1 ------------------------------------------------------------------------------
3 -- GNAT RUN-TIME LIBRARY (GNARL) COMPONENTS --
5 -- S Y S T E M . I N T E R R U P T S --
9 -- Copyright (C) 1992-2005, Free Software Foundation, Inc. --
11 -- GNARL is free software; you can redistribute it and/or modify it under --
12 -- terms of the GNU General Public License as published by the Free Soft- --
13 -- ware Foundation; either version 2, or (at your option) any later ver- --
14 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
15 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
16 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
17 -- for more details. You should have received a copy of the GNU General --
18 -- Public License distributed with GNARL; see file COPYING. If not, write --
19 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
20 -- MA 02111-1307, USA. --
22 -- As a special exception, if other files instantiate generics from this --
23 -- unit, or you link this unit with other files to produce an executable, --
24 -- this unit does not by itself cause the resulting executable to be --
25 -- covered by the GNU General Public License. This exception does not --
26 -- however invalidate any other reasons why the executable file might be --
27 -- covered by the GNU Public License. --
29 -- GNARL was developed by the GNARL team at Florida State University. --
30 -- Extensive contributions were provided by Ada Core Technologies, Inc. --
32 ------------------------------------------------------------------------------
34 -- This is an OpenVMS/Alpha version of this package
38 -- Once we associate a Server_Task with an interrupt, the task never
39 -- goes away, and we never remove the association.
41 -- There is no more than one interrupt per Server_Task and no more than
42 -- one Server_Task per interrupt.
44 -- Within this package, the lock L is used to protect the various status
45 -- tables. If there is a Server_Task associated with an interrupt, we use
46 -- the per-task lock of the Server_Task instead so that we protect the
47 -- status between Interrupt_Manager and Server_Task. Protection among
48 -- service requests are done using User Request to Interrupt_Manager
51 with Ada.Task_Identification;
52 -- used for Task_Id type
55 -- used for Raise_Exception
57 with System.Task_Primitives;
61 with System.Interrupt_Management;
65 -- Abort_Task_Interrupt
67 with System.Interrupt_Management.Operations;
68 -- used for Thread_Block_Interrupt
69 -- Thread_Unblock_Interrupt
70 -- Install_Default_Action
71 -- Install_Ignore_Action
72 -- Copy_Interrupt_Mask
74 -- Empty_Interrupt_Mask
75 -- Fill_Interrupt_Mask
76 -- Add_To_Interrupt_Mask
77 -- Delete_From_Interrupt_Mask
79 -- Interrupt_Self_Process
84 pragma Elaborate_All (System.Interrupt_Management.Operations);
86 with System.Task_Primitives.Operations;
87 -- used for Write_Lock
94 with System.Task_Primitives.Interrupt_Operations;
95 -- used for Set_Interrupt_ID
97 with System.Storage_Elements;
98 -- used for To_Address
107 -- Interrupt_Manager_ID
109 with System.Tasking.Utilities;
110 -- used for Make_Independent
112 with System.Tasking.Rendezvous;
113 -- used for Call_Simple
114 pragma Elaborate_All (System.Tasking.Rendezvous);
116 with System.Tasking.Initialization;
117 -- used for Defer_Abort
120 with System.Parameters;
121 -- used for Single_Lock
123 with Unchecked_Conversion;
125 package body System.Interrupts is
128 use System.Parameters;
131 package POP renames System.Task_Primitives.Operations;
132 package PIO renames System.Task_Primitives.Interrupt_Operations;
133 package IMNG renames System.Interrupt_Management;
134 package IMOP renames System.Interrupt_Management.Operations;
136 function To_System is new Unchecked_Conversion
137 (Ada.Task_Identification.Task_Id, Task_Id);
143 -- WARNING: System.Tasking.Stages performs calls to this task with
144 -- low-level constructs. Do not change this spec without synchronizing it.
