the environment task, and sets its own interrupt mask to that
|
|
-- value.
|
|
|
|
-- The environment task will call the entry of Interrupt_Manager some
|
|
-- during elaboration of the body of this package.
|
|
|
|
accept Initialize (Mask : IMNG.Interrupt_Mask) do
|
|
declare
|
|
The_Mask : aliased IMNG.Interrupt_Mask;
|
|
begin
|
|
IMOP.Copy_Interrupt_Mask (The_Mask, Mask);
|
|
IMOP.Set_Interrupt_Mask (The_Mask'Access);
|
|
end;
|
|
end Initialize;
|
|
|
|
-- Note: All tasks in RTS will have all the Reserve Interrupts being
|
|
-- masked (except the Interrupt_Manager) and Keep_Unmasked unmasked
|
|
-- when created.
|
|
|
|
-- Abort_Task_Interrupt is one of the Interrupt unmasked in all tasks.
|
|
-- We mask the Interrupt in this particular task so that "sigwait" is
|
|
-- possible to catch an explicitly sent Abort_Task_Interrupt from the
|
|
-- Server_Tasks.
|
|
|
|
-- This sigwaiting is needed so that we make sure a Server_Task is out
|
|
-- of its own sigwait state. This extra synchronization is necessary to
|
|
-- prevent following scenarios.
|
|
|
|
-- 1) Interrupt_Manager sends an Abort_Task_Interrupt to the
|
|
-- Server_Task then changes its own interrupt mask (OS level).
|
|
-- If an interrupt (corresponding to the Server_Task) arrives
|
|
-- in the mean time we have the Interrupt_Manager unmasked and
|
|
-- the Server_Task waiting on sigwait.
|
|
|
|
-- 2) For unbinding handler, we install a default action in the
|
|
-- Interrupt_Manager. POSIX.1c states that the result of using
|
|
-- "sigwait" and "sigaction" simultaneously on the same interrupt
|
|
-- is undefined. Therefore, we need to be informed from the
|
|
-- Server_Task of the fact that the Server_Task is out of its
|
|
-- sigwait stage.
|
|
|
|
IMOP.Empty_Interrupt_Mask (Intwait_Mask'Access);
|
|
IMOP.Add_To_Interrupt_Mask
|
|
(Intwait_Mask'Access, IMNG.Abort_Task_Interrupt);
|
|
IMOP.Thread_Block_Interrupt
|
|
(IMNG.Abort_Task_Interrupt);
|
|
|
|
loop
|
|
-- A block is needed to absorb Program_Error exception
|
|
|
|
begin
|
|
select
|
|
accept Attach_Handler
|
|
(New_Handler : Parameterless_Handler;
|
|
Interrupt : Interrupt_ID;
|
|
Static : Boolean;
|
|
Restoration : Boolean := False)
|
|
do
|
|
Unprotected_Exchange_Handler
|
|
(Old_Handler, New_Handler, Interrupt, Static, Restoration);
|
|
end Attach_Handler;
|
|
|
|
or
|
|
accept Exchange_Handler
|
|
(Old_Handler : out Parameterless_Handler;
|
|
New_Handler : Parameterless_Handler;
|
|
Interrupt : Interrupt_ID;
|
|
Static : Boolean)
|
|
do
|
|
Unprotected_Exchange_Handler
|
|
(Old_Handler, New_Handler, Interrupt, Static);
|
|
end Exchange_Handler;
|
|
|
|
or
|
|
accept Detach_Handler
|
|
(Interrupt : Interrupt_ID;
|
|
Static : Boolean)
|
|
do
|
|
Unprotected_Detach_Handler (Interrupt, Static);
|
|
end Detach_Handler;
|
|
|
|
or
|
|
accept Bind_Interrupt_To_Entry
|
|
(T : Task_Id;
|
|
E : Task_Entry_Index;
|
|
Interrupt : Interrupt_ID)
|
|
do
|
|
-- If there is a binding already (either a procedure or an
|
|
-- entry), raise Program_Error (propagate it to the caller).
