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ubuntu-buildroot/output/build/host-gcc-initial-11.4.0/gcc/ada/libgnarl/s-interr__hwint.adb

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2024-04-01 15:19:46 +00:00
------------------------------------------------------------------------------
-- --
-- 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-handlable signals are masked at all times in all tasks/threads
-- except possibly for the Interrupt_Manager task.
-- When a user task wants to have the effect of masking/unmasking an signal,
-- it must call Block_Interrupt/Unblock_Interrupt, which will have the effect
-- of unmasking/masking the signal in the Interrupt_Manager task. These
-- comments do not apply to vectored hardware interrupts, which may be masked
-- or unmasked using routined interfaced to the relevant embedded RTOS system
-- calls.
-- Once we associate a Signal_Server_Task with an signal, the task never goes
-- away, and we never remove the association. On the other hand, it is more
-- convenient to terminate an associated Interrupt_Server_Task for a vectored
-- hardware interrupt (since we use a binary semaphore for synchronization
-- with the umbrella handler).
-- There is no more than one signal per Signal_Server_Task and no more than
-- one Signal_Server_Task per signal. The same relation holds for hardware
-- interrupts and Interrupt_Server_Task's at any given time. That is, only
-- one non-terminated Interrupt_Server_Task exists for a give interrupt at
-- any time.
-- Within this package, the lock L is used to protect the various status
-- tables. If there is a Server_Task associated with a signal or 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 ensured via user calls to the Interrupt_Manager entries.
-- This is reasonably generic version of this package, supporting vectored
-- hardware interrupts using non-RTOS specific adapter routines which should
-- easily implemented on any RTOS capable of supporting GNAT.
with Ada.Unchecked_Conversion;
with Ada.Task_Identification;
with Interfaces.C; use Interfaces.C;
with System.OS_Interface; use System.OS_Interface;
with System.Interrupt_Management;
with System.Task_Primitives.Operations;
with System.Storage_Elements;
with System.Tasking.Utilities;
with System.Tasking.Rendezvous;
pragma Elaborate_All (System.Tasking.Rendezvous);
package body System.Interrupts is
use Tasking;
package POP renames System.Task_Primitives.Operations;
function To_Ada is new Ada.Unchecked_Conversion
(System.Tasking.Task_Id, Ada.Task_Identification.Task_Id);
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 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);
pragma Interrupt_Priority (System.Interrupt_Priority'First);
end Interrupt_Manager;
task type Interrupt_Server_Task
(Interrupt : Interrupt_ID;
Int_Sema : Binary_Semaphore_Id)
is
-- Server task for vectored hardware interrupt handling
pragma Interrupt_Priority (System.Interrupt_Priority'First + 2);
end Interrupt_Server_Task;
type Interrupt_Task_Access is access Interrupt_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) 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 or signal. A handler is static iff it
-- is specified through the pragma Attach_Handler.
User_Entry : array (Interrupt_ID) 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 / signal
-- 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;
Server_ID : array (Interrupt_ID) of System.Tasking.Task_Id :=
(others => System.Tasking.Null_Task);
pragma Atomic_Components (Server_ID);
-- Holds the Task_Id of the Server_Task for each interrupt / signal.
-- Task_Id is needed to accomplish locking per interrupt base. Also
-- is needed to determine whether to create a new Server_Task.
Semaphore_ID_Map : array
(Interrupt_ID range 0 .. System.OS_Interface.Max_HW_Interrupt) of
Binary_Semaphore_Id := (others => 0);
-- Array of binary semaphores associated with vectored interrupts. Note
-- that the last bound should be Max_HW_Interrupt, but this will raise
-- Storage_Error if Num_HW_Interrupts is null so use extra 4 bytes instead.
Interrupt_Access_Hold : Interrupt_Task_Access;
-- Variable for allocating an Interrupt_Server_Task
Handler_Installed : array (HW_Interrupt) of Boolean := (others => False);
-- True if Notify_Interrupt was connected to the interrupt. Handlers can
-- be connected but disconnection is not possible on VxWorks. Therefore
-- we ensure Notify_Installed is connected at most once.
-----------------------
-- Local Subprograms --
-----------------------
procedure Check_Reserved_Interrupt (Interrupt : Interrupt_ID);
-- Check if Id is a reserved interrupt, and if so raise Program_Error
-- with an appropriate message, otherwise return.
procedure Finalize_Interrupt_Servers;
-- Unbind the handlers for hardware interrupt server tasks at program
-- termination.
function Is_Registered (Handler : Parameterless_Handler) return Boolean;
-- See if Handler has been "pragma"ed using Interrupt_Handler.
