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* c-decl.c (duplicate_decls): Conditionalize DECL_SAVED_TREE copy.
[official-gcc.git] / gcc / ada / 5zinterr.adb
blob5e428f26c083f53bbcf9264b2b2f650690ee77ca
1 ------------------------------------------------------------------------------
2 -- --
3 -- GNU ADA RUN-TIME LIBRARY (GNARL) COMPONENTS --
4 -- --
5 -- S Y S T E M . I N T E R R U P T S --
6 -- --
7 -- B o d y --
8 -- --
9 -- $Revision: 1.7 $
10 -- --
11 -- Copyright (C) 1991-2001 Free Software Foundation, Inc. --
12 -- --
13 -- GNARL is free software; you can redistribute it and/or modify it under --
14 -- terms of the GNU General Public License as published by the Free Soft- --
15 -- ware Foundation; either version 2, or (at your option) any later ver- --
16 -- sion. GNARL is distributed in the hope that it will be useful, but WITH- --
17 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
18 -- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
19 -- for more details. You should have received a copy of the GNU General --
20 -- Public License distributed with GNARL; see file COPYING. If not, write --
21 -- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
22 -- MA 02111-1307, USA. --
23 -- --
24 -- As a special exception, if other files instantiate generics from this --
25 -- unit, or you link this unit with other files to produce an executable, --
26 -- this unit does not by itself cause the resulting executable to be --
27 -- covered by the GNU General Public License. This exception does not --
28 -- however invalidate any other reasons why the executable file might be --
29 -- covered by the GNU Public License. --
30 -- --
31 -- GNARL was developed by the GNARL team at Florida State University. It is --
32 -- now maintained by Ada Core Technologies Inc. in cooperation with Florida --
33 -- State University (http://www.gnat.com). --
34 -- --
35 ------------------------------------------------------------------------------
36
37 -- Invariants:
38
39 -- All user-handleable signals are masked at all times in all
40 -- tasks/threads except possibly for the Interrupt_Manager task.
41
42 -- When a user task wants to have the effect of masking/unmasking an
43 -- signal, it must call Block_Interrupt/Unblock_Interrupt, which
44 -- will have the effect of unmasking/masking the signal in the
45 -- Interrupt_Manager task. These comments do not apply to vectored
46 -- hardware interrupts, which may be masked or unmasked using routined
47 -- interfaced to the relevant VxWorks system calls.
48
49 -- Note : Direct calls to sigaction, sigprocmask, pthread_sigsetmask or any
50 -- other low-level interface that changes the signal action or
51 -- signal mask needs careful consideration.
52 -- One may achieve the effect of system calls first masking RTS blocked
53 -- (by calling Block_Interrupt) for the signal under consideration.
54 -- This will make all the tasks in RTS blocked for the signal.
55
56 -- Once we associate a Signal_Server_Task with an signal, the task never
57 -- goes away, and we never remove the association. On the other hand, it
58 -- is more convenient to terminate an associated Interrupt_Server_Task
59 -- for a vectored hardware interrupt (since we use a binary semaphore
60 -- for synchronization with the umbrella handler).
61
62 -- There is no more than one signal per Signal_Server_Task and no more than
63 -- one Signal_Server_Task per signal. The same relation holds for hardware
64 -- interrupts and Interrupt_Server_Task's at any given time. That is,
65 -- only one non-terminated Interrupt_Server_Task exists for a give
66 -- interrupt at any time.
67
68 -- Within this package, the lock L is used to protect the various status
69 -- tables. If there is a Server_Task associated with a signal or interrupt,
70 -- we use the per-task lock of the Server_Task instead so that we protect the
71 -- status between Interrupt_Manager and Server_Task. Protection among
72 -- service requests are ensured via user calls to the Interrupt_Manager
73 -- entries.
74
75 -- This is the VxWorks version of this package, supporting both signals
76 -- and vectored hardware interrupts.
77
78 with Unchecked_Conversion;
79
80 with System.OS_Interface; use System.OS_Interface;
81
82 with System.VxWorks;
83
84 with Interfaces.VxWorks;
85
86 with Ada.Task_Identification;
87 -- used for Task_ID type
88
89 with Ada.Exceptions;
90 -- used for Raise_Exception
91
92 with System.Task_Primitives;
93 -- used for RTS_Lock
94 -- Self
95
96 with System.Interrupt_Management;
97 -- used for Reserve
98 -- Interrupt_ID
99 -- Interrupt_Mask
100 -- Abort_Task_Interrupt
101
102 with System.Interrupt_Management.Operations;
103 -- used for Thread_Block_Interrupt
104 -- Thread_Unblock_Interrupt
105 -- Install_Default_Action
106 -- Install_Ignore_Action
107 -- Copy_Interrupt_Mask
108 -- Set_Interrupt_Mask
109 -- Empty_Interrupt_Mask
110 -- Fill_Interrupt_Mask
111 -- Add_To_Interrupt_Mask
112 -- Delete_From_Interrupt_Mask
113 -- Interrupt_Wait
114 -- Interrupt_Self_Process
115 -- Get_Interrupt_Mask
116 -- Set_Interrupt_Mask
117 -- IS_Member
118 -- Environment_Mask
119 -- All_Tasks_Mask
120 pragma Elaborate_All (System.Interrupt_Management.Operations);
121
122 with System.Error_Reporting;
123 -- used for Shutdown
124
125 with System.Task_Primitives.Operations;
126 -- used for Write_Lock
127 -- Unlock
128 -- Abort
129 -- Wakeup_Task
130 -- Sleep
131 -- Initialize_Lock
132
133 with System.Task_Primitives.Interrupt_Operations;
134 -- used for Set_Interrupt_ID
135
136 with System.Storage_Elements;
137 -- used for To_Address
138 -- To_Integer
139 -- Integer_Address
140
141 with System.Tasking;
142 -- used for Task_ID
143 -- Task_Entry_Index
144 -- Null_Task
145 -- Self
146 -- Interrupt_Manager_ID
147
148 with System.Tasking.Utilities;
149 -- used for Make_Independent
150
151 with System.Tasking.Rendezvous;
152 -- used for Call_Simple
153 pragma Elaborate_All (System.Tasking.Rendezvous);
154
155 with System.Tasking.Initialization;
156 -- used for Defer_Abort
157 -- Undefer_Abort
158
159 package body System.Interrupts is
160
161 use Tasking;
162 use System.Error_Reporting;
163 use Ada.Exceptions;
164
165 package PRI renames System.Task_Primitives;
166 package POP renames System.Task_Primitives.Operations;
167 package PIO renames System.Task_Primitives.Interrupt_Operations;
168 package IMNG renames System.Interrupt_Management;
169 package IMOP renames System.Interrupt_Management.Operations;
170
171 function To_Ada is new Unchecked_Conversion
172 (System.Tasking.Task_ID, Ada.Task_Identification.Task_Id);
173
174 function To_System is new Unchecked_Conversion
175 (Ada.Task_Identification.Task_Id, Task_ID);
176
177 -----------------
178 -- Local Tasks --
179 -----------------
180
181 -- WARNING: System.Tasking.Utilities performs calls to this task
182 -- with low-level constructs. Do not change this spec without synchro-
183 -- nizing it.
