| ------------------------------------------------------------------------------ |
| -- -- |
| -- 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 $ |
| -- -- |
| -- 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 interrupts 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 |
| -- interrupt, it must call Block_Interrupt/Unblock_Interrupt, which |
| -- will have the effect of unmasking/masking the interrupt in the |
| -- Interrupt_Manager task. |
| |
| -- Note : Direct calls to sigaction, sigprocmask, pthread_sigsetmask or any |
| -- other low-level interface that changes the interrupt action or |
| -- interrupt mask needs a careful thought. |
| -- One may acheive the effect of system calls first masking RTS blocked |
| -- (by calling Block_Interrupt) for the interrupt under consideration. |
| -- This will make all the tasks in RTS blocked for the Interrupt. |
| |
| -- Once we associate a Server_Task with an interrupt, the task never |
| -- goes away, and we never remove the association. |
| |
| -- There is no more than one interrupt per Server_Task and no more than |
| -- one Server_Task per interrupt. |
| |
| -- Within this package, the lock L is used to protect the various status |
| -- tables. If there is a Server_Task associated with an interrupt, we use |
| -- the per-task lock of the Server_Task instead so that we protect the |
| -- status between Interrupt_Manager and Server_Task. Protection among |
| -- service requests are done using User Request to Interrupt_Manager |
| -- rendezvous. |
| |
| with Ada.Task_Identification; |
| -- used for Task_ID type |
| |
| with Ada.Exceptions; |
| -- used for Raise_Exception |
| |
| with System.Task_Primitives; |
| -- used for RTS_Lock |
| -- Self |
| |
| with System.Interrupt_Management; |
| -- used for Reserve |
| -- Interrupt_ID |
| -- Interrupt_Mask |
| -- Abort_Task_Interrupt |
| |
| with System.Interrupt_Management.Operations; |
| -- used for Thread_Block_Interrupt |
| -- Thread_Unblock_Interrupt |
| -- Install_Default_Action |
| -- Install_Ignore_Action |
| -- Copy_Interrupt_Mask |
| -- Set_Interrupt_Mask |
| -- Empty_Interrupt_Mask |
| -- Fill_Interrupt_Mask |
| -- Add_To_Interrupt_Mask |
| -- Delete_From_Interrupt_Mask |
| -- Interrupt_Wait |
| -- Interrupt_Self_Process |
| -- Get_Interrupt_Mask |
| -- Set_Interrupt_Mask |
| -- IS_Member |
| -- Environment_Mask |
| -- 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 |
| |
| with Unchecked_Conversion; |
| |
| 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_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 : in Parameterless_Handler; |
| Interrupt : in Interrupt_ID; |
| Static : in Boolean; |
| Restoration : in Boolean := False); |
| |
| entry Exchange_Handler |
| (Old_Handler : out Parameterless_Handler; |
| New_Handler : in Parameterless_Handler; |
| Interrupt : in Interrupt_ID; |
| Static : in Boolean); |
| |
| entry Detach_Handler |
| (Interrupt : in Interrupt_ID; |
| Static : in Boolean); |
| |
| entry Bind_Interrupt_To_Entry |
| (T : Task_ID; |
| E : Task_Entry_Index; |
| Interrupt : Interrupt_ID); |
| |
| entry Detach_Interrupt_Entries (T : Task_ID); |
| |
| entry Block_Interrupt (Interrupt : Interrupt_ID); |
| |
| entry Unblock_Interrupt (Interrupt : Interrupt_ID); |
| |
| entry Ignore_Interrupt (Interrupt : Interrupt_ID); |
| |
| entry Unignore_Interrupt (Interrupt : Interrupt_ID); |
| |
| pragma Interrupt_Priority (System.Interrupt_Priority'Last); |
| end Interrupt_Manager; |
| |
| task type Server_Task (Interrupt : Interrupt_ID) is |
| pragma Priority (System.Interrupt_Priority'Last); |
| end Server_Task; |
| |
| type Server_Task_Access is access Server_Task; |
| |
| -------------------------------- |
| -- Local Types and Variables -- |
| -------------------------------- |
| |
| type Entry_Assoc is record |
| T : Task_ID; |
| E : Task_Entry_Index; |
| end record; |
| |
| type Handler_Assoc is record |
| H : Parameterless_Handler; |
| Static : Boolean; -- Indicates static binding; |
| end record; |
| |
| User_Handler : array (Interrupt_ID'Range) of Handler_Assoc := |
| (others => (null, Static => False)); |
| pragma Volatile_Components (User_Handler); |
| -- Holds the protected procedure handler (if any) and its Static |
| -- information for each interrupt. A handler is a Static one if |
| -- it is specified through the pragma Attach_Handler. |
| -- Attach_Handler. Otherwise, not static) |
| |
| User_Entry : array (Interrupt_ID'Range) of Entry_Assoc := |
| (others => (T => Null_Task, E => Null_Task_Entry)); |
| pragma Volatile_Components (User_Entry); |
| -- Holds the task and entry index (if any) for each interrupt |
| |
| Blocked : array (Interrupt_ID'Range) of Boolean := (others => False); |
| pragma Volatile_Components (Blocked); |
| -- True iff the corresponding interrupt is blocked in the process level |