-- Always consider a null handler as registered.
procedure Notify_Interrupt (Param : System.Address);
pragma Convention (C, Notify_Interrupt);
-- Umbrella handler for vectored interrupts (not signals)
procedure Install_Umbrella_Handler
(Interrupt : HW_Interrupt;
Handler : System.OS_Interface.Interrupt_Handler);
-- Install the runtime umbrella handler for a vectored hardware
-- interrupt
procedure Unimplemented (Feature : String);
pragma No_Return (Unimplemented);
-- Used to mark a call to an unimplemented function. Raises Program_Error
-- with an appropriate message noting that Feature is unimplemented.
--------------------
-- 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
Check_Reserved_Interrupt (Interrupt);
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
Check_Reserved_Interrupt (Interrupt);
Interrupt_Manager.Bind_Interrupt_To_Entry (T, E, Interrupt);
end Bind_Interrupt_To_Entry;
---------------------
-- Block_Interrupt --
---------------------
procedure Block_Interrupt (Interrupt : Interrupt_ID) is
begin
Unimplemented ("Block_Interrupt");
end Block_Interrupt;
------------------------------
-- Check_Reserved_Interrupt --
------------------------------
procedure Check_Reserved_Interrupt (Interrupt : Interrupt_ID) is
begin
if Is_Reserved (Interrupt) then
raise Program_Error with
"interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved";
else
return;
end if;
end Check_Reserved_Interrupt;
---------------------
-- Current_Handler --
---------------------
function Current_Handler
(Interrupt : Interrupt_ID) return Parameterless_Handler
is
begin
Check_Reserved_Interrupt (Interrupt);
-- ??? 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
Check_Reserved_Interrupt (Interrupt);
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. we 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
Check_Reserved_Interrupt (Interrupt);
Interrupt_Manager.Exchange_Handler
(Old_Handler, New_Handler, Interrupt, Static);
end Exchange_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 / signal 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;
--------------------------------
-- Finalize_Interrupt_Servers --
--------------------------------
-- Restore default handlers for interrupt servers
-- This is called by the Interrupt_Manager task when it receives the abort
-- signal during program finalization.
procedure Finalize_Interrupt_Servers is
HW_Interrupts : constant Boolean := HW_Interrupt'Last >= 0;
begin
if HW_Interrupts then
for Int in HW_Interrupt loop
if Server_ID (Interrupt_ID (Int)) /= null
and then
not Ada.Task_Identification.Is_Terminated
(To_Ada (Server_ID (Interrupt_ID (Int))))
then
Interrupt_Manager.Attach_Handler
(New_Handler => null,
Interrupt => Interrupt_ID (Int),
Static => True,
Restoration => True);
end if;
end loop;
end if;
end Finalize_Interrupt_Servers;
-------------------------------------
-- Has_Interrupt_Or_Attach_Handler --
-------------------------------------
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
Unimplemented ("Ignore_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;
------------------------------
-- Install_Umbrella_Handler --
------------------------------
procedure Install_Umbrella_Handler
(Interrupt : HW_Interrupt;
Handler : System.OS_Interface.Interrupt_Handler)
is
Vec : constant Interrupt_Vector :=
Interrupt_Number_To_Vector (int (Interrupt));
Status : int;
begin
-- Only install umbrella handler when no Ada handler has already been
-- installed. Note that the interrupt number is passed as a parameter
-- when an interrupt occurs, so the umbrella handler has a different
-- wrapper generated by intConnect for each interrupt number.
if not Handler_Installed (Interrupt) then
Status :=
Interrupt_Connect (Vec, Handler, System.Address (Interrupt));
pragma Assert (Status = 0);
Handler_Installed (Interrupt) := True;
end if;
end Install_Umbrella_Handler;
----------------
-- Is_Blocked --
----------------
function Is_Blocked (Interrupt : Interrupt_ID) return Boolean is
begin
Unimplemented ("Is_Blocked");
return False;
end Is_Blocked;
-----------------------
-- Is_Entry_Attached --
-----------------------
function Is_Entry_Attached (Interrupt : Interrupt_ID) return Boolean is
begin
Check_Reserved_Interrupt (Interrupt);
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
Check_Reserved_Interrupt (Interrupt);
return User_Handler (Interrupt).H /= null;
end Is_Handler_Attached;
----------------
-- Is_Ignored --
----------------
function Is_Ignored (Interrupt : Interrupt_ID) return Boolean is
begin
Unimplemented ("Is_Ignored");
return False;
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
use System.Interrupt_Management;
begin
return Reserve (System.Interrupt_Management.Interrupt_ID (Interrupt));
end Is_Reserved;
----------------------
-- Notify_Interrupt --
----------------------
-- Umbrella handler for vectored hardware interrupts (as opposed to signals
-- and exceptions). As opposed to the signal implementation, this handler
-- is installed in the vector table when the first Ada handler is attached
-- to the interrupt. However because VxWorks don't support disconnecting
-- handlers, this subprogram always test whether or not an Ada handler is
-- effectively attached.
