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------------------------------------------------------------------------------
-- --
-- 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) 1992-2006, 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 an OpenVMS/Alpha version of this package
-- Invariants:
-- 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.
-- Within this package, the lock L is used to protect the various status
-- tables. If there is a Server_Task associated with an interrupt, we use
-- the per-task lock of the Server_Task instead so that we protect the
-- status between Interrupt_Manager and Server_Task. Protection among
-- service requests are done using User Request to Interrupt_Manager
-- rendezvous.
with Ada.Task_Identification;
-- used for Task_Id type
with Ada.Exceptions;
-- used for Raise_Exception
with System.Task_Primitives;
-- used for RTS_Lock
-- Self
with System.Interrupt_Management;
-- used for Reserve
-- Interrupt_ID
-- Interrupt_Mask
-- Abort_Task_Interrupt
with System.Interrupt_Management.Operations;
-- used for Thread_Block_Interrupt
-- Thread_Unblock_Interrupt
-- Install_Default_Action
-- Install_Ignore_Action
-- Copy_Interrupt_Mask
-- Set_Interrupt_Mask
-- Empty_Interrupt_Mask
-- Fill_Interrupt_Mask
-- Add_To_Interrupt_Mask
-- Delete_From_Interrupt_Mask
-- Interrupt_Wait
-- Interrupt_Self_Process
-- Get_Interrupt_Mask
-- Set_Interrupt_Mask
-- IS_Member
-- Environment_Mask
pragma Elaborate_All (System.Interrupt_Management.Operations);
with System.Task_Primitives.Operations;
-- used for Write_Lock
-- Unlock
-- Abort
-- Wakeup_Task
-- Sleep
-- Initialize_Lock
with System.Task_Primitives.Interrupt_Operations;
-- used for Set_Interrupt_ID
with System.Storage_Elements;
-- used for To_Address
-- To_Integer
-- Integer_Address
with System.Tasking.Utilities;
-- used for Make_Independent
with System.Tasking.Rendezvous;
-- used for Call_Simple
pragma Elaborate_All (System.Tasking.Rendezvous);
with System.Tasking.Initialization;
-- used for Defer_Abort
-- Undefer_Abort
with System.Parameters;
-- used for Single_Lock
with Unchecked_Conversion;
package body System.Interrupts is
use Tasking;
use System.Parameters;
use Ada.Exceptions;
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 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 : constant array (Interrupt_ID'Range) of Boolean :=
(others => False);
-- ??? pragma Volatile_Components (Blocked);
-- True iff the corresponding interrupt is blocked in the process level
Ignored : array (Interrupt_ID'Range) of Boolean := (others => False);
pragma Volatile_Components (Ignored);
-- True iff the corresponding interrupt is blocked in the process level
Last_Unblocker : constant array (Interrupt_ID'Range) of Task_Id :=
(others => Null_Task);
-- ??? pragma Volatile_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.
--------------------------------
-- 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 rgistered.
-- 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;
-------------------
-- Is_Registered --
-------------------
function Is_Registered (Handler : Parameterless_Handler) return Boolean is
type Fat_Ptr is record
Object_Addr : System.Address;
Handler_Addr : System.Address;
end record;
function To_Fat_Ptr is new 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 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;
-----------------------
-- Is_Entry_Attached --
-----------------------
function Is_Entry_Attached (Interrupt : Interrupt_ID) return Boolean is
begin
if Is_Reserved (Interrupt) then
Raise_Exception (Program_Error'Identity, "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_Exception (Program_Error'Identity, "Interrupt" &
Interrupt_ID'Image (Interrupt) & " is reserved");
end if;
return User_Handler (Interrupt).H /= null;
end Is_Handler_Attached;
----------------
-- Is_Blocked --
----------------
function Is_Blocked (Interrupt : Interrupt_ID) return Boolean is
begin
if Is_Reserved (Interrupt) then
Raise_Exception (Program_Error'Identity, "Interrupt" &
Interrupt_ID'Image (Interrupt) & " is reserved");
end if;
return Blocked (Interrupt);
end Is_Blocked;
----------------
-- Is_Ignored --
----------------
function Is_Ignored (Interrupt : Interrupt_ID) return Boolean is
begin
if Is_Reserved (Interrupt) then
Raise_Exception (Program_Error'Identity, "Interrupt" &
Interrupt_ID'Image (Interrupt) & " is reserved");
end if;
return Ignored (Interrupt);
end Is_Ignored;
---------------------
-- Current_Handler --
---------------------
function Current_Handler
(Interrupt : Interrupt_ID) return Parameterless_Handler
is
begin
if Is_Reserved (Interrupt) then
Raise_Exception (Program_Error'Identity, "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;
--------------------
-- 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 (ie. 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_Exception (Program_Error'Identity, "Interrupt" &
Interrupt_ID'Image (Interrupt) & " is reserved");
end if;