| |
| Ignored : array (Interrupt_ID'Range) of Boolean := (others => False); |
| pragma Volatile_Components (Ignored); |
| -- True iff the corresponding interrupt is blocked in the process level |
| |
| Last_Unblocker : |
| array (Interrupt_ID'Range) of Task_ID := (others => Null_Task); |
| pragma Volatile_Components (Last_Unblocker); |
| -- Holds the ID of the last Task which Unblocked this Interrupt. |
| -- It contains Null_Task if no tasks have ever requested the |
| -- Unblocking operation or the Interrupt is currently Blocked. |
| |
| Server_ID : array (Interrupt_ID'Range) of Task_ID := |
| (others => Null_Task); |
| pragma Atomic_Components (Server_ID); |
| -- Holds the Task_ID of the Server_Task for each interrupt. |
| -- Task_ID is needed to accomplish locking per Interrupt base. Also |
| -- is needed to decide whether to create a new Server_Task. |
| |
| -- Type and Head, Tail of the list containing Registered Interrupt |
| -- Handlers. These definitions are used to register the handlers |
| -- specified by the pragma Interrupt_Handler. |
| |
| type Registered_Handler; |
| type R_Link is access all Registered_Handler; |
| |
| type Registered_Handler is record |
| H : System.Address := System.Null_Address; |
| Next : R_Link := null; |
| end record; |
| |
| Registered_Handler_Head : R_Link := null; |
| Registered_Handler_Tail : R_Link := null; |
| |
| Access_Hold : Server_Task_Access; |
| -- variable used to allocate Server_Task using "new". |
| |
| L : aliased PRI.RTS_Lock; |
| -- L protects contents in tables above corresponding to interrupts |
| -- for which Server_ID (T) = null. |
| -- |
| -- If Server_ID (T) /= null then protection is via |
| -- per-task (TCB) lock of Server_ID (T). |
| -- |
| -- 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'Range) of Boolean := (others => False); |
| -- Boolean flags to give matching Locking and Unlocking. See the comments |
| -- in Lock_Interrupt. |
| |
| ----------------------- |
| -- Local Subprograms -- |
| ----------------------- |
| |
| procedure Lock_Interrupt |
| (Self_ID : Task_ID; |
| Interrupt : Interrupt_ID); |
| -- protect the tables using L or 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); |
| |
| function Is_Registered (Handler : Parameterless_Handler) return Boolean; |
| -- ??? spec needs comments |
| |
| -------------------- |
| -- 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 : in Parameterless_Handler; |
| Interrupt : in Interrupt_ID; |
| Static : in Boolean := False) |
| is |
| begin |
| if Is_Reserved (Interrupt) then |
| Raise_Exception (Program_Error'Identity, "Interrupt" & |
| Interrupt_ID'Image (Interrupt) & " is reserved"); |
| end if; |
| |
| Interrupt_Manager.Attach_Handler (New_Handler, Interrupt, Static); |
| |
| end Attach_Handler; |
| |
| ----------------------------- |
| -- Bind_Interrupt_To_Entry -- |
| ----------------------------- |
| |
| -- This procedure raises a Program_Error if it tries to |
| -- bind an interrupt to which an Entry or a Procedure is |
| -- already bound. |
| |
| procedure Bind_Interrupt_To_Entry |
| (T : Task_ID; |
| E : Task_Entry_Index; |
| Int_Ref : System.Address) |
| is |
| Interrupt : constant Interrupt_ID := |
| Interrupt_ID (Storage_Elements.To_Integer (Int_Ref)); |
| |
| begin |
| if Is_Reserved (Interrupt) then |
| Raise_Exception (Program_Error'Identity, "Interrupt" & |
| Interrupt_ID'Image (Interrupt) & " is reserved"); |
| end if; |
| |
| Interrupt_Manager.Bind_Interrupt_To_Entry (T, E, Interrupt); |
| |
| end Bind_Interrupt_To_Entry; |
| |
| --------------------- |
| -- Block_Interrupt -- |
| --------------------- |
| |
| procedure Block_Interrupt (Interrupt : Interrupt_ID) is |
| begin |
| if Is_Reserved (Interrupt) then |
| Raise_Exception (Program_Error'Identity, "Interrupt" & |
| Interrupt_ID'Image (Interrupt) & " is reserved"); |
| end if; |
| |
| Interrupt_Manager.Block_Interrupt (Interrupt); |
| end Block_Interrupt; |
| |
| --------------------- |
| -- Current_Handler -- |
| --------------------- |
| |
| function Current_Handler |
| (Interrupt : Interrupt_ID) |
| return Parameterless_Handler |
| is |
| begin |
| if Is_Reserved (Interrupt) then |
| Raise_Exception (Program_Error'Identity, "Interrupt" & |
| Interrupt_ID'Image (Interrupt) & " is reserved"); |
| end if; |
| |
| -- ??? Since Parameterless_Handler is not Atomic, the |
| -- current implementation is wrong. We need a new service in |
| -- Interrupt_Manager to ensure atomicity. |
| |
| return User_Handler (Interrupt).H; |
| end Current_Handler; |
| |
| -------------------- |
| -- 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 : in Interrupt_ID; |
| Static : in Boolean := False) |
| is |
| begin |
| if Is_Reserved (Interrupt) then |
| Raise_Exception (Program_Error'Identity, "Interrupt" & |