146 task Interrupt_Manager is
147 entry Detach_Interrupt_Entries (T : Task_Id);
149 entry Initialize (Mask : IMNG.Interrupt_Mask);
152 (New_Handler : Parameterless_Handler;
153 Interrupt : Interrupt_ID;
155 Restoration : Boolean := False);
157 entry Exchange_Handler
158 (Old_Handler : out Parameterless_Handler;
159 New_Handler : Parameterless_Handler;
160 Interrupt : Interrupt_ID;
164 (Interrupt : Interrupt_ID;
167 entry Bind_Interrupt_To_Entry
169 E : Task_Entry_Index;
170 Interrupt : Interrupt_ID);
172 entry Block_Interrupt (Interrupt : Interrupt_ID);
174 entry Unblock_Interrupt (Interrupt : Interrupt_ID);
176 entry Ignore_Interrupt (Interrupt : Interrupt_ID);
178 entry Unignore_Interrupt (Interrupt : Interrupt_ID);
180 pragma Interrupt_Priority (System.Interrupt_Priority'Last);
181 end Interrupt_Manager;
183 task type Server_Task (Interrupt : Interrupt_ID) is
184 pragma Priority (System.Interrupt_Priority'Last);
185 -- Note: the above pragma Priority is strictly speaking improper since
186 -- it is outside the range of allowed priorities, but the compiler
187 -- treats system units specially and does not apply this range checking
188 -- rule to system units.
192 type Server_Task_Access is access Server_Task;
194 -------------------------------
195 -- Local Types and Variables --
196 -------------------------------
198 type Entry_Assoc is record
200 E : Task_Entry_Index;
203 type Handler_Assoc is record
204 H : Parameterless_Handler;
205 Static : Boolean; -- Indicates static binding;
208 User_Handler : array (Interrupt_ID'Range) of Handler_Assoc :=
209 (others => (null, Static => False));
210 pragma Volatile_Components (User_Handler);
211 -- Holds the protected procedure handler (if any) and its Static
212 -- information for each interrupt. A handler is a Static one if it is
213 -- specified through the pragma Attach_Handler. Attach_Handler. Otherwise,
216 User_Entry : array (Interrupt_ID'Range) of Entry_Assoc :=
217 (others => (T => Null_Task, E => Null_Task_Entry));
218 pragma Volatile_Components (User_Entry);
219 -- Holds the task and entry index (if any) for each interrupt
221 Blocked : constant array (Interrupt_ID'Range) of Boolean :=
223 -- ??? pragma Volatile_Components (Blocked);
224 -- True iff the corresponding interrupt is blocked in the process level
226 Ignored : array (Interrupt_ID'Range) of Boolean := (others => False);
227 pragma Volatile_Components (Ignored);
228 -- True iff the corresponding interrupt is blocked in the process level
230 Last_Unblocker : constant array (Interrupt_ID'Range) of Task_Id :=
231 (others => Null_Task);
232 -- ??? pragma Volatile_Components (Last_Unblocker);
233 -- Holds the ID of the last Task which Unblocked this Interrupt.
234 -- It contains Null_Task if no tasks have ever requested the
235 -- Unblocking operation or the Interrupt is currently Blocked.
237 Server_ID : array (Interrupt_ID'Range) of Task_Id :=
238 (others => Null_Task);
239 pragma Atomic_Components (Server_ID);
240 -- Holds the Task_Id of the Server_Task for each interrupt. Task_Id is
241 -- needed to accomplish locking per Interrupt base. Also is needed to
242 -- decide whether to create a new Server_Task.
244 -- Type and Head, Tail of the list containing Registered Interrupt
245 -- Handlers. These definitions are used to register the handlers specified
246 -- by the pragma Interrupt_Handler.
248 type Registered_Handler;
249 type R_Link is access all Registered_Handler;
251 type Registered_Handler is record
252 H : System.Address := System.Null_Address;
253 Next : R_Link := null;
256 Registered_Handler_Head : R_Link := null;
257 Registered_Handler_Tail : R_Link := null;
259 Access_Hold : Server_Task_Access;
260 -- variable used to allocate Server_Task using "new".
262 -----------------------
263 -- Local Subprograms --
264 -----------------------
266 function Is_Registered (Handler : Parameterless_Handler) return Boolean;
267 -- See if the Handler has been "pragma"ed using Interrupt_Handler.
268 -- Always consider a null handler as registered.
270 --------------------------------
271 -- Register_Interrupt_Handler --
272 --------------------------------
274 procedure Register_Interrupt_Handler (Handler_Addr : System.Address) is
275 New_Node_Ptr : R_Link;
277 -- This routine registers the Handler as usable for Dynamic
278 -- Interrupt Handler. Routines attaching and detaching Handler
279 -- dynamically should first consult if the Handler is rgistered.
280 -- A Program Error should be raised if it is not registered.
