------------------------------------------------------------------------------ -- -- -- 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) 1992-2009, 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 -- -- . -- -- -- -- GNARL was developed by the GNARL team at Florida State University. -- -- Extensive contributions were provided by Ada Core Technologies, Inc. -- -- -- ------------------------------------------------------------------------------ -- Invariants: -- All user-handleable 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 an 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. 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 (Handlers : New_Handler_Array) is 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 Fat_Ptr is record Object_Addr : System.Address; Handler_Addr : System.Address; 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 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 -------------------- -- 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 -- By making this task independent of any master, when the process -- goes away, the Interrupt_Manager will terminate gracefully. System.Tasking.Utilities.Make_Independent; 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 Self_Id : constant Task_Id := Self; Tmp_Handler : Parameterless_Handler; Tmp_ID : Task_Id; Tmp_Entry_Index : Task_Entry_Index; Status : int; begin System.Tasking.Utilities.Make_Independent; 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;