| Interrupt_ID'Image (Interrupt) & " is reserved"); |
| end if; |
| |
| Interrupt_Manager.Detach_Handler (Interrupt, Static); |
| |
| end Detach_Handler; |
| |
| ------------------------------ |
| -- 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 : in Parameterless_Handler; |
| Interrupt : in Interrupt_ID; |
| Static : in Boolean := False) |
| is |
| begin |
| if Is_Reserved (Interrupt) then |
| Raise_Exception (Program_Error'Identity, "Interrupt" & |
| Interrupt_ID'Image (Interrupt) & " is reserved"); |
| end if; |
| |
| Interrupt_Manager.Exchange_Handler |
| (Old_Handler, New_Handler, Interrupt, Static); |
| |
| end Exchange_Handler; |
| |
| ---------------- |
| -- Finalize -- |
| ---------------- |
| |
| procedure Finalize (Object : in out Static_Interrupt_Protection) is |
| begin |
| -- ??? loop to be executed only when we're not doing library level |
| -- finalization, since in this case all interrupt tasks are gone. |
| if not Interrupt_Manager'Terminated then |
| for N in reverse Object.Previous_Handlers'Range loop |
| Interrupt_Manager.Attach_Handler |
| (New_Handler => Object.Previous_Handlers (N).Handler, |
| Interrupt => Object.Previous_Handlers (N).Interrupt, |
| Static => Object.Previous_Handlers (N).Static, |
| Restoration => True); |
| end loop; |
| end if; |
| |
| Tasking.Protected_Objects.Entries.Finalize |
| (Tasking.Protected_Objects.Entries.Protection_Entries (Object)); |
| end Finalize; |
| |
| ------------------------------------- |
| -- Has_Interrupt_Or_Attach_Handler -- |
| ------------------------------------- |
| |
| function Has_Interrupt_Or_Attach_Handler |
| (Object : access 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 |
| if Is_Reserved (Interrupt) then |
| Raise_Exception (Program_Error'Identity, "Interrupt" & |
| Interrupt_ID'Image (Interrupt) & " is reserved"); |
| end if; |
| |
| Interrupt_Manager.Ignore_Interrupt (Interrupt); |
| end Ignore_Interrupt; |
| |
| ---------------------- |
| -- Install_Handlers -- |
| ---------------------- |
| |
| procedure Install_Handlers |
| (Object : access Static_Interrupt_Protection; |
| New_Handlers : in 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; |
| |
| ---------------- |
| -- Is_Blocked -- |
| ---------------- |
| |
| function Is_Blocked (Interrupt : Interrupt_ID) return Boolean is |
| begin |
| if Is_Reserved (Interrupt) then |
| Raise_Exception (Program_Error'Identity, "Interrupt" & |
| Interrupt_ID'Image (Interrupt) & " is reserved"); |
| end if; |
| |
| return Blocked (Interrupt); |
| end Is_Blocked; |
| |
| ----------------------- |
| -- Is_Entry_Attached -- |
| ----------------------- |
| |
| function Is_Entry_Attached (Interrupt : Interrupt_ID) return Boolean is |
| begin |
| if Is_Reserved (Interrupt) then |
| Raise_Exception (Program_Error'Identity, "Interrupt" & |
| Interrupt_ID'Image (Interrupt) & " is reserved"); |
| end if; |
| |
| return User_Entry (Interrupt).T /= Null_Task; |
| end Is_Entry_Attached; |
| |
| ------------------------- |
| -- Is_Handler_Attached -- |
| ------------------------- |
| |
| function Is_Handler_Attached (Interrupt : Interrupt_ID) return Boolean is |
| begin |
| if Is_Reserved (Interrupt) then |
| Raise_Exception (Program_Error'Identity, "Interrupt" & |
| Interrupt_ID'Image (Interrupt) & " is reserved"); |
| end if; |
| |
| return User_Handler (Interrupt).H /= null; |
| end Is_Handler_Attached; |
| |
| ---------------- |
| -- Is_Ignored -- |
| ---------------- |
| |
| function Is_Ignored (Interrupt : Interrupt_ID) return Boolean is |
| begin |
| if Is_Reserved (Interrupt) then |
| Raise_Exception (Program_Error'Identity, "Interrupt" & |
| Interrupt_ID'Image (Interrupt) & " is reserved"); |
| end if; |
| |
| return Ignored (Interrupt); |
| end Is_Ignored; |
| |
| ------------------- |
| -- Is_Registered -- |
| ------------------- |
| |
| -- See if the 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 |
| return IMNG.Reserve (IMNG.Interrupt_ID (Interrupt)); |
| 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 |
| |
| -- We need to use per-task lock. |
| |
| POP.Unlock (L'Access); |
| POP.Write_Lock (Server_ID (Interrupt)); |
| |
| -- Rely on the fact that once Server_ID is set to a non-null |
| -- value it will never be set back to null. |
| |
| elsif Server_ID (Interrupt) /= Null_Task then |
| |
| -- We need to use per-task lock. |
| |
| Task_Lock (Interrupt) := True; |
| POP.Unlock (L'Access); |
| POP.Write_Lock (Server_ID (Interrupt)); |
| end if; |
| end Lock_Interrupt; |
| |
| --------------- |
| -- Reference -- |
| --------------- |
| |
| function Reference (Interrupt : Interrupt_ID) return System.Address is |
| begin |
| if Is_Reserved (Interrupt) then |
| Raise_Exception (Program_Error'Identity, "Interrupt" & |
| Interrupt_ID'Image (Interrupt) & " is reserved"); |