184
185 task Interrupt_Manager is
186 entry Initialize (Mask : IMNG.Interrupt_Mask);
187
188 entry Attach_Handler
189 (New_Handler : Parameterless_Handler;
190 Interrupt : Interrupt_ID;
191 Static : Boolean;
192 Restoration : Boolean := False);
193
194 entry Exchange_Handler
195 (Old_Handler : out Parameterless_Handler;
196 New_Handler : Parameterless_Handler;
197 Interrupt : Interrupt_ID;
198 Static : Boolean);
199
200 entry Detach_Handler
201 (Interrupt : Interrupt_ID;
202 Static : Boolean);
203
204 entry Bind_Interrupt_To_Entry
205 (T : Task_ID;
206 E : Task_Entry_Index;
207 Interrupt : Interrupt_ID);
208
209 entry Detach_Interrupt_Entries (T : Task_ID);
210
211 pragma Interrupt_Priority (System.Interrupt_Priority'First);
212 end Interrupt_Manager;
213
214 task type Signal_Server_Task (Interrupt : Interrupt_ID) is
215 pragma Interrupt_Priority (System.Interrupt_Priority'First + 1);
216 end Signal_Server_Task;
217 -- Server task for signal handling
218
219 type Signal_Task_Access is access Signal_Server_Task;
220
221 task type Interrupt_Server_Task
222 (Interrupt : Interrupt_ID; Int_Sema : SEM_ID) is
223 -- Server task for vectored hardware interrupt handling
224 pragma Interrupt_Priority (System.Interrupt_Priority'First + 2);
225 end Interrupt_Server_Task;
226
227 type Interrupt_Task_Access is access Interrupt_Server_Task;
228
229 -------------------------------
230 -- Local Types and Variables --
231 -------------------------------
232
233 type Entry_Assoc is record
234 T : Task_ID;
235 E : Task_Entry_Index;
236 end record;
237
238 type Handler_Assoc is record
239 H : Parameterless_Handler;
240 Static : Boolean; -- Indicates static binding;
241 end record;
242
243 User_Handler : array (Interrupt_ID) of Handler_Assoc :=
244 (others => (null, Static => False));
245 pragma Volatile_Components (User_Handler);
246 -- Holds the protected procedure handler (if any) and its Static
247 -- information for each interrupt or signal. A handler is static
248 -- iff it is specified through the pragma Attach_Handler.
249
250 User_Entry : array (Interrupt_ID) of Entry_Assoc :=
251 (others => (T => Null_Task, E => Null_Task_Entry));
252 pragma Volatile_Components (User_Entry);
253 -- Holds the task and entry index (if any) for each interrupt / signal
254
255 -- Type and Head, Tail of the list containing Registered Interrupt
256 -- Handlers. These definitions are used to register the handlers
257 -- specified by the pragma Interrupt_Handler.
258
259 type Registered_Handler;
260 type R_Link is access all Registered_Handler;
261
262 type Registered_Handler is record
263 H : System.Address := System.Null_Address;
264 Next : R_Link := null;
265 end record;
266
267 Registered_Handler_Head : R_Link := null;
268 Registered_Handler_Tail : R_Link := null;
269
270 Server_ID : array (Interrupt_ID) of System.Tasking.Task_ID :=
271 (others => System.Tasking.Null_Task);
272 pragma Atomic_Components (Server_ID);
273 -- Holds the Task_ID of the Server_Task for each interrupt / signal.
274 -- Task_ID is needed to accomplish locking per interrupt base. Also
275 -- is needed to determine whether to create a new Server_Task.
276
277 Semaphore_ID_Map : array
278 (Interrupt_ID range 0 .. System.VxWorks.Num_HW_Interrupts) of SEM_ID :=
279 (others => 0);
280 -- Array of binary semaphores associated with vectored interrupts
281 -- Note that the last bound should be Max_HW_Interrupt, but this will raise
282 -- Storage_Error if Num_HW_Interrupts is null, so use an extra 4 bytes
283 -- instead.
284
285 Signal_Access_Hold : Signal_Task_Access;
286 -- Variable for allocating a Signal_Server_Task
287
288 Interrupt_Access_Hold : Interrupt_Task_Access;
289 -- Variable for allocating an Interrupt_Server_Task
290
291 L : aliased PRI.RTS_Lock;
292 -- L protects the contents of the above tables for interrupts / signals
293 -- for which Server_ID (I) = Null_Task.
294 --
295 -- If Server_ID (I) /= Null_Task then protection is via the
296 -- per-task (TCB) lock of Server_ID (I).
297 --
298 -- For deadlock prevention, L should not be locked after
299 -- any other lock is held, hence we use PO_Level which is the highest
300 -- lock level for error checking.
301
302 Task_Lock : array (Interrupt_ID) of Boolean := (others => False);
303 -- Booleans indicating whether the per task lock is used
304
305 Default_Handler : array (HW_Interrupt) of Interfaces.VxWorks.VOIDFUNCPTR;
306 -- Vectored interrupt handlers installed prior to program startup.
307 -- These are saved only when the umbrella handler is installed for
308 -- a given interrupt number.
309
310 -----------------------
311 -- Local Subprograms --
312 -----------------------
313
314 procedure Check_Reserved_Interrupt (Interrupt : Interrupt_ID);
315 -- Check if Id is a reserved interrupt, and if so raise Program_Error
316 -- with an appropriate message, otherwise return.
317
318 procedure Finalize_Interrupt_Servers;
319 -- Unbind the handlers for hardware interrupt server tasks at program
320 -- termination.
321
322 procedure Lock_Interrupt
323 (Self_ID : Task_ID;
324 Interrupt : Interrupt_ID);
325 -- Protect the tables using L or the per-task lock. Set the Boolean
326 -- value Task_Lock if the lock is made using per-task lock.
327 -- This information is needed so that Unlock_Interrupt
328 -- performs unlocking on the same lock. The situation we are preventing
329 -- is, for example, when Attach_Handler is called for the first time
330 -- we lock L and create an Server_Task. For a matching unlocking, if we
331 -- rely on the fact that there is a Server_Task, we will unlock the
332 -- per-task lock.
333
334 procedure Unlock_Interrupt
335 (Self_ID : Task_ID;
336 Interrupt : Interrupt_ID);
337 -- Unlock interrupt previously locked by Lock_Interrupt
338
339 function Is_Registered (Handler : Parameterless_Handler) return Boolean;
340 -- Needs comment ???
341
342 procedure Notify_Interrupt (Param : System.Address);
343 -- Umbrella handler for vectored interrupts (not signals)
344
345 procedure Install_Default_Action (Interrupt : HW_Interrupt);
346 -- Restore a handler that was in place prior to program execution
347
348 procedure Install_Umbrella_Handler
349 (Interrupt : HW_Interrupt;
350 Handler : Interfaces.VxWorks.VOIDFUNCPTR);
351 -- Install the runtime umbrella handler for a vectored hardware
352 -- interrupt
353
354 function To_Signal (S : Interrupt_ID) return IMNG.Interrupt_ID;
355 -- Convert interrupt ID to signal number.
356
357 procedure Unimplemented (Feature : String);
358 pragma No_Return (Unimplemented);
359 -- Used to mark a call to an unimplemented function. Raises Program_Error
360 -- with an appropriate message noting that Feature is unimplemented.
361
362 --------------------
363 -- Attach_Handler --
364 --------------------
365
366 -- Calling this procedure with New_Handler = null and Static = True
367 -- means we want to detach the current handler regardless of the
368 -- previous handler's binding status (ie. do not care if it is a
369 -- dynamic or static handler).
370
371 -- This option is needed so that during the finalization of a PO, we
372 -- can detach handlers attached through pragma Attach_Handler.
373
374 procedure Attach_Handler
375 (New_Handler : Parameterless_Handler;
376 Interrupt : Interrupt_ID;
377 Static : Boolean := False)
378 is
379 begin
380 Check_Reserved_Interrupt (Interrupt);
381 Interrupt_Manager.Attach_Handler (New_Handler, Interrupt, Static);
382 end Attach_Handler;
383
384 -----------------------------
385 -- Bind_Interrupt_To_Entry --
386 -----------------------------
387
388 -- This procedure raises a Program_Error if it tries to
389 -- bind an interrupt to which an Entry or a Procedure is
390 -- already bound.