Interrupt_Manager.Attach_Handler (New_Handler, Interrupt, Static);
end Attach_Handler;
----------------------
-- 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 (ie. do not care if it is 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_Exception (Program_Error'Identity, "Interrupt" &
Interrupt_ID'Image (Interrupt) & " is reserved");
end if;
Interrupt_Manager.Exchange_Handler
(Old_Handler, New_Handler, Interrupt, Static);
end Exchange_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_Exception (Program_Error'Identity, "Interrupt" &
Interrupt_ID'Image (Interrupt) & " is reserved");
end if;
Interrupt_Manager.Detach_Handler (Interrupt, Static);
end Detach_Handler;
---------------
-- Reference --
---------------
function Reference (Interrupt : Interrupt_ID) return System.Address is
begin
if Is_Reserved (Interrupt) then
Raise_Exception (Program_Error'Identity, "Interrupt" &
Interrupt_ID'Image (Interrupt) & " is reserved");
end if;
return Storage_Elements.To_Address
(Storage_Elements.Integer_Address (Interrupt));
end Reference;
-----------------------------
-- 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_Exception (Program_Error'Identity, "Interrupt" &
Interrupt_ID'Image (Interrupt) & " is reserved");
end if;
Interrupt_Manager.Bind_Interrupt_To_Entry (T, E, Interrupt);
end Bind_Interrupt_To_Entry;
------------------------------
-- Detach_Interrupt_Entries --
------------------------------
procedure Detach_Interrupt_Entries (T : Task_Id) is
begin
Interrupt_Manager.Detach_Interrupt_Entries (T);
end Detach_Interrupt_Entries;
---------------------
-- Block_Interrupt --
---------------------
procedure Block_Interrupt (Interrupt : Interrupt_ID) is
begin
if Is_Reserved (Interrupt) then
Raise_Exception (Program_Error'Identity, "Interrupt" &
Interrupt_ID'Image (Interrupt) & " is reserved");
end if;
Interrupt_Manager.Block_Interrupt (Interrupt);
end Block_Interrupt;
-----------------------
-- Unblock_Interrupt --
-----------------------
procedure Unblock_Interrupt (Interrupt : Interrupt_ID) is
begin
if Is_Reserved (Interrupt) then
Raise_Exception (Program_Error'Identity, "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_Exception (Program_Error'Identity, "Interrupt" &
Interrupt_ID'Image (Interrupt) & " is reserved");
end if;
return Last_Unblocker (Interrupt);
end Unblocked_By;
----------------------
-- Ignore_Interrupt --
----------------------
procedure Ignore_Interrupt (Interrupt : Interrupt_ID) is
begin
if Is_Reserved (Interrupt) then
Raise_Exception (Program_Error'Identity, "Interrupt" &
Interrupt_ID'Image (Interrupt) & " is reserved");
end if;
Interrupt_Manager.Ignore_Interrupt (Interrupt);
end Ignore_Interrupt;
------------------------
-- Unignore_Interrupt --
------------------------
procedure Unignore_Interrupt (Interrupt : Interrupt_ID) is
begin
if Is_Reserved (Interrupt) then
Raise_Exception (Program_Error'Identity, "Interrupt" &
Interrupt_ID'Image (Interrupt) & " is reserved");
end if;
Interrupt_Manager.Unignore_Interrupt (Interrupt);
end Unignore_Interrupt;
-----------------------
-- Interrupt_Manager --
-----------------------
task body Interrupt_Manager is
--------------------
-- Local Routines --
--------------------
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);
----------------------------------
-- 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_Exception (Program_Error'Identity,
"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_Exception (Program_Error'Identity,
"Trying to overwrite a static Interrupt Handler with a " &
"dynamic Handler");
end if;
-- The interrupt should no longer be ingnored 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
Access_Hold := new Server_Task (Interrupt);
Server_ID (Interrupt) := To_System (Access_Hold.all'Identity);
else
POP.Wakeup (Server_ID (Interrupt), Interrupt_Server_Idle_Sleep);
end if;
end Unprotected_Exchange_Handler;
--------------------------------
-- Unprotected_Detach_Handler --
--------------------------------
procedure Unprotected_Detach_Handler
(Interrupt : Interrupt_ID;
Static : Boolean)
is
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_Exception (Program_Error'Identity,
"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_Exception (Program_Error'Identity,
"Trying to detach a static Interrupt Handler");
end if;
-- The interrupt should no longer be ignored if
-- it was ever ignored.
Ignored (Interrupt) := False;
-- The new handler
User_Handler (Interrupt).H := null;
User_Handler (Interrupt).Static := False;
IMOP.Interrupt_Self_Process (IMNG.Interrupt_ID (Interrupt));
end Unprotected_Detach_Handler;
-- Start of processing for Interrupt_Manager
begin
-- By making this task independent of master, when the process
-- goes away, the Interrupt_Manager will terminate gracefully.
System.Tasking.Utilities.Make_Independent;
-- Environmen 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
pragma Warnings (Off, Mask);
null;
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 explicitely 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 senarios.
