------------------------------------------------------------------------------ -- -- -- GNU ADA 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 -- -- -- -- $Revision: 1.1.1.2 $ -- -- -- Copyright (C) 1991-2001 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, 59 Temple Place - Suite 330, Boston, -- -- MA 02111-1307, 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. It is -- -- now maintained by Ada Core Technologies Inc. in cooperation with Florida -- -- State University (http://www.gnat.com). -- -- -- ------------------------------------------------------------------------------ -- 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 VxWorks system calls. -- Note : Direct calls to sigaction, sigprocmask, pthread_sigsetmask or any -- other low-level interface that changes the signal action or -- signal mask needs careful consideration. -- One may achieve the effect of system calls first masking RTS blocked -- (by calling Block_Interrupt) for the signal under consideration. -- This will make all the tasks in RTS blocked for the signal. -- 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 the VxWorks version of this package, supporting both signals -- and vectored hardware interrupts. with Unchecked_Conversion; with System.OS_Interface; use System.OS_Interface; with System.VxWorks; with Interfaces.VxWorks; 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 -- All_Tasks_Mask pragma Elaborate_All (System.Interrupt_Management.Operations); with System.Error_Reporting; -- used for Shutdown 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; -- used for Task_ID -- Task_Entry_Index -- Null_Task -- Self -- Interrupt_Manager_ID 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 package body System.Interrupts is use Tasking; use System.Error_Reporting; use Ada.Exceptions; package PRI renames System.Task_Primitives; 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_Ada is new Unchecked_Conversion (System.Tasking.Task_ID, Ada.Task_Identification.Task_Id); function To_System is new Unchecked_Conversion (Ada.Task_Identification.Task_Id, Task_ID); ----------------- -- Local Tasks -- ----------------- -- WARNING: System.Tasking.Utilities performs calls to this task -- with low-level constructs. Do not change this spec without synchro- -- nizing it. task Interrupt_Manager is 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 Detach_Interrupt_Entries (T : Task_ID); pragma Interrupt_Priority (System.Interrupt_Priority'First); end Interrupt_Manager; task type Signal_Server_Task (Interrupt : Interrupt_ID) is pragma Interrupt_Priority (System.Interrupt_Priority'First + 1); end Signal_Server_Task; -- Server task for signal handling type Signal_Task_Access is access Signal_Server_Task; task type Interrupt_Server_Task (Interrupt : Interrupt_ID; Int_Sema : SEM_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.VxWorks.Num_HW_Interrupts) of SEM_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. Signal_Access_Hold : Signal_Task_Access; -- Variable for allocating a Signal_Server_Task Interrupt_Access_Hold : Interrupt_Task_Access; -- Variable for allocating an Interrupt_Server_Task L : aliased PRI.RTS_Lock; -- L protects the contents of the above tables for interrupts / signals -- for which Server_ID (I) = Null_Task. -- -- If Server_ID (I) /= Null_Task then protection is via the -- per-task (TCB) lock of Server_ID (I). -- -- For deadlock prevention, L should not be locked after -- any other lock is held, hence we use PO_Level which is the highest -- lock level for error checking. Task_Lock : array (Interrupt_ID) of Boolean := (others => False); -- Booleans indicating whether the per task lock is used Default_Handler : array (HW_Interrupt) of Interfaces.VxWorks.VOIDFUNCPTR; -- Vectored interrupt handlers installed prior to program startup. -- These are saved only when the umbrella handler is installed for -- a given interrupt number. ----------------------- -- 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. procedure Lock_Interrupt (Self_ID : Task_ID; Interrupt : Interrupt_ID); -- Protect the