391
392 procedure Bind_Interrupt_To_Entry
393 (T : Task_ID;
394 E : Task_Entry_Index;
395 Int_Ref : System.Address)
396 is
397 Interrupt : constant Interrupt_ID :=
398 Interrupt_ID (Storage_Elements.To_Integer (Int_Ref));
399
400 begin
401 Check_Reserved_Interrupt (Interrupt);
402 Interrupt_Manager.Bind_Interrupt_To_Entry (T, E, Interrupt);
403 end Bind_Interrupt_To_Entry;
404
405 ---------------------
406 -- Block_Interrupt --
407 ---------------------
408
409 procedure Block_Interrupt (Interrupt : Interrupt_ID) is
410 begin
411 Unimplemented ("Block_Interrupt");
412 end Block_Interrupt;
413
414 ------------------------------
415 -- Check_Reserved_Interrupt --
416 ------------------------------
417
418 procedure Check_Reserved_Interrupt (Interrupt : Interrupt_ID) is
419 begin
420 if Is_Reserved (Interrupt) then
421 Raise_Exception
422 (Program_Error'Identity,
423 "Interrupt" & Interrupt_ID'Image (Interrupt) & " is reserved");
424 else
425 return;
426 end if;
427 end Check_Reserved_Interrupt;
428
429 ---------------------
430 -- Current_Handler --
431 ---------------------
432
433 function Current_Handler
434 (Interrupt : Interrupt_ID)
435 return Parameterless_Handler
436 is
437 begin
438 Check_Reserved_Interrupt (Interrupt);
439
440 -- ??? Since Parameterless_Handler is not Atomic, the
441 -- current implementation is wrong. We need a new service in
442 -- Interrupt_Manager to ensure atomicity.
443
444 return User_Handler (Interrupt).H;
445 end Current_Handler;
446
447 --------------------
448 -- Detach_Handler --
449 --------------------
450
451 -- Calling this procedure with Static = True means we want to Detach the
452 -- current handler regardless of the previous handler's binding status
453 -- (i.e. do not care if it is a dynamic or static handler).
454
455 -- This option is needed so that during the finalization of a PO, we can
456 -- detach handlers attached through pragma Attach_Handler.
457
458 procedure Detach_Handler
459 (Interrupt : Interrupt_ID;
460 Static : Boolean := False)
461 is
462 begin
463 Check_Reserved_Interrupt (Interrupt);
464 Interrupt_Manager.Detach_Handler (Interrupt, Static);
465 end Detach_Handler;
466
467 ------------------------------
468 -- Detach_Interrupt_Entries --
469 ------------------------------
470
471 procedure Detach_Interrupt_Entries (T : Task_ID) is
472 begin
473 Interrupt_Manager.Detach_Interrupt_Entries (T);
474 end Detach_Interrupt_Entries;
475
476 ----------------------
477 -- Exchange_Handler --
478 ----------------------
479
480 -- Calling this procedure with New_Handler = null and Static = True
481 -- means we want to detach the current handler regardless of the
482 -- previous handler's binding status (ie. do not care if it is a
483 -- dynamic or static handler).
484
485 -- This option is needed so that during the finalization of a PO, we
486 -- can detach handlers attached through pragma Attach_Handler.
487
488 procedure Exchange_Handler
489 (Old_Handler : out Parameterless_Handler;
490 New_Handler : Parameterless_Handler;
491 Interrupt : Interrupt_ID;
492 Static : Boolean := False)
493 is
494 begin
495 Check_Reserved_Interrupt (Interrupt);
496 Interrupt_Manager.Exchange_Handler
497 (Old_Handler, New_Handler, Interrupt, Static);
498 end Exchange_Handler;
499
500 --------------
501 -- Finalize --
502 --------------
503
504 procedure Finalize (Object : in out Static_Interrupt_Protection) is
505 begin
506 -- ??? loop to be executed only when we're not doing library level
507 -- finalization, since in this case all interrupt / signal tasks are
508 -- gone.
509
510 if not Interrupt_Manager'Terminated then
511 for N in reverse Object.Previous_Handlers'Range loop
512 Interrupt_Manager.Attach_Handler
513 (New_Handler => Object.Previous_Handlers (N).Handler,
514 Interrupt => Object.Previous_Handlers (N).Interrupt,
515 Static => Object.Previous_Handlers (N).Static,
516 Restoration => True);
517 end loop;
518 end if;
519
520 Tasking.Protected_Objects.Entries.Finalize
521 (Tasking.Protected_Objects.Entries.Protection_Entries (Object));
522 end Finalize;
523
524 --------------------------------
525 -- Finalize_Interrupt_Servers --
526 --------------------------------
527
528 -- Restore default handlers for interrupt servers. Signal servers
529 -- restore the default handlers when they're aborted. This is called
530 -- by the Interrupt_Manager task when it receives the abort signal
531 -- during program finalization.
532
533 procedure Finalize_Interrupt_Servers is
534 begin
535 if HW_Interrupt'Last >= 0 then
536 for Int in HW_Interrupt loop
537 if Server_ID (Interrupt_ID (Int)) /= null
538 and then
539 not Ada.Task_Identification.Is_Terminated
540 (To_Ada (Server_ID (Interrupt_ID (Int))))
541 then
542 Interrupt_Manager.Attach_Handler
543 (New_Handler => null,
544 Interrupt => Interrupt_ID (Int),
545 Static => True,
546 Restoration => True);
547 end if;
548 end loop;
549 end if;
550 end Finalize_Interrupt_Servers;
551
552 -------------------------------------
553 -- Has_Interrupt_Or_Attach_Handler --
554 -------------------------------------
555
556 function Has_Interrupt_Or_Attach_Handler
557 (Object : access Dynamic_Interrupt_Protection)
558 return Boolean
559 is
560 begin
561 return True;
562 end Has_Interrupt_Or_Attach_Handler;
563
564 function Has_Interrupt_Or_Attach_Handler
565 (Object : access Static_Interrupt_Protection)
566 return Boolean
567 is
568 begin
569 return True;
570 end Has_Interrupt_Or_Attach_Handler;
571
572 ----------------------
573 -- Ignore_Interrupt --
574 ----------------------
575
576 procedure Ignore_Interrupt (Interrupt : Interrupt_ID) is
577 begin
578 Unimplemented ("Ignore_Interrupt");
579 end Ignore_Interrupt;
580
581 ----------------------------
582 -- Install_Default_Action --
583 ----------------------------
584
585 procedure Install_Default_Action (Interrupt : HW_Interrupt) is
586 begin
587 -- Restore original interrupt handler
588
589 Interfaces.VxWorks.intVecSet
590 (Interfaces.VxWorks.INUM_TO_IVEC (Integer (Interrupt)),
591 Default_Handler (Interrupt));
592 Default_Handler (Interrupt) := null;
593 end Install_Default_Action;
594
595 ----------------------
596 -- Install_Handlers --
597 ----------------------
598
599 procedure Install_Handlers
600 (Object : access Static_Interrupt_Protection;
601 New_Handlers : New_Handler_Array) is
602 begin
603 for N in New_Handlers'Range loop
604 -- We need a lock around this ???
605
606 Object.Previous_Handlers (N).Interrupt := New_Handlers (N).Interrupt;
607 Object.Previous_Handlers (N).Static := User_Handler
608 (New_Handlers (N).Interrupt).Static;
609
610 -- We call Exchange_Handler and not directly Interrupt_Manager.