|
|
|
|
if User_Handler (Interrupt).H /= null
|
|
or else User_Entry (Interrupt).T /= Null_Task
|
|
then
|
|
raise Program_Error with
|
|
"a binding for this interrupt is already present";
|
|
end if;
|
|
|
|
-- The interrupt should no longer be ignored if
|
|
-- it was ever ignored.
|
|
|
|
Ignored (Interrupt) := False;
|
|
User_Entry (Interrupt) := Entry_Assoc'(T => T, E => E);
|
|
|
|
-- Indicate the attachment of Interrupt Entry in ATCB.
|
|
-- This is need so that when an Interrupt Entry task
|
|
-- terminates the binding can be cleaned. The call to
|
|
-- unbinding must be made by the task before it terminates.
|
|
|
|
T.Interrupt_Entry := True;
|
|
|
|
-- Invoke a corresponding Server_Task if not yet created.
|
|
-- Place Task_Id info in Server_ID array.
|
|
|
|
if Server_ID (Interrupt) = Null_Task then
|
|
|
|
-- When a new Server_Task is created, it should have its
|
|
-- signal mask set to the All_Tasks_Mask.
|
|
|
|
IMOP.Set_Interrupt_Mask
|
|
(IMOP.All_Tasks_Mask'Access, Old_Mask'Access);
|
|
Access_Hold := new Server_Task (Interrupt);
|
|
IMOP.Set_Interrupt_Mask (Old_Mask'Access);
|
|
Server_ID (Interrupt) :=
|
|
To_System (Access_Hold.all'Identity);
|
|
end if;
|
|
|
|
Bind_Handler (Interrupt);
|
|
end Bind_Interrupt_To_Entry;
|
|
|
|
or
|
|
accept Detach_Interrupt_Entries (T : Task_Id) do
|
|
for J in Interrupt_ID'Range loop
|
|
if not Is_Reserved (J) then
|
|
if User_Entry (J).T = T then
|
|
|
|
-- The interrupt should no longer be ignored if
|
|
-- it was ever ignored.
|
|
|
|
Ignored (J) := False;
|
|
User_Entry (J) := Entry_Assoc'
|
|
(T => Null_Task, E => Null_Task_Entry);
|
|
Unbind_Handler (J);
|
|
end if;
|
|
end if;
|
|
end loop;
|
|
|
|
-- Indicate in ATCB that no Interrupt Entries are attached
|
|
|
|
T.Interrupt_Entry := False;
|
|
end Detach_Interrupt_Entries;
|
|
|
|
or
|
|
accept Block_Interrupt (Interrupt : Interrupt_ID) do
|
|
if Blocked (Interrupt) then
|
|
return;
|
|
end if;
|
|
|
|
Blocked (Interrupt) := True;
|
|
Last_Unblocker (Interrupt) := Null_Task;
|
|
|
|
-- Mask this task for the given Interrupt so that all tasks
|
|
-- are masked for the Interrupt.
|
|
|
|
IMOP.Thread_Block_Interrupt (IMNG.Interrupt_ID (Interrupt));
|
|
|
|
if User_Handler (Interrupt).H /= null
|
|
or else User_Entry (Interrupt).T /= Null_Task
|
|
then
|
|
-- This is the case where the Server_Task
|
|
-- is waiting on"sigwait." Wake it up by sending an
|
|
-- Abort_Task_Interrupt so that the Server_Task waits
|
|
-- on Cond.
|
|
|
|
POP.Abort_Task (Server_ID (Interrupt));
|
|
|
|
-- Make sure corresponding Server_Task is out of its own
|
|
-- sigwait state.
|
|
|
|
Ret_Interrupt := Interrupt_ID
|
|
(IMOP.Interrupt_Wait (Intwait_Mask'Access));
|
|
pragma Assert
|
|
(Ret_Interrupt =
|
|
Interrupt_ID (IMNG.Abort_Task_Interrupt));
|
|
end if;
|
|
end Block_Interrupt;
|
|
|
|
or
|
|
accept Unblock_Interrupt (Interrupt : Interrupt_ID) do
|
|
if not Blocked (Interrupt) then
|
|
return;
|
|
end if;
|
|
|
|
Blocked (Interrupt) := False;
|
|
Last_Unblocker (Interrupt) :=
|
|
To_System (Unblock_Interrupt'Caller);
|
|
|
|
if User_Handler (Interrupt).H = null
|
|
and then User_Entry (Interrupt).T = Null_Task
|
|
then
|
|
-- No handler is attached. Unmask the Interrupt so that
|
|
-- the default action can be carried out.