tables using L or the per-task lock. Set the Boolean -- value Task_Lock if the lock is made using per-task lock. -- This information is needed so that Unlock_Interrupt -- performs unlocking on the same lock. The situation we are preventing -- is, for example, when Attach_Handler is called for the first time -- we lock L and create an Server_Task. For a matching unlocking, if we -- rely on the fact that there is a Server_Task, we will unlock the -- per-task lock. procedure Unlock_Interrupt (Self_ID : Task_ID; Interrupt : Interrupt_ID); -- Unlock interrupt previously locked by Lock_Interrupt function Is_Registered (Handler : Parameterless_Handler) return Boolean; -- Needs comment ??? procedure Notify_Interrupt (Param : System.Address); -- Umbrella handler for vectored interrupts (not signals) procedure Install_Default_Action (Interrupt : HW_Interrupt); -- Restore a handler that was in place prior to program execution procedure Install_Umbrella_Handler (Interrupt : HW_Interrupt; Handler : Interfaces.VxWorks.VOIDFUNCPTR); -- Install the runtime umbrella handler for a vectored hardware -- interrupt function To_Signal (S : Interrupt_ID) return IMNG.Interrupt_ID; -- Convert interrupt ID to signal number. 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 (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 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_Exception (Program_Error'Identity, "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 (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 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. Signal servers -- restore the default handlers when they're aborted. This is called -- by the Interrupt_Manager task when it receives the abort signal -- during program finalization. procedure Finalize_Interrupt_Servers is begin if HW_Interrupt'Last >= 0 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 begin return True; end Has_Interrupt_Or_Attach_Handler; function Has_Interrupt_Or_Attach_Handler (Object : access Static_Interrupt_Protection) return Boolean is 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_Default_Action -- ---------------------------- procedure Install_Default_Action (Interrupt : HW_Interrupt) is begin -- Restore original interrupt handler Interfaces.VxWorks.intVecSet (Interfaces.VxWorks.INUM_TO_IVEC (Integer (Interrupt)), Default_Handler (Interrupt)); Default_Handler (Interrupt) := null; end Install_Default_Action; ---------------------- -- 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_Umbrella_Handler -- ------------------------------ procedure Install_Umbrella_Handler (Interrupt : HW_Interrupt; Handler : Interfaces.VxWorks.VOIDFUNCPTR) is use Interfaces.VxWorks; Vec : constant Interrupt_Vector := INUM_TO_IVEC (Interfaces.VxWorks.int (Interrupt)); Old_Handler : constant VOIDFUNCPTR := intVecGet (INUM_TO_IVEC (Interfaces.VxWorks.int (Interrupt))); Stat : Interfaces.VxWorks.STATUS; 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 Default_Handler (Interrupt) = null then Stat := intConnect (Vec, VOIDFUNCPTR (Handler), System.Address (Interrupt)); Default_Handler (Interrupt) := Old_Handler; 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 -- ------------------- -- See if Handler has been "pragma"ed using Interrupt_Handler. -- Always consider a null handler as 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 if Interrupt < System.VxWorks.Num_HW_Interrupts then return False; else return IMNG.Reserve (To_Signal (Interrupt)); end if; end Is_Reserved; -------------------- -- Lock_Interrupt -- -------------------- -- ????? -- This package has been modified several times. -- Do we still need this fancy locking scheme, now that more operations -- are entries of the interrupt manager task? -- ????? -- More likely, we will need to convert one or more entry calls to -- protected operations, because presently we are violating locking order -- rules by calling a task entry from within the runtime system. procedure Lock_Interrupt (Self_ID : Task_ID; Interrupt : Interrupt_ID) is begin Initialization.Defer_Abort (Self_ID); POP.Write_Lock (L'Access); if Task_Lock (Interrupt) then pragma Assert (Server_ID (Interrupt) /= null, "Task_Lock is true for null server task"); pragma Assert (not Ada.Task_Identification.Is_Terminated (To_Ada (Server_ID (Interrupt))), "Attempt to lock per task lock of terminated server: " & "Task_Lock => True"); POP.Unlock (L'Access); POP.Write_Lock (Server_ID (Interrupt)); elsif Server_ID (Interrupt) /= Null_Task then pragma Assert (not Ada.Task_Identification.Is_Terminated (To_Ada (Server_ID (Interrupt))), "Attempt to lock per task lock of terminated server: " & "Task_Lock => False"); Task_Lock (Interrupt) := True; POP.Unlock (L'Access); POP.Write_Lock (Server_ID (Interrupt)); end if; end Lock_Interrupt; ------------------------ -- Notify_Interrupt -- ------------------------ -- Umbrella handler for vectored hardware interrupts (as opposed to -- signals and exceptions). As opposed to the signal implementation, -- this handler is only installed in the vector table while there is -- an active association of an Ada handler to the interrupt. -- 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 and issues a semGive call, waking -- the server task. When a handler is unbound, -- System.Interrupts.Unbind_Handler issues a semFlush, and the -- server task deletes its semaphore and terminates. procedure Notify_Interrupt (Param : System.Address) is Interrupt : Interrupt_ID := Interrupt_ID (Param); Discard_Result : STATUS; begin Discard_Result := semGive (Semaphore_ID_Map (Interrupt)); 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; --------------- -- To_Signal -- --------------- function To_Signal (S : Interrupt_ID) return IMNG.Interrupt_ID is begin return IMNG.Interrupt_ID (S - System.VxWorks.Num_HW_Interrupts); end To_Signal; ----------------------- -- 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_Exception (Program_Error'Identity, Feature & " not implemented on VxWorks"); end Unimplemented; ---------------------- -- Unlock_Interrupt -- ---------------------- procedure Unlock_Interrupt (Self_ID : Task_ID; Interrupt : Interrupt_ID) is begin if Task_Lock (Interrupt) then pragma Assert (not Ada.Task_Identification.Is_Terminated (To_Ada (Server_ID (Interrupt))), "Attempt to unlock per task lock of terminated server"); POP.Unlock (Server_ID (Interrupt)); else POP.Unlock (L'Access); end if; Initialization.Undefer_Abort (Self_ID); end Unlock_Interrupt; ----------------------- -- Interrupt_Manager -- ----------------------- task body Interrupt_Manager is --------------------- -- Local Variables -- --------------------- Intwait_Mask : aliased IMNG.Interrupt_Mask; Old_Mask : aliased IMNG.Interrupt_Mask; Self_ID : Task_ID := POP.Self; -------------------- -- 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. -- The following two procedures are labelled Unprotected... in order to -- indicate that Lock/Unlock_Interrupt operations are needed around -- around calls to them. procedure Unprotected_Exchange_Handler (Old_Handler : out Parameterless_Handler; New_Handler : Parameterless_Handler; Interrupt : Interrupt_ID; Static : Boolean; Restoration : Boolean := False); procedure Unprotected_Detach_Handler (Interrupt : Interrupt_ID; Static : Boolean); ------------------ -- Bind_Handler -- ------------------ procedure Bind_Handler (Interrupt : Interrupt_ID) is begin if Interrupt < System.VxWorks.Num_HW_Interrupts then Install_Umbrella_Handler (HW_Interrupt (Interrupt), Notify_Interrupt'Access); else -- Mask this task for the given signal so that all tasks -- are masked for the signal and the actual delivery of the -- signal will be caught using "sigwait" by the -- corresponding Server_Task. IMOP.Thread_Block_Interrupt (To_Signal (Interrupt)); -- We have installed a handler or an entry before we called -- this procedure. If the handler task is waiting to be -- awakened, do it here. Otherwise, the signal will be -- discarded. POP.Wakeup (Server_ID (Interrupt), Interrupt_Server_Idle_Sleep); end if; end Bind_Handler; -------------------- -- Unbind_Handler -- -------------------- procedure Unbind_Handler (Interrupt : Interrupt_ID) is