| end if; |
| |
| return Storage_Elements.To_Address |
| (Storage_Elements.Integer_Address (Interrupt)); |
| end Reference; |
| |
| --------------------------------- |
| -- Register_Interrupt_Handler -- |
| --------------------------------- |
| |
| procedure Register_Interrupt_Handler (Handler_Addr : System.Address) is |
| New_Node_Ptr : R_Link; |
| |
| begin |
| -- This routine registers the Handler as usable for Dynamic |
| -- Interrupt Handler. Routines attaching and detaching Handler |
| -- dynamically should first consult if the Handler is rgistered. |
| -- A Program Error should be raised if it is not registered. |
| |
| -- The pragma Interrupt_Handler can only appear in the library |
| -- level PO definition and instantiation. Therefore, we do not need |
| -- to implement Unregistering operation. Neither we need to |
| -- protect the queue structure using a Lock. |
| |
| pragma Assert (Handler_Addr /= System.Null_Address); |
| |
| New_Node_Ptr := new Registered_Handler; |
| New_Node_Ptr.H := Handler_Addr; |
| |
| if Registered_Handler_Head = null then |
| Registered_Handler_Head := New_Node_Ptr; |
| Registered_Handler_Tail := New_Node_Ptr; |
| |
| else |
| Registered_Handler_Tail.Next := New_Node_Ptr; |
| Registered_Handler_Tail := New_Node_Ptr; |
| end if; |
| end Register_Interrupt_Handler; |
| |
| ----------------------- |
| -- Unblock_Interrupt -- |
| ----------------------- |
| |
| procedure Unblock_Interrupt (Interrupt : Interrupt_ID) is |
| begin |
| if Is_Reserved (Interrupt) then |
| Raise_Exception (Program_Error'Identity, "Interrupt" & |
| Interrupt_ID'Image (Interrupt) & " is reserved"); |
| end if; |
| |
| Interrupt_Manager.Unblock_Interrupt (Interrupt); |
| end Unblock_Interrupt; |
| |
| ------------------ |
| -- Unblocked_By -- |
| ------------------ |
| |
| function Unblocked_By |
| (Interrupt : Interrupt_ID) |
| return System.Tasking.Task_ID |
| is |
| begin |
| if Is_Reserved (Interrupt) then |
| Raise_Exception (Program_Error'Identity, "Interrupt" & |
| Interrupt_ID'Image (Interrupt) & " is reserved"); |
| end if; |
| |
| return Last_Unblocker (Interrupt); |
| end Unblocked_By; |
| |
| ------------------------ |
| -- Unignore_Interrupt -- |
| ------------------------ |
| |
| procedure Unignore_Interrupt (Interrupt : Interrupt_ID) is |
| begin |
| if Is_Reserved (Interrupt) then |
| Raise_Exception (Program_Error'Identity, "Interrupt" & |
| Interrupt_ID'Image (Interrupt) & " is reserved"); |
| end if; |
| |
| Interrupt_Manager.Unignore_Interrupt (Interrupt); |
| end Unignore_Interrupt; |
| |
| ---------------------- |
| -- Unlock_Interrupt -- |
| ---------------------- |
| |
| procedure Unlock_Interrupt |
| (Self_ID : Task_ID; |
| Interrupt : Interrupt_ID) |
| is |
| begin |
| if Task_Lock (Interrupt) then |
| 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; |
| Ret_Interrupt : Interrupt_ID; |
| 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 the Interrupt is blocked. |
| -- Otherwise, we have to interrupt Server_Task for status change through |
| -- Wakeup interrupt. |
| |
| procedure Unbind_Handler (Interrupt : Interrupt_ID); |
| -- This procedure does not do anything if the Interrupt is blocked. |
| -- Otherwise, we have to interrupt Server_Task for status change |
| -- through abort interrupt. |
| |
| -- Following two procedure are named Unprotected... in order to |
| -- indicate that Lock/Unlock_Interrupt operations are needed around. |
| |
| procedure Unprotected_Exchange_Handler |
| (Old_Handler : out Parameterless_Handler; |
| New_Handler : in Parameterless_Handler; |
| Interrupt : in Interrupt_ID; |
| Static : in Boolean; |
| Restoration : in Boolean := False); |
| |
| procedure Unprotected_Detach_Handler |
| (Interrupt : in Interrupt_ID; |
| Static : in Boolean); |
| |
| ------------------ |
| -- Bind_Handler -- |
| ------------------ |
| |
| procedure Bind_Handler (Interrupt : Interrupt_ID) is |
| begin |
| if not Blocked (Interrupt) then |
| |
| -- Mask this task for the given Interrupt so that all tasks |
| -- are masked for the Interrupt and the actuall delivery of the |
| -- Interrupt will be caught using "sigwait" by the |
| -- corresponding Server_Task. |
| |
| IMOP.Thread_Block_Interrupt (IMNG.Interrupt_ID (Interrupt)); |
| |
| -- We have installed a Handler or an Entry before we called |
| -- this procedure. If the Handler Task is waiting to be awakened, |
| -- do it here. Otherwise, the interrupt will be discarded. |
| |
| POP.Wakeup (Server_ID (Interrupt), Interrupt_Server_Idle_Sleep); |
| end if; |
| end Bind_Handler; |
| |
| -------------------- |
| -- Unbind_Handler -- |
| -------------------- |
| |
| procedure Unbind_Handler (Interrupt : Interrupt_ID) is |
| begin |
| if not Blocked (Interrupt) then |
| |