|
|
|
|
IMOP.Thread_Unblock_Interrupt
|
|
(IMNG.Interrupt_ID (Interrupt));
|
|
|
|
else
|
|
-- The Server_Task must be waiting on the Cond variable
|
|
-- since it was being blocked and an Interrupt Hander or
|
|
-- an Entry was there. Wake it up and let it change it
|
|
-- place of waiting according to its new state.
|
|
|
|
POP.Wakeup (Server_ID (Interrupt),
|
|
Interrupt_Server_Blocked_Interrupt_Sleep);
|
|
end if;
|
|
end Unblock_Interrupt;
|
|
|
|
or
|
|
accept Ignore_Interrupt (Interrupt : Interrupt_ID) do
|
|
if Ignored (Interrupt) then
|
|
return;
|
|
end if;
|
|
|
|
Ignored (Interrupt) := True;
|
|
|
|
-- If there is a handler associated with the Interrupt,
|
|
-- detach it first. In this way we make sure that the
|
|
-- Server_Task is not on sigwait. This is legal since
|
|
-- Unignore_Interrupt is to install the default action.
|
|
|
|
if User_Handler (Interrupt).H /= null then
|
|
Unprotected_Detach_Handler
|
|
(Interrupt => Interrupt, Static => True);
|
|
|
|
elsif User_Entry (Interrupt).T /= Null_Task then
|
|
User_Entry (Interrupt) := Entry_Assoc'
|
|
(T => Null_Task, E => Null_Task_Entry);
|
|
Unbind_Handler (Interrupt);
|
|
end if;
|
|
|
|
IMOP.Install_Ignore_Action (IMNG.Interrupt_ID (Interrupt));
|
|
end Ignore_Interrupt;
|
|
|
|
or
|
|
accept Unignore_Interrupt (Interrupt : Interrupt_ID) do
|
|
Ignored (Interrupt) := False;
|
|
|
|
-- If there is a handler associated with the Interrupt,
|
|
-- detach it first. In this way we make sure that the
|
|
-- Server_Task is not on sigwait. This is legal since
|
|
-- Unignore_Interrupt is to install the default action.
|
|
|
|
if User_Handler (Interrupt).H /= null then
|
|
Unprotected_Detach_Handler
|
|
(Interrupt => Interrupt, Static => True);
|
|
|
|
elsif User_Entry (Interrupt).T /= Null_Task then
|
|
User_Entry (Interrupt) := Entry_Assoc'
|
|
(T => Null_Task, E => Null_Task_Entry);
|
|
Unbind_Handler (Interrupt);
|
|
end if;
|
|
|
|
IMOP.Install_Default_Action (IMNG.Interrupt_ID (Interrupt));
|
|
end Unignore_Interrupt;
|
|
end select;
|
|
|
|
exception
|
|
-- If there is a program error we just want to propagate it to
|
|
-- the caller and do not want to stop this task.
|
|
|
|
when Program_Error =>
|
|
null;
|
|
|
|
when X : others =>
|
|
System.IO.Put_Line ("Exception in Interrupt_Manager");
|
|
System.IO.Put_Line (Ada.Exceptions.Exception_Information (X));
|
|
pragma Assert (False);
|
|
end;
|
|
end loop;
|
|
end Interrupt_Manager;
|
|
|
|
-----------------
|
|
-- Server_Task --
|
|
-----------------
|
|
|
|
task body Server_Task is
|
|
-- By making this task independent of master, when the process goes
|
|
-- away, the Server_Task will terminate gracefully.