S : STATUS; Ret_Interrupt : IMNG.Interrupt_ID; use type IMNG.Interrupt_ID; use type STATUS; begin if Interrupt < System.VxWorks.Num_HW_Interrupts then -- Hardware interrupt Install_Default_Action (HW_Interrupt (Interrupt)); -- Flush server task off semaphore, allowing it to terminate S := semFlush (Semaphore_ID_Map (Interrupt)); pragma Assert (S = 0); else -- Currently, there is a handler or an entry attached and -- the corresponding Server_Task is waiting on "sigwait." -- We have to wake up the Server_Task and make it -- wait on a condition variable by sending an -- Abort_Task_Interrupt -- Make sure corresponding Server_Task is out of its own -- sigwait state. POP.Abort_Task (Server_ID (Interrupt)); Ret_Interrupt := IMOP.Interrupt_Wait (Intwait_Mask'Access); pragma Assert (Ret_Interrupt = IMNG.Abort_Task_Interrupt); IMOP.Install_Default_Action (To_Signal (Interrupt)); -- Unmake the Interrupt for this task in order to allow default -- action again. IMOP.Thread_Unblock_Interrupt (To_Signal (Interrupt)); end if; end Unbind_Handler; -------------------------------- -- Unprotected_Detach_Handler -- -------------------------------- procedure Unprotected_Detach_Handler (Interrupt : Interrupt_ID; Static : Boolean) is Old_Handler : Parameterless_Handler; begin if User_Entry (Interrupt).T /= Null_Task then -- If an interrupt entry is installed raise -- Program_Error. (propagate it to the caller). Unlock_Interrupt (Self_ID, Interrupt); Raise_Exception (Program_Error'Identity, "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. Unlock_Interrupt (Self_ID, Interrupt); Raise_Exception (Program_Error'Identity, "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). Unlock_Interrupt (Self_ID, Interrupt); Raise_Exception (Program_Error'Identity, "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 Unlock_Interrupt (Self_ID, Interrupt); Raise_Exception (Program_Error'Identity, "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 -- When a new Server_Task is created, it should have its -- signal mask set to the All_Tasks_Mask. IMOP.Set_Interrupt_Mask (IMOP.All_Tasks_Mask'Access, Old_Mask'Access); if Interrupt < System.VxWorks.Num_HW_Interrupts then -- Vectored hardware interrupt Interrupt_Access_Hold := new Interrupt_Server_Task (Interrupt, semBCreate (SEM_Q_FIFO, SEM_EMPTY)); Server_ID (Interrupt) := To_System (Interrupt_Access_Hold.all'Identity); else -- Signal Signal_Access_Hold := new Signal_Server_Task (Interrupt); Server_ID (Interrupt) := To_System (Signal_Access_Hold.all'Identity); end if; IMOP.Set_Interrupt_Mask (Old_Mask'Access); 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; -- Environment task gets its own interrupt mask, saves it, -- and then masks all signals except the Keep_Unmasked set. -- During rendezvous, the Interrupt_Manager receives the old -- signal mask of the environment task, and sets its own -- signal mask to that value. -- The environment task will call this entry of Interrupt_Manager -- during elaboration of the body of this package. accept Initialize (Mask : IMNG.Interrupt_Mask) do declare The_Mask : aliased IMNG.Interrupt_Mask; begin IMOP.Copy_Interrupt_Mask (The_Mask, Mask); IMOP.Set_Interrupt_Mask (The_Mask'Access); end; end Initialize; -- Note: All tasks in RTS will have all reserved signals -- being masked (except the Interrupt_Manager) and Keep_Unmasked -- signals unmasked when created. -- Abort_Task_Interrupt is one of the signals unmasked -- in all tasks. We mask the signal in this particular task -- so that "sigwait" is can catch an explicit -- Abort_Task_Interrupt from a Server_Task. -- This sigwaiting is needed to ensure that a Signal_Server_Task is -- out of its own sigwait state. This extra synchronization is -- necessary to prevent following scenarios: -- 1) Interrupt_Manager sends an Abort_Task_Interrupt to a -- Signal_Server_Task then changes its own signal mask (OS level). -- If a signal (corresponding to the Signal_Server_Task) arrives -- in the meantime, we have the Interrupt_Manager umnasked and -- the Signal_Server_Task waiting on sigwait. -- 2) For unbinding a