611 -- Exchange_Handler so we get the Is_Reserved check.
612
613 Exchange_Handler
614 (Old_Handler => Object.Previous_Handlers (N).Handler,
615 New_Handler => New_Handlers (N).Handler,
616 Interrupt => New_Handlers (N).Interrupt,
617 Static => True);
618 end loop;
619 end Install_Handlers;
620
621 ------------------------------
622 -- Install_Umbrella_Handler --
623 ------------------------------
624
625 procedure Install_Umbrella_Handler
626 (Interrupt : HW_Interrupt;
627 Handler : Interfaces.VxWorks.VOIDFUNCPTR)
628 is
629 use Interfaces.VxWorks;
630
631 Vec : constant Interrupt_Vector :=
632 INUM_TO_IVEC (Interfaces.VxWorks.int (Interrupt));
633 Old_Handler : constant VOIDFUNCPTR :=
634 intVecGet
635 (INUM_TO_IVEC (Interfaces.VxWorks.int (Interrupt)));
636 Stat : Interfaces.VxWorks.STATUS;
637
638 begin
639 -- Only install umbrella handler when no Ada handler has already been
640 -- installed. Note that the interrupt number is passed as a parameter
641 -- when an interrupt occurs, so the umbrella handler has a different
642 -- wrapper generated by intConnect for each interrupt number.
643
644 if Default_Handler (Interrupt) = null then
645 Stat :=
646 intConnect (Vec, VOIDFUNCPTR (Handler), System.Address (Interrupt));
647 Default_Handler (Interrupt) := Old_Handler;
648 end if;
649 end Install_Umbrella_Handler;
650
651 ----------------
652 -- Is_Blocked --
653 ----------------
654
655 function Is_Blocked (Interrupt : Interrupt_ID) return Boolean is
656 begin
657 Unimplemented ("Is_Blocked");
658 return False;
659 end Is_Blocked;
660
661 -----------------------
662 -- Is_Entry_Attached --
663 -----------------------
664
665 function Is_Entry_Attached (Interrupt : Interrupt_ID) return Boolean is
666 begin
667 Check_Reserved_Interrupt (Interrupt);
668 return User_Entry (Interrupt).T /= Null_Task;
669 end Is_Entry_Attached;
670
671 -------------------------
672 -- Is_Handler_Attached --
673 -------------------------
674
675 function Is_Handler_Attached (Interrupt : Interrupt_ID) return Boolean is
676 begin
677 Check_Reserved_Interrupt (Interrupt);
678 return User_Handler (Interrupt).H /= null;
679 end Is_Handler_Attached;
680
681 ----------------
682 -- Is_Ignored --
683 ----------------
684
685 function Is_Ignored (Interrupt : Interrupt_ID) return Boolean is
686 begin
687 Unimplemented ("Is_Ignored");
688 return False;
689 end Is_Ignored;
690
691 -------------------
692 -- Is_Registered --
693 -------------------
694
695 -- See if Handler has been "pragma"ed using Interrupt_Handler.
696 -- Always consider a null handler as registered.
697
698 function Is_Registered (Handler : Parameterless_Handler) return Boolean is
699 type Fat_Ptr is record
700 Object_Addr : System.Address;
701 Handler_Addr : System.Address;
702 end record;
703
704 function To_Fat_Ptr is new Unchecked_Conversion
705 (Parameterless_Handler, Fat_Ptr);
706
707 Ptr : R_Link;
708 Fat : Fat_Ptr;
709
710 begin
711 if Handler = null then
712 return True;
713 end if;
714
715 Fat := To_Fat_Ptr (Handler);
716
717 Ptr := Registered_Handler_Head;
718
719 while (Ptr /= null) loop
720 if Ptr.H = Fat.Handler_Addr then
721 return True;
722 end if;
723
724 Ptr := Ptr.Next;
725 end loop;
726
727 return False;
728
729 end Is_Registered;
730
731 -----------------
732 -- Is_Reserved --
733 -----------------
734
735 function Is_Reserved (Interrupt : Interrupt_ID) return Boolean is
736 begin
737 if Interrupt < System.VxWorks.Num_HW_Interrupts then
738 return False;
739 else
740 return IMNG.Reserve (To_Signal (Interrupt));
741 end if;
742 end Is_Reserved;
743
744 --------------------
745 -- Lock_Interrupt --
746 --------------------
747
748 -- ?????
749 -- This package has been modified several times.
750 -- Do we still need this fancy locking scheme, now that more operations
751 -- are entries of the interrupt manager task?
752 -- ?????
753 -- More likely, we will need to convert one or more entry calls to
754 -- protected operations, because presently we are violating locking order
755 -- rules by calling a task entry from within the runtime system.
756
757 procedure Lock_Interrupt
758 (Self_ID : Task_ID;
759 Interrupt : Interrupt_ID) is
760 begin
761 Initialization.Defer_Abort (Self_ID);
762
763 POP.Write_Lock (L'Access);
764
765 if Task_Lock (Interrupt) then
766 pragma Assert (Server_ID (Interrupt) /= null,
767 "Task_Lock is true for null server task");
768 pragma Assert
769 (not Ada.Task_Identification.Is_Terminated
770 (To_Ada (Server_ID (Interrupt))),
771 "Attempt to lock per task lock of terminated server: " &
772 "Task_Lock => True");
773
774 POP.Unlock (L'Access);
775 POP.Write_Lock (Server_ID (Interrupt));
776
777 elsif Server_ID (Interrupt) /= Null_Task then
778 pragma Assert
779 (not Ada.Task_Identification.Is_Terminated
780 (To_Ada (Server_ID (Interrupt))),
781 "Attempt to lock per task lock of terminated server: " &
782 "Task_Lock => False");
783
784 Task_Lock (Interrupt) := True;
785 POP.Unlock (L'Access);
786 POP.Write_Lock (Server_ID (Interrupt));
787 end if;
788
789 end Lock_Interrupt;
790
791 ------------------------
792 -- Notify_Interrupt --
793 ------------------------
794
795 -- Umbrella handler for vectored hardware interrupts (as opposed to
796 -- signals and exceptions). As opposed to the signal implementation,
797 -- this handler is only installed in the vector table while there is
798 -- an active association of an Ada handler to the interrupt.
799
800 -- Otherwise, the handler that existed prior to program startup is
801 -- in the vector table. This ensures that handlers installed by
802 -- the BSP are active unless explicitly replaced in the program text.
803
804 -- Each Interrupt_Server_Task has an associated binary semaphore
805 -- on which it pends once it's been started. This routine determines
806 -- The appropriate semaphore and and issues a semGive call, waking
807 -- the server task. When a handler is unbound,
808 -- System.Interrupts.Unbind_Handler issues a semFlush, and the
809 -- server task deletes its semaphore and terminates.
810
811 procedure Notify_Interrupt (Param : System.Address) is
812 Interrupt : Interrupt_ID := Interrupt_ID (Param);
813 Discard_Result : STATUS;
814
815 begin
816 Discard_Result := semGive (Semaphore_ID_Map (Interrupt));
817 end Notify_Interrupt;
818
819 ---------------
820 -- Reference --
821 ---------------
822
823 function Reference (Interrupt : Interrupt_ID) return System.Address is
824 begin
825 Check_Reserved_Interrupt (Interrupt);
826 return Storage_Elements.To_Address
827 (Storage_Elements.Integer_Address (Interrupt));
828 end Reference;
829
830 --------------------------------
831 -- Register_Interrupt_Handler --
832 --------------------------------
833
834 procedure Register_Interrupt_Handler (Handler_Addr : System.Address) is
835 New_Node_Ptr : R_Link;
836 begin
837 -- This routine registers a handler as usable for dynamic
838 -- interrupt handler association. Routines attaching and detaching
839 -- handlers dynamically should determine whether the handler is
840 -- registered. Program_Error should be raised if it is not registered.