-- Otherwise, the handler that existed prior to program startup is in the
-- vector table. This ensures that handlers installed by the BSP are active
-- unless explicitly replaced in the program text.
-- Each Interrupt_Server_Task has an associated binary semaphore on which
-- it pends once it's been started. This routine determines The appropriate
-- semaphore and issues a semGive call, waking the server task. When
-- a handler is unbound, System.Interrupts.Unbind_Handler issues a
-- Binary_Semaphore_Flush, and the server task deletes its semaphore
-- and terminates.
procedure Notify_Interrupt (Param : System.Address) is
Interrupt : constant Interrupt_ID := Interrupt_ID (Param);
Id : constant Binary_Semaphore_Id := Semaphore_ID_Map (Interrupt);
Status : int;
begin
if Id /= 0 then
Status := Binary_Semaphore_Release (Id);
pragma Assert (Status = 0);
end if;
end Notify_Interrupt;
---------------
-- Reference --
---------------
function Reference (Interrupt : Interrupt_ID) return System.Address is
begin
Check_Reserved_Interrupt (Interrupt);
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 a handler as usable for dynamic interrupt
-- handler association. Routines attaching and detaching handlers
-- dynamically should determine whether the handler is registered.
-- Program_Error should be raised if it is not registered.
-- Pragma Interrupt_Handler can only appear in a library level PO
-- definition and instantiation. Therefore, we do not need to implement
-- an unregister operation. Nor do we need to protect the queue
-- structure with 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
Unimplemented ("Unblock_Interrupt");
end Unblock_Interrupt;
------------------
-- Unblocked_By --
------------------
function Unblocked_By
(Interrupt : Interrupt_ID) return System.Tasking.Task_Id
is
begin
Unimplemented ("Unblocked_By");
return Null_Task;
end Unblocked_By;
------------------------
-- Unignore_Interrupt --
------------------------
procedure Unignore_Interrupt (Interrupt : Interrupt_ID) is
begin
Unimplemented ("Unignore_Interrupt");
end Unignore_Interrupt;
-------------------
-- Unimplemented --
-------------------
procedure Unimplemented (Feature : String) is
begin
raise Program_Error with Feature & " not implemented on VxWorks";
end Unimplemented;
-----------------------
-- Interrupt_Manager --
-----------------------
task body Interrupt_Manager is
-- By making this task independent of any master, when the process goes
-- away, the Interrupt_Manager will terminate gracefully.
Ignore : constant Boolean := System.Tasking.Utilities.Make_Independent;
pragma Unreferenced (Ignore);
--------------------
-- Local Routines --
--------------------
procedure Bind_Handler (Interrupt : Interrupt_ID);
-- This procedure does not do anything if a signal is blocked.
-- Otherwise, we have to interrupt Server_Task for status change
-- through a wakeup signal.
procedure Unbind_Handler (Interrupt : Interrupt_ID);
-- This procedure does not do anything if a signal is blocked.
-- Otherwise, we have to interrupt Server_Task for status change
-- through an abort signal.
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
Install_Umbrella_Handler
(HW_Interrupt (Interrupt), Notify_Interrupt'Access);
end Bind_Handler;
--------------------
-- Unbind_Handler --
--------------------
procedure Unbind_Handler (Interrupt : Interrupt_ID) is
Status : int;
begin
-- Flush server task off semaphore, allowing it to terminate
Status := Binary_Semaphore_Flush (Semaphore_ID_Map (Interrupt));
pragma Assert (Status = 0);
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
-- If an interrupt entry is installed raise 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. This 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
-- Trying to detach a static Interrupt Handler, raise
-- Program_Error.