handler, we install a default action in the -- Interrupt_Manager. POSIX.1c states that the result of using -- "sigwait" and "sigaction" simultaneously on the same signal -- is undefined. Therefore, we need to be informed from the -- Signal_Server_Task that it is out of its sigwait stage. IMOP.Empty_Interrupt_Mask (Intwait_Mask'Access); IMOP.Add_To_Interrupt_Mask (Intwait_Mask'Access, IMNG.Abort_Task_Interrupt); IMOP.Thread_Block_Interrupt (IMNG.Abort_Task_Interrupt); loop -- A block is needed to absorb Program_Error exception declare Old_Handler : Parameterless_Handler; begin select accept Attach_Handler (New_Handler : Parameterless_Handler; Interrupt : Interrupt_ID; Static : Boolean; Restoration : Boolean := False) do Lock_Interrupt (Self_ID, Interrupt); Unprotected_Exchange_Handler (Old_Handler, New_Handler, Interrupt, Static, Restoration); Unlock_Interrupt (Self_ID, Interrupt); end Attach_Handler; or accept Exchange_Handler (Old_Handler : out Parameterless_Handler; New_Handler : Parameterless_Handler; Interrupt : Interrupt_ID; Static : Boolean) do Lock_Interrupt (Self_ID, Interrupt); Unprotected_Exchange_Handler (Old_Handler, New_Handler, Interrupt, Static); Unlock_Interrupt (Self_ID, Interrupt); end Exchange_Handler; or accept Detach_Handler (Interrupt : Interrupt_ID; Static : Boolean) do Lock_Interrupt (Self_ID, Interrupt); Unprotected_Detach_Handler (Interrupt, Static); Unlock_Interrupt (Self_ID, Interrupt); end Detach_Handler; or accept Bind_Interrupt_To_Entry (T : Task_ID; E : Task_Entry_Index; Interrupt : Interrupt_ID) do Lock_Interrupt (Self_ID, Interrupt); -- 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 Unlock_Interrupt (Self_ID, Interrupt); Raise_Exception (Program_Error'Identity, "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 -- When a new Server_Task is created, it should have its -- signal mask set to the All_Tasks_Mask. IMOP.Set_Interrupt_Mask (IMOP.All_Tasks_Mask'Access, Old_Mask'Access); if Interrupt < System.VxWorks.Num_HW_Interrupts then Interrupt_Access_Hold := new Interrupt_Server_Task (Interrupt, semBCreate (SEM_Q_FIFO, SEM_EMPTY)); Server_ID (Interrupt) := To_System (Interrupt_Access_Hold.all'Identity); else Signal_Access_Hold := new Signal_Server_Task (Interrupt); Server_ID (Interrupt) := To_System (Signal_Access_Hold.all'Identity); end if; IMOP.Set_Interrupt_Mask (Old_Mask'Access); end if; Bind_Handler (Interrupt); Unlock_Interrupt (Self_ID, 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 Lock_Interrupt (Self_ID, Int); if User_Entry (Int).T = T then User_Entry (Int) := Entry_Assoc' (T => Null_Task, E => Null_Task_Entry); Unbind_Handler (Int); end if; Unlock_Interrupt (Self_ID, Int); 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 E : others => pragma Assert (Shutdown ("Interrupt_Manager---exception not expected" & ASCII.LF & Exception_Information (E))); null; end; end loop; pragma Assert (Shutdown ("Interrupt_Manager---should not get here")); exception when Standard'Abort_Signal => -- Flush interrupt server semaphores, so they can terminate Finalize_Interrupt_Servers; raise; end Interrupt_Manager; ------------------------ -- Signal_Server_Task -- ------------------------ task body Signal_Server_Task is Intwait_Mask : aliased IMNG.Interrupt_Mask; Ret_Interrupt : IMNG.Interrupt_ID; Self_ID : Task_ID := Self; Tmp_Handler : Parameterless_Handler; Tmp_ID : Task_ID; Tmp_Entry_Index : Task_Entry_Index; use type IMNG.Interrupt_ID; 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 (To_Signal (Interrupt)); -- Note: All tasks in RTS will have all reserved signals -- masked (except the Interrupt_Manager) and Keep_Unmasked -- unmasked when created. -- Abort_Task_Interrupt is one of the signals unmasked -- in all tasks. We mask it in this particular task -- so that "sigwait" can catch an explicit -- Abort_Task_Interrupt from the Interrupt_Manager. -- There are two signals that this task catches through -- "sigwait." One is the signal it is designated to catch -- in order to execute an user handler or entry. The other is -- Abort_Task_Interrupt. This signal is sent from