| -- Currently, there is a Handler or an Entry attached and |
| -- corresponding Server_Task is waiting on "sigwait." |
| -- We have to wake up the Server_Task and make it |
| -- wait on condition variable by sending an |
| -- Abort_Task_Interrupt |
| |
| POP.Abort_Task (Server_ID (Interrupt)); |
| |
| -- Make sure corresponding Server_Task is out of its own |
| -- sigwait state. |
| |
| Ret_Interrupt := |
| Interrupt_ID (IMOP.Interrupt_Wait (Intwait_Mask'Access)); |
| |
| pragma Assert |
| (Ret_Interrupt = Interrupt_ID (IMNG.Abort_Task_Interrupt)); |
| |
| IMOP.Install_Default_Action (IMNG.Interrupt_ID (Interrupt)); |
| |
| -- Unmake the Interrupt for this task in order to allow default |
| -- action again. |
| |
| IMOP.Thread_Unblock_Interrupt (IMNG.Interrupt_ID (Interrupt)); |
| |
| else |
| IMOP.Install_Default_Action (IMNG.Interrupt_ID (Interrupt)); |
| end if; |
| |
| end Unbind_Handler; |
| |
| -------------------------------- |
| -- Unprotected_Detach_Handler -- |
| -------------------------------- |
| |
| procedure Unprotected_Detach_Handler |
| (Interrupt : in Interrupt_ID; |
| Static : in Boolean) |
| is |
| Old_Handler : Parameterless_Handler; |
| |
| begin |
| if User_Entry (Interrupt).T /= Null_Task then |
| |
| -- In case we have an Interrupt Entry installed. |
| -- raise a program error. (propagate it to the caller). |
| |
| 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. That is the |
| -- case when we want to detach a handler regardless of the static |
| -- status of the current_Handler. |
| |
| if not Static and then User_Handler (Interrupt).Static then |
| |
| -- Tries to detach a static Interrupt Handler. |
| -- raise a program error. |
| |
| Unlock_Interrupt (Self_ID, Interrupt); |
| Raise_Exception (Program_Error'Identity, |
| "Trying to detach a static Interrupt Handler"); |
| end if; |
| |
| -- The interrupt should no longer be ignored if |
| -- it was ever ignored. |
| |
| Ignored (Interrupt) := False; |
| |
| 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 : in Parameterless_Handler; |
| Interrupt : in Interrupt_ID; |
| Static : in Boolean; |
| Restoration : in Boolean := False) |
| is |
| begin |
| if User_Entry (Interrupt).T /= Null_Task then |
| |
| -- In case we have an Interrupt Entry already installed. |
| -- raise a program error. (propagate it to the caller). |
| |
| 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. That is the case when we want to |
| -- Detach a handler regardless of the Static status |
| -- of the current_Handler. |
| -- We don't check anything if Restoration is True, since we |
| -- may be detaching a static handler to restore a dynamic one. |
| |
| if not Restoration and then not Static |
| |
| -- Tries to overwrite a static Interrupt Handler with a |
| -- dynamic Handler |
| |
| and then (User_Handler (Interrupt).Static |
| |
| -- The new handler is not specified as an |
| -- Interrupt Handler by a pragma. |
| |
| or else not Is_Registered (New_Handler)) |
| then |
| Unlock_Interrupt (Self_ID, Interrupt); |
| Raise_Exception (Program_Error'Identity, |
| "Trying to overwrite a static Interrupt Handler with a " & |
| "dynamic Handler"); |
| end if; |
| |
| -- The interrupt should no longer be ingnored if |
| -- it was ever ignored. |
| |
| Ignored (Interrupt) := False; |
| |
| -- Save the old handler |
| |
| Old_Handler := User_Handler (Interrupt).H; |
| |
| -- The new handler |
| |
| User_Handler (Interrupt).H := New_Handler; |
| |
| if New_Handler = null then |
| |
| -- The null handler means we are detaching the handler. |
| |
| User_Handler (Interrupt).Static := False; |
| |
| else |
| User_Handler (Interrupt).Static := Static; |
| end if; |
| |
| -- Invoke a corresponding Server_Task if not yet created. |
| -- Place Task_ID info in Server_ID array. |
| |
| if Server_ID (Interrupt) = Null_Task then |
| |
| -- When a new Server_Task is created, it should have its |
| -- signal mask set to the All_Tasks_Mask. |
| |
| IMOP.Set_Interrupt_Mask |
| (IMOP.All_Tasks_Mask'Access, Old_Mask'Access); |
| Access_Hold := new Server_Task (Interrupt); |
| IMOP.Set_Interrupt_Mask (Old_Mask'Access); |
| |
| Server_ID (Interrupt) := To_System (Access_Hold.all'Identity); |
| end if; |
| |
| if (New_Handler = null) then |
| if Old_Handler /= null then |
| Unbind_Handler (Interrupt); |
| end if; |
| |
| return; |
| end if; |
| |
| if Old_Handler = null then |
| Bind_Handler (Interrupt); |
| end if; |
| |
| end Unprotected_Exchange_Handler; |
| |
| -- Start of processing for Interrupt_Manager |
| |
| begin |
| -- By making this task independent of master, when the process |
| -- goes away, the Interrupt_Manager will terminate gracefully. |
| |
| System.Tasking.Utilities.Make_Independent; |
| |
| -- Environmen task gets its own interrupt mask, saves it, |