282 -- The pragma Interrupt_Handler can only appear in the library
283 -- level PO definition and instantiation. Therefore, we do not need
284 -- to implement Unregistering operation. Neither we need to
285 -- protect the queue structure using a Lock.
287 pragma Assert (Handler_Addr /= System.Null_Address);
289 New_Node_Ptr := new Registered_Handler;
290 New_Node_Ptr.H := Handler_Addr;
292 if Registered_Handler_Head = null then
293 Registered_Handler_Head := New_Node_Ptr;
294 Registered_Handler_Tail := New_Node_Ptr;
297 Registered_Handler_Tail.Next := New_Node_Ptr;
298 Registered_Handler_Tail := New_Node_Ptr;
300 end Register_Interrupt_Handler;
306 function Is_Registered (Handler : Parameterless_Handler) return Boolean is
307 type Fat_Ptr is record
308 Object_Addr : System.Address;
309 Handler_Addr : System.Address;
312 function To_Fat_Ptr is new Unchecked_Conversion
313 (Parameterless_Handler, Fat_Ptr);
319 if Handler = null then
323 Fat := To_Fat_Ptr (Handler);
325 Ptr := Registered_Handler_Head;
327 while Ptr /= null loop
328 if Ptr.H = Fat.Handler_Addr then
342 function Is_Reserved (Interrupt : Interrupt_ID) return Boolean is
344 return IMNG.Reserve (IMNG.Interrupt_ID (Interrupt));
347 -----------------------
348 -- Is_Entry_Attached --
349 -----------------------
351 function Is_Entry_Attached (Interrupt : Interrupt_ID) return Boolean is
353 if Is_Reserved (Interrupt) then
354 Raise_Exception (Program_Error'Identity, "Interrupt" &
355 Interrupt_ID'Image (Interrupt) & " is reserved");
358 return User_Entry (Interrupt).T /= Null_Task;
359 end Is_Entry_Attached;
361 -------------------------
362 -- Is_Handler_Attached --
363 -------------------------
365 function Is_Handler_Attached (Interrupt : Interrupt_ID) return Boolean is
367 if Is_Reserved (Interrupt) then
368 Raise_Exception (Program_Error'Identity, "Interrupt" &
369 Interrupt_ID'Image (Interrupt) & " is reserved");
372 return User_Handler (Interrupt).H /= null;
373 end Is_Handler_Attached;
379 function Is_Blocked (Interrupt : Interrupt_ID) return Boolean is
381 if Is_Reserved (Interrupt) then
382 Raise_Exception (Program_Error'Identity, "Interrupt" &
383 Interrupt_ID'Image (Interrupt) & " is reserved");
386 return Blocked (Interrupt);
393 function Is_Ignored (Interrupt : Interrupt_ID) return Boolean is
395 if Is_Reserved (Interrupt) then
396 Raise_Exception (Program_Error'Identity, "Interrupt" &
397 Interrupt_ID'Image (Interrupt) & " is reserved");
400 return Ignored (Interrupt);
403 ---------------------
404 -- Current_Handler --
405 ---------------------
407 function Current_Handler
408 (Interrupt : Interrupt_ID) return Parameterless_Handler
411 if Is_Reserved (Interrupt) then
412 Raise_Exception (Program_Error'Identity, "Interrupt" &
413 Interrupt_ID'Image (Interrupt) & " is reserved");
416 -- ??? Since Parameterless_Handler is not Atomic, the current
417 -- implementation is wrong. We need a new service in Interrupt_Manager
418 -- to ensure atomicity.
420 return User_Handler (Interrupt).H;
427 -- Calling this procedure with New_Handler = null and Static = True
428 -- means we want to detach the current handler regardless of the
429 -- previous handler's binding status (ie. do not care if it is a
430 -- dynamic or static handler).
432 -- This option is needed so that during the finalization of a PO, we
433 -- can detach handlers attached through pragma Attach_Handler.
435 procedure Attach_Handler
436 (New_Handler : Parameterless_Handler;
437 Interrupt : Interrupt_ID;
438 Static : Boolean := False) is
440 if Is_Reserved (Interrupt) then
441 Raise_Exception (Program_Error'Identity, "Interrupt" &
442 Interrupt_ID'Image (Interrupt) & " is reserved");
445 Interrupt_Manager.Attach_Handler (New_Handler, Interrupt, Static);
449 ----------------------
450 -- Exchange_Handler --
451 ----------------------
453 -- Calling this procedure with New_Handler = null and Static = True means
454 -- we want to detach the current handler regardless of the previous
455 -- handler's binding status (ie. do not care if it is dynamic or static
458 -- This option is needed so that during the finalization of a PO, we can
459 -- detach handlers attached through pragma Attach_Handler.