the -- Interrupt_Manager to inform of status changes (e.g: become Blocked, -- or a handler or entry is to be detached). -- Prepare the mask to be used for sigwait. IMOP.Empty_Interrupt_Mask (Intwait_Mask'Access); IMOP.Add_To_Interrupt_Mask (Intwait_Mask'Access, To_Signal (Interrupt)); IMOP.Add_To_Interrupt_Mask (Intwait_Mask'Access, IMNG.Abort_Task_Interrupt); IMOP.Thread_Block_Interrupt (IMNG.Abort_Task_Interrupt); PIO.Set_Interrupt_ID (To_Signal (Interrupt), Self_ID); loop System.Tasking.Initialization.Defer_Abort (Self_ID); POP.Write_Lock (Self_ID); if User_Handler (Interrupt).H = null and then User_Entry (Interrupt).T = Null_Task then -- No signal binding. If a signal is received, -- Interrupt_Manager will take the default action. Self_ID.Common.State := Interrupt_Server_Blocked_Interrupt_Sleep; POP.Sleep (Self_ID, Interrupt_Server_Idle_Sleep); Self_ID.Common.State := Runnable; else -- A handler or an entry is installed. At this point all tasks -- mask for the signal is masked. Catch it using -- sigwait. -- This task may wake up from sigwait by receiving a signal -- (Abort_Task_Interrupt) from the Interrupt_Manager for unbinding -- a procedure handler or an entry. Or it could be a wake up -- from status change (Unblocked -> Blocked). If that is not -- the case, we should execute the attached procedure or entry. POP.Unlock (Self_ID); Ret_Interrupt := IMOP.Interrupt_Wait (Intwait_Mask'Access); if Ret_Interrupt = IMNG.Abort_Task_Interrupt then -- Inform the Interrupt_Manager of wakeup from above sigwait. POP.Abort_Task (Interrupt_Manager_ID); POP.Write_Lock (Self_ID); else POP.Write_Lock (Self_ID); -- Even though we have received a signal, the status may -- have changed before we got the Self_ID lock above. -- Therefore we make sure a handler or an entry is still -- bound and make appropriate call. -- If there is no call to make we need to regenerate the -- signal in order not to lose it. if User_Handler (Interrupt).H /= null then Tmp_Handler := User_Handler (Interrupt).H; -- RTS calls should not be made with self being locked. POP.Unlock (Self_ID); Tmp_Handler.all; POP.Write_Lock (Self_ID); elsif User_Entry (Interrupt).T /= Null_Task then Tmp_ID := User_Entry (Interrupt).T; Tmp_Entry_Index := User_Entry (Interrupt).E; -- RTS calls should not be made with self being locked. POP.Unlock (Self_ID); System.Tasking.Rendezvous.Call_Simple (Tmp_ID, Tmp_Entry_Index, System.Null_Address); POP.Write_Lock (Self_ID); else -- This is a situation where this task woke up receiving a -- signal and before it got the lock the signal was blocked. -- We do not want to lose the signal so we regenerate it at -- the process level. IMOP.Interrupt_Self_Process (Ret_Interrupt); end if; end if; end if; POP.Unlock (Self_ID); 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 Signal_Server_Task; --------------------------- -- Interrupt_Server_Task -- --------------------------- -- Server task for vectored hardware interrupt handling task body Interrupt_Server_Task is Self_ID : Task_ID := Self; Tmp_Handler : Parameterless_Handler; Tmp_ID : Task_ID; Tmp_Entry_Index : Task_Entry_Index; S : STATUS; use type STATUS; 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 S := semTake (Int_Sema, WAIT_FOREVER); pragma Assert (S = 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); -- Delete the associated semaphore S := semDelete (Int_Sema); pragma Assert (S = 0); -- Set status for the Interrupt_Manager Semaphore_ID_Map (Interrupt) := 0; Task_Lock (Interrupt) := False; Server_ID (Interrupt) := Null_Task; POP.Unlock (Self_ID); exit; end if; end loop; end Interrupt_Server_Task; begin -- Elaboration code for package System.Interrupts -- Get Interrupt_Manager's ID so that Abort_Interrupt can be sent. Interrupt_Manager_ID := To_System (Interrupt_Manager'Identity); -- Initialize the lock L. Initialization.Defer_Abort (Self); POP.Initialize_Lock (L'Access, POP.PO_Level); Initialization.Undefer_Abort (Self); -- During the elaboration of this package body we want the RTS to -- inherit its signal 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;