841
842 -- Pragma Interrupt_Handler can only appear in a library
843 -- level PO definition and instantiation. Therefore, we do not need
844 -- to implement an unregister operation. Nor do we need to
845 -- protect the queue structure with a lock.
846
847 pragma Assert (Handler_Addr /= System.Null_Address);
848
849 New_Node_Ptr := new Registered_Handler;
850 New_Node_Ptr.H := Handler_Addr;
851
852 if Registered_Handler_Head = null then
853 Registered_Handler_Head := New_Node_Ptr;
854 Registered_Handler_Tail := New_Node_Ptr;
855
856 else
857 Registered_Handler_Tail.Next := New_Node_Ptr;
858 Registered_Handler_Tail := New_Node_Ptr;
859 end if;
860 end Register_Interrupt_Handler;
861
862 ---------------
863 -- To_Signal --
864 ---------------
865
866 function To_Signal (S : Interrupt_ID) return IMNG.Interrupt_ID is
867 begin
868 return IMNG.Interrupt_ID (S - System.VxWorks.Num_HW_Interrupts);
869 end To_Signal;
870
871 -----------------------
872 -- Unblock_Interrupt --
873 -----------------------
874
875 procedure Unblock_Interrupt (Interrupt : Interrupt_ID) is
876 begin
877 Unimplemented ("Unblock_Interrupt");
878 end Unblock_Interrupt;
879
880 ------------------
881 -- Unblocked_By --
882 ------------------
883
884 function Unblocked_By
885 (Interrupt : Interrupt_ID) return System.Tasking.Task_ID is
886 begin
887 Unimplemented ("Unblocked_By");
888 return Null_Task;
889 end Unblocked_By;
890
891 ------------------------
892 -- Unignore_Interrupt --
893 ------------------------
894
895 procedure Unignore_Interrupt (Interrupt : Interrupt_ID) is
896 begin
897 Unimplemented ("Unignore_Interrupt");
898 end Unignore_Interrupt;
899
900 -------------------
901 -- Unimplemented --
902 -------------------
903
904 procedure Unimplemented (Feature : String) is
905 begin
906 Raise_Exception
907 (Program_Error'Identity,
908 Feature & " not implemented on VxWorks");
909 end Unimplemented;
910
911 ----------------------
912 -- Unlock_Interrupt --
913 ----------------------
914
915 procedure Unlock_Interrupt
916 (Self_ID : Task_ID;
917 Interrupt : Interrupt_ID) is
918 begin
919 if Task_Lock (Interrupt) then
920 pragma Assert
921 (not Ada.Task_Identification.Is_Terminated
922 (To_Ada (Server_ID (Interrupt))),
923 "Attempt to unlock per task lock of terminated server");
924
925 POP.Unlock (Server_ID (Interrupt));
926 else
927 POP.Unlock (L'Access);
928 end if;
929
930 Initialization.Undefer_Abort (Self_ID);
931 end Unlock_Interrupt;
932
933 -----------------------
934 -- Interrupt_Manager --
935 -----------------------
936
937 task body Interrupt_Manager is
938 ---------------------
939 -- Local Variables --
940 ---------------------
941
942 Intwait_Mask : aliased IMNG.Interrupt_Mask;
943 Old_Mask : aliased IMNG.Interrupt_Mask;
944 Self_ID : Task_ID := POP.Self;
945
946 --------------------
947 -- Local Routines --
948 --------------------
949
950 procedure Bind_Handler (Interrupt : Interrupt_ID);
951 -- This procedure does not do anything if a signal is blocked.
952 -- Otherwise, we have to interrupt Server_Task for status change through
953 -- a wakeup signal.
954
955 procedure Unbind_Handler (Interrupt : Interrupt_ID);
956 -- This procedure does not do anything if a signal is blocked.
957 -- Otherwise, we have to interrupt Server_Task for status change
958 -- through an abort signal.
959
960 -- The following two procedures are labelled Unprotected... in order to
961 -- indicate that Lock/Unlock_Interrupt operations are needed around
962 -- around calls to them.
963
964 procedure Unprotected_Exchange_Handler
965 (Old_Handler : out Parameterless_Handler;
966 New_Handler : Parameterless_Handler;
967 Interrupt : Interrupt_ID;
968 Static : Boolean;
969 Restoration : Boolean := False);
970
971 procedure Unprotected_Detach_Handler
972 (Interrupt : Interrupt_ID;
973 Static : Boolean);
974
975 ------------------
976 -- Bind_Handler --
977 ------------------
978
979 procedure Bind_Handler (Interrupt : Interrupt_ID) is
980 begin
981 if Interrupt < System.VxWorks.Num_HW_Interrupts then
982 Install_Umbrella_Handler
983 (HW_Interrupt (Interrupt), Notify_Interrupt'Access);
984
985 else
986 -- Mask this task for the given signal so that all tasks
987 -- are masked for the signal and the actual delivery of the
988 -- signal will be caught using "sigwait" by the
989 -- corresponding Server_Task.
990
991 IMOP.Thread_Block_Interrupt (To_Signal (Interrupt));
992 -- We have installed a handler or an entry before we called
993 -- this procedure. If the handler task is waiting to be
994 -- awakened, do it here. Otherwise, the signal will be
995 -- discarded.
996
997 POP.Wakeup (Server_ID (Interrupt), Interrupt_Server_Idle_Sleep);
998 end if;
999 end Bind_Handler;
1000
1001 --------------------
1002 -- Unbind_Handler --
1003 --------------------
1004
1005 procedure Unbind_Handler (Interrupt : Interrupt_ID) is
1006 S : STATUS;
1007 Ret_Interrupt : IMNG.Interrupt_ID;
1008
1009 use type IMNG.Interrupt_ID;
1010 use type STATUS;
1011
1012 begin
1013 if Interrupt < System.VxWorks.Num_HW_Interrupts then
1014
1015 -- Hardware interrupt
1016
1017 Install_Default_Action (HW_Interrupt (Interrupt));
1018
1019 -- Flush server task off semaphore, allowing it to terminate
1020
1021 S := semFlush (Semaphore_ID_Map (Interrupt));
1022 pragma Assert (S = 0);
1023
1024 else
1025 -- Currently, there is a handler or an entry attached and
1026 -- the corresponding Server_Task is waiting on "sigwait."
1027 -- We have to wake up the Server_Task and make it
1028 -- wait on a condition variable by sending an
1029 -- Abort_Task_Interrupt
1030
1031 -- Make sure corresponding Server_Task is out of its own
1032 -- sigwait state.
1033
1034 POP.Abort_Task (Server_ID (Interrupt));
1035 Ret_Interrupt := IMOP.Interrupt_Wait (Intwait_Mask'Access);
1036 pragma Assert (Ret_Interrupt = IMNG.Abort_Task_Interrupt);
1037
1038 IMOP.Install_Default_Action (To_Signal (Interrupt));
1039
1040 -- Unmake the Interrupt for this task in order to allow default
1041 -- action again.
1042
1043 IMOP.Thread_Unblock_Interrupt (To_Signal (Interrupt));
1044 end if;
1045 end Unbind_Handler;
1046
1047 --------------------------------
1048 -- Unprotected_Detach_Handler --
1049 --------------------------------
1050
1051 procedure Unprotected_Detach_Handler
1052 (Interrupt : Interrupt_ID;
1053 Static : Boolean)
1054 is
1055 Old_Handler : Parameterless_Handler;
1056 begin
1057 if User_Entry (Interrupt).T /= Null_Task then
1058
1059 -- If an interrupt entry is installed raise
1060 -- Program_Error. (propagate it to the caller).