raise Program_Error with
"trying to detach a static Interrupt Handler";
end if;
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
-- If an interrupt entry is already installed, raise
-- 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. This is the case when we want to detach a handler
-- regardless of the Static status of 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
and then (User_Handler (Interrupt).Static
-- Trying to overwrite a static Interrupt Handler with a dynamic
-- Handler
-- 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;
-- 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 New_Handler /= null
and then
(Server_ID (Interrupt) = Null_Task
or else
Ada.Task_Identification.Is_Terminated
(To_Ada (Server_ID (Interrupt))))
then
Interrupt_Access_Hold :=
new Interrupt_Server_Task (Interrupt, Binary_Semaphore_Create);
Server_ID (Interrupt) :=
To_System (Interrupt_Access_Hold.all'Identity);
end if;
if (New_Handler = null) and then Old_Handler /= null then
-- Restore default handler
Unbind_Handler (Interrupt);
elsif Old_Handler = null then
-- Save default handler
Bind_Handler (Interrupt);
end if;
end Unprotected_Exchange_Handler;
-- Start of processing for Interrupt_Manager
begin
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 Program_Error with
"a binding for this interrupt is already present";
end if;
User_Entry (Interrupt) := Entry_Assoc'(T => T, E => E);
-- Indicate the attachment of interrupt entry in the ATCB.
-- This is needed so 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
or else
Ada.Task_Identification.Is_Terminated
(To_Ada (Server_ID (Interrupt)))
then
Interrupt_Access_Hold := new Interrupt_Server_Task
(Interrupt, Binary_Semaphore_Create);
Server_ID (Interrupt) :=
To_System (Interrupt_Access_Hold.all'Identity);
end if;
Bind_Handler (Interrupt);
end Bind_Interrupt_To_Entry;
or
accept Detach_Interrupt_Entries (T : Task_Id) do
for Int in Interrupt_ID'Range loop
if not Is_Reserved (Int) then
if User_Entry (Int).T = T then
User_Entry (Int) :=
Entry_Assoc'
(T => Null_Task, E => Null_Task_Entry);
Unbind_Handler (Int);
end if;
end if;
end loop;
-- Indicate in ATCB that no interrupt entries are attached
T.Interrupt_Entry := False;
end Detach_Interrupt_Entries;
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;
exception
when Standard'Abort_Signal =>
-- Flush interrupt server semaphores, so they can terminate
Finalize_Interrupt_Servers;
raise;
end Interrupt_Manager;
---------------------------
-- Interrupt_Server_Task --
---------------------------
-- Server task for vectored hardware interrupt handling
task body Interrupt_Server_Task is
Ignore : constant Boolean := System.Tasking.Utilities.Make_Independent;
Self_Id : constant Task_Id := Self;
Tmp_Handler : Parameterless_Handler;
Tmp_ID : Task_Id;
Tmp_Entry_Index : Task_Entry_Index;
Status : int;
begin
Semaphore_ID_Map (Interrupt) := Int_Sema;
loop
-- Pend on semaphore that will be triggered by the umbrella handler
-- when the associated interrupt comes in.
Status := Binary_Semaphore_Obtain (Int_Sema);
pragma Assert (Status = 0);
if User_Handler (Interrupt).H /= null then
-- Protected procedure handler
Tmp_Handler := User_Handler (Interrupt).H;
Tmp_Handler.all;
elsif User_Entry (Interrupt).T /= Null_Task then
-- Interrupt entry handler
Tmp_ID := User_Entry (Interrupt).T;
Tmp_Entry_Index := User_Entry (Interrupt).E;
System.Tasking.Rendezvous.Call_Simple
(Tmp_ID, Tmp_Entry_Index, System.Null_Address);
else
-- Semaphore has been flushed by an unbind operation in the
-- Interrupt_Manager. Terminate the server task.
-- Wait for the Interrupt_Manager to complete its work
POP.Write_Lock (Self_Id);
-- Unassociate the interrupt handler
Semaphore_ID_Map (Interrupt) := 0;
-- Delete the associated semaphore
Status := Binary_Semaphore_Delete (Int_Sema);
pragma Assert (Status = 0);
-- Set status for the Interrupt_Manager
Server_ID (Interrupt) := Null_Task;
POP.Unlock (Self_Id);
exit;
end if;
end loop;
end Interrupt_Server_Task;
begin
-- Get Interrupt_Manager's ID so that Abort_Interrupt can be sent
Interrupt_Manager_ID := To_System (Interrupt_Manager'Identity);
end System.Interrupts;