461 procedure Exchange_Handler
462 (Old_Handler : out Parameterless_Handler;
463 New_Handler : Parameterless_Handler;
464 Interrupt : Interrupt_ID;
465 Static : Boolean := False)
468 if Is_Reserved (Interrupt) then
469 Raise_Exception (Program_Error'Identity, "Interrupt" &
470 Interrupt_ID'Image (Interrupt) & " is reserved");
473 Interrupt_Manager.Exchange_Handler
474 (Old_Handler, New_Handler, Interrupt, Static);
476 end Exchange_Handler;
482 -- Calling this procedure with Static = True means we want to Detach the
483 -- current handler regardless of the previous handler's binding status
484 -- (i.e. do not care if it is a dynamic or static handler).
486 -- This option is needed so that during the finalization of a PO, we can
487 -- detach handlers attached through pragma Attach_Handler.
489 procedure Detach_Handler
490 (Interrupt : Interrupt_ID;
491 Static : Boolean := False)
494 if Is_Reserved (Interrupt) then
495 Raise_Exception (Program_Error'Identity, "Interrupt" &
496 Interrupt_ID'Image (Interrupt) & " is reserved");
499 Interrupt_Manager.Detach_Handler (Interrupt, Static);
506 function Reference (Interrupt : Interrupt_ID) return System.Address is
508 if Is_Reserved (Interrupt) then
509 Raise_Exception (Program_Error'Identity, "Interrupt" &
510 Interrupt_ID'Image (Interrupt) & " is reserved");
513 return Storage_Elements.To_Address
514 (Storage_Elements.Integer_Address (Interrupt));
517 -----------------------------
518 -- Bind_Interrupt_To_Entry --
519 -----------------------------
521 -- This procedure raises a Program_Error if it tries to
522 -- bind an interrupt to which an Entry or a Procedure is
525 procedure Bind_Interrupt_To_Entry
527 E : Task_Entry_Index;
528 Int_Ref : System.Address)
530 Interrupt : constant Interrupt_ID :=
531 Interrupt_ID (Storage_Elements.To_Integer (Int_Ref));
534 if Is_Reserved (Interrupt) then
535 Raise_Exception (Program_Error'Identity, "Interrupt" &
536 Interrupt_ID'Image (Interrupt) & " is reserved");
539 Interrupt_Manager.Bind_Interrupt_To_Entry (T, E, Interrupt);
541 end Bind_Interrupt_To_Entry;
543 ------------------------------
544 -- Detach_Interrupt_Entries --
545 ------------------------------
547 procedure Detach_Interrupt_Entries (T : Task_Id) is
549 Interrupt_Manager.Detach_Interrupt_Entries (T);
550 end Detach_Interrupt_Entries;
552 ---------------------
553 -- Block_Interrupt --
554 ---------------------
556 procedure Block_Interrupt (Interrupt : Interrupt_ID) is
558 if Is_Reserved (Interrupt) then
559 Raise_Exception (Program_Error'Identity, "Interrupt" &
560 Interrupt_ID'Image (Interrupt) & " is reserved");
563 Interrupt_Manager.Block_Interrupt (Interrupt);
566 -----------------------
567 -- Unblock_Interrupt --
568 -----------------------
570 procedure Unblock_Interrupt (Interrupt : Interrupt_ID) is
572 if Is_Reserved (Interrupt) then
573 Raise_Exception (Program_Error'Identity, "Interrupt" &
574 Interrupt_ID'Image (Interrupt) & " is reserved");
577 Interrupt_Manager.Unblock_Interrupt (Interrupt);
578 end Unblock_Interrupt;
584 function Unblocked_By
585 (Interrupt : Interrupt_ID) return System.Tasking.Task_Id is
587 if Is_Reserved (Interrupt) then
588 Raise_Exception (Program_Error'Identity, "Interrupt" &
589 Interrupt_ID'Image (Interrupt) & " is reserved");
592 return Last_Unblocker (Interrupt);
595 ----------------------
596 -- Ignore_Interrupt --
597 ----------------------
599 procedure Ignore_Interrupt (Interrupt : Interrupt_ID) is
601 if Is_Reserved (Interrupt) then
602 Raise_Exception (Program_Error'Identity, "Interrupt" &
603 Interrupt_ID'Image (Interrupt) & " is reserved");
606 Interrupt_Manager.Ignore_Interrupt (Interrupt);