1061
1062 Unlock_Interrupt (Self_ID, Interrupt);
1063 Raise_Exception (Program_Error'Identity,
1064 "An interrupt entry is already installed");
1065 end if;
1066
1067 -- Note : Static = True will pass the following check. This is the
1068 -- case when we want to detach a handler regardless of the static
1069 -- status of the Current_Handler.
1070
1071 if not Static and then User_Handler (Interrupt).Static then
1072
1073 -- Trying to detach a static Interrupt Handler.
1074 -- raise Program_Error.
1075
1076 Unlock_Interrupt (Self_ID, Interrupt);
1077 Raise_Exception (Program_Error'Identity,
1078 "Trying to detach a static Interrupt Handler");
1079 end if;
1080
1081 Old_Handler := User_Handler (Interrupt).H;
1082
1083 -- The new handler
1084
1085 User_Handler (Interrupt).H := null;
1086 User_Handler (Interrupt).Static := False;
1087
1088 if Old_Handler /= null then
1089 Unbind_Handler (Interrupt);
1090 end if;
1091
1092 end Unprotected_Detach_Handler;
1093
1094 ----------------------------------
1095 -- Unprotected_Exchange_Handler --
1096 ----------------------------------
1097
1098 procedure Unprotected_Exchange_Handler
1099 (Old_Handler : out Parameterless_Handler;
1100 New_Handler : Parameterless_Handler;
1101 Interrupt : Interrupt_ID;
1102 Static : Boolean;
1103 Restoration : Boolean := False) is
1104 begin
1105 if User_Entry (Interrupt).T /= Null_Task then
1106
1107 -- If an interrupt entry is already installed, raise
1108 -- Program_Error. (propagate it to the caller).
1109
1110 Unlock_Interrupt (Self_ID, Interrupt);
1111 Raise_Exception (Program_Error'Identity,
1112 "An interrupt is already installed");
1113 end if;
1114
1115 -- Note : A null handler with Static = True will
1116 -- pass the following check. This is the case when we want to
1117 -- detach a handler regardless of the Static status
1118 -- of Current_Handler.
1119 -- We don't check anything if Restoration is True, since we
1120 -- may be detaching a static handler to restore a dynamic one.
1121
1122 if not Restoration and then not Static
1123 and then (User_Handler (Interrupt).Static
1124
1125 -- Trying to overwrite a static Interrupt Handler with a
1126 -- dynamic Handler
1127
1128 -- The new handler is not specified as an
1129 -- Interrupt Handler by a pragma.
1130
1131 or else not Is_Registered (New_Handler))
1132 then
1133 Unlock_Interrupt (Self_ID, Interrupt);
1134 Raise_Exception
1135 (Program_Error'Identity,
1136 "Trying to overwrite a static Interrupt Handler with a " &
1137 "dynamic Handler");
1138 end if;
1139
1140 -- Save the old handler
1141
1142 Old_Handler := User_Handler (Interrupt).H;
1143
1144 -- The new handler
1145
1146 User_Handler (Interrupt).H := New_Handler;
1147
1148 if New_Handler = null then
1149
1150 -- The null handler means we are detaching the handler.
1151
1152 User_Handler (Interrupt).Static := False;
1153
1154 else
1155 User_Handler (Interrupt).Static := Static;
1156 end if;
1157
1158 -- Invoke a corresponding Server_Task if not yet created.
1159 -- Place Task_ID info in Server_ID array.
1160
1161 if New_Handler /= null
1162 and then
1163 (Server_ID (Interrupt) = Null_Task
1164 or else
1165 Ada.Task_Identification.Is_Terminated
1166 (To_Ada (Server_ID (Interrupt))))
1167 then
1168 -- When a new Server_Task is created, it should have its
1169 -- signal mask set to the All_Tasks_Mask.
1170
1171 IMOP.Set_Interrupt_Mask
1172 (IMOP.All_Tasks_Mask'Access, Old_Mask'Access);
1173
1174 if Interrupt < System.VxWorks.Num_HW_Interrupts then
1175
1176 -- Vectored hardware interrupt
1177
1178 Interrupt_Access_Hold :=
1179 new Interrupt_Server_Task
1180 (Interrupt, semBCreate (SEM_Q_FIFO, SEM_EMPTY));
1181 Server_ID (Interrupt) :=
1182 To_System (Interrupt_Access_Hold.all'Identity);
1183
1184 else
1185 -- Signal
1186
1187 Signal_Access_Hold := new Signal_Server_Task (Interrupt);
1188 Server_ID (Interrupt) :=
1189 To_System (Signal_Access_Hold.all'Identity);
1190 end if;
1191
1192 IMOP.Set_Interrupt_Mask (Old_Mask'Access);
1193 end if;
1194
1195 if (New_Handler = null) and then Old_Handler /= null then
1196
1197 -- Restore default handler
1198
1199 Unbind_Handler (Interrupt);
1200
1201 elsif Old_Handler = null then
1202
1203 -- Save default handler
1204
1205 Bind_Handler (Interrupt);
1206 end if;
1207
1208 end Unprotected_Exchange_Handler;
1209
1210 -- Start of processing for Interrupt_Manager
1211
1212 begin
1213 -- By making this task independent of any master, when the process
1214 -- goes away, the Interrupt_Manager will terminate gracefully.
1215
1216 System.Tasking.Utilities.Make_Independent;
1217
1218 -- Environment task gets its own interrupt mask, saves it,
1219 -- and then masks all signals except the Keep_Unmasked set.
1220
1221 -- During rendezvous, the Interrupt_Manager receives the old
1222 -- signal mask of the environment task, and sets its own
1223 -- signal mask to that value.
1224
1225 -- The environment task will call this entry of Interrupt_Manager
1226 -- during elaboration of the body of this package.
1227
1228 accept Initialize (Mask : IMNG.Interrupt_Mask) do
1229 declare
1230 The_Mask : aliased IMNG.Interrupt_Mask;
1231
1232 begin
1233 IMOP.Copy_Interrupt_Mask (The_Mask, Mask);
1234 IMOP.Set_Interrupt_Mask (The_Mask'Access);
1235 end;
1236 end Initialize;
1237
1238 -- Note: All tasks in RTS will have all reserved signals
1239 -- being masked (except the Interrupt_Manager) and Keep_Unmasked
1240 -- signals unmasked when created.
1241
1242 -- Abort_Task_Interrupt is one of the signals unmasked
1243 -- in all tasks. We mask the signal in this particular task
1244 -- so that "sigwait" is can catch an explicit
1245 -- Abort_Task_Interrupt from a Server_Task.
1246
1247 -- This sigwaiting is needed to ensure that a Signal_Server_Task is
1248 -- out of its own sigwait state. This extra synchronization is
1249 -- necessary to prevent following scenarios:
1250
1251 -- 1) Interrupt_Manager sends an Abort_Task_Interrupt to a
1252 -- Signal_Server_Task then changes its own signal mask (OS level).
1253 -- If a signal (corresponding to the Signal_Server_Task) arrives
1254 -- in the meantime, we have the Interrupt_Manager umnasked and
1255 -- the Signal_Server_Task waiting on sigwait.
1256
1257 -- 2) For unbinding a handler, we install a default action in the
1258 -- Interrupt_Manager. POSIX.1c states that the result of using
1259 -- "sigwait" and "sigaction" simultaneously on the same signal
1260 -- is undefined. Therefore, we need to be informed from the
1261 -- Signal_Server_Task that it is out of its sigwait stage.