| -- and then masks all interrupts except the Keep_Unmasked set. |
| |
| -- During rendezvous, the Interrupt_Manager receives the old |
| -- interrupt mask of the environment task, and sets its own |
| -- interrupt mask to that value. |
| |
| -- The environment task will call the entry of Interrupt_Manager some |
| -- during elaboration of the body of this package. |
| |
| accept Initialize (Mask : IMNG.Interrupt_Mask) do |
| declare |
| The_Mask : aliased IMNG.Interrupt_Mask; |
| |
| begin |
| IMOP.Copy_Interrupt_Mask (The_Mask, Mask); |
| IMOP.Set_Interrupt_Mask (The_Mask'Access); |
| end; |
| end Initialize; |
| |
| -- Note: All tasks in RTS will have all the Reserve Interrupts |
| -- being masked (except the Interrupt_Manager) and Keep_Unmasked |
| -- unmasked when created. |
| |
| -- Abort_Task_Interrupt is one of the Interrupt unmasked |
| -- in all tasks. We mask the Interrupt in this particular task |
| -- so that "sigwait" is possible to catch an explicitly sent |
| -- Abort_Task_Interrupt from the Server_Tasks. |
| |
| -- This sigwaiting is needed so that we make sure a Server_Task is |
| -- out of its own sigwait state. This extra synchronization is |
| -- necessary to prevent following senarios. |
| |
| -- 1) Interrupt_Manager sends an Abort_Task_Interrupt to the |
| -- Server_Task then changes its own interrupt mask (OS level). |
| -- If an interrupt (corresponding to the Server_Task) arrives |
| -- in the nean time we have the Interrupt_Manager umnasked and |
| -- the Server_Task waiting on sigwait. |
| |
| -- 2) For unbinding handler, we install a default action in the |
| -- Interrupt_Manager. POSIX.1c states that the result of using |
| -- "sigwait" and "sigaction" simaltaneously on the same interrupt |
| -- is undefined. Therefore, we need to be informed from the |
| -- Server_Task of the fact that the Server_Task is out of its |
| -- sigwait stage. |
| |
| 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 : in Parameterless_Handler; |
| Interrupt : in Interrupt_ID; |
| Static : in Boolean; |
| Restoration : in 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 : in Parameterless_Handler; |
| Interrupt : in Interrupt_ID; |
| Static : in 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 : in Interrupt_ID; |
| Static : in 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; |
| |
| -- The interrupt should no longer be ingnored if |
| -- it was ever ignored. |
| |
| Ignored (Interrupt) := False; |
| User_Entry (Interrupt) := Entry_Assoc' (T => T, E => E); |
| |
| -- Indicate the attachment of Interrupt Entry in ATCB. |
| -- This is need so that when an Interrupt Entry task terminates |
| -- the binding can be cleaned. The call to unbinding must be |
| -- make by the task before it terminates. |
| |
| T.Interrupt_Entry := True; |
| |
| -- Invoke a corresponding Server_Task if not yet created. |
| -- Place Task_ID info in Server_ID array. |
| |
| if Server_ID (Interrupt) = Null_Task then |
| |
| -- When a new Server_Task is created, it should have its |
| -- signal mask set to the All_Tasks_Mask. |
| |
| IMOP.Set_Interrupt_Mask |
| (IMOP.All_Tasks_Mask'Access, Old_Mask'Access); |
| Access_Hold := new Server_Task (Interrupt); |
| IMOP.Set_Interrupt_Mask (Old_Mask'Access); |
| Server_ID (Interrupt) := |
| To_System (Access_Hold.all'Identity); |
| end if; |
| |
| Bind_Handler (Interrupt); |
| Unlock_Interrupt (Self_ID, Interrupt); |
| end Bind_Interrupt_To_Entry; |
| |
| or accept Detach_Interrupt_Entries (T : Task_ID) |
| do |
| for I in Interrupt_ID'Range loop |
| if not Is_Reserved (I) then |
| Lock_Interrupt (Self_ID, I); |
| |
| if User_Entry (I).T = T then |
| |
| -- The interrupt should no longer be ingnored if |
| -- it was ever ignored. |
| |
| Ignored (I) := False; |
| User_Entry (I) := Entry_Assoc' |
| (T => Null_Task, E => Null_Task_Entry); |
| Unbind_Handler (I); |
| end if; |
| |
| Unlock_Interrupt (Self_ID, I); |
| end if; |
| end loop; |
| |
| -- Indicate in ATCB that no Interrupt Entries are attached. |
| |
| T.Interrupt_Entry := False; |
| end Detach_Interrupt_Entries; |
| |
| or accept Block_Interrupt (Interrupt : Interrupt_ID) do |
| Lock_Interrupt (Self_ID, Interrupt); |
| |
| if Blocked (Interrupt) then |
| Unlock_Interrupt (Self_ID, Interrupt); |
| return; |
| end if; |
| |
| Blocked (Interrupt) := True; |
| Last_Unblocker (Interrupt) := Null_Task; |
| |
| -- Mask this task for the given Interrupt so that all tasks |
| -- are masked for the Interrupt. |
| |
| IMOP.Thread_Block_Interrupt (IMNG.Interrupt_ID (Interrupt)); |
| |
| if User_Handler (Interrupt).H /= null |
| or else User_Entry (Interrupt).T /= Null_Task |
| then |
| -- This is the case where the Server_Task is waiting on |
| -- "sigwait." Wake it up by sending an Abort_Task_Interrupt |
| -- so that the Server_Task waits on Cond. |
| |