607 end Ignore_Interrupt;
609 ------------------------
610 -- Unignore_Interrupt --
611 ------------------------
613 procedure Unignore_Interrupt (Interrupt : Interrupt_ID) is
615 if Is_Reserved (Interrupt) then
616 Raise_Exception (Program_Error'Identity, "Interrupt" &
617 Interrupt_ID'Image (Interrupt) & " is reserved");
620 Interrupt_Manager.Unignore_Interrupt (Interrupt);
621 end Unignore_Interrupt;
623 -----------------------
624 -- Interrupt_Manager --
625 -----------------------
627 task body Interrupt_Manager is
633 procedure Unprotected_Exchange_Handler
634 (Old_Handler : out Parameterless_Handler;
635 New_Handler : Parameterless_Handler;
636 Interrupt : Interrupt_ID;
638 Restoration : Boolean := False);
640 procedure Unprotected_Detach_Handler
641 (Interrupt : Interrupt_ID;
644 ----------------------------------
645 -- Unprotected_Exchange_Handler --
646 ----------------------------------
648 procedure Unprotected_Exchange_Handler
649 (Old_Handler : out Parameterless_Handler;
650 New_Handler : Parameterless_Handler;
651 Interrupt : Interrupt_ID;
653 Restoration : Boolean := False)
656 if User_Entry (Interrupt).T /= Null_Task then
657 -- In case we have an Interrupt Entry already installed.
658 -- raise a program error. (propagate it to the caller).
660 Raise_Exception (Program_Error'Identity,
661 "An interrupt is already installed");
664 -- Note : A null handler with Static = True will
665 -- pass the following check. That is the case when we want to
666 -- Detach a handler regardless of the Static status
667 -- of the current_Handler.
668 -- We don't check anything if Restoration is True, since we
669 -- may be detaching a static handler to restore a dynamic one.
671 if not Restoration and then not Static
672 -- Tries to overwrite a static Interrupt Handler with a
675 and then (User_Handler (Interrupt).Static
677 -- The new handler is not specified as an
678 -- Interrupt Handler by a pragma.
680 or else not Is_Registered (New_Handler))
682 Raise_Exception (Program_Error'Identity,
683 "Trying to overwrite a static Interrupt Handler with a " &
687 -- The interrupt should no longer be ingnored if
688 -- it was ever ignored.
690 Ignored (Interrupt) := False;
692 -- Save the old handler
694 Old_Handler := User_Handler (Interrupt).H;
698 User_Handler (Interrupt).H := New_Handler;
700 if New_Handler = null then
702 -- The null handler means we are detaching the handler.
704 User_Handler (Interrupt).Static := False;
707 User_Handler (Interrupt).Static := Static;
710 -- Invoke a corresponding Server_Task if not yet created.
711 -- Place Task_Id info in Server_ID array.
713 if Server_ID (Interrupt) = Null_Task then
714 Access_Hold := new Server_Task (Interrupt);
715 Server_ID (Interrupt) := To_System (Access_Hold.all'Identity);
717 POP.Wakeup (Server_ID (Interrupt), Interrupt_Server_Idle_Sleep);
720 end Unprotected_Exchange_Handler;
722 --------------------------------
723 -- Unprotected_Detach_Handler --
724 --------------------------------
726 procedure Unprotected_Detach_Handler
727 (Interrupt : Interrupt_ID;
731 if User_Entry (Interrupt).T /= Null_Task then
732 -- In case we have an Interrupt Entry installed.
733 -- raise a program error. (propagate it to the caller).
735 Raise_Exception (Program_Error'Identity,
736 "An interrupt entry is already installed");
739 -- Note : Static = True will pass the following check. That is the
740 -- case when we want to detach a handler regardless of the static
741 -- status of the current_Handler.
743 if not Static and then User_Handler (Interrupt).Static then
744 -- Tries to detach a static Interrupt Handler.
745 -- raise a program error.