-- 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 nean time we have the Interrupt_Manager umnasked 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" simaltaneously 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.
loop
-- A block is needed to absorb Program_Error exception
declare
Old_Handler : Parameterless_Handler;
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_Exception (Program_Error'Identity,
"A binding for this interrupt is already present");
end if;
-- The interrupt should no longer be ingnored 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
-- make 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
Access_Hold := new Server_Task (Interrupt);
Server_ID (Interrupt) :=
To_System (Access_Hold.all'Identity);
else
POP.Wakeup (Server_ID (Interrupt),
Interrupt_Server_Idle_Sleep);
end if;
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);
IMOP.Interrupt_Self_Process (IMNG.Interrupt_ID (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
pragma Warnings (Off, Interrupt);
raise Program_Error;
end Block_Interrupt;
or accept Unblock_Interrupt (Interrupt : Interrupt_ID) do
pragma Warnings (Off, Interrupt);
raise Program_Error;
end Unblock_Interrupt;
or accept Ignore_Interrupt (Interrupt : Interrupt_ID) do
pragma Warnings (Off, Interrupt);
raise Program_Error;
end Ignore_Interrupt;
or accept Unignore_Interrupt (Interrupt : Interrupt_ID) do
pragma Warnings (Off, Interrupt);
raise Program_Error;
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 others =>
pragma Assert (False);
null;
end;
end loop;
end Interrupt_Manager;
-----------------
-- Server_Task --
-----------------
task body Server_Task is
Self_ID : constant Task_Id := Self;
Tmp_Handler : Parameterless_Handler;
Tmp_ID : Task_Id;
Tmp_Entry_Index : Task_Entry_Index;
Intwait_Mask : aliased IMNG.Interrupt_Mask;
begin
-- By making this task independent of master, when the process
-- goes away, the Server_Task will terminate gracefully.
System.Tasking.Utilities.Make_Independent;
-- Install default action in system level.
IMOP.Install_Default_Action (IMNG.Interrupt_ID (Interrupt));
-- Set up the mask (also clears the event flag)
IMOP.Empty_Interrupt_Mask (Intwait_Mask'Access);
IMOP.Add_To_Interrupt_Mask
(Intwait_Mask'Access, IMNG.Interrupt_ID (Interrupt));
-- Remember the Interrupt_ID for Abort_Task.
PIO.Set_Interrupt_ID (IMNG.Interrupt_ID (Interrupt), Self_ID);
-- Note: All tasks in RTS will have all the Reserve Interrupts
-- being masked (except the Interrupt_Manager) and Keep_Unmasked
-- unmasked when created.
loop
System.Tasking.Initialization.Defer_Abort (Self_ID);
-- 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 exceute the attached Procedure or Entry.
if Single_Lock then
POP.Lock_RTS;
end if;
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_Idle_Sleep;
POP.Sleep (Self_ID, Interrupt_Server_Idle_Sleep);
Self_ID.Common.State := Runnable;
else
Self_ID.Common.State := Interrupt_Server_Blocked_On_Event_Flag;
Self_ID.Common.State := Runnable;
if not (Self_ID.Deferral_Level = 0
and then Self_ID.Pending_ATC_Level
< Self_ID.ATC_Nesting_Level)
then
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);
if Single_Lock then
POP.Unlock_RTS;
end if;
Tmp_Handler.all;
if Single_Lock then
POP.Lock_RTS;
end if;
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);
if Single_Lock then
POP.Unlock_RTS;
end if;
System.Tasking.Rendezvous.Call_Simple
(Tmp_ID, Tmp_Entry_Index, System.Null_Address);
if Single_Lock then
POP.Lock_RTS;
end if;
POP.Write_Lock (Self_ID);
end if;
end if;
end if;
POP.Unlock (Self_ID);
if Single_Lock then
POP.Unlock_RTS;
end if;
System.Tasking.Initialization.Undefer_Abort (Self_ID);
-- Undefer abort here to allow a window for this task
-- to be aborted at the time of system shutdown.
end loop;
end Server_Task;
-------------------------------------
-- Has_Interrupt_Or_Attach_Handler --
-------------------------------------
function Has_Interrupt_Or_Attach_Handler
(Object : access Dynamic_Interrupt_Protection) return Boolean
is
pragma Warnings (Off, Object);
begin
return True;
end Has_Interrupt_Or_Attach_Handler;
--------------
-- Finalize --
--------------
procedure Finalize (Object : in out Static_Interrupt_Protection) is
begin
-- ??? loop to be executed only when we're not doing library level
-- finalization, since in this case all interrupt tasks are gone.
if not Interrupt_Manager'Terminated 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 --
-------------------------------------
function Has_Interrupt_Or_Attach_Handler
(Object : access Static_Interrupt_Protection) return Boolean
is
pragma Warnings (Off, Object);
begin
return True;
end Has_Interrupt_Or_Attach_Handler;
----------------------
-- 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;
-- 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 RTS to inherit the
-- interrupt mask from the Environment Task.
-- The Environment Task should have gotten its mask from the enclosing
-- process during the RTS start up. (See 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 (including RTS internal
-- servers) are masked for non-reserved signals (see s-taprop.adb). 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;