|
|
|
|
Ignore : constant Boolean := System.Tasking.Utilities.Make_Independent;
|
|
|
|
Intwait_Mask : aliased IMNG.Interrupt_Mask;
|
|
Ret_Interrupt : Interrupt_ID;
|
|
Self_ID : constant Task_Id := Self;
|
|
Tmp_Handler : Parameterless_Handler;
|
|
Tmp_ID : Task_Id;
|
|
Tmp_Entry_Index : Task_Entry_Index;
|
|
|
|
begin
|
|
-- Install default action in system level
|
|
|
|
IMOP.Install_Default_Action (IMNG.Interrupt_ID (Interrupt));
|
|
|
|
-- Note: All tasks in RTS will have all the Reserve Interrupts being
|
|
-- masked (except the Interrupt_Manager) and Keep_Unmasked unmasked when
|
|
-- created.
|
|
|
|
-- Abort_Task_Interrupt is one of the Interrupt unmasked in all tasks.
|
|
-- We mask the Interrupt in this particular task so that "sigwait" is
|
|
-- possible to catch an explicitly sent Abort_Task_Interrupt from the
|
|
-- Interrupt_Manager.
|
|
|
|
-- There are two Interrupt interrupts that this task catch through
|
|
-- "sigwait." One is the Interrupt this task is designated to catch
|
|
-- in order to execute user handler or entry. The other one is
|
|
-- the Abort_Task_Interrupt. This interrupt is being sent from the
|
|
-- Interrupt_Manager to inform status changes (e.g: become Blocked,
|
|
-- Handler or Entry is to be detached).
|
|
|
|
-- Prepare a mask to used for sigwait
|
|
|
|
IMOP.Empty_Interrupt_Mask (Intwait_Mask'Access);
|
|
|
|
IMOP.Add_To_Interrupt_Mask
|
|
(Intwait_Mask'Access, IMNG.Interrupt_ID (Interrupt));
|
|
|
|
IMOP.Add_To_Interrupt_Mask
|
|
(Intwait_Mask'Access, IMNG.Abort_Task_Interrupt);
|
|
|
|
IMOP.Thread_Block_Interrupt
|
|
(IMNG.Abort_Task_Interrupt);
|
|
|
|
PIO.Set_Interrupt_ID (IMNG.Interrupt_ID (Interrupt), Self_ID);
|
|
|
|
loop
|
|
System.Tasking.Initialization.Defer_Abort (Self_ID);
|
|
POP.Write_Lock (Self_ID);
|
|
|
|
if User_Handler (Interrupt).H = null
|
|
and then User_Entry (Interrupt).T = Null_Task
|
|
then
|
|
-- No Interrupt binding. If there is an interrupt,
|
|
-- Interrupt_Manager will take default action.
|
|
|
|
Self_ID.Common.State := Interrupt_Server_Blocked_Interrupt_Sleep;
|
|
POP.Sleep (Self_ID, Interrupt_Server_Idle_Sleep);
|
|
Self_ID.Common.State := Runnable;
|
|
|
|
elsif Blocked (Interrupt) then
|
|
|
|
-- Interrupt is blocked, stay here, so we won't catch it
|
|
|
|
Self_ID.Common.State := Interrupt_Server_Blocked_Interrupt_Sleep;
|
|
POP.Sleep (Self_ID, Interrupt_Server_Blocked_Interrupt_Sleep);
|
|
Self_ID.Common.State := Runnable;
|
|
|
|
else
|
|
-- A Handler or an Entry is installed. At this point all tasks
|
|
-- mask for the Interrupt is masked. Catch the Interrupt using
|
|
-- sigwait.
|
|
|
|
-- This task may wake up from sigwait by receiving an interrupt
|
|
-- (Abort_Task_Interrupt) from the Interrupt_Manager for unbinding
|
|
-- a Procedure Handler or an Entry. Or it could be a wake up
|
|
-- from status change (Unblocked -> Blocked). If that is not
|
|
-- the case, we should execute the attached Procedure or Entry.
|
|
|
|
Self_ID.Common.State := Interrupt_Server_Blocked_On_Event_Flag;
|
|
POP.Unlock (Self_ID);
|
|
|
|
-- Avoid race condition when terminating application and
|
|
-- System.Parameters.No_Abort is True.