747 Raise_Exception (Program_Error'Identity,
748 "Trying to detach a static Interrupt Handler");
751 -- The interrupt should no longer be ignored if
752 -- it was ever ignored.
754 Ignored (Interrupt) := False;
758 User_Handler (Interrupt).H := null;
759 User_Handler (Interrupt).Static := False;
760 IMOP.Interrupt_Self_Process (IMNG.Interrupt_ID (Interrupt));
762 end Unprotected_Detach_Handler;
764 -- Start of processing for Interrupt_Manager
767 -- By making this task independent of master, when the process
768 -- goes away, the Interrupt_Manager will terminate gracefully.
770 System.Tasking.Utilities.Make_Independent;
772 -- Environmen task gets its own interrupt mask, saves it,
773 -- and then masks all interrupts except the Keep_Unmasked set.
775 -- During rendezvous, the Interrupt_Manager receives the old
776 -- interrupt mask of the environment task, and sets its own
777 -- interrupt mask to that value.
779 -- The environment task will call the entry of Interrupt_Manager some
780 -- during elaboration of the body of this package.
782 accept Initialize (Mask : IMNG.Interrupt_Mask) do
783 pragma Warnings (Off, Mask);
787 -- Note: All tasks in RTS will have all the Reserve Interrupts
788 -- being masked (except the Interrupt_Manager) and Keep_Unmasked
789 -- unmasked when created.
791 -- Abort_Task_Interrupt is one of the Interrupt unmasked
792 -- in all tasks. We mask the Interrupt in this particular task
793 -- so that "sigwait" is possible to catch an explicitely sent
794 -- Abort_Task_Interrupt from the Server_Tasks.
796 -- This sigwaiting is needed so that we make sure a Server_Task is
797 -- out of its own sigwait state. This extra synchronization is
798 -- necessary to prevent following senarios.
800 -- 1) Interrupt_Manager sends an Abort_Task_Interrupt to the
801 -- Server_Task then changes its own interrupt mask (OS level).
802 -- If an interrupt (corresponding to the Server_Task) arrives
803 -- in the nean time we have the Interrupt_Manager umnasked and
804 -- the Server_Task waiting on sigwait.
806 -- 2) For unbinding handler, we install a default action in the
807 -- Interrupt_Manager. POSIX.1c states that the result of using
808 -- "sigwait" and "sigaction" simaltaneously on the same interrupt
809 -- is undefined. Therefore, we need to be informed from the
810 -- Server_Task of the fact that the Server_Task is out of its
814 -- A block is needed to absorb Program_Error exception
817 Old_Handler : Parameterless_Handler;
821 accept Attach_Handler
822 (New_Handler : Parameterless_Handler;
823 Interrupt : Interrupt_ID;
825 Restoration : Boolean := False)
827 Unprotected_Exchange_Handler
828 (Old_Handler, New_Handler, Interrupt, Static, Restoration);
831 or accept Exchange_Handler
832 (Old_Handler : out Parameterless_Handler;
833 New_Handler : Parameterless_Handler;
834 Interrupt : Interrupt_ID;
837 Unprotected_Exchange_Handler
838 (Old_Handler, New_Handler, Interrupt, Static);
839 end Exchange_Handler;
841 or accept Detach_Handler
842 (Interrupt : Interrupt_ID;
845 Unprotected_Detach_Handler (Interrupt, Static);
848 or accept Bind_Interrupt_To_Entry
850 E : Task_Entry_Index;
851 Interrupt : Interrupt_ID)
853 -- if there is a binding already (either a procedure or an
854 -- entry), raise Program_Error (propagate it to the caller).
856 if User_Handler (Interrupt).H /= null
857 or else User_Entry (Interrupt).T /= Null_Task
859 Raise_Exception (Program_Error'Identity,
860 "A binding for this interrupt is already present");
863 -- The interrupt should no longer be ingnored if
864 -- it was ever ignored.
866 Ignored (Interrupt) := False;
867 User_Entry (Interrupt) := Entry_Assoc'(T => T, E => E);
869 -- Indicate the attachment of Interrupt Entry in ATCB.
870 -- This is need so that when an Interrupt Entry task
871 -- terminates the binding can be cleaned.
872 -- The call to unbinding must be
873 -- make by the task before it terminates.
875 T.Interrupt_Entry := True;
877 -- Invoke a corresponding Server_Task if not yet created.
878 -- Place Task_Id info in Server_ID array.