| POP.Abort_Task (Server_ID (Interrupt)); |
| |
| -- Make sure corresponding Server_Task is out of its own |
| -- sigwait state. |
| |
| Ret_Interrupt := |
| Interrupt_ID (IMOP.Interrupt_Wait (Intwait_Mask'Access)); |
| pragma Assert |
| (Ret_Interrupt = Interrupt_ID (IMNG.Abort_Task_Interrupt)); |
| end if; |
| |
| Unlock_Interrupt (Self_ID, Interrupt); |
| end Block_Interrupt; |
| |
| or accept Unblock_Interrupt (Interrupt : Interrupt_ID) do |
| Lock_Interrupt (Self_ID, Interrupt); |
| |
| if not Blocked (Interrupt) then |
| Unlock_Interrupt (Self_ID, Interrupt); |
| return; |
| end if; |
| |
| Blocked (Interrupt) := False; |
| Last_Unblocker (Interrupt) := |
| To_System (Unblock_Interrupt'Caller); |
| |
| if User_Handler (Interrupt).H = null |
| and then User_Entry (Interrupt).T = Null_Task |
| then |
| -- No handler is attached. Unmask the Interrupt so that |
| -- the default action can be carried out. |
| IMOP.Thread_Unblock_Interrupt |
| (IMNG.Interrupt_ID (Interrupt)); |
| |
| else |
| -- The Server_Task must be waiting on the Cond variable |
| -- since it was being blocked and an Interrupt Hander or |
| -- an Entry was there. Wake it up and let it change |
| -- it place of waiting according to its new state. |
| POP.Wakeup (Server_ID (Interrupt), |
| Interrupt_Server_Blocked_Interrupt_Sleep); |
| end if; |
| |
| Unlock_Interrupt (Self_ID, Interrupt); |
| end Unblock_Interrupt; |
| |
| or accept Ignore_Interrupt (Interrupt : Interrupt_ID) do |
| Lock_Interrupt (Self_ID, Interrupt); |
| |
| if Ignored (Interrupt) then |
| Unlock_Interrupt (Self_ID, Interrupt); |
| return; |
| end if; |
| |
| Ignored (Interrupt) := True; |
| |
| -- If there is a handler associated with the Interrupt, |
| -- detach it first. In this way we make sure that the |
| -- Server_Task is not on sigwait. This is legal since |
| -- Unignore_Interrupt is to install the default action. |
| |
| if User_Handler (Interrupt).H /= null then |
| Unprotected_Detach_Handler |
| (Interrupt => Interrupt, Static => True); |
| |
| elsif User_Entry (Interrupt).T /= Null_Task then |
| User_Entry (Interrupt) := Entry_Assoc' |
| (T => Null_Task, E => Null_Task_Entry); |
| Unbind_Handler (Interrupt); |
| end if; |
| |
| IMOP.Install_Ignore_Action (IMNG.Interrupt_ID (Interrupt)); |
| Unlock_Interrupt (Self_ID, Interrupt); |
| end Ignore_Interrupt; |
| |
| or accept Unignore_Interrupt (Interrupt : Interrupt_ID) do |
| Lock_Interrupt (Self_ID, Interrupt); |
| Ignored (Interrupt) := False; |
| |
| -- If there is a handler associated with the Interrupt, |
| -- detach it first. In this way we make sure that the |
| -- Server_Task is not on sigwait. This is legal since |
| -- Unignore_Interrupt is to install the default action. |
| |
| if User_Handler (Interrupt).H /= null then |
| Unprotected_Detach_Handler |
| (Interrupt => Interrupt, Static => True); |
| |
| elsif User_Entry (Interrupt).T /= Null_Task then |
| User_Entry (Interrupt) := Entry_Assoc' |
| (T => Null_Task, E => Null_Task_Entry); |
| Unbind_Handler (Interrupt); |
| end if; |
| |
| IMOP.Install_Default_Action (IMNG.Interrupt_ID (Interrupt)); |
| Unlock_Interrupt (Self_ID, Interrupt); |
| end Unignore_Interrupt; |
| |
| end select; |
| |
| exception |
| |
| -- If there is a program error we just want to propagate it to |
| -- the caller and do not want to stop this task. |
| |
| when Program_Error => |
| null; |
| |
| when others => |
| pragma Assert |
| (Shutdown ("Interrupt_Manager---exception not expected")); |
| null; |
| end; |
| |
| end loop; |
| |
| pragma Assert (Shutdown ("Interrupt_Manager---should not get here")); |
| |
| end Interrupt_Manager; |
| |
| ----------------- |
| -- Server_Task -- |
| ----------------- |
| |
| task body Server_Task is |
| Intwait_Mask : aliased IMNG.Interrupt_Mask; |
| Ret_Interrupt : Interrupt_ID; |
| Self_ID : Task_ID := Self; |
| Tmp_Handler : Parameterless_Handler; |
| Tmp_ID : Task_ID; |
| Tmp_Entry_Index : Task_Entry_Index; |
| |
| begin |
| -- By making this task independent of master, when the process |
| -- goes away, the Server_Task will terminate gracefully. |
| |
| System.Tasking.Utilities.Make_Independent; |
| |
| -- Install default action in system level. |
| |
| IMOP.Install_Default_Action (IMNG.Interrupt_ID (Interrupt)); |
| |
| -- Note: All tasks in RTS will have all the Reserve Interrupts |
| -- being masked (except the Interrupt_Manager) and Keep_Unmasked |
| -- unmasked when created. |
| |
| -- Abort_Task_Interrupt is one of the Interrupt unmasked |
| -- in all tasks. We mask the Interrupt in this particular task |
| -- so that "sigwait" is possible to catch an explicitly sent |
| -- Abort_Task_Interrupt from the Interrupt_Manager. |
| |
| -- There are two Interrupt interrupts that this task catch through |
| -- "sigwait." One is the Interrupt this task is designated to catch |