1262
1263 IMOP.Empty_Interrupt_Mask (Intwait_Mask'Access);
1264 IMOP.Add_To_Interrupt_Mask
1265 (Intwait_Mask'Access, IMNG.Abort_Task_Interrupt);
1266 IMOP.Thread_Block_Interrupt (IMNG.Abort_Task_Interrupt);
1267
1268 loop
1269 -- A block is needed to absorb Program_Error exception
1270
1271 declare
1272 Old_Handler : Parameterless_Handler;
1273
1274 begin
1275 select
1276
1277 accept Attach_Handler
1278 (New_Handler : Parameterless_Handler;
1279 Interrupt : Interrupt_ID;
1280 Static : Boolean;
1281 Restoration : Boolean := False)
1282 do
1283 Lock_Interrupt (Self_ID, Interrupt);
1284 Unprotected_Exchange_Handler
1285 (Old_Handler, New_Handler, Interrupt, Static, Restoration);
1286 Unlock_Interrupt (Self_ID, Interrupt);
1287 end Attach_Handler;
1288
1289 or accept Exchange_Handler
1290 (Old_Handler : out Parameterless_Handler;
1291 New_Handler : Parameterless_Handler;
1292 Interrupt : Interrupt_ID;
1293 Static : Boolean)
1294 do
1295 Lock_Interrupt (Self_ID, Interrupt);
1296 Unprotected_Exchange_Handler
1297 (Old_Handler, New_Handler, Interrupt, Static);
1298 Unlock_Interrupt (Self_ID, Interrupt);
1299 end Exchange_Handler;
1300
1301 or accept Detach_Handler
1302 (Interrupt : Interrupt_ID;
1303 Static : Boolean)
1304 do
1305 Lock_Interrupt (Self_ID, Interrupt);
1306 Unprotected_Detach_Handler (Interrupt, Static);
1307 Unlock_Interrupt (Self_ID, Interrupt);
1308 end Detach_Handler;
1309
1310 or accept Bind_Interrupt_To_Entry
1311 (T : Task_ID;
1312 E : Task_Entry_Index;
1313 Interrupt : Interrupt_ID)
1314 do
1315 Lock_Interrupt (Self_ID, Interrupt);
1316
1317 -- If there is a binding already (either a procedure or an
1318 -- entry), raise Program_Error (propagate it to the caller).
1319
1320 if User_Handler (Interrupt).H /= null
1321 or else User_Entry (Interrupt).T /= Null_Task
1322 then
1323 Unlock_Interrupt (Self_ID, Interrupt);
1324 Raise_Exception
1325 (Program_Error'Identity,
1326 "A binding for this interrupt is already present");
1327 end if;
1328
1329 User_Entry (Interrupt) := Entry_Assoc' (T => T, E => E);
1330
1331 -- Indicate the attachment of interrupt entry in the ATCB.
1332 -- This is needed so when an interrupt entry task terminates
1333 -- the binding can be cleaned. The call to unbinding must be
1334 -- make by the task before it terminates.
1335
1336 T.Interrupt_Entry := True;
1337
1338 -- Invoke a corresponding Server_Task if not yet created.
1339 -- Place Task_ID info in Server_ID array.
1340
1341 if Server_ID (Interrupt) = Null_Task or else
1342 Ada.Task_Identification.Is_Terminated
1343 (To_Ada (Server_ID (Interrupt))) then
1344
1345 -- When a new Server_Task is created, it should have its
1346 -- signal mask set to the All_Tasks_Mask.
1347
1348 IMOP.Set_Interrupt_Mask
1349 (IMOP.All_Tasks_Mask'Access, Old_Mask'Access);
1350
1351 if Interrupt < System.VxWorks.Num_HW_Interrupts then
1352 Interrupt_Access_Hold := new Interrupt_Server_Task
1353 (Interrupt, semBCreate (SEM_Q_FIFO, SEM_EMPTY));
1354 Server_ID (Interrupt) :=
1355 To_System (Interrupt_Access_Hold.all'Identity);
1356
1357 else
1358 Signal_Access_Hold := new Signal_Server_Task (Interrupt);
1359 Server_ID (Interrupt) :=
1360 To_System (Signal_Access_Hold.all'Identity);
1361 end if;
1362
1363 IMOP.Set_Interrupt_Mask (Old_Mask'Access);
1364 end if;
1365
1366 Bind_Handler (Interrupt);
1367 Unlock_Interrupt (Self_ID, Interrupt);
1368 end Bind_Interrupt_To_Entry;
1369
1370 or accept Detach_Interrupt_Entries (T : Task_ID)
1371 do
1372 for Int in Interrupt_ID'Range loop
1373 if not Is_Reserved (Int) then
1374 Lock_Interrupt (Self_ID, Int);
1375
1376 if User_Entry (Int).T = T then
1377
1378 User_Entry (Int) := Entry_Assoc'
1379 (T => Null_Task, E => Null_Task_Entry);
1380 Unbind_Handler (Int);
1381 end if;
1382
1383 Unlock_Interrupt (Self_ID, Int);
1384 end if;
1385 end loop;
1386
1387 -- Indicate in ATCB that no interrupt entries are attached.
1388
1389 T.Interrupt_Entry := False;
1390 end Detach_Interrupt_Entries;
1391
1392 end select;
1393
1394 exception
1395
1396 -- If there is a Program_Error we just want to propagate it to
1397 -- the caller and do not want to stop this task.
1398
1399 when Program_Error =>
1400 null;
1401
1402 when E : others =>
1403 pragma Assert
1404 (Shutdown ("Interrupt_Manager---exception not expected" &
1405 ASCII.LF &
1406 Exception_Information (E)));
1407 null;
1408 end;
1409 end loop;
1410
1411 pragma Assert (Shutdown ("Interrupt_Manager---should not get here"));
1412 exception
1413 when Standard'Abort_Signal =>
1414 -- Flush interrupt server semaphores, so they can terminate
1415 Finalize_Interrupt_Servers;
1416 raise;
1417 end Interrupt_Manager;
1418
1419 ------------------------
1420 -- Signal_Server_Task --
1421 ------------------------
1422
1423 task body Signal_Server_Task is
1424 Intwait_Mask : aliased IMNG.Interrupt_Mask;
1425 Ret_Interrupt : IMNG.Interrupt_ID;
1426 Self_ID : Task_ID := Self;
1427 Tmp_Handler : Parameterless_Handler;
1428 Tmp_ID : Task_ID;
1429 Tmp_Entry_Index : Task_Entry_Index;
1430
1431 use type IMNG.Interrupt_ID;
1432
1433 begin
1434 -- By making this task independent of master, when the process
1435 -- goes away, the Server_Task will terminate gracefully.
1436
1437 System.Tasking.Utilities.Make_Independent;
1438
1439 -- Install default action in system level.
1440
1441 IMOP.Install_Default_Action (To_Signal (Interrupt));
1442
1443 -- Note: All tasks in RTS will have all reserved signals
1444 -- masked (except the Interrupt_Manager) and Keep_Unmasked
1445 -- unmasked when created.
1446
1447 -- Abort_Task_Interrupt is one of the signals unmasked
1448 -- in all tasks. We mask it in this particular task
1449 -- so that "sigwait" can catch an explicit
1450 -- Abort_Task_Interrupt from the Interrupt_Manager.
1451
1452 -- There are two signals that this task catches through
1453 -- "sigwait." One is the signal it is designated to catch
1454 -- in order to execute an user handler or entry. The other is
1455 -- Abort_Task_Interrupt. This signal is sent from the
1456 -- Interrupt_Manager to inform of status changes (e.g: become Blocked,
1457 -- or a handler or entry is to be detached).
1458
1459 -- Prepare the mask to be used for sigwait.