880 if Server_ID (Interrupt) = Null_Task then
882 Access_Hold := new Server_Task (Interrupt);
883 Server_ID (Interrupt) :=
884 To_System (Access_Hold.all'Identity);
886 POP.Wakeup (Server_ID (Interrupt),
887 Interrupt_Server_Idle_Sleep);
889 end Bind_Interrupt_To_Entry;
891 or accept Detach_Interrupt_Entries (T : Task_Id)
893 for J in Interrupt_ID'Range loop
894 if not Is_Reserved (J) then
895 if User_Entry (J).T = T then
897 -- The interrupt should no longer be ignored if
898 -- it was ever ignored.
900 Ignored (J) := False;
902 Entry_Assoc'(T => Null_Task, E => Null_Task_Entry);
903 IMOP.Interrupt_Self_Process (IMNG.Interrupt_ID (J));
908 -- Indicate in ATCB that no Interrupt Entries are attached.
910 T.Interrupt_Entry := False;
911 end Detach_Interrupt_Entries;
913 or accept Block_Interrupt (Interrupt : Interrupt_ID) do
914 pragma Warnings (Off, Interrupt);
918 or accept Unblock_Interrupt (Interrupt : Interrupt_ID) do
919 pragma Warnings (Off, Interrupt);
921 end Unblock_Interrupt;
923 or accept Ignore_Interrupt (Interrupt : Interrupt_ID) do
924 pragma Warnings (Off, Interrupt);
926 end Ignore_Interrupt;
928 or accept Unignore_Interrupt (Interrupt : Interrupt_ID) do
929 pragma Warnings (Off, Interrupt);
931 end Unignore_Interrupt;
936 -- If there is a program error we just want to propagate it
937 -- to the caller and do not want to stop this task.
939 when Program_Error =>
943 pragma Assert (False);
947 end Interrupt_Manager;
953 task body Server_Task is
954 Self_ID : constant Task_Id := Self;
955 Tmp_Handler : Parameterless_Handler;
957 Tmp_Entry_Index : Task_Entry_Index;
958 Intwait_Mask : aliased IMNG.Interrupt_Mask;
961 -- By making this task independent of master, when the process
962 -- goes away, the Server_Task will terminate gracefully.
964 System.Tasking.Utilities.Make_Independent;
966 -- Install default action in system level.
968 IMOP.Install_Default_Action (IMNG.Interrupt_ID (Interrupt));
970 -- Set up the mask (also clears the event flag)
972 IMOP.Empty_Interrupt_Mask (Intwait_Mask'Access);
973 IMOP.Add_To_Interrupt_Mask
974 (Intwait_Mask'Access, IMNG.Interrupt_ID (Interrupt));
976 -- Remember the Interrupt_ID for Abort_Task.
978 PIO.Set_Interrupt_ID (IMNG.Interrupt_ID (Interrupt), Self_ID);
980 -- Note: All tasks in RTS will have all the Reserve Interrupts
981 -- being masked (except the Interrupt_Manager) and Keep_Unmasked
982 -- unmasked when created.
985 System.Tasking.Initialization.Defer_Abort (Self_ID);
987 -- A Handler or an Entry is installed. At this point all tasks
988 -- mask for the Interrupt is masked. Catch the Interrupt using
991 -- This task may wake up from sigwait by receiving an interrupt
992 -- (Abort_Task_Interrupt) from the Interrupt_Manager for unbinding
993 -- a Procedure Handler or an Entry. Or it could be a wake up
994 -- from status change (Unblocked -> Blocked). If that is not
995 -- the case, we should exceute the attached Procedure or Entry.
1001 POP.Write_Lock (Self_ID);
1003 if User_Handler (Interrupt).H = null
1004 and then User_Entry (Interrupt).T = Null_Task
1006 -- No Interrupt binding. If there is an interrupt,
1007 -- Interrupt_Manager will take default action.
1009 Self_ID.Common.State := Interrupt_Server_Idle_Sleep;
1010 POP.Sleep (Self_ID, Interrupt_Server_Idle_Sleep);
1011 Self_ID.Common.State := Runnable;
1014 Self_ID.Common.State := Interrupt_Server_Blocked_On_Event_Flag;
1015 Self_ID.Common.State := Runnable;
1017 if not (Self_ID.Deferral_Level = 0
1018 and then Self_ID.Pending_ATC_Level
1019 < Self_ID.ATC_Nesting_Level)
1021 if User_Handler (Interrupt).H /= null then
1022 Tmp_Handler := User_Handler (Interrupt).H;
1024 -- RTS calls should not be made with self being locked.