| -- in order to execure user handler or entry. The other one is the |
| -- Abort_Task_Interrupt. This interrupt is being sent from the |
| -- Interrupt_Manager to inform status changes (e.g: become Blocked, |
| -- Handler or Entry is to be detached). |
| |
| -- Prepare a mask to used for sigwait. |
| |
| IMOP.Empty_Interrupt_Mask (Intwait_Mask'Access); |
| |
| IMOP.Add_To_Interrupt_Mask |
| (Intwait_Mask'Access, IMNG.Interrupt_ID (Interrupt)); |
| |
| IMOP.Add_To_Interrupt_Mask |
| (Intwait_Mask'Access, IMNG.Abort_Task_Interrupt); |
| |
| IMOP.Thread_Block_Interrupt |
| (IMNG.Abort_Task_Interrupt); |
| |
| PIO.Set_Interrupt_ID (IMNG.Interrupt_ID (Interrupt), Self_ID); |
| |
| loop |
| System.Tasking.Initialization.Defer_Abort (Self_ID); |
| POP.Write_Lock (Self_ID); |
| |
| if User_Handler (Interrupt).H = null |
| and then User_Entry (Interrupt).T = Null_Task |
| then |
| -- No Interrupt binding. If there is an interrupt, |
| -- Interrupt_Manager will take default action. |
| |
| Self_ID.Common.State := Interrupt_Server_Blocked_Interrupt_Sleep; |
| POP.Sleep (Self_ID, Interrupt_Server_Idle_Sleep); |
| Self_ID.Common.State := Runnable; |
| |
| elsif Blocked (Interrupt) then |
| |
| -- Interrupt is blocked. Stay here, so we won't catch |
| -- the Interrupt. |
| |
| Self_ID.Common.State := Interrupt_Server_Blocked_Interrupt_Sleep; |
| POP.Sleep (Self_ID, Interrupt_Server_Blocked_Interrupt_Sleep); |
| Self_ID.Common.State := Runnable; |
| |
| else |
| -- A Handler or an Entry is installed. At this point all tasks |
| -- mask for the Interrupt is masked. Catch the Interrupt using |
| -- sigwait. |
| |
| -- This task may wake up from sigwait by receiving an interrupt |
| -- (Abort_Task_Interrupt) from the Interrupt_Manager for unbinding |
| -- a Procedure Handler or an Entry. Or it could be a wake up |
| -- from status change (Unblocked -> Blocked). If that is not |
| -- the case, we should exceute the attached Procedure or Entry. |
| |
| POP.Unlock (Self_ID); |
| |
| Ret_Interrupt := |
| Interrupt_ID (IMOP.Interrupt_Wait (Intwait_Mask'Access)); |
| |
| if Ret_Interrupt = Interrupt_ID (IMNG.Abort_Task_Interrupt) then |
| |
| -- Inform the Interrupt_Manager of wakeup from above sigwait. |
| |
| POP.Abort_Task (Interrupt_Manager_ID); |
| POP.Write_Lock (Self_ID); |
| |
| else |
| pragma Assert (Ret_Interrupt = Interrupt); |
| |
| POP.Write_Lock (Self_ID); |
| |
| -- Even though we have received an Interrupt the status may |
| -- have changed already before we got the Self_ID lock above. |
| -- Therefore we make sure a Handler or an Entry is still |
| -- there and make appropriate call. |
| -- If there is no calls to make we need to regenerate the |
| -- Interrupt in order not to lose it. |
| |
| if User_Handler (Interrupt).H /= null then |
| Tmp_Handler := User_Handler (Interrupt).H; |
| |
| -- RTS calls should not be made with self being locked. |
| |
| POP.Unlock (Self_ID); |
| |
| Tmp_Handler.all; |
| POP.Write_Lock (Self_ID); |
| |
| elsif User_Entry (Interrupt).T /= Null_Task then |
| Tmp_ID := User_Entry (Interrupt).T; |
| Tmp_Entry_Index := User_Entry (Interrupt).E; |
| |
| -- RTS calls should not be made with self being locked. |
| |
| POP.Unlock (Self_ID); |
| |
| System.Tasking.Rendezvous.Call_Simple |
| (Tmp_ID, Tmp_Entry_Index, System.Null_Address); |
| |
| POP.Write_Lock (Self_ID); |
| else |
| -- This is a situation that this task wake up |
| -- receiving an Interrupt and before it get the lock |
| -- the Interrupt is blocked. We do not |
| -- want to lose the interrupt in this case so that |
| -- regenerate the Interrupt to process level; |
| |
| IMOP.Interrupt_Self_Process (IMNG.Interrupt_ID (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; |
| |
| pragma Assert (Shutdown ("Server_Task---should not get here")); |
| end Server_Task; |
| |
| -- Elaboration code for package System.Interrupts |
| |
| begin |
| |
| -- Get Interrupt_Manager's ID so that Abort_Interrupt can be sent. |
| |
| Interrupt_Manager_ID := To_System (Interrupt_Manager'Identity); |
| |
| -- 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 RTS to |
| -- inherit the interrupt mask from the Environment Task. |
| |
| -- The Environment Task should have gotten its mask from |
| -- the enclosing process during the RTS start up. (See |
| -- in s-inmaop.adb). Pass the Interrupt_Mask of the Environment |
| -- task to the Interrupt_Manager. |
| |
| -- Note : At this point we know that all tasks (including |
| -- RTS internal servers) are masked for non-reserved signals |
| -- (see s-taprop.adb). Only the Interrupt_Manager will have |
| -- masks set up differently inheriting the original Environment |
| -- Task's mask. |
| |
| Interrupt_Manager.Initialize (IMOP.Environment_Mask); |
| end System.Interrupts; |