1460
1461 IMOP.Empty_Interrupt_Mask (Intwait_Mask'Access);
1462
1463 IMOP.Add_To_Interrupt_Mask
1464 (Intwait_Mask'Access, To_Signal (Interrupt));
1465
1466 IMOP.Add_To_Interrupt_Mask
1467 (Intwait_Mask'Access, IMNG.Abort_Task_Interrupt);
1468
1469 IMOP.Thread_Block_Interrupt (IMNG.Abort_Task_Interrupt);
1470
1471 PIO.Set_Interrupt_ID (To_Signal (Interrupt), Self_ID);
1472
1473 loop
1474 System.Tasking.Initialization.Defer_Abort (Self_ID);
1475 POP.Write_Lock (Self_ID);
1476
1477 if User_Handler (Interrupt).H = null
1478 and then User_Entry (Interrupt).T = Null_Task
1479 then
1480
1481 -- No signal binding. If a signal is received,
1482 -- Interrupt_Manager will take the default action.
1483
1484 Self_ID.Common.State := Interrupt_Server_Blocked_Interrupt_Sleep;
1485 POP.Sleep (Self_ID, Interrupt_Server_Idle_Sleep);
1486 Self_ID.Common.State := Runnable;
1487
1488 else
1489 -- A handler or an entry is installed. At this point all tasks
1490 -- mask for the signal is masked. Catch it using
1491 -- sigwait.
1492
1493 -- This task may wake up from sigwait by receiving a signal
1494 -- (Abort_Task_Interrupt) from the Interrupt_Manager for unbinding
1495 -- a procedure handler or an entry. Or it could be a wake up
1496 -- from status change (Unblocked -> Blocked). If that is not
1497 -- the case, we should excecute the attached procedure or entry.
1498
1499 POP.Unlock (Self_ID);
1500
1501 Ret_Interrupt := IMOP.Interrupt_Wait (Intwait_Mask'Access);
1502
1503 if Ret_Interrupt = IMNG.Abort_Task_Interrupt then
1504 -- Inform the Interrupt_Manager of wakeup from above sigwait.
1505
1506 POP.Abort_Task (Interrupt_Manager_ID);
1507 POP.Write_Lock (Self_ID);
1508
1509 else
1510 POP.Write_Lock (Self_ID);
1511
1512 -- Even though we have received a signal, the status may
1513 -- have changed before we got the Self_ID lock above.
1514 -- Therefore we make sure a handler or an entry is still
1515 -- bound and make appropriate call.
1516 -- If there is no call to make we need to regenerate the
1517 -- signal in order not to lose it.
1518
1519 if User_Handler (Interrupt).H /= null then
1520
1521 Tmp_Handler := User_Handler (Interrupt).H;
1522
1523 -- RTS calls should not be made with self being locked.
1524
1525 POP.Unlock (Self_ID);
1526
1527 Tmp_Handler.all;
1528 POP.Write_Lock (Self_ID);
1529
1530 elsif User_Entry (Interrupt).T /= Null_Task then
1531
1532 Tmp_ID := User_Entry (Interrupt).T;
1533 Tmp_Entry_Index := User_Entry (Interrupt).E;
1534
1535 -- RTS calls should not be made with self being locked.
1536
1537 POP.Unlock (Self_ID);
1538
1539 System.Tasking.Rendezvous.Call_Simple
1540 (Tmp_ID, Tmp_Entry_Index, System.Null_Address);
1541
1542 POP.Write_Lock (Self_ID);
1543 else
1544 -- This is a situation where this task woke up receiving a
1545 -- signal and before it got the lock the signal was blocked.
1546 -- We do not want to lose the signal so we regenerate it at
1547 -- the process level.
1548
1549 IMOP.Interrupt_Self_Process (Ret_Interrupt);
1550 end if;
1551 end if;
1552 end if;
1553
1554 POP.Unlock (Self_ID);
1555 System.Tasking.Initialization.Undefer_Abort (Self_ID);
1556
1557 -- Undefer abort here to allow a window for this task
1558 -- to be aborted at the time of system shutdown.
1559 end loop;
1560 end Signal_Server_Task;
1561
1562 ---------------------------
1563 -- Interrupt_Server_Task --
1564 ---------------------------
1565
1566 -- Server task for vectored hardware interrupt handling
1567
1568 task body Interrupt_Server_Task is
1569 Self_ID : Task_ID := Self;
1570 Tmp_Handler : Parameterless_Handler;
1571 Tmp_ID : Task_ID;
1572 Tmp_Entry_Index : Task_Entry_Index;
1573 S : STATUS;
1574
1575 use type STATUS;
1576
1577 begin
1578 System.Tasking.Utilities.Make_Independent;
1579 Semaphore_ID_Map (Interrupt) := Int_Sema;
1580
1581 loop
1582 -- Pend on semaphore that will be triggered by the
1583 -- umbrella handler when the associated interrupt comes in
1584
1585 S := semTake (Int_Sema, WAIT_FOREVER);
1586 pragma Assert (S = 0);
1587
1588 if User_Handler (Interrupt).H /= null then
1589
1590 -- Protected procedure handler
1591
1592 Tmp_Handler := User_Handler (Interrupt).H;
1593 Tmp_Handler.all;
1594
1595 elsif User_Entry (Interrupt).T /= Null_Task then
1596
1597 -- Interrupt entry handler
1598
1599 Tmp_ID := User_Entry (Interrupt).T;
1600 Tmp_Entry_Index := User_Entry (Interrupt).E;
1601 System.Tasking.Rendezvous.Call_Simple
1602 (Tmp_ID, Tmp_Entry_Index, System.Null_Address);
1603
1604 else
1605 -- Semaphore has been flushed by an unbind operation in
1606 -- the Interrupt_Manager. Terminate the server task.
1607
1608 -- Wait for the Interrupt_Manager to complete its work
1609
1610 POP.Write_Lock (Self_ID);
1611
1612 -- Delete the associated semaphore
1613
1614 S := semDelete (Int_Sema);
1615
1616 pragma Assert (S = 0);
1617
1618 -- Set status for the Interrupt_Manager
1619
1620 Semaphore_ID_Map (Interrupt) := 0;
1621 Task_Lock (Interrupt) := False;
1622 Server_ID (Interrupt) := Null_Task;
1623 POP.Unlock (Self_ID);
1624
1625 exit;
1626 end if;
1627 end loop;
1628 end Interrupt_Server_Task;
1629
1630 begin
1631 -- Elaboration code for package System.Interrupts
1632
1633 -- Get Interrupt_Manager's ID so that Abort_Interrupt can be sent.
1634
1635 Interrupt_Manager_ID := To_System (Interrupt_Manager'Identity);
1636
1637 -- Initialize the lock L.
1638
1639 Initialization.Defer_Abort (Self);
1640 POP.Initialize_Lock (L'Access, POP.PO_Level);
1641 Initialization.Undefer_Abort (Self);
1642
1643 -- During the elaboration of this package body we want the RTS to
1644 -- inherit its signal mask from the Environment Task.
1645
1646 -- The Environment Task should have gotten its mask from
1647 -- the enclosing process during the RTS start up. (See
1648 -- in s-inmaop.adb). Pass the Interrupt_Mask of the Environment
1649 -- task to the Interrupt_Manager.
1650
1651 -- Note : At this point we know that all tasks (including
1652 -- RTS internal servers) are masked for non-reserved signals
1653 -- (see s-taprop.adb). Only the Interrupt_Manager will have
1654 -- masks set up differently, inheriting the original Environment
1655 -- Task's mask.
1656
1657 Interrupt_Manager.Initialize (IMOP.Environment_Mask);
1658 end System.Interrupts;
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