1026 POP.Unlock (Self_ID);
1038 POP.Write_Lock (Self_ID);
1040 elsif User_Entry (Interrupt).T /= Null_Task then
1041 Tmp_ID := User_Entry (Interrupt).T;
1042 Tmp_Entry_Index := User_Entry (Interrupt).E;
1044 -- RTS calls should not be made with self being locked.
1046 POP.Unlock (Self_ID);
1052 System.Tasking.Rendezvous.Call_Simple
1053 (Tmp_ID, Tmp_Entry_Index, System.Null_Address);
1059 POP.Write_Lock (Self_ID);
1064 POP.Unlock (Self_ID);
1070 System.Tasking.Initialization.Undefer_Abort (Self_ID);
1072 -- Undefer abort here to allow a window for this task
1073 -- to be aborted at the time of system shutdown.
1077 -------------------------------------
1078 -- Has_Interrupt_Or_Attach_Handler --
1079 -------------------------------------
1081 function Has_Interrupt_Or_Attach_Handler
1082 (Object : access Dynamic_Interrupt_Protection) return Boolean
1084 pragma Warnings (Off, Object);
1088 end Has_Interrupt_Or_Attach_Handler;
1094 procedure Finalize (Object : in out Static_Interrupt_Protection) is
1096 -- ??? loop to be executed only when we're not doing library level
1097 -- finalization, since in this case all interrupt tasks are gone.
1099 if not Interrupt_Manager'Terminated then
1100 for N in reverse Object.Previous_Handlers'Range loop
1101 Interrupt_Manager.Attach_Handler
1102 (New_Handler => Object.Previous_Handlers (N).Handler,
1103 Interrupt => Object.Previous_Handlers (N).Interrupt,
1104 Static => Object.Previous_Handlers (N).Static,
1105 Restoration => True);
1109 Tasking.Protected_Objects.Entries.Finalize
1110 (Tasking.Protected_Objects.Entries.Protection_Entries (Object));
1113 -------------------------------------
1114 -- Has_Interrupt_Or_Attach_Handler --
1115 -------------------------------------
1117 function Has_Interrupt_Or_Attach_Handler
1118 (Object : access Static_Interrupt_Protection) return Boolean
1120 pragma Warnings (Off, Object);
1123 end Has_Interrupt_Or_Attach_Handler;
1125 ----------------------
1126 -- Install_Handlers --
1127 ----------------------
1129 procedure Install_Handlers
1130 (Object : access Static_Interrupt_Protection;
1131 New_Handlers : New_Handler_Array)
1134 for N in New_Handlers'Range loop
1136 -- We need a lock around this ???
1138 Object.Previous_Handlers (N).Interrupt := New_Handlers (N).Interrupt;
1139 Object.Previous_Handlers (N).Static := User_Handler
1140 (New_Handlers (N).Interrupt).Static;
1142 -- We call Exchange_Handler and not directly Interrupt_Manager.
1143 -- Exchange_Handler so we get the Is_Reserved check.
1146 (Old_Handler => Object.Previous_Handlers (N).Handler,
1147 New_Handler => New_Handlers (N).Handler,
1148 Interrupt => New_Handlers (N).Interrupt,
1151 end Install_Handlers;
1153 -- Elaboration code for package System.Interrupts
1157 -- Get Interrupt_Manager's ID so that Abort_Interrupt can be sent.
1159 Interrupt_Manager_ID := To_System (Interrupt_Manager'Identity);
1161 -- During the elaboration of this package body we want RTS to inherit the
1162 -- interrupt mask from the Environment Task.
1164 -- The Environment Task should have gotten its mask from the enclosing
1165 -- process during the RTS start up. (See in s-inmaop.adb). Pass the
1166 -- Interrupt_Mask of the Environment task to the Interrupt_Manager.
1168 -- Note : At this point we know that all tasks (including RTS internal
1169 -- servers) are masked for non-reserved signals (see s-taprop.adb). Only
1170 -- the Interrupt_Manager will have masks set up differently inheriting the
1171 -- original Environment Task's mask.
1173 Interrupt_Manager.Initialize (IMOP.Environment_Mask);
1174 end System.Interrupts;