|
|
|
|
if Parameters.No_Abort and then Self_ID.Pending_Action then
|
|
Initialization.Do_Pending_Action (Self_ID);
|
|
end if;
|
|
|
|
Ret_Interrupt :=
|
|
Interrupt_ID (IMOP.Interrupt_Wait (Intwait_Mask'Access));
|
|
Self_ID.Common.State := Runnable;
|
|
|
|
if Ret_Interrupt = Interrupt_ID (IMNG.Abort_Task_Interrupt) then
|
|
|
|
-- Inform the Interrupt_Manager of wakeup from above sigwait
|
|
|
|
POP.Abort_Task (Interrupt_Manager_ID);
|
|
POP.Write_Lock (Self_ID);
|
|
|
|
else
|
|
POP.Write_Lock (Self_ID);
|
|
|
|
if Ret_Interrupt /= Interrupt then
|
|
|
|
-- On some systems (e.g. recent linux kernels), sigwait
|
|
-- may return unexpectedly (with errno set to EINTR).
|
|
|
|
null;
|
|
|
|
else
|
|
-- Even though we have received an Interrupt the status may
|
|
-- have changed already before we got the Self_ID lock above
|
|
-- Therefore we make sure a Handler or an Entry is still
|
|
-- there and make appropriate call.
|
|
|
|
-- If there is no calls to make we need to regenerate the
|
|
-- Interrupt in order not to lose it.
|
|
|
|
if User_Handler (Interrupt).H /= null then
|
|
Tmp_Handler := User_Handler (Interrupt).H;
|
|
|
|
-- RTS calls should not be made with self being locked
|
|
|
|
POP.Unlock (Self_ID);
|
|
Tmp_Handler.all;
|
|
POP.Write_Lock (Self_ID);
|
|
|
|
elsif User_Entry (Interrupt).T /= Null_Task then
|
|
Tmp_ID := User_Entry (Interrupt).T;
|
|
Tmp_Entry_Index := User_Entry (Interrupt).E;
|
|
|
|
-- RTS calls should not be made with self being locked
|
|
|
|
POP.Unlock (Self_ID);
|
|
|
|
System.Tasking.Rendezvous.Call_Simple
|
|
(Tmp_ID, Tmp_Entry_Index, System.Null_Address);
|
|
|
|
POP.Write_Lock (Self_ID);
|
|
|
|
else
|
|
-- This is a situation that this task wakes up receiving
|
|
-- an Interrupt and before it gets the lock the Interrupt
|
|
-- is blocked. We do not want to lose the interrupt in
|
|
-- this case so we regenerate the Interrupt to process
|
|
-- level.
|
|
|
|
IMOP.Interrupt_Self_Process
|
|
(IMNG.Interrupt_ID (Interrupt));
|
|
end if;
|
|
end if;
|
|
end if;
|
|
end if;
|
|
|
|
POP.Unlock (Self_ID);
|
|
System.Tasking.Initialization.Undefer_Abort (Self_ID);
|
|
|
|
if Self_ID.Pending_Action then
|
|
Initialization.Do_Pending_Action (Self_ID);
|
|
end if;
|
|
|
|
-- Undefer abort here to allow a window for this task to be aborted
|
|
-- at the time of system shutdown. We also explicitly test for
|
|
-- Pending_Action in case System.Parameters.No_Abort is True.
|
|
|
|
end loop;
|
|
end Server_Task;
|
|
|
|
-- Elaboration code for package System.Interrupts
|
|
|
|
begin
|
|
-- Get Interrupt_Manager's ID so that Abort_Interrupt can be sent
|
|
|
|
Interrupt_Manager_ID := To_System (Interrupt_Manager'Identity);
|
|
|
|
-- During the elaboration of this package body we want the RTS
|
|
-- to inherit the interrupt mask from the Environment Task.
|
|
|
|
IMOP.Setup_Interrupt_Mask;
|
|
|
|
-- The environment task should have gotten its mask from the enclosing
|
|
-- process during the RTS start up. (See processing in s-inmaop.adb). Pass
|
|
-- the Interrupt_Mask of the environment task to the Interrupt_Manager.
|
|
|
|
-- Note: At this point we know that all tasks are masked for non-reserved
|
|
-- signals. Only the Interrupt_Manager will have masks set up differently
|
|
-- inheriting the original environment task's mask.
|
|
|
|
Interrupt_Manager.Initialize (IMOP.Environment_Mask);
|
|
end